PRACTICAL STEAM AND HOTW/^ M E ATI N G AND VENTILATION ALFRED G.KING LIBRARY OF THE UNIVERSITY OF CALIFORNIA. Class PRACTICAL / STEAM AND HOT WATER HEATING AND VENTILATION BY ALFRED G. KING PRACTICAL STEAM AND HOT WATER HEATING AND VENTILATION A MODERN PRACTICAL WORK ON STEAM AND HOT WATER HEATING AND VENTILATION, W T ITH DESCRIPTIONS AND DATA OF ALL MATERIALS AND APPLIANCES USED IN THE CONSTRUCTION OF SUCH APPARATUS; RULES, TABLES, ETC. BY ALFRED G. KING (A. G. KING) AUTHOR OF "STEAM AND HOT WATER HEATING CHARTS," "PRACTICAL HEATING ILLUSTRATED," ETC. CONTAINING OVER THREE HUNDRED SPECIALLY MADE ILLUSTRATIONS SHOWING IX DETAIL ALL OF THE VARIOUS HEATING SYSTEMS, WITH PIPE, RADIATOR AND BOILER CONNECTIONS NEW YORK THE NORMAN W. HEXLEY PUBLISHING COMPANY 132 NASSAU STEEET 1908 COPYRIGHTED, 1908, BY THE NORMAN W. HENLEY PUBLISHING COMPANY COMPOSITION, ELECTROTYPING, AND PRESS- WORK BY TROW DIRECTORY, PRINTING AND BOOKBINDING COMPANY, NEW YORK, U. 8. A. PREFACE FROM a more or less experimental stage to one of an exact science has been the progress of the art of artificial heating and ventilation during the period covering the past twenty-five or thirty years. In the early days of this industry there were but few competent fitters located outside of the larger cities. However, of later years the above conditions have changed, due in a great measure to the constant advancement and education of the steam fitting trade. To-day it is not an uncommon thing to find in a small city or town one or more steam fitters entirely competent to install almost any kind of a steam or hot-water heating appa- ratus. This education of the steam fitter has been accomplished largely by the frequent publication in the trade papers of much practical information, accompanied by drawings and data which could be readily understood by him. The publication of a number of books on the subject of Steam and Hot-Water Heating and Ventilation has also been of great assistance to the steam fitter in his mental advancement. How- ever, much of the matter contained in these books is too technical and of a nature too difficult to be clearly understood by a man of average education. In presenting this work the author wishes to give a brief history of the science of steam and hot-water heating and ventilation and the early methods of constructing work, and to describe and illus- trate the advancement and improvements over the earlier methods. By the illustrations, rules and explanations given, we shall aim to make plain to the steam fitter or apprentice the best methods of 7 179740 8 PREFACE estimating and installing heating work by any one of the modern methods or systems now in use. To keep pace with the means and methods employed we must be continually studying and actively interesting ourselves in the improvements as they are brought out. The methods of a score of years ago have given place to other and improved methods and further experimenting and study by the wide-awake American mechanics are bound to result in still further progress. To those authors and authorities from whose works we have quoted and to the manufacturers of heating appliances who have so kindly assisted us, we extend our thanks. Our effort is not to criticise but rather to comment upon the various heating and ventilating systems in vogue at the present time and to instruct the steam fitter in a practical way regarding their application and installation. We have also added such tables, rules and general informa- tion as will make this valuable as a reference book for the con- tracting steam fitter. A. G. KING. FEBRUARY, 1908. CONTENTS CHAPTER I PAGE Introduction Modern methods of steam and hot-water heating and ventilation Evolution of steam and hot-water heating and ventilation The practice of heating and ventilation Steam and hot-water heating and "ventilation A practical treatise Steam and hot-water heating and ventilation and practice ."-.. . . --. ~. . . . .... . . 15 CHAPTER II Heat Nature of heat How measured How transmitted The heat unit (B. T. U.) Radiating power of bodies Absorption of heat . . . .18 CHAPTER III Evolution of artificial heating apparatus Open fire-places Stoves Furnaces Average life and cost Healthfulness Early type of boilers Steam boilers, Hot-water heaters 22 CHAPTER IV Boiler surfaces and settings Grate surface Water surface Boiler setting The safety valve The steam gauge The automatic damper regulator The water column and gauge glass The blow-off cock The firing tools and brushes The fusible plug . .40 CHAPTER V The chimney flue Sizes of chimneys Elements of a good flue Proper construc- tion of chimney flues Heights of chimneys Table of heights and areas . 56 10 CONTENTS CHAPTER VI PAGE Pipe and fittings Pipe Table of sizes Threading of pipe Bending of pipe Expansion of pipe Table of pipe expansion Wrought-iron or steel pipe Nipples Couplings Fittings Branch tees Flanges Table of flanges Measuring pipe and fittings . . . . . . . . . .63 CHAPTER VII Valves, various kinds Air valves, various kinds 73 CHAPTER VIII Forms of radiating surfaces Radiators Pipe coils Coil building . . . 81 CHAPTER IX [Locating of radiating surfaces Direct radiators Indirect radiators Table of air ducts Direct-indirect radiators . '. . , . . . . . 91 CHAPTER X Estimating radiation Rules for estimating For steam For hot water Some dependable rules 97 CHAPTER XI Steam-heating apparatus The circuit system The divided-circuit system The one-pipe system Dry returns The overhead system The two-pipe system Advantages of steam heating Tables Sizes of mains . .. . .. .103 CHAPTER XII Exhaust-steam heating Value of exhaust steam Necessary fixtures Heating capacity of exhaust steam . . ... . . ... . 115 CHAPTER XIII Hot-water heating Two-pipe system Sizes of mains for two-pipe system The expansion tank Water connection Table of expansion-tank sizes The overhead system Expansion-tank connections for overhead system The circuit system Sizes of mains for circuit system Why water circulates . 120 CONTENTS 11 CHAPTER XIV PAGE Pressure systems of hot-water work Table of temperatures Expansion-tank connections for pressure work Evans and Almirall systems . . . .141 CHAPTER XV Hot-water appliances The altitude gauge The hot-water thermometer Floor and ceiling plates Pressure appliances The Honeywell system The Phelps heat retainer 146 CHAPTER XVI Greenhouse heating Early method Modern greenhouse heating Estimating radiation for greenhouses Table of temperatures Methods of greenhouse piping if . 155 CHAPTER XVH Vacuum vapor and vacuum exhaust heating Explanation of a vacuum Im- proved methods of exhaust heating The Webster system The Paul system The Van Auken system Mercury seal systems The K.M.C. system The Trane system The Ryan system Vapor heating The Broomell system Vacuum vapor heating The Gorton system The vacuum-vapor system Dunham vacuo-vapor system The future of vacuum heating . 163 CHAPTER XVIII Miscellaneous heating The heating of swimming pools Heating water for domestic purposes Steam for cooking and manufacturing .... 189 CHAPTER XIX Radiator and pipe connections Steam radiator connections, hot-water radiator connections Improper use of tees Methods of pipe construction Artificial water-Lines Cross-connecting boilers Pipe measurements for 45 and other angles . . 199 CHAPTER XX Ventilation Importance of ventilation Air necessary for ventilation Amount of air required Methods of ventilation 211 12 CONTENTS CHAPTER XXI PAGE Mechanical ventilation and hot-blast heating Growth and improvement Methods employed Exhaust and plenum Heat losses and heating capacity required Quality of the air supplied An ideal system Fans for blowing and exhausting. Types of heaters Methods of driving fans Some details of construction Factory heating Relative cost of installation and opera- tion Apparatus for testing . . . ._ . .. -..',. . '. . . 224- CHAPTER XXII Steam appliances Steam traps Return traps Separators Oil separators Steam separators Feed-water heaters Steam pumps Boiler feed pumps Vacuum pumps Pump governors and regulators Back-pressure valves Pressure-reducing valves Injectors Inspirators Automatic water feeders . 262 CHAPTER XXIII District heating Early methods Modern methods Central station hot-water heating Scale of hot-water temperatures 288 CHAPTER XXIV Pipe and boiler covering Importance of covering pipes Saving effected by covering Materials used Underground covering . . . . . . 29S CHAPTER XXV Temperature regulation and heat control Automatic steam damper regulator, automatic temperature regulators The Powers thermostat, the Powers system The National regulator The D. & R. regulator The Howard regulator The Minneapolis regulator The Lawler thermostatic regulator The Johnson pneumatic system . . 299 CHAPTER XXVI Business methods Estimating Proposal and bid Specifications for steam heat- ing Specifications for hot-water heating Special features of contracts . 31 ft CONTENTS 13 CHAPTER XXVII PAGE Miscellaneous Care of heating apparatus Summer care Proper attention to boilers Removal of oil and dirt Summer tests to determine efficiency- Care of tools Labor-saving suggestions Bronzing, painting, and decoration Guaranty Boiler explosions Prevention of boiler explosions Utilizing waste heat . - - - . . 329 CHAPTER XXVm Rules, Tables, and Useful Information . . . . f 347 PRACTICAL HEATING AND VENTILATION CHAPTER I Introduction IT is well in beginning the study and consideration of the science of heating and ventilation to look back to the start of what has grown to be one of our most important industries. We may properly term it Domestic Engineering, as on the work of the heating and ventilating engineer depends largely the health, and consequently the happiness, of the great body of civ- ilized people of the world. There is no doubt that the use of hot water for heating pur- poses antedates the use of steam. We have a more or less obscure record of the use of hot water in this respect by the Romans. In the beginning of the eighteenth century we have records of green- houses (at that time called "hothouses") being successfully heated by hot water and later in the same century, about the year 1775, we find a Frenchman, Bonnemain, using hot water to heat a brooder on a chicken farm. This may be said to be the beginning of the practical application of hot water for heating purposes. Steam was probably first used for heating purposes in the early part of the nineteenth century, when efforts were made to heat a factory by steam at a high pressure. The development of steam heating from that date to the present time has been both rapid and constant, although the last decade has seen this industry ad- vanced to a state of perfection never dreamed of by the early heating engineers. From a loose and haphazard method of figur- ing and installing work of this character, it has reached a scientific stage, and as such is more or less understood by a large majority of those engaged in the business. 15 16 PRACTICAL HEATING AND VENTILATION Heating and Ventilation are kindred trades and sciences, each, in a measure, dependent on the other. The early effort to ventilate the British House of Commons, in 1723, was probably the real be- ginning of artificial ventilation. Dr. J. F. Desaguliers, a French boy, whose father removed to England when Desaguliers was but an infant, was, without doubt, the most distinguished student of physics and mechanics of that time. To him was intrusted the problem of ventilating the House of Commons. Previous to this date, however, other plans had been tried to provide a means of ventilation, but we believe the first scientific study and experiments were conducted by Dr. Desaguliers. Efforts were put forth during the early part of the nineteenth century to improve on this ventilating apparatus by the pro- viding of large fans or blowers, which were propelled by hand. The ventilation of other public buildings was then undertaken and the science had advanced to such a stage that in the year 1824< an English engineer, Tredgold by name, published a book entitled " Principles of Warming and Ventilating Public Buildings " a standard work still referred to at this date. While the history of the sciences of heating and ventilation and the endeavors of many engineers of eminence may be both interesting as well as instructive, we refer only to the beginning in order that our readers may realize, to the fullest extent, the evolution of the methods of heating by steam and hot water and ventilating by natural or mechanical means. To such men as Tredgold, Dr. Reid, Charles Hood, E. Peclet, Robert Briggs and others of earlier date, and Mills, Billings, Baldwin, Carpenter and other engineers of these latter times, are we indebted for the advancement and perfecting of the various methods of estimating and constructing the warming and ventilat- ing systems of to-day. The remainder of the credit is justly due to those who manu- facture and install the work and who have, by the use of modern machinery and up-to-date ideas, reduced the cost of steam and hot-water warming and ventilating apparatus to such an extent as to place it within the reach of those in moderate circumstances. Our public schools are better warmed and ventilated than ever INTRODUCTION 17 before, as are also the majority of our other public and semi-public buildings. Our architects now study and consider the subject of heating and ventilation and we firmly believe that the coming decade will witness far greater advancement in these sciences than we have known before. An estimate made in the year 1906 shows that but a little over one tenth of our homes and public buildings are provided with steam or hot-water heating apparatus. Such an estimate further reveals the fact that less than two per cent of our homes are pro- vided with even a partial ventilating apparatus. As a nation we seem to have been satisfied to roast one side of our body while the other side was chilled, or, when fresh air was absolutely needed in the room, to open the door or window, re- gardless of the outside temperature or the condition of the weather. These sudden changes, of course, produced colds and bodily ills of like nature, which, no doubt, in many cases, proved fatal. We knew of no uniformity in either the temperature of the house or the purity of the atmosphere in the several rooms. Becoming aware of our mistakes of the past, we now demand a uniform temperature within our homes ; we are swiftly coming to the conclusion that we might better pay the coal dealer for the energy to produce heat, ventilation and comfort than to pay our physician for doctoring the ills resulting from our carelessness. It will be readily noted what a tremendous field there is for study and work along these lines, and to the journeyman steam fitter or contractor who fits himself thoroughly for this work, we see an abundant reward in store. CHAPTER II Heat HEAT is motion, or a form of energy. Scientists tell us that it is their belief that all matter is made up of small vibrating par- ticles called molecules. The faster these particles move or vibrate, the more heat is produced, and the more the matter or body is expanded. This expansion may be carried to such an extent as to transform the body into another state. For, example, note the formation of gas from coal or oil, or the formation of steam from water. With a hammer we may pound upon a piece of iron until it becomes hot. The Indians started a fire by briskly rubbing to- gether two pieces of wood, the energy of motion producing the necessary heat to ignite the dry moss, or other material used for kindling. The nature of heat is peculiar and it is well that we become somewhat acquainted with these peculiarities. Heat cannot be measured as to quantity, but the intensity of heat may be measured by a thermometer, and this measure we call temperature, and for registering this temperature we use the Fah- renheit scale. For example, water freezes at 32 F. and boils at 212 F. (Fahrenheit was a German, who in 1721 made the first mercurial thermometer. ) Heat may be transferred from one body to another by three distinct methods, namely, Conduction, Convection and Radiation. Lay a piece of hot iron upon another piece of iron, or a different object, and a certain proportion of the heat from the heated iron is transferred to the under object. This method is by Conduction. Water which has been heated and transferred to a storage tank through pipes makes the tank hot. This is heating by Convection. We may place a chair too near a heated stove and burn or blister the paint or finish upon same. The chair has not been 18 HEAT 19 against the stove, neither has there been any direct connection between it and the heat producer, yet it has received the heat from the stove to such an intensity as to damage it. This damage was caused by radiation of heat, the heat being carried to the chair upon waves of air usually imperceptible to the eye. It is this latter method of heat transfer which is employed in the warming of buildings. The energy is developed at a boiler, or heater, placed usually in the basement of the building, the heat being transferred to the radiators, or radiating surfaces placed within or adjacent to the room to be heated and the heat again transferred to the room by radiation. While we cannot properly measure heat itself, we may measure it by the effect it produces, and this is accomplished by the so-called Heat Unit. The Heat Unit as adopted for engineering and scien- tific purposes is of three measures : viz., British, French and Ger- man. In this country it is the former that has come into general use. A British Thermal Heat Unit (B. T. U.) is the amount of heat required to raise the temperature of a pound of water one degree Fahrenheit, or one degree on the Fahrenheit scale of measuring. The British system of measuring heating work, or the effect pro- duced by the action of heat, is by what is known as foot pounds. Professor Allen's definition of this term foot pounds is as simple as we have come across. He says : " Ten units of work or ten foot pounds would be the amount of work done in raising ten pounds one foot high, or one pound ten feet high." Professor Allen thus calls our attention to the definite relationship between heat and work, which was probably first determined by Joule in 1838 while conducting a series of experiments. In measuring work the term horse power (H. P.) is fre- quently made use of. A horse power is 33,000 foot pounds per minute, or the amount of work required to raise 33,000 pounds one foot high per minute, and this is equivalent to 42.5 heat units per minute. As in this country the capacity of all engines and machinery, and all tubular and power boilers, is expressed by horse power, it is well to remember that a horse power represents the energy de- veloped by evaporating 2.655 pounds of water into steam, and which is sufficient to supply 100 square feet of radiation. Fur- 20 PRACTICAL HEATING AND VENTILATION thermore, a horse power represents the condensation from 100 square feet of direct cast-iron radiation, or approximately 90 square feet of pipe radiation or heating coils. The steam is condensed by loss of heat or cooling, and we must know in what manner certain elements act upon the heating surface to cool it, and again in what manner the heat is given off from the radiator or heated body. All building material is porous and there is a loss of heat through walls and window glass. Again, a ventilating register may be open in the room. There is a constant loss of heat through this aperture until such time as it is closed. Therefore, to de- termine upon the amount of heat necessary we must take into con- sideration all heat losses and this we shall discuss later on in this work. Heat is radiated in straight lines or in waves from a heated body. If certain objects are placed in the line of these waves they will absorb the heat and transmit it again to some cooler body. On the contrary, such substances as magnesia, asbestos, hair felt, and the like, will prevent the radiation of the heat beyond their influence. For example, note the plastic covering on boilers, or the asbestos and hair-felt coverings placed on steam and hot-water pipes. Air and other gases are almost transparent to heat and, in fact, in many cases assist in conveying it from the source of energy to the body to be warmed. The radiating power of bodies differs materially. Polished or enameled surfaces radiate less heat than rough or unfinished sur- faces. Peclet gives the following table of the radiating power of bodies, the figures equaling heat units given off from a square foot of surface per hour for a difference of one degree Fahrenheit : TABLE NO. I RADIATING POWER OF BODIES Polished Copper 0327 Sheet Iron 0920 Glass 5940 Cast Iron (rusted) 6480 Stone, Wood or Brick 7358 Woolen Material 7522 Water... 1.0850 HEAT 21 A cast-iron radiator will radiate much less heat when enameled than when painted with bronze or a mineral paint. Specific heat is the amount of heat necessary to raise the tem- perature of a solid or liquid body a certain number of degrees, taking water as a unit or standard of comparison. Some bodies absorb heat more rapidly than others. According to Walter Jones, M.E., the heat necessary to raise one pound of water one degree will raise 32 Ibs. of Lead 31 Ibs. of Mercury 9 Ibs. of Iron 41/2 Ibs. of Air or 2 Ibs. of Ice one degree. For the practical purposes of the steam fitter it is necessary only that he consider: 1. The energy necessary to produce a certain amount of heat, or number of heat units ; how produced, and how measured. 2. How these heat units may be transferred, radiated or con- ducted from one body to another. 3. The effect of this heat upon the cooler body to which it is transferred, or the so-called cooling surfaces of a room or building. 4. . The percentage of loss of energy by radiation, or other- wise, between the production of the heat and its delivery to the bod\ T to be warmed. In the discussion of radiation, ventilation, etc., we shall give other peculiarities and facts regarding the loss of heat, the causes leading to the same and rules for providing against the amount of heat loss under varying conditions. CHAPTER III Evolution of Artificial Heating Apparatus THE arrangement of some form or method of securing warmth within our homes or buildings is a matter to which our attention has grown in keeping with our advancement as a nation. History relates that among the ancient Romans it was custom- ary for the poorer class to build fires upon a stone or brick floor located at one side or end of a room, the smoke and soot passing out of -the room through holes in the roof. The wealthier class used braziers in their living rooms, in which was burned carefully dried wood. The heating apparatus of our forefathers was the open fire- place, and it is related of the old New England type of fireplace that it was six or eight feet in length and so deep that the children had blocks on which they sat far within, where they could see the stars up the chimney. Large logs of wood were used for fuel. Later, after coal could be purchased, the fireplace was built very much smaller. In either case a very large proportion of the heat thus obtained escaped up the chimney, probably from seventy-five to ninety per cent being lost in this manner. As the country grew in population, cities and towns sprang up and fuel became scarcer. Larger buildings were erected and the number of rooms increased until, as a matter of economy, it became necessary to provide some other form of heating apparatus. To this end the old Franklin stove was designed, followed by later styles more improved, all in order to provide better combus- tion and save the lost heat. Again was " necessity the mother of invention," as, to save labor of carrying fuel and ashes for many fires, the idea of cen- tralizing the heating apparatus and of warming several rooms from one fire, led to the adoption of the inclosed stove. Tin or 22 EVOLUTION OF HEATING APPARATUS 23 sheet-iron pipes were used to convey the heated air to each separate room and from this arrangement developed the modern furnace. Experiments were next conducted with heated water and steam as means of conveying heat from a central point to various parts of a building, a form of heating which has been carried to such a state of perfection as to warrant the use of either system under almost any known condition, and the establishing of foundries and shops for the manufacture of heating apparatus. The develop- ment has been such that at the present time there are many millions of dollars invested in the business of manufacturing and installing apparatus for heating by steam and hot water. The relative efficiency of the several methods of heating may be given as follows: 1. Open Fireplaces. 2. Stoves. 3. Hot-Air Furnaces. 4. Steam. 5. Hot Water. In classifying them in this order, we consider not only efficiency, but healthfulness, durability, and cost of maintenance, i. e., cost for fuel. Were healthfulness alone considered, we should prefer the open fireplace to either stoves or furnaces. The waste of fuel in fireplaces and stoves, largely also in hot-air furnaces, is too well known to need many comments. Fireplaces radiate the heat from one side of the room only, and stoves warm but in spots. Furnaces fail to produce the right results when placed in build- ings not well protected from the wind ; and there is no uniformity in temperature where any one of the three above-mentioned sys- tems are used. Furnaces as ordinarily installed are not much more satisfactory than stoves, and nine tenths of them are too small. They are used in preference to a steam or hot-water apparatus because of the apparent saving in cost. We say apparent saving in cost, as after all things are weighed, there is no saving in using a furnace in preference to steam or hot water, and it is well that the steam fitter or heating contractor has this fact clearly in mind. There- 24 PRACTICAL HEATING AND VENTILATION fore, we shall discuss this feature of furnace heating very freely and shall consider the matter, endeavoring to show a comparison between the furnace and steam or hot-water heat. First: As to cost and average life of the apparatus. Second: As to comfort and healthfulness. Average Life and Cost Where a furnace too small is installed, it is necessary, in ex- treme cold weather, to raise the heating surfaces to an exceedingly high temperature, often a red heat, in order to secure comfort. As a result, the expansion and contraction loosens the joints of the furnace and allows the sulphurous and carbonic-oxide gases and other poisonous products of combustion to escape through the hot- air pipes into the rooms above. This is true of both wrought- iron and cast-iron furnaces. Again, heating the furnace to this extremely high temperature shortens the life of the apparatus, with the result that ten per cent of the first cost is needed for repairs during the first five years, while, as a rule, the next five years find the furnace entirely worn out. A steam-heating apparatus has an average life of probably twenty-five years, the first ten years of this period without any repairs except of a trivial nature, such as the repacking of valves, etc. A hot-water-heating apparatus will last an even greater length of time, without the expense of repairs, the system being practi- cally indestructible. Thus it will be readily seen that while the cost of a furnace, as usually installed, is but one half that of a steam-heating apparatus, or probably two fifths that of a hot- water-heating apparatus, it is, as an investment, not counting healthfulness or the excess amount of fuel consumed, by far the more costly of the three systems. In pondering the question of cost, we have not taken into con- sideration the long list of fires and damaged buildings resulting from the " defective flue," nor the damage to house furnishings, due to dust and dirt from the furnace. The housewife, more than anyone else, knows of the constant dusting and cleaning and the frequency with which it is necessary to renew carpets and draperies. EVOLUTION OF HEATING APPARATUS 25 Healthfulness of Furnace Heating vs. Steam or Hot Water We have mentioned some of the disadvantages of heating with a furnace. Let us now consider the healthfulness of the various systems, the quality of the heat produced and its effect on the human system. A furnace must of necessity have an air supply. The source of this air supply is often very had. Perhaps the air is admitted to the furnace direct from the basement or cellar in which it is located. This air may be contaminated with the odors from de- caying vegetable matter, or gases from a sewer. The air is ad- mitted to the furnace at its base, or from underneath the base, and when a fresh air supply is taken from outside the building, it is frequently conveyed to the furnace through an underground duct which is not air tight, with the result that it gathers impurities from the earth. The duct may run across the basement floor and if not air tight, will, owing to the draught produced by the fur- nace, suck in the impure air from the basement through the numer- ous cracks or crevices. With an impure air supply, it is impossible to serve the occupants of the building with pure air. Again, the air is devitalized by passing over metal, heated often to 1,200 or 1,500 degrees Fahr., which robs it of all its health-giving prop- erties. The advocate of the furnace will endeavor to tell of the pure air which is constantly admitted to the building, and its advan- tages an exploded theory, as every heating and ventilating en- gineer knows. What then with devitalized air, often charged with dust or poisoned by gases, can we say in favor of the healthfulness of heat- ing with a hot-air furnace? Nothing, except possibly the apparent saving in first cost and the freedom of the house owner from par- ticipating in the " semiannual stovepipe performance," viz. that of taking down or putting up a miscellaneous assortment of stovepipe loaded with soot, as would be the case where stoves were used. Heating by either steam or hot water has none of the disad- vantages mentioned and for this reason, since the large reduction in cost during the last decade, have in their several forms and 26 PRACTICAL HEATING AND VENTILATION variations, been generally adopted as the best methods of heating known. There are many buildings more or less protected from the vari- able winds of winter, where a furnace properly installed will heat all parts of the building to a uniformly comfortable temperature. We emphasize " properly installed " and " all parts " for the rea- son that the average furnace has neither of these conditions to recommend it. As a rule, the contractor setting the furnace places it near to the center of the basement in order to shorten the hot-air supply pipes and thereby simplify or cheapen the work. It is impossible to force the heated air to the side of the building against which the wind is blowing, and for this reason the furnace should be set near to the side which most frequently receives the action of the wind. We think it safe to say that a furnace installed in this manner and built heavy enough to last' a considerable term of years, with the tin work of first quality, will cost one third more than the average furnace job as regularly installed, or to within a very small amount of the price of a low-pressure steam-heating apparatus. The Heart of the System In a steam or hot-water heating apparatus, the boiler or heater is the real heart of the system and largely upon the char- acter of the boiler or heater installed, depends the success of the apparatus as a whole. It has become customary to refer to the heart of a steam-heat- ing apparatus as a " boiler," and to the heart of a hot-water-heat- ing apparatus as a " heater," probably from the fact that in a steam-heating apparatus it is necessary to boil the water to make steam, while in a hot-water-heating apparatus it is necessary only to heat or expand the water in the heater to produce a circulation in the system. Early Types of Boilers There seems to be no question but that the original type of boiler used for steam heating was the horizontal tubular, or the upright tubular wrought-iron boiler, or the same character of a boiler as was used for power, and very much the same in outward appearance as those in use to-day. EVOLUTION OF HEATING APPARATUS 27 Fig. 1 shows a standard make of tubular boiler, with full- arch front and manner of bricking. FIG. 1. Standard type of tubular boiler with full-arch front. Fig. 2 shows the same character of a boiler, with half-arch front and manner of bricking. Under " Boiler Setting " will be found explanations and di- FIG. 2. Standard type of tubular boiler with half-arch front. rections for setting each of the above, with sketches showing ground plan, longitudinal section and cross section of brickwork, etc. The original type of upright tubular was mounted on a brick 28 PRACTICAL HEATING AND VENTILATION and iron base, forming the ash pit and supporting the grate. Fig. 3 shows this boiler as it is now commonly used, with a cast- iron portable base and without brickwork. One of the earliest types of wrought-iron boilers used exclu- sively for heating purposes was designed and patented by Mr. William B. Dunning, of Geneva, N. Y., and is yet manufactured as the Dunning Boiler in an improved form by the New York Cen- tral Iron Works Company. Fig. 4 shows the shell of this boiler; Fig. 5, the boiler as it appears when bricked. Another early type and somewhat similar character of a boiler FIG. 3. Common type of upright tubular boiler. FIG. 4. Shell of Dunning boiler. is shown by Fig. 6. This is known as the " Haxtun " boiler, manu- factured by the Kewanee Boiler Company, Kewanee, 111. Many other boilers of similar construction were built and sold, following the introduction of those illustrated, some of them having a local sale only, being used in the immediate vicinity where they were manufactured. It is probable that the H. B. Smith Company, of Westfield, Mass., were the pioneers in the manufacture of the cast-iron boiler for steam heating, as the Gold Boiler (see Fig. 7), manufactured EVOLUTION OF HEATING APPARATUS 29 by this concern, was undoubtedly the first of the cast-iron steam boilers, and as such should receive more than a passing mention. FIG. 5. Dunning boiler set in brickwork. Reference to the illustration (Fig. 8) will show the Mills Boiler and the manner in which this boiler is constructed. The FIG. 6. The Haxtun boiler. sections are cast in halves, and on the square or rectangular base supporting the grate, these half sections are erected in pairs. The PRACTICAL HEATING AND VENTILATION upper parts of the half sections are joined to a central dome or header, lock-nut nipples being used for this purpose. The upper part of each half section, as well as the header suspended between these half sections, form a steam chamber from which the supply FIG. 7. The Gold boiler. pipes are taken. In depth these sections are about six inches, and they may be arranged to form a boiler of practically any size desired. Along either side of the boiler is a cast-iron header into which FIG. 8. The Mills boiler. the various return pipes are connected, the water being admitted to the boiler through nipples connecting each individual half sec- tion with the return header. This connection is made in the same manner as the connections to the steam header with lock-nut EVOLUTION OF HEATING APPARATUS 31 nipples. Each half section, therefore, is a unit or boiler by itself, contributing its quota of steam to the steam chamber above. This proved to be a very strong type of boiler, able to withstand OOOGO oooco 000 00 FlG. 9. Locomotive fire-box boiler. a considerable pressure and being also a quick and powerful steamer. It is worthy of note that some of the more modern boilers are FIG. 10. Locomotive fire-box boiler sho\ving smoke travel. built along the lines of the Mills Boiler, without the brick setting. We refer to the " divided-section " or " half-section " idea of boiler construction which we illustrate elsewhere. PRACTICAL HEATING AND VENTILATION Aside from those already mentioned, the most common type of wrought-iron boiler now used for heating is the locomotive fire- box boiler, as illustrated by Fig. 9 and Fig. 10. Fig. 9 shows a view of the boiler as it appears in the bricking, and Fig. 10 shows the smoke travel. In some localities these boilers are used largely FIG. 11. Page safety sectional boiler. FIG. 12. Original type of Furman boiler. FIG. 13. Original type of Volunteer boiler. FIG. 14. The Florida boiler. in apartment houses and business blocks, and while there is con- siderable argument as to their longevity and economical qualities, it is an established fact that they are comparatively quick steam- ers and do the work required of them. Still another of the early types of sectional brick-set boilers is EVOLUTION OF HEATING APPARATUS 33 shown by Fig. 11. It is the Page Safety Sectional Boiler and it also is capable of withstanding a heavy pressure for a cast-iron heater. A few of the earlier designs of heating boilers had maga- FIG. 15. The All Right boiler. FIG. 16. The Bundy cast-iron tubular boiler. zine feeds similar to that of a parlor stove, although at the present time the number of boilers sold so equipped is very small. The Furman Boiler, Fig. 12, the Volunteer Boiler, Fig. 13, the FIG. 17. Sections of cast-iron tubular boiler. Florida Boiler, Fig. 14, the All Right, Fig. 15, comprise some of the earlier round and sectional boilers. Many of the early models of round boilers were cased with a jacket of black or galvanized iron, frequently lined with asbestos. 34 PRACTICAL HEATING AND VENTILATION The latest method of boiler construction, however, dispenses with the brick setting and the sheet-iron casing, the sectional, as well as the round boilers, being portable, and, when covered, are coated to the depth of 1", or more, with a plastic cement made of a mix- ture of magnesia and asbestos. A departure from the regular style of cast-iron sectional boiler is shown by Figs. 16 and 17. It is the Buridy Tubular Boiler FIG. 18. The Gorton boiler. and is on the order of the Scotch Marine type of construction. The Gorton Side-feed Boiler, as shown by Fig. 18, is a peculiar type of wrought-iron boiler construction. So rapid has been the advancement in methods of boiler con- struction during the past ten to twenty years that a large number of styles have been and are now being manufactured, approximat- ing probably over one hundred varieties. Among the round boilers may be found, in addition to those EVOLUTION OF HEATING APPARATUS 35 already mentioned, the Doric, Richardson, Boynton, Cambridge, Ideal, Richmond, Orbis, Winchester, Capitol Mascot, Arco and Radiant. In the list of manufactured sectional boilers we find the Mercer, Richmond, American, Ideal, Thermo, Carton, Sunray, Sunshine, FIG. 19. Early type of Gurney hot- water heater. FIG. 20. The Spence hot-water heater. Boynton, Cornell, Monarch, Furman, Capitol, Gem, Model, Thatcher, Richardson, Royal and many others which lack of space prevents our mentioning. Hot-Water Heaters What has been said regarding the multiplicity of steam boilers is equally applicable to hot-water heaters. One of the pioneer heaters was the Gurney, shown by Fig. 19. In the Spence Heater, Fig. 20, we have another early design of a hot-water heater. Each of these heaters was originally made in Canada, as was also the Champion, a heater of square construction manufactured at Montreal by Rogers & King. The Spence Heater in Canada was known by the name " Daisy," and it was after being brought to this country that it was called the " Spence." This heater in this country was orig- inally manufactured by The National Hot Water Heater Co., 36 PRACTICAL HEATING AND VENTILATION of Boston, Mass., long since out of business, and is now one of the productions of the Pierce, Butler & Pierce Mfg. Co., Syra- cuse, N. Y. The firm of E. & C. Gurney Co., of Toronto, Canada, were the FIG. 21. Improved Gurney heater. FIG. 22. The Perfect hot- water heater. original builders of the Gurney, which, when brought to this coun- try in the year 1884, was manufactured under the same firm name, but now known as the Gurney Heater Mfg. Co. This boiler was FIG. 23. The Hitchings hot- water heater. FIG. 24. Sectional view of hot-water heater. further improved as shown by Fig. 21, and later, still other im- provements were made in its construction. The Perfect Heater, Fig. 22, was another of the old-time heaters which helped to contribute to the success of hot-water heating in this country. EVOLUTION OF HEATING APPARATUS 37 We have still another type in the Hitchings Boiler, Fig. 23 and Fig. 24. This was an old-time cast-iron heater of peculiar construction, originally intended for the heating of hothouses, and known as a Corrugated Fire-Box Boiler. It was first made about the year 1867. The concern who manufactured it was es- tablished in 1844, and their first production was a conical-shaped affair. Fig. 25 shows the Carton, one of a number of later styles of sectional hot-water heaters. The advancement in the manufacture of hot-water heaters has kept pace with the improvements in the steam boiler, and many FIG. 25. The Carton hot-water heater. manufacturers make both steam and hot-water heaters under the same name and with the same general form of construction. We have spoken of the half-section or divided-section type of boiler construction, as shown by the original Mills Boiler. This has, in a very great measure, come to be a favorite method of build- ing sectional boilers. The Capitol, The Monarch Sunshine, and the Henderson Thermo are boilers of this type. Fig. 26 shows a line drawing of the Thermo, illustrating the style of sections and the manner of nippling them together. Naturally it would seem that with such a large number of makes and types of boilers, the steam fitter or heating contractor would get confused in the selection of a suitable boiler or heater, but such should not be the case. Each individual fitter may have 38 PRACTICAL HEATING AND VENTILATION his own ideas of what constitutes a good boiler or heater, and select his favorite type of boiler construction. Again, his cus- tomer may have previously decided upon the make of heater he FIG. 26. Line cut of the Thermo hot-water heater. wishes installed, a fact which the fitter cannot afford to overlook, as it is much easier to sell a prospective customer what he wants than what he does not desire, or thinks that he does not. What Constitutes a Good Boiler There are a number of features that should be considered when endeavoring to select a good boiler for steam heating, or a heater for hot-water heating. A few pointers : 1. Select a boiler manufactured by a Company or firm of unquestioned business standing a reputable concern whose guar- antee is good. Reliable manufacturers of first-class goods never EVOLUTION OF HEATING APPARATUS 39 hesitate to make good any defect which may develop in their product. 2. Select a boiler which is so constructed as to permit of easy and perfect cleaning of all heating surfaces. Soot is one of the greatest of nonconductors and a boiler which cannot be thor- oughly cleaned, while it is in operation, will be expensive to use and short-lived. 3. The fire box should be spacious and deep below the feed door, in order to provide for perfect combustion and a depth of fire that will last for hours without attention. 4. The boiler should have no packed joints to dry out and leak. Push or screw nipples should be the medium for connecting the various parts ; and so far as is possible, no bolts should pass through the water ways. 5. The grate is a particular part of the apparatus. It should be of such a construction as to admit of easy cleaning and at the same time heavy enough to carry its load of coal without sag- ging. The grate should be so arranged as to be readily removable from the heater and replaced, in case repairs are necessary. 6. Select a boiler with a large amount of fire surface and so constructed as to have sufficient fire travel, or flue surface to utilize as many of the heat units from the coal consumed as is possible. 7. The height of the boiler should not be so great as to inter- fere with a giving of the proper pitch to the piping. 8. If a steam boiler, see that there is provision for a sufficient depth of water above the crown sheet, or prime heating surfaces, to allow the bubbles or globules of steam passing upward through the water to liberate without commotion. This means a steady water line in the boiler. 9. There should be a positive circulation of the water through all parts of the boiler. 10. Select a boiler full large for the work, in order to avoid straining the boiler or wasting fuel by forcing. The greatest economy in the consumption of fuel is attained when the fire burns freely and evenly under normal conditions of draught. The ratings of house-heating boilers have, as a rule, been worked out from actual use and experience and they may generally be safely accepted by the steam fitter or house owner. CHAPTER IV Boiler Surfaces and Settings THE heating surfaces in all boilers, whether cast or wrought iron, are of two kinds, namely, direct surface and flue surface. Direct surface is that immediately above and surrounding the fire, or those parts of a boiler against which the light from the incan- descent fuel shines. Flue surface is that which receives the heat from the burning gases while traversing from the combustion cham- ber to the smoke outlet of the boiler. Direct surface is more effective than flue surface, the propor- tion being about three to one. It would seem, therefore, that the boiler presenting the most direct surface to the action of the fire would be the most effective. This is true only in a measure, as a boiler may have a large amount of direct surface and yet have so little flue surface, or distance of fire travel, that the heat from the gases of combustion is not thoroughly extracted before pass- ing out into the chimney, and a large number of heat units from the fuel consumed are therefore wasted. While it is desirable to have a large proportion of direct heat- ing surface, there must be sufficient flue surface, or distance of fire travel, to consume the gases and render the direct surface effective. It is also desirable that the heating surface should be broken up in such shape that the heat from the fire and the hot gases should impinge at right angles against it and extract as much of the available heat as is. possible. In the manufacture of some of the earlier types of sectional boilers, the builders were imbued with the idea that the length of a boiler or size of it might be increased indefinitely by adding more sections, each having the same area or size of flues. Manifestly this is wrong, and most manufacturers have come to understand that if a certain area of flue opening through sections is right for a five-section heater, this same area is too small for a heater of 40 BOILER SURFACES AND SETTINGS 41 ten sections, and the flue surfaces are now increased by making the heater in several widths. The proportion of direct and flue surfaces in any heater depends entirely upon the character of its construction. Grate Surface In all house-heating boilers there should be a low rate of com- bustion, and the grate surface should be so proportioned with the heating surface that this may be accomplished. The consumption of fuel should not exceed six or eight pounds of coal per square foot per hour, depending upon the quality of the fuel and the management of the apparatus. Tests are usually made by evaporation and under perfect con- ditions of draught, a pound of the best anthracite coal will evapo- rate from twelve to fifteen pounds of water. However, we never reach perfect conditions of draught in a heating apparatus, as there is always a loss of from twenty-five to forty per cent of the heat up the chimney flue. Some manufacturers of boilers claim a rate of evaporation of ten pounds of water per pound of fuel. The average is much less, and a low-pressure boiler that will evaporate eight pounds of water per pound of fuel is considered as economical. In the locomotive fire-box type of heating boiler, the ratio of grate to steam radiation capacity (gross) is from 1 to 190 in the smaller sizes, to 1 to 275 in the larger sizes; that is to say, for each square foot of grate, 190 to 275 sq. ft. of steam radiation capacity is figured. In cast-iron sectional boilers, the ratio of grate surface and steam radiation capacity is from 1 to 175, to 1 to 220, while in round cast-iron heaters, the rating is quite a little less, the ratio being from 1 to 160, up to 1 to 180. Where tubular boilers are used for heating, it is customary to allow one hundred feet of direct cast-iron radiation per horse power, considering 15 sq. ft. of heating surface as one horse power. Water Surface The water surface necessary in a low-pressure boiler depends largely upon the construction of the same. A boiler so con- structed as to have a perfect circulation in all of its parts, re- 42 PRACTICAL HEATING AND VENTILATION quires less water than a boiler in which this circulation is not maintained. It is necessary to have sufficient water surface in order that the steam bubbles may liberate easily without disturb- ing the water line, or carrying water into the steam supply pipes of the heating system. A boiler constructed so that all of the water ways are small and the water consequently divided into small parts, should steam quicker and prove more economical than a boiler where the water is held in large bodies. The water divided into smaller parts is more easily and quickly heated and a circu- lation of the water within the boiler more readily established. Boiler Setting The large majority of boilers now used for heating have what is known as a " portable setting." The early types of heating boilers were bricked in. At the present time, aside from the tubular or fire-box boilers, but very few of the modern boilers are bricked. Many require no covering whatever, although it is customary to cover some of the heaters with a plastic covering of magnesia and asbestos, which, as its name indicates, is applied in the form of plaster and is dried or baked on the surfaces to be covered. This covering is usually put on about 2" thick and is sufficient to pre- vent the radiation of heat in the cellar or boiler room, and also adds to the efficiency and appearance of the boiler. The castings should be heated before applying the covering. Many boilers have a somewhat low or shallow base or ash pit, and when using a boiler of this nature, and the height of boiler cellar will allow, it is a good plan to set it on a raised foundation of brick two or three courses in height, leaving the center hollow. This provides a good, deep ash pit, reducing the probability of burning out the grate, which frequently happens when the ashes are packed underneath it. Fig. 27 shows the manner of bricking a locomotive fire-box boiler, when it is desired to take the smoke out at the front end, and Fig. 28 shows the method of bricking the same boiler, where the smoke is taken out at the back end. As in this boiler the fire or flame does not come in contact with the brickwork, no fire brick are necessary. BOILER SURFACES AND SETTINGS 44 PRACTICAL HEATING AND VENTILATION BOILER SURFACES AND SETTINGS 3 g s O a O O 00X8 O O O Qt & 00 O O O O OT O O } llil lil llll o* o< i< , t^l-J>l>S0<^'^'*'*^Tf.O?(N 0* G G> O>OO G40*0< (5* O* > G* > x ci o SSSS 00 O OO 00 00 00 00 OO 00 00 00 CO s$33$S3$3 -3* ^< ^ ^ ^ O> -S* O* O< ^ O* S< ^ ;> -3JJ o< ^ ^ SSSol^^^l^SSS^^S 48 PRACTICAL HEATING AND VENTILATION given, the fire brick are indicated by the heavy shading of the drawing. The tables given, accompanying each illustration, give measurements, as indicated by the letters on the drawing and the number of common and fire brick necessary for each size of boiler that is given. BOILER SURFACES AND SETTINGS 49 AH steam boilers used for heating should be provided with the regulation set of trimmings. By " regulation set " we mean safety valve, steam gauge, automatic damper regulator, water column and glass, blow-off or draw-off cock, and a complete set of cleaning and firing tools, and of these trimmings and tools we wish to speak in detail. The Safety Valve The safety valve on a steam boiler should be of a kind not liable to stick or become inoperative, as accidents are frequently the result of this occurrence. There are three kinds of safety valves in general use, the weighted valve, as shown by Fig. 31, the lever valve, shown by FIG. 32. Lever safety valve. FIG. 31. Weighted safety valve. FIG. 33. Spring safety valve. Fig. 3, and the spring valve, often called the " pop safety valve," shown by Fig. 33. The weighted safety valve is a simple ground seat valve, the disc of which is held against the seat by a weight usually in the form of a cast-iron ball placed or screwed on the top of the stem. This ball varies in weight, according to the size of the valve. The lever safety valve shown is a type of valve in general use not only on steam boilers, but on other work as well, and this is an excellent form of safety valve. It may be regulated to operate at different pressures by adjusting the weight or hanging it in different positions on the lever until sufficient pressure has accumu- lated to operate it. 50 PRACTICAL HEATING AND VENTILATION This type of valve, as well as the others mentioned, is used ex- tensively on low-pressure as well as high-pressure boilers. The safety valve should never be weighted down with a w r eight heavier than that accompanying the valve. We have seen the levers of safety valves held down by a block or board wedged between the lever and a joist of the floor above a very careless practice and one liable to cause serious damage to person or property. We, therefore, favor the spring, or " pop," valve, owing to the fact that it cannot be easily tampered with. The attendant of a steam boiler should frequently try the safety valve by releasing it, in order that he may know that it is in good condition. The Steam Gauge Low-pressure steam gauges, as used with boilers for heating, are made to register about thirty pounds. Fig. 34 illustrates a gauge of this character and while it is customary to provide for all boilers, high or low pressure, a gauge registering double the working pressure, it is very seldom that the pressure exceeds ten pounds on a boiler used for low-pressure heating. A stopcock should always be provided with the gauge in case it is found necessary to remove it for cleaning or adjustment. In connecting the gauge, a siphon should be used to prevent dry steam from entering the gauge. It is good practice to fill the loop of this siphon with water before screwing on the gauge. The Automatic Damper Regulator All steam boilers, high or low pressure, should be provided with an automatic damper regulator. Without this regulation it would be impossible to control the boiler except by constant watching and w r ork of the attendant in charge of the boiler. Automatic damper regulators for low-pressure boilers are very simple affairs, the regulators for high pressure being more com- plicated. There are a variety of high-pressure regulators on the market, which our space will not permit of illustrating or describ- ing. It is of the low-pressure regulator that we desire more par- ticularly to speak. All of them are alike in principle and very similar in design, to that shown by Fig. 35. Two castings shaped BOILER SURFACES AND SETTINGS 51 almost exactly like the old-fashioned soup plate form the bowl of the regulator, the upper one inverted and bolted face to face with the lower, with the rubber diaphragm between, the lower casting of the bowl being tapped for a connection with the boiler. The upper casting of the bowl has a round orifice or opening in the center, through which a small plunger protrudes, the lower side of the plunger resting on the rubber diaphragm. As the pressure increases under the rubber diaphragm, it is expanded, forcing the plunger upward. To the top of the plunger is bolted a wrought- iron rod or lever, at point marked " A " on the illustration. At point marked " B " there are two lips which extend upward from the outer edge of the upper bowl casting, these lips forming the fulcrum, the lever being bolted between the lips at this point. The FIG. 35. Low-pressure damper regulator. FIG. 34. Low-pressure steam gauge. regulator is set so that the fulcrum is on the side toward the front of the boiler. A weight, marked " C," is placed on the lever at a point back of the plunger. This weight is movable and by placing it on the lever farther from or nearer to the plunger, a greater or lesser pressure is required to operate the lever. On some regulators there is a chain extending from the front end of the lever only, this chain connecting with the draught door of the boiler. On most regulators, however, there are two chains, one from either end of the rod. The front chain connects with the draught door and the rear chain connects with the cold-air check door at the rear of the boiler, the chains being so adjusted that when the lever moves to close the draught door, it will also open the cold-air check. 52 PRACTICAL HEATING AND VENTILATION The steam should never come in contact with the rubber dia- phragm, and for this reason a water bottle or trap is used in connecting the regulator to the boiler. FIG. 36. Showing connection and action of regulator. FIG. 37. Showing connection and action of regulator. Many fitters of limited experience become confused in adjust- ing the chains to draught and check doors, and in order to make this plain, we illustrate as in Figs. 36, 37 and 38, showing the three positions of the regulator in action. " A " represents the FIG. 38. Showing connection and action of regulator. draught door being a part of the base or ash-pit front ; " B " the cold-air check, a door on the smoke connection at rear of boiler; " C " the trap used in connecting regulator to boiler ; " D " the BOILER SURFACES AND SETTINGS 53 diaphragm castings with rubber between ; " E " the weight, or ball, on lever ; " F " the smoke pipe, and " G " the smoke con- nection to boiler. Fig. 36 shows the adjustment of chains when draught is on the boiler. Note that the front chain is taut, the draught door being held open. The rear chain is slack, the check door being shut. In this position the doors remain until sufficient pressure is raised to operate regulator, when the plunger is slowly raised, the lever allowing draught door " A " to gradually close. Fig. 37 shows the operation of the chains when draught door is closed. Note that the rear chain is yet slack, although there is no draught on the boiler. If the pressure of the boiler is not held in check by the closing of the draught door, the plunger in the diaphragm will continue to rise until, as shown by Fig. 38, the rear chain becomes taut and opens the check draught door at the rear of boiler, thus effectually checking the fire. The weight on the lever may be set in such a manner that both draught and check doors remain closed. The Water Column and Gauge Glass Fig. 39 shows a standard size of water column, with gauge cocks and water gauge. The try cocks, of which there are three, are not shown on the drawing. These try cocks are screwed into the water column at points marked " A " on the drawing. While it is desirable to use three try cocks, it is not absolutely necessary, and many manufacturers of heating boilers make use of but two. The water column should be at least two and one half inches (21/2") in diameter and fourteen (14") or fifteen (15") inches in length. On the illustration, " B " is the gauge glass, " C " the guard rods, " D " the drip cock, which should be placed at the bottom of all water gauges, and " E " the packing or rubber washer used to make tight joints around the glass. The Blow-Off Cock Fig. 40, the blow off or drain cock, often called, also, sediment cock, is a necessary trimming to every boiler. At the lowest part of the boiler, there should be an opening to which a pipe con- 54 PRACTICAL HEATING AND VENTILATION nection can be made to drain the boiler or heating system. This connection must have a valve, and we have seen all sorts of valves used for this purpose. A drain cock, known also as a plug cock, should always be used, as it has a straight opening through which FIG. 40 .Steam or "blow-off" cock. FIG. 39. Water column and gauge. the sediment or scale from the boiler can pass without choking. Many of the smaller sizes of boilers are tapped for a %" blow off; " opening would be better. or Firing Tools and Brushes All boilers should be provided with firing tools, consisting of ash hoe, poker and slice bar, and with brushes for cleaning the heating surfaces and flues, in order that the attendant may properly fire and clean the boiler. Nearly all makers of low-pressure boilers furnish firing tools, as well as specially designed brushes. Fusible Plug When we take into consideration the thousands of boilers in use for heating purposes and the fact that but very few explosions occur, it would seem that all necessary precautions had been taken when the boiler is provided with a complete set of trimmings. How- BOILER SURFACES AND SETTINGS 55 ever the Boiler Inspection Bureaus of some states, and some in- surance companies, demand that a fusible plug be placed on all heating boilers. This consists of a brass plug, having usually a hexagon head, through the center of which there is an opening or core. This core is filled with Banca Tin, a metal which melts at about 430 degrees Fahr. The boiler is tapped at a point below what might be termed the low-water line, and the fusible plug inserted. Should the water in the boiler get below the plug, the heat from the hot iron will melt the tin, thus making an opening to the atmosphere and giving relief. CHAPTER V The Chimney Flue THERE is no one part of a steam or hot-water heating appara- tus which contributes so largely to its success or failure as the chimney to which the boiler or heater is connected. The chimney is comparatively a modern invention. It is said that none of the old Roman ruins, nor the restored buildings in Herculaneum or Pompeii have chimneys ; the chimney of that period consisted of a hole in the roof. The modern chimney was first used in the fourteenth century. At the time steam and hot water were first used for heating PLASTERED BRICK, FIG. 41. Round and square chimney flues. purposes in this country but very little attention was given to the chimney, with the result that many of the heating plants then installed failed to work satisfactorily. Experience has taught us several facts in the building and use of chimneys : First : A chimney used for a low-pressure steam or a hot- water heating apparatus should have no other opening than that used for the heating apparatus. Second : The draught in a chimney is spiral ; therefore, round chimneys, or those as nearly square as possible, are most 56 THE CHIMNEY FLUE effective. A round chimney 12" in diameter, having an area of approximately 113 sq. in., is as effective as a chimney 12" X 12" having an area of 144 sq. in. See Fig. 41. POOR DRAFT . FIG. 42. Proper and improper construction of chimneys. Third : Adding height to a chimney will increase the velocity of the draught and add to the fuel consumption. As we desire a low rate of combustion in a low-pressure boiler or hot-water heater, greater area and less proportionate height of the flue is desirable. FIG. 43. Tile-lined chimney flue. Fourth : The height of a chimney should be great enough to preclude the possibility of interference with the draught by sur- 58 PRACTICAL HEATING AND VENTILATION rounding buildings, trees, or the roof of the building of which the chimney forms a part. Fig. 42 illustrates the character of this interference. Fifth : The chimney should be built straight upward without any offsets, which cause friction and interfere with the draught ; and the inside lining should be as smooth as possible, a tile-lined flue being superior to all others. See Fig. 43. Sizes of Chimneys The following table we give as the result of practical expe- rience with chimneys on heating work and may be safely accepted TABLE IV Square or Cubic Feet. Contents of Building. Sq. Ft. Direct Steam Radn. Sq. Ft. Hot-Water Radn. Tile or Iron Inside. Inches. Rectangu- larTile or Brick. Inches. 10,000- 20,000 250 to 450 300 to 800 8 8X 8 20,000- 45,000 450 to 700 800 to 1,200 10 8X12 45,000- 75,000 700 to 1,200 1,200 to 2,200 12 12X12 75,000-140,000 1,200 to 2,400 2,200 to 3,600 14 12X16 140,000-200,000 2,400 to 3,500 3,600 to 5,200 16 16X16 200,000-350,000 3,500 to 5,000 5,200 to 8,000 18 16X20 It will interest our readers to know what other authorities say regarding chimney sizes, and we shall therefore quote from some of them. Lawler in his work on steam and hot-water heating gives a graphic diagram (see Fig. 44) which gives the proportion of grate surface, heating surface and chimney area, and he says : " It will be noticed that one square foot of grate surface will sup- ply 36 sq. ft. of boiler surface ; and this amount of grate arid boiler surface will carry 196 sq. ft. of direct radiating surface for heating purposes. The area of the chimney must be taken into consideration and for this amount of grate and boiler surface, we allow 49 sq. in. For low-pressure gravity steam-heating plants, carrying over 1,000 sq. ft. of radiation, the size of chimney may be reduced somewhat less in proportion to that shown." Jones, an English authority, says : " For steam boilers where THE CHIMNEY FLUE 59 a keen or rapid draught is required, it is necessary to have lofty chimneys, but for hot-water boilers they are not often available, low chimneys being generally sufficient. Where practicable the height of chimney should be twenty-five per cent to fifty per cent greater than the total length of horizontal flues." n 196 8Q. FEET GRATE SURFACE BOILER SURFACE CHIMNEr SURFACE DIRECT STEAM RADIATING SURFACE FIG. 44. Diagram of flue capacity. (The author refers to length of fire travel.) "The total length (horizontal) of flues should not in any case exceed the height of the chimney." Baldwin says : " The chimney must be capable of passing suffi- cient air for the greatest consumption of fuel ever likely to be used in the apparatus. Less air will not do. More than is needed does no harm, for it is within the power of the operator or the auto- matic draught regulator to diminish the quantity of air." We would like to add to the above by saying that a chimney is only as large as its smallest area, and if at any point in its con- struction, for no matter now short a distance, the area is reduced for any cause whatsoever, the area of the entire flue must be figured according to its size at the point of reduction. Elements of a Good Flue The flue should be properly proportioned according to the size of heater or amount of radiating surface used. It should have no obstructions, and in height should extend 60 PRACTICAL HEATING AND VENTILATION well above the roof and higher than surrounding buildings, trees,, etc. There should be only one smoke-pipe hole, and that used to connect with boiler. The area of the flue should be maintained full size from bot- tom to top without offsets. A flue 8" X 8" is the smallest that should be provided for a heating, apparatus. Velocity sufficient to carry burning paper up the flue does not indicate a perfect chimney. See that area is provided as well as velocity (meaning height). If flue opening extends below the smoke-pipe entrance, fill it up with dirt, broken brick or other material at hand, to a point level with the bottom of smoke-pipe hole. If this is neglected, an air pocket will be formed, causing down draught in the chimney. Take no chances on a chimney until the above conditions are fulfilled. There are some few facts regarding chimney construction that are worthy of note. We have particular reference to the materials used in their erection and to the location of the chimneys. In the observance of various chimneys note that at the top, frequently for a distance of from four to five feet, the bricks have become loosened and seem about ready to fall. The reason for this is that such bricks were laid with lime mortar, and the action of the sul- phuric acid on the lime decomposes it, thus allowing the sand to loosen. Through the action of the wind and weather and also the settling of the bricks they blow or fall out, leaving cracks or openings in the brickwork of the chimney. Brick chimneys laid with cement are better, as the sulphuric acid will not injuriously affect the cement. Unlined chimneys should be plastered smooth on the inside in order to reduce the friction as much as possible and thereby in- crease the velocity of the draught. It is a very good plan to build the chimney up through the center of the house. The warmer the air surrounding the chim- ney, the less condensation of the smoke and gases and the greater the efficiency of the flue. The foundation for the chimney should be adequate to support the weight upon it without settling. Cracked walls, loose chim- THE CHIMNEY FLUE 61 neys and the like can usually be traced to a weak foundation, which is also frequently the cause of disastrous fires. With the pressure of the atmosphere exerted against the ascending column of smoke and gases, the smallest crack or opening in the walls of the chimney will prove troublesome and dangerous. Masons and contractors give too little attention to chimney building, with the result that many chimneys are improperly and loosely built, of too small area or poor design. In order to justly protect themselves from the unsatisfactory results arising from such methods of chimney erection, many heating contractors state clearly in their specifications that the owner must furnish a good and sufficient flue, and that the heating contractor will not be re- sponsible for failure of the apparatus due to poor draught. Heights of Chimneys The following table of heights and area will be found to be substantially correct. One hundred square feet of radiation may be allowed for each H. P. given in the table. TABLE V Square Chimney. Side of Square. Round Chimney. Diam. in Inches. Area in Square Feet. Effective Area in Square Feet. Height of Chimnej's in Feet. 50 60 70 80 90 100 110 125 150 175 Commercial Horse Power of Boilers. 16X16 19X19 22X22 24X24 27X27 30X30 32X32 35X35 38X38 43X43 48X48 54X54 59X59 64X64 70X70 75X75 80X80 86X86 18 21 24 27 30 33 36 39 42 48 54 60 66 72 78 84 90 96 1.77 2.41 3.14 3.98 4.91 5.94 7.07 8.30 9.62 12.57 15.90 19.64 23.76 28.27 33.18 38.48 44.18 50.27 .97 1.47 2.08 2.78 3.58 4.48 5.47 6.57 7.76 10.44 13.51 16.98 20.83 25.08 29.73 34.76 40.19 46.01 23 35 49 65 84 25 38 54 72 92 115 141 27 41 58 78 100 125 152 183 216 62 83 107 133 163 196 231 an 113 141 173 208 245 330 427 536 183 219 258 348 448 565 694 835 271 365 472 593 728 876 1,038 1,214 .... 389 503 632 776 934 1,107 1,294 1,496 551 692 849 1,023 1,212 1,418 1,639 1,876 748 918 1,105 1,300 1,500 1,800 2,000 62 PRACTICAL HEATING AND VENTILATION Attention is called to the table " Capacities of Stacks " given in the last chapter of this book. The height of the average house or other building is usually sufficient for a chimney of ordinary area. However, for larger work it is well that the height, area, etc., of the chimney be care- fully proportioned in order that the best results may be obtained from the heating apparatus and the most economical service from the amount of fuel consumed. CHAPTER VI PIPE AND FITTINGS Pipe WROUGHT-IRON tubes of the character we to-day call pipe were first made in England and later (about the year 1834) were originally manufactured in this country by the firm of Morris, Tasker & Morris at Philadelphia, who afterwards built a tube mill known as the Pascal Iron Works. In 1849 a tube plant was erected at Maiden, Mass., known as the Wanalancet Iron & Tube Works, the firm of Walworth & Nason, of Boston, being the prin- cipal owners of this Company. The manufacture of pipe has now come to be a very important part of the iron and steel industry of this country. TABLE VI STANDARD WROUGHT IRON PIPE Internal Diameter. Inches. 'I'hickness. 02 ~ i .S"5^ S'SPt, &* MH sis & *c -'-' J= ~ MH=H tgl'l 3**3 5< ^|s 03 Weight of Water in 1 Ft. of Pipe. Pounds. li'S* e 3-3 ^.5 ^ cr u coc-3 o Sfc'-sS MPnSt: C O 3 *.&j "!^fe Ys .068 .24 27 2513. .024 0.0583 9.44 H .088 .42 18 1383.3 .044 0.1041 7.075 % .091 .56 18 751.5 .082 0.1917 5.657 Vo .109 .84 14 472 . 4 .132 0.3048 4.547 M .113 1,13 14 270.00 .25 0.5333 3.637 i .134 1.67 HH 160.90 .006 .37 0.8627 2.903 1H .140 2.24 uit 96.25 .010 .647 1.496 2.301 1^ .145 2.68 iVA 70.66 .014 .881 2.038 2.010 2 .154 3.61 HH 42.91 .023 1.45 3.356 1.608 2^ .204 5.74 8 30.10 .032 2.07 4.784 1.328 3 .217 7.54 8 19.50 .051 3.20 7.388 1.091 &A . 226 9.00 8 14.57 .069 4.28 9.887 0.955 4 .237 10.66 8 11.31 .088 5.50 12.730 0.849 *M .246 12.49 8 9.02 .111 6.92 15.961 0.764 5 .259 14.50 8 7.20 .138 8.63 19.990 0.687 6 .280 18.76 8 4.98 .197 12.25 28.889 0.577 7 .301 23.27 8 3.72 .270 16.87 38.738 0.501 8 .322 28.18 8 2.88 .340 21.61 50.039 0.443 9 .344 33.70 8 2.29 .440 27.25 62.733 0.397 10 .366 40.00 8 1.82 .550 34.50 78.838 0.355 63 64 PRACTICAL HEATING AND VENTILATION The pipe used for steam, water and gas is graded in size from %" upward to the larger sizes. The internal diameter forms the basis of the pipe size as given. Pipe at present is manufac- tured in three thicknesses or weights, known commercially as " Standard," " Extra Strong " and " Double Extra Strong," the " Standard " weight being used on all steam and hot-water heat- ing work, and all reference to pipe in this book will apply to the standard weight unless stated otherwise. Among the tables published in the last chapter of this work will be found tables of sizes, weights, etc., of " Extra Strong " and " Double Extra Strong " pipe. Pipe up to and including l 1 /^" in size is what is known as " butt welded," I 1 /-}" an d larger, being " lap welded " and is manu- factured in lengths varying from 16 to 20 feet. Threading of Pipe All pipe is now threaded uniformly, the Briggs' standard of pipe-thread sizes being used by all manufacturers. The taper is an inclination of 1 in 32 to the axis, or %" to 1 foot. Bending of Pipe Some years ago it was a common occurrence to bend pipe, where offsets were needed, or change of direction required. The piece of pipe to be bent was filled with sand and both ends capped, the sand acting as an aid in preserving the form of the pipe, without flattening. It was then heated to a cherry-red color and bent to the desired form. In these later years but very little pipe is bent, the offsets or changes of direction being made with the use of cast- iron or malleable-iron fittings. The smaller sizes of pipe, such as are used for water or gas service, are frequently bent by the plumber without heating and without the use of sand. When it becomes necessary to do any considerable amount of work of this character, it is better to use bending blocks or bending forms. Expansion of Pipe In heating work the expansion of pipe, when heated, must al- ways be taken into consideration and opportunity given the pipe PIPE AND FITTINGS 65 to stretch without breaking fittings or straining joints. To this end all mains should be hung or supported by expansion hangers as shown by Fig. 45. Pipe connections, particularly on steam work, should be made by using elbows to form a swing or expan- sion joint. We shall speak of this more fully in discussing methods of steam piping. Whenever pipe is run through boxing, tile or other form of conduit, a roller support (see Fig. 46) should be used. FIG. 45. Expansion pipe hangers. FIG. 46. Roller support for piping. degrees will expand about Pipe heated from 30 degrees to 1%" in 100 feet of length. The following table gives the expansion of 100 lineal feet of pipe heated to various degrees of temperature. TABLE VH EXPANSION OF WROUGHT-!RON PIPE Temperature of the Air When Pipe Is Fitted. Length of Pipe When Fitted. Length of Pipe When Heated to 215 265 297 338 Ft. Ft. In. Ft. In. Ft. In. Ft. In. Zero 100 100 1.72 100 2.12 100 2.31 100 2.70 32 100 100 1.47 100 1.78 100 2.12 100 2.45 64 100 100 1.21 100 1.61 100 1.87 100 2.19 The number of degrees pipe is heated, corresponding approx- imately to steam pressure, as follows: 215 = 1 Ib. pressure. 265 = 25 Ibs. pressure. 297 = 50 Ibs. pressure. 338 = 100 Ibs. pressure. 66 PRACTICAL HEATING AND VENTILATION Wrought-iron or Steel Pipe Up to the year 1885, approximately, all pipe was made of wrought iron. At about this time the manufacture of welded steel pipe on a commercial basis was started. The difficulties experi- enced before in its manufacture, principally in welding, had been overcome by improvement, so that it could now be readily welded. The first of the steel pipe seemed hard and brittle and the steam fitter had considerable trouble in threading it. However, as now manufactured it is soft and tough in fiber and a die, if blunt, will tear the thread. Consequently it is necessary that the die be sharp in threading steel pipe. In appearance, iron pipe is rough and has a heavy scale, while steel pipe has a lighter scale, underneath which the surface is smooth. The grain of steel pipe is fine, while that of wrought-iron pipe is coarse. The author of this work is located near the center of the iron and steel industry and has endeavored to ascertain the difference in value between steel and wrought-iron pipe and our investigation may be summed up as follows : Steel pipe costs less to manufacture than wrought-iron pipe ; it is, therefore, cheaper. With improved dies, threads may be cut on steel pipe as good, but not as quickly, as on wrought- iron pipe. When steel pipe is new it has a higher tensile strength than wrought iron. We are told that after a few years' use the reverse is the case. There seems to be no doubt but that wrought-iron pipe will last much longer than pipe made of steel, as it is less liable to cor- rode, the difference in longevity, under certain conditions, more than making up for the increased cost. To Ascertain Whether Pipe Is Made of Iron or Steel The following test is given us by an officer of an iron company : " Cut off a short piece of pipe file the end smooth to oblit- erate the marks of the cutting tool. Suspend the piece of pipe in a solution of nine parts of water, three parts of sulphuric acid and one part muriatic acid. Place the water in a porcelain or glass dish, adding the sulphuric and then the muriatic acid. Suspend the pipe in such a manner that the end will not touch the bottom PIPE AND FITTINGS 67 of the dish. After an immersion of about two hours, remove the piece of pipe and wash off the acid. If the pipe is steel, the end will present a bright, solid, unbroken surface; if made of iron, FIG. 47. Wrought-iron and steel pipe. it will show faint ridges or rings, displaying the different layers of iron and streaks of cinder," as shown by Fig. 47. Nipples Short pieces of standard pipe threaded at both ends are called " nipples " and are known commercially as " close," " short," or " long." A close nipple is one so short that in threading the ends, the threads join at the center of the nipple, and by the use of which two fittings or valves may be joined together close to each other. From this fact the nipple is called " close." The short nipple is one showing a small amount of bare pipe between the threads, the length varying from l 1 /^" for %" to y 2 " nipples to 5" for nipples made from 7" to 12" pipe. SHOULDER NIPPLE CLOSE NIPPLE FIG. 48. Nipples. Long nipples run from 2" to 6 1 /:/' in length, according to the size of pipe. Fig. 48 shows the two kinds of nipples and the following table gives lists of lengths and sizes. 68 PRACTICAL HEATING AND VENTILATION TABLE VIII WROUGHT-!RON NIPPLES Close. Short. 3* 2 Length in Inches. 3 3 3 3K Long. Sizes. M IK 2 ^ 3 2 5 (i 7 8 10 Couplings Pipe is joined together by what is known as a coupling a sleeve of wrought iron tapped out or threaded right hand on the inside. Pipe mills furnish one coupling with each full length of pipe. They may also be obtained tapped right and left hand, if desired, although it is customary when using a right and left coupling to use one made of malleable iron. Reducing couplings WROUGHT .IRON COUPLING R. A L. MALLEABLE COUPLING FIG. 49. Couplings. are also made of malleable iron, reducing from one pipe size to another of smaller size. Fig. 49 shows the wrought-iron right- hand coupling and the malleable right and left hand coupling. PIPE AND FITTINGS 69 Fittings The fittings used in connection with steam, gas or water pipe are of two general kinds, viz. : those made of cast iron and those made of malleable iron. By fittings we mean elbows, tees, crosses, flanges, bushings, caps, plugs, etc. For heating work the cast-iron fitting is used ; for gas piping, the malleable-iron fitting, and for domestic water supply, the gal- vanized malleable-iron fitting. We shall illustrate and describe only the cast-iron fitting. Cast-iron fittings are of two kinds, viz.: those having a flat bead, and those having a round bead, Fig. 50. " Straight " fit- ELBOW, ROUND BEAD ELBOW, FLAT BEAD FIG. 50. Beaded fittings. tings are those having all openings tapped for the same size of pipe. " Reducing " fittings are those tapped for different sizes of pipes. Fig. 51 shows a group of flat beaded fittings. The terms " male " and " female " fittings are sometimes used. By " male " fitting we mean one with the threads on the outside ; by " female " fitting we mean one with the threads on the inside. When reading or describing a tee fitting, the run is named first, the side opening last. If the run is tapped reducing, the larger tapping is read first. Thus a tee whose tappings are 3" X 2" X 1%" is read: three by two by one and one half inch. The top and side outlets of a cross are all of the same size, while the inlet may be the same size or larger. Thus a 2 X 1 X 1" cross would indicate that the bottom or inlet was 2" and the top and side outlets 1" in size. Branch Tees A fitting used largely on coil work is known as a Branch Tee, frequently (but erroneously) called a Branch Header. Shown by Fig. 52. All branch tees are tapped right hand in the run and 70 PRACTICAL HEATING AND VENTILATION in the branches, excepting when used in making box coils, when the branches are tapped left hand and the back opening right hand. R. FIG. 73. Victor automatic air valve with wood wheel. FIG. 71. Inte- rior of Baker automatic air valve. of valve the strip of brass or tube used in the interior of the valve, when expanded by contact with the steam, will seat or close the valve, which will again open when the steam pressure is removed. VALVES 79 As automatic valves are now manufactured, the expansion post or tube is made of carbon or a composite material, which will ex- pand more quickly than metal, as shown by Fig. 72 and Fig. 73. Others are made with a combination of the expansion post and a float, which temporarily closes the valve should there be any water forced through the air-valve opening of the radiator. Fig. 74 shows an air valve of this type. Still another variety is that shown by Fig. 75. The float of this valve is sealed and contains a liquid extremely sensitive to FIG. 74. Automatic air valve with expansion post and float. FIG. 75. Russell automatic air valve. heat, which vaporizes at a temperature of 151 Fahr., expanding the ends of the float, which are corrugated, closing the valve. Some makes of air valves are provided with a vacuum attach- ment, which, working in connection with the float and expansion post, allows the air to escape under pressure from the steam, clos- ing against the steam when all air is expelled. When the steam pressure is removed, or the system is cooled, the attachment ef- fectually closes the air port preventing the return again of air through the valve. Thus the system is placed under a partial vacuum. 80 PRACTICAL HEATING AND VENTILATION One of the greatest of the troubles that the steam fitter has to contend with is air in the system. The radiators or radiating surfaces becoming air bound, the steam cannot enter, nor the hot water circulate. It is of importance then that the steam fitter should use a type of air valve which will effectually do the work required. CHAPTER VIII Forms of Radiating Surfaces ONE of the most interesting parts of the study of the science of steam and hot-water heating is to be found in following up the improvements in the beauty and utility of the radiating surfaces employed in the distribution of heat. Perhaps no part of a heat- ing apparatus shows so well the effort of " Yankee " ingenuity FIG. 77. The Whittier radiator. FIG. 76. The Verona radiator. as the various styles of heating surfaces we to-day call radiators, for the radiator is of American origin. From the old pipe box coil, or the " pan " radiator made of sheet iron, to the American Radiator Company's " Verona," as shown by Fig. 76, or, in fact, almost any one of the present orna- 81 82 PRACTICAL HEATING AND VENTILATION mental cast-iron radiators, is an achievement of which any person connected with the heating industry may be justly proud. FIG. 78. The Bundy loop radiator. FIG. 79. The Reed radiator. It is probable that the first direct radiator to be manufactured and sold in any quantity was the original " Bundy " radiator, FORMS OF RADIATING SURFACES 83 made with a cast-iron base into which were screwed short lengths of one-inch pipe capped at the top and covered with a cast-iron FIG. 80. The Union radiator. FIG. 81. The Pyro radiator. fretwork top. This was followed by other makes of pipe-tube radiators of similar design. The first of the cast-iron direct radiators were the " Whittier," FIG. 82. The Elite radiator. Fig. 77, and the " Bimdy " loop radiator, shown by Fig. 78. These radiators were placed on the market about the year 1873 or 1874, the former bv the H. B. Smith Co. and the latter bv the 84 PRACTICAL HEATING AND VENTILATION A. A. Griffing Iron Co. Improvements in design and manufac- ture followed almost immediately, the H. B. Smith Co. bringing out the " Reed " radiator, Fig. 79, and still later the " Union," shown by Fig. 80. The A. A. Griffing Iron Co. followed the "Bundy" with the " Pyro," Fig. 81 (1876), and the "Elite," Fig. 82 (1877). The Exeter Machine Co., of Exeter, N. H., were early in the field with the " Exeter," a cast-iron radiator of double- tube construction. FIG. 83. The Gold Pin indirect radiator. Of the cast-iron indirect radiators the " Gold " pin radiator, Fig. 83, was the first, the original being manufactured as early as 1862, and is no doubt the oldest of the cast-iron radiators in any form used for heating. The illustration shows the improved style which, however, is quite similar to the original. The "Bundy Climax," Fig. 84, is another type of the early indirect radiators. FIG. 84. The Bundy Climax indirect radiator. Radiators may now be obtained in numerous heights and widths to fill any desired space and in a multitude of designs of orna- mentation, which when properly decorated become a thing of beauty as compared with the ugly looking box coil. Illustrative of this we show a low-down window radiator, Fig. 85, of such a height that a seat may be built over it, thus making not only a warm and comfortable window seat, but adding also largely to the beauty of the room. FORMS OF RADIATING SURFACES 85 Pipe coils in residence heating have been almost entirely su- perseded by what is known as the Wall Radiator, Fig. 86. This FIG. 85. Window radiator. type of radiator is largely used in narrow halls, bath rooms, or in fact, any place where there is an abundance of wall space and FIG. 86. Wall radiator. but little floor space, and while not so effective as a pipe coil, is much more effective than the regular type of radiator. 86 PRACTICAL HEATING AND VENTILATION Cast-iron radiators, direct and indirect, and direct-indirect, are now manufactured by many concerns, the largest of which is the American Radiator Company, originally formed by the merging of the Tierce Company, of Buffalo, and the Detroit and Perfection Radiator Companies, of Detroit. The extremely large output of this concern, together with the other manufacturers of radiators, bears witness to the great popularity of steam and hot-water heat- ing in this country. Pipe Coils Pipe coils are still used largely on factory or other work where their appearance is not objectionable. There are several styles of pipe coils as generally used. Fig. 87 illustrates the Miter Coil BRANCH TEE- MITRE COIL FIG. 87. Mitre pipe coil. made with branch tees and right and left elbows. The position of the air valve, as shown at A, is for hot water. If for steam, the coil should be vented at end marked B and the air valve should be placed on the branch tee just above the lowest pipe of the coil. In building all coils used for steam, expansion must be provided for, and the angles in this style of coil formed by the right and left elbows provide for the expansion. It should always be used on walls at the position shown in the illustration, with the miter end up, and it may also be used as a ceiling coil. Fig. 88 shows the Corner Coil. This coil as shown and vented s for hot water, but may also be used for steam. The Return Bend Coil, Fig. 89, is not so good for steam FORMS OF RADIATING SURFACES 87 Feed FIG. 88. Corner pipe coil. Reiur n tf\ i c i V ] \% p vJ | l<- Return Return Bend Coil FIG. 89. Return bend pipe coil. RETURN BRANCH TEE COIL FIG. 90. Return branch tee pipe coil. 88 PRACTICAL HEATING AND VENTILATION as either of those already mentioned, as the steam must travel through the entire coil in a single pipe. When used for steam it should be vented at B ; when used for hot water it should be vented at A. Fig. 90 illustrates the Return Branch Tee Coil. Where the length of wall space is limited, this is a very compact type of coil Standing Wall Coil FIG. 91. Upright coil pipe. to use. It is made with one set of right hand elbows, the other set being right and left hand elbows. When used for hot water, vent as shown at A; when used for steam, vent at end marked B, but place vent lower down on the coil, as recommended for coil shown by Fig. SI. FORMS OF RADIATING SURFACES 89 A style of coil used for hot water is shown by Fig. 91. Do not use a coil of this character for steam, as suitable provision is not made for expansion and trouble would ensue. To those who have had no very great experience in building coils it may not be amiss to say a few words regarding coil building. There are many methods of procedure, any one of which when the details are properly worked out will result in a neat and well- proportioned coil. We will take the miter coil for illustration, and our method is as follows : Determine the center to center measurements of the openings of the branch tees to be used and with an ordinary chalked W-H- i FIG. 92. Diagram for coil making. line snap as many chalk lines upon the shop floor as there are openings in the branch tees to be used, making the distance be- tween the lines the center to center measurement of the openings in the branch tees. Calling these the horizontal lines, make at one end the same number of vertical lines the same distance apart. Determine the length and height of coil according to the space to be used, and then lay the branch tees and R. and L. elbows on the marks as shown by Fig. 92. It is well to have the left hand thread of the elbow looking toward the short or expansion end of the coil. Accurate measurements for the pipes may now be taken. The line A is the longest pipe of the coil. The line B is the longest of the upright or expansion pipes. To make a symmetrical and 90 PRACTICAL HEATING AND VENTILATION neat appearing coil the shortest upright pipe C should be iu length but one third that of D, the shortest horizontal pipe. Cut right hand threads on each end of the long pipes and a right hand thread on one end of the short pipes and a left hand thread on the other end. Make the right hand side of the elbows on one end of the long pipes and make the other end of the pipe into one of the branch tees, with the elbows in proper position to receive the short end of the coil. FIG. 93. Coil partially completed. This portion of the coil now looks as shown by Fig. 93. Next Legin with the pipe marked C on Fig. 92 and make this up in the usual manner of making right and left hand connec- tions, following with the next shortest pipe and so on until coil is completed. While yet on the shop floor, see that the alignment of the pipes is perfect. If not, make it so, when the coil is ready to hang in position. HOOK PLATE EXPANSION PLATE RING PLATE CO!L STANDS FIG. 94. Hook plates and coil stands. The same general method of laying out measurements is used in making all styles of coils. Wall coils are held in place by hook plates fastened singly or in groups, as shown by Fig. 94. Ceil- in gf coils are hung or suspended by different forms of hangers so arranged as to give the proper pitch or drip to the coil and to allow of expansion and contraction. CHAPTER IX Locating Radiating Surfaces THE proper location of the radiator, whether direct, indirect, or direct-indirect, has much to do with the success of a heating plant. Direct radiators should be located on outside walls or under the windows of the most exposed parts of a building. Indirect radia- REGISTER FOR INDIRECT RADIATOR FIG. 95. Locating radiators and registers. tors, or more properly speaking, the register openings from in- direct radiators, should be located on the warmer or less exposed side of the room. With direct-indirect radiators it is well, if pos- sible, to place them under windows. To illustrate this we show 91 92 PRACTICAL HEATING AND VENTILATION by Fig. 95 a room with two walls exposed. The dotted line divid- ing the room cornerwise shows the warm and cold or exposed parts of the room. If heated by a direct radiator, it should be located in either of the positions shown, and if heated by indirect radiation the register should be located in the floor or wall at or near either position shown on the illustration. When called upon to place and box an indirect radiator the steam fitter frequently becomes confused. As an aid to the proper hanging and boxing of indirects we shall illustrate and describe the usual methods followed. Fig. 96 shows a method of installing an indirect where the hot- air flue and register are placed in the wall. Figs. 97 and 98 show FIG. 96. Indirect radiator register in wall. two methods of installing indirect radiators when floor registers are used. The casing or boxing should fit snugly against the radiator sections in order that the air will pass through the radiator and not around it, and the cold-air supply or duct should always be provided with a damper. It is well to take the hot-air duct from the boxing at the end opposite to that where the cold air enters in order that the air will travel as great a distance through the radiator sections as possible. A number of sections of indirect radiation when nippled or bolted together are usually referred to as a " stack " of indirect LOCATING RADIATING SURFACES radiation, or as an " indirect stack." The space between the top of a stack and the casing should be from eight to ten inches and the space between the bottom of the stack and the lower side of the casing should be six or eight inches. FIG. 97. Indirect radiator register in floor. The hot-air supply or area of the hot-air duct should be, for hot water, 2 sq. in. of area, or for steam 1% sq. in. of area for each sq. ft. of radiation in the stack. As a general rule, the cold- - Register \ FIG. 98. Indirect radiator register in floor. 94 PRACTICAL HEATING AND . VENTILATION air supply or area of the cold-air duct should be from two thirds (66|$) to three fourths (75^) of the area of the hot-air flue. Cir- cumstances vary these figures somewhat, but the above represents a fair average. The following table gives the proper sizes of hot and cold air ducts and sizes of registers for both steam and hot-wai;er indirect heating under ordinary conditions. TABLE X INDIRECT WORK. SIZES OF COLD AND HOT AIR DUCTS AND REGISTERS FOR FIRST FLOOR INDIRECT HOT WATER INDIRECT STEAM Sq. ft. of Heating Surface. Sq. in. Cold-air Duct. Sq. in. Hot-air Duct. Size of Register. Sq. ft. of Heating Surface. Sq. in. Cold-air Duct. Sq. in. Hot-air Duct. Size of Register. 26 36 48 8X12 13 36 48 8X12 52 54 72 9X12 26 54 72 9X12 78 72 96 10X14 39 72 96 10X14 104 96 120 12X15 52 90 120 12X15 130 108 144 12X19 65 108 144 12X19 156 126 168 14X22 78 126 168 14X22 182 144 192 14X24 91 144 192 14X24 208 162 216 16X20 104 162 216 20X20 234 180 240 16X24 117 180 240 20X24 260 198 264 20X20 130 198 264 20X24 286 216 288 20X24 143 216 288 24X24 312 234 312 20X24 156 234 312 24X24 NOTE. Registers and hoi-air ducts to upper floors should be from 25 to 30 per cent, smaller than for first floor as given above. It is well to be generous in the size of flues, as if properly dampered they may be reduced at any time as desired. There are two good methods in vogue of hanging a stack of indirect radiation. Fig. 99 shows one method, that of eye bolts screwed into the joists, suspending a cross bar of pipe on which the stack rests. Fig. 100 shows another method and one which we favor, owing to the fact that the weight of the radiator is dis- tributed across several joists. Heavy stacks suspended on a pair of supports or hangers in this manner will not weaken or strain the flooring as much as when the former method is employed. Casings may be made of wood lined with tin or of sheet iron, as may be desired. A casing of galvanized iron with joints seamed LOCATING RADIATING SURFACES 95 or bolted together is without doubt the best method to use, as it not only presents a neat appearance, but is the most durable. Fig. 101 shows the method of setting a direct-indirect radiator FIG. 99. Method of supporting indirect stack. DA V PER FIG. 100. Another method of supporting indirect stack. FIG. 101. Method of setting direct-indirect radiator. and while there are several modifications of this style, the principle for the setting of all direct-indirects is the same. The wall boxes, Fig. 102, are of standard size, conforming to brick measurements and are furnished by all manufacturers of ra- FIG. 10-2. Wall box for direct-indirect radiator. diators. The radiator itself is of the ordinary direct pattern. It is fitted with and rests on a box base. This base is provided with a damper and is connected to the cold-air wall box by a boxing 96 PRACTICAL HEATING AND VENTILATION made of galvanized iron or tin. Fig. 108 shows a base of this kind. By closing the damper to the cold-air duct and opening the damper in the box base, the radiator may be used as a direct radiator. This FIG. 103. Box base for direct-indirect radiator. is of importance in connection with the heating of a cold room or when ventilation is not necessary. The " flue " type of radiator is the best design for direct-in- direct, owing to the length of air travel through the flues between FIG. 104. Flue type of direct-indirect radiator. the sections. Fig. 104 shows a section of a flue radiator. By refer- ence to the following chapter our readers will learn why we believe a radiator of this type is best adapted for work of this character. CHAPTER X Estimating Radiation HAVING considered the various forms of radiating surfaces and their proper location, we have now reached that part of the work which the steam fitter frequently finds confusing, viz.: the estimating of radiation. This requires careful thought and study on the part of the steam fitter, as no two jobs of heating are alike, excepting, of course, there be two buildings erected from the same plans ; therefore, each j ob or contract for heating must be consid- ered separately and the radiation estimated accordingly. As a rule, all radiation is first estimated as direct, that is to say, the amount of direct radiation necessary to do the work required, and certain percentages are added if the radiation or any por- tion of it is to be direct-indirect or indirect. Many good rules are in vogue for estimating, any one of which will give proper results if applied with good judgment, but just as there are exceptions to all other rules, so that it is in estimating radiation. To use good judgment it is necessary that we should understand something of the cooling surfaces in a room or build- ing, the action of the heat from a radiator upon the air in a room and the heat loss from a radiator under certain varying con- ditions. The principal cooling surfaces of a room are the exposed or exterior walls and the glass surface (windows) and outside doors. A room with two sides exposed, for instance, a corner room, will require more radiation than an intermediate room with but one v^all exposed, while a room having two windows and an outside door will require correspondingly more radiation than a room with but one window. Just how much more is determined by rule. Again, if there be no objects such as trees or adjacent buildings to protect any one of the sides of a house, the north, west, or 97 98 PRACTICAL HEATING AND VENTILATION northwest rooms will need more radiating surface than the rooms on the south, east, or southeast sides of the building. The rea- son for this is readily seen, as practically all the chilly winter winds come from the north, west, or northwest. A frame building without weather board or paper used in its construction requires more radiation than one with this additional protection, and either one requires more than a brick or stone building. FIG. 105. Circulation of air bv direct radiator. As to the action of the heat from a radiator upon the air of the room, the radiator, if direct, should be placed in the coldest place in the room, as stated in the preceding chapter, for the rea- son that it meets and warms the cold air entering through the out- side walls and windows, tempers and heats it, causing it to cir- culate or turn in the room, thus warming all portions of the room to a uniform temperature. Fig. 105 shows the action of a direct radiator upon the air ESTIMATING RADIATION 99 in a room, the arrows indicating the direction of the air currents. We note that the heated air first rises to the ceiling where the air of the room is lighter than below, then passes to an inside wall, where it is forced downward and drawn across the floor again to the radiator, where it receives the same treatment as before, the rapidity of the circulation depending upon the volume of heat from the radiator. Note also the downward draught of the cold air entering at the window, and how it is prevented from entering the Screen FIG. 106. Circulation of air by indirect radiator. body of the room. Should the radiator be placed along an outside wall between two windows, or in a corner, the cold air entering through the windows would pass downward to the floor and then be drawn along the floor to the radiator. Heat, or more properly, heated air, from an indirect radiator passes directly to the ceiling, then across to the windows or out- side wall where, as it cools, it settles to the floor and is drawn across the floor again to the register as shown by Fig. 106. It 100 PRACTICAL HEATING AND VENTILATION is for this reason that churches or rooms with very high ceil- ings are very difficult to heat with indirect radiation without the assistance of some direct radiators to aid in turning the air of the room. Where direct-indirect radiation is placed the action upon the air in the room is similar to that of the direct radiator as shown by Fig. 105. Rules for Estimating Radiation Some one has aptly said, " We gain knowledge and profit by the mistakes of others," and truly this is exemplified in figuring radia- tion. Many years ago the writer was taught to estimate radiation by the following rule: For Steam To ascertain the amount of radiation required find the cubical contents and divide the result by the following factors Living rooms, ordinary exposure 50 Living rooms, extraordinary exposure 40 Bath and dressing rooms 40 Staircase halls 50- 70 Sleeping rooms 55 70 School rooms 60- 80 .Churches, theaters, halls, etc 65-100 Factories 75-150 For Hot Water Add one third to the result obtained for steam. For direct-indirect, add twenty-five per cent, and for indirect, add fifty per cent. It will readily be seen that the results obtained by this old rule, which is now almost entirely obsolete, were anything but cor- rect, and unless the person using the rule was thoroughly con- versant as to the requirements of certain rooms, or was endowed with extraordinary good judgment, many errors would result. Yet many heating contractors are to-day using this rule or some other " rule of thumb " just as antiquated. ESTIMATING RADIATION 101 Some Dependable Rules Baldwin's : " Divide the difference in temperature between that at which the room is to be kept and the coldest outside atmosphere, by the difference between the temperature of the steam in the radia- tor and that at which you wish to keep the room and the product will be the square feet of radiating surface to be allowed for each square foot of equivalent glass surface." (Mr. Baldwin estimates that a square foot of glass and a square yard of ordinary outside wall have about the same cooling value.) As an example of this, take outside temperature at zero and the rule results as follows : Temperature desired in room .............. 70 Outside temperature (zero) ............... Difference ............................. 70 Again: Temperature of steam in radiator 212 minus 70 (temperature of room) equals 142; 142 divided by 70 equals 0.493, or about one half a square foot of radiation for each square foot of glass or its equivalent (one square yard of out- side wall). The above covers only the exposure of the room and is for a well-built building. Loose windows, poor construction, etc., must be taken into consideration and the proper allowances made. Another rule (and the one used by the author for quick fig- uring) is that of Mills, and briefly stated, is as follows: To find the amount of radiation required to heat a room with low-pressure steam to 70 Fahr. when the outside temperature is at Fahr., allow one square foot of radiation for each 200 cubic feet of contents, one square foot of radiation for each 20 square feet of outside wall surface, and one square foot of radiation for each 2 square feet of glass surface (counting outside doors as glass surface). The product of these results will be the amount of radiation required. For hot water add 60 per cent to this result. As an example consider a room 12' X 15' in size, having a 10 ft. ceiling. The cubical contents, found by multiplying 12 X 15 X 10, equals 1,800 cu. ft. One 12 ft. side is exposed wall: 102 PRACTICAL HEATING AND VENTILATION 12 X 10 = 120 sq. ft. of exposed wall surface. The room has two windows 3 X 6' : 3 X 6 = 18 X 2 = 36 sq. ft. of glass surface. 1,800 200= 9 120 20= 6 36 2 = 18 Total S3 sq. ft. radiation. For hot water: 33 X 60$ = 19.8 + 33 = 52.8 sq. ft. of ra- diation required. It is the custom of the author to add 25$ to the amount of direct for direct-indirect, either steam or hot water, and for in- direct to add 50$ for steam and 60$ for hot water. While there are many rules for estimating and some of them possibly a little more accurate than the above, we consider either Baldwin's or Mills's rule to be the simplest and best, as they are free from complicated methods not readily understood. The author has found that it was excellent practice to increase the radiation somewhat on the north and west sides of a building, also that when a building is heated intermittently (as is the case with some churches, halls, etc.) the radiation should be increased 25$ over and above the normal amount required should the build- ing be heated continuously. It is well to become familiar with two or more rules, using one as a check upon the other. CHAPTER XI Steam-Heating Apparatus IN one of the early chapters of this book we gave a brief his- tory of steam heating and its introduction in this country. We shall now take up the many various systems and consider the advantages or disadvantages of each, showing also the various styles of piping. The early method of heating by steam was with the two-pipe system, small sizes of pipe being used and a high pressure of steam maintained. As our knowledge of steam heating increased, larger piping and a lower pressure were made use of. At the present time there are many buildings, such as factories and offices, or commercial buildings, where a medium or compara- tively high pressure is used, the steam being generated at high pressure by the boilers and reduced for use in the heating system. On work of this character the water of condensation is returned to the boiler by return steam traps or by a pump. For the heating of residences and small buildings, we use what is called a " gravity system," the pressure of steam being from one to five pounds, the condensed steam returning to boiler by its own gravity. The boiler is located below the level of all mains and radiators. It is of this latter method that we shall treat, illustrat- ing and explaining each system. Low-pressure gravity steam heating may be divided into sev- eral systems or styles of construction, as follows : (a) The one-pipe system, where the radiators are connected by a single pipe which is used both as flow and return. (b) The two-pipe system, where each radiator has a separate flow and return pipe. This system also necessitates a double sys- tem of cellar piping. These two methods may be subdivided into several styles or systems, viz. : 103 104 PRACTICAL HEATING AND VENTILATION (a) The Circuit System. (b) The Divided Circuit System. (c) The One-pipe System with Dry Returns. (d) The Overhead System. Fig. 107 illustrates the regular circuit system. The steam main rises from the boiler as high as possible, or as high as circum- FIG. 107. Circuit system of steam heating. stances or height of basement will permit. This is the high point of the system, so far as the steam main is concerned. From this point the main makes a circuit of the building, as shown by illus- tration. This circuit is made at a distance of from two to six feet STEAM-HEATING APPARATUS 105 from basement wall (circumstances governing this distance), the main pitching- downward from the boiler from %" to V in each ten feet of length. In making the circuit of the basement, the main is carried to a point as near to the boiler as is possible. At this point a reducing elbow is placed on the end of the main, re- ducing one or two sizes. Connection is then made with return opening of boiler. This reducing elbow should be tapped for an air vent and an automatic air vent be placed on the same. As the main acts as a steam reservoir to supply the various radiators, it is well to free it of all air, in order that the steam may be supplied to all radiators at the same time, thus allowing them to ^-BRANCH ELBOW FIG. 108. Branching from main with 45 elbow. heat uniformly. The automatic air vent placed on the_ elbow at the end of the main accomplishes this purpose. The various branches should be taken from the main by the use of a nipple and a 45-degree elbow, as shown by Fig. 108. As a general rule, the branches should be one size larger than the vertical pipe or " spud " supplying the radiator valve, or one size larger than the risers which they feed. Most of the old-time steam fitters, as well as many fitters of the present day, make a practice of taking the connection for branch from the top of the main. This practice is wrong, as the con- densation returning through the branch to the main drops directly into the steam supply, saturating and cooling it. Fig. 109 illus- 106 PRACTICAL HEATING AND VENTILATION trates this. We may add, for example, that a main where all the branches are taken off with the use of 45-degree elbows, as shown by Fig. 108, will do 25$ more work, and prove 25$ more economi- cal than if taken off main from the top. Fig. 108 also shows how the water of condensation joins that in the main without interference with the steam, when 45-degree el- bows are used. The main on a circuit job of heating should not be reduced in size, but should be carried full size to point where air vent is used, The principal reason for this is that it is constantly being reduced ^-BRANCH ""-WfELBOW ^NIPPLE MII FIG. 109. Branching from main with 90 elbow. in area by the water of condensation from the various radiators entering it, so that its area at the end may not be more than one half the full capacity of the pipe. The branches should have a pitch upward from main of at least 1" in 5 feet of length, and a greater pitch is desirable. Special elbows, called pitch elbows, for use on end of branch, in order to throw the vertical spud or riser straight, may be purchased from those who deal in steam-fitting supplies. Where the circuit system can be used to advantage, we would recommend it on account of its utility and good appearance. For STEAM-HEATING APPARATUS 107 an L-shaped building, it is necessary to take a separate loop from the main circuit, as shown by Fig. 110; otherwise the work is similar to the single loop. FIG. 110. Circuit system of steam heating with loop. The Divided Circuit System When installing a steam-heating apparatus in a long building where the boiler is located near the center of the basement, and on either side of the same, we may use what is called the Divided 108 PRACTICAL HEATING AND VENTILATION Circuit System, as illustrated by Fig. 111. The convenience of installing this system can be readily seen from the illustration. In installing this system and also the Single Circuit, it is well to keep the end of mains at least 14" above the water line of the boiler. With the Divided Circuit System it is necessary that an auto- matic air vent be placed on the end of each loop. The returns should be connected together below the water line of the boiler, as shown by illustration. The One-pipe System Dry Returns When it is necessary to install steam heat in a long, narrow building, such as one side of a double house, where the radiators are all placed along the outside wall, this system, as illustrated by Fig. 112, is particularly adaptable. The flow pipes, as shown, pitch downward from the boiler to end of main. On the end of main a reducing elbow is placed. Into this elbow is connected a close nipple with a 90-degree elbow on the end of same, and from this elbow the return is taken dry to the boiler, as shown. These elbows should be " thrown " or turned upward until the top of the return is level with the bottom of the main, in order to gain head room. A short piece of pipe, with crooked thread on one end, should be used in starting the return; the longer pipe should be attached to this piece with an ordinary coupling. In this manner the return may be taken to boiler almost directly under and par- allel to the main, making a good appearing and workmanlike job. At a point near the boiler, elbows should be placed on end of returns and drop made to return opening of boiler. These elbows should be tapped for air vent and automatic air vents placed on same. Note the coil shown on illustration. All pipe coils should be connected " two pipe " with return connected below the water line of the boiler. The Overhead System The Overhead System of steam heating is necessarily a combina- tion of the one and two pipe systems and it may have either a wet or a dry return, although the wet return is by far preferable. We illustrate by Fig. 113 an adaptation of the overhead system STEAM-HEATING APPARATUS 109 110 PRACTICAL HEATING AND VENTILATION STEAM-HEATING APPARATUS 111 and show the many different methods by which the radiators may be connected. The riser or risers (there may be more than one) rise directly to the top floor or attic of the building and here branch in the several directions necessary to feed the various drop risers sup- plying the radiators. The branches connecting these risers are PRACTICAL HEATING AND VENTILATION IP STEAM-HEATING APPARATUS 113 taken from the side of the main. Should it be necessary to run the main any considerable distance from the boiler in the basement be- fore rising to top of building, it is well to " heel drip " the elbow at bottom of the riser and connect the drip with the wet return. At the left of the illustration in the basement we show one method of creating a false water line, in order that the returns from risers in an unexcavated portion of the basement may be con- nected into a wet return^ We shall in a later chapter illustrate and describe the false water line more fully. At the right of the illustration we show in the basement a wall radiator for heating a basement room, which is warmed par- tially by steam, above the water line of the boiler, and partially by the water of condensation, below the water line of the boiler and is connected in such a manner, without valves, that it might be designated as a cooling coil. The illustration shown is composed of three sections of wall radiation, although a pipe coil could be used in the same manner. The Two-pipe System Illustrated by Fig. 114 we show the Two-pipe System of steam heating. This system has been discarded generally on ordinary work, being succeeded by the One-pipe System, although it still has some adherents among the fitters. Smaller piping for both flow and returns and flow and return risers is used for this system than for either of those already de- scribed. The cost of installation will, however, exceed that of either style of the single-pipe systems. It is customary when using the FIG. 115. Eccentric fittings the right method. two-pipe system, to reduce the size of the main as the various radiators are taken off. We would caution against reducing the main too rapidly, as so much friction would result that it would be necessary to carry a considerable pressure at the boiler in order to supply the radiators at the far end of the system and this PRACTICAL HEATING AND VENTILATION would thereby destroy the economical features of the job. When- ever the main is reduced, a tee should be used and a drip con- nected to return, or, what is better, eccentric fittings should be used, FIG. 116. Common fittings the wrong method. as shown by Fig. 115. Unless this course is pursued, the water of condensation will lodge in the main (see Fig. 116) and cause " water hammer " or pounding in the piping. Advantages of Steam Heating The advantages of steam heating over other systems, not consid- ering the patented vacuum or vapor systems, are: (1) there is less liability of damage by frost; (2). smaller radiators and piping are used ; (3) rooms are more quickly warmed and cooled, and (4) where a system of ventilation is used, the air is more quickly purified. By the use of automatic damper regulators, safety valves, etc., the danger of explosion has been practically eliminated, so that now steam may be used with as great a degree of safety as any other system. TABLE XI SIZES OF STEAM MAINS ONE-PIPE SYSTEM. TWO-PIPE SYSTEM. Size of Steam Main. Size of Main Radiation Supplied. Radiation Supplied. Flow. Return. U4" 2" 125 to 250 sc 250 to 400 !' t. \w 2" w \y" or %" in size, running from the overflow of the expan- sion tank to the basement. This was called a " tell-tale," and the operator in filling the apparatus would leave the water pressure turned on until the water was heard running from the tell-tale. The Altitude Gauge This crude arrangement has been dispensed with and in its place we now employ the altitude gauge, Fig. 142. This is or- dinarily a spring gauge of the Bourdon type. The gauge has two dials, a black and a red one. The black . dial is attached to the mechanism of the gauge and registers the height of the water in the system, by feet. The red dial is stationary and is movable only by hand. After filling the system to the proper height, the same being registered on the gauge, the face of the gauge is re- moved and the red dial moved to the same position as that occu- pied by the black dial, when the face of the gauge is then replaced. As the water in the system evaporates, the black dial will drop away from the red one, indicating to the attendant that the water is low in the system. As the gauge is attached to the apparatus at or near the heater, it is necessary only for the attendant to admit sufficient water to the system to bring the black dial back to 146 HOT-WATER HEATING APPLIANCES 147 the position held by the red one, thus indicating that the system is properly filled. The Hot-water Thermometer The hot-water thermometer used on a hot-water heating ap- paratus is a mercurial thermometer, as shown by Fig. 143. The framework is of iron, or brass, on the face of which is the indi- cator. Attached to the face of the indicator is the glass mercury tube, the lower end of which extends through the center of a small FIG. 142. Altitude gauge. FIG. 143. Hot-water thermometer. brass casting. The lower part of this brass casting forms a cup, and this cup part of the casting is turned down until it is very thin. This renders this portion of it very susceptible to the heat. A standard pipe thread is cut on the outside of the casting, which may then be screwed into an opening in the heater or other portion of the heating apparatus. This leaves the lower and thinner part of the appliance submerged in the water. In order to get a true register of the temperature of the water it is necessary that the lower part of the thermometer containing the bulb of mercury be submerged in the water, as shown by Fig. 144. Unless this is done the thermometer will register falsely. 148 PRACTICAL HEATING AND VENTILATION H. W. Thermometer FIG. 144. Right method of attaching thermometer. We have seen thermometers used where they were screwed into an opening which had been reduced in size by the use of several H.w. Thermometer FIG. 145. Wrong method of attaching thermometer. HOT-WATER HEATING APPLIANCES 149 bushings, with the result that the thermometer did not reach the water in the system. Fig. 145 illustrates this, and under such conditions it is impossible to register the correct temperature. Floor and Ceiling Plates Not a very long time ago we were accustomed to notice cumber- some cast-iron plates surrounding the pipes where they passed through floors or ceilings. They would frequently drop a distance FIG. 146. Brass floor and ceiling plates nickeled. from the ceiling, and sometimes fall entirely to the floor below, be- cause they were insecurely fastened in place. These crude affairs have been replaced by a nickeled plate of spun brass, Fig. 146, or iron, Fig. 147. These plates are made in two parts and so FIG. 147. Cast-iron floor and ceiling plates nickeled. constructed as to be adjustable. They are held to the pipe by springs and this method keeps them firmly in their proper posi- tions. The heating contractor now gives much attention to the fin- ished appearance of his work and this fact, no doubt, has led to the use of better trimmings on heating jobs. 150 PRACTICAL HEATING AND VENTILATION Pressure Appliances Some of the more recent developments in accessories to a hot- water heating apparatus are various appliances for putting the system under a nominal pressure without sealing or closing the vent opening of the expansion tank. There is no element of danger presented by the use of any one of these appliances, as the system remains an open one, but is, however, weighted down in a manner which allows of a nominal pressure under the force caused by the expansion of the water within the apparatus. A considerable saving is made in the first cost of the heating apparatus by using an appliance of this character, as not only may there be a reduction made in the amount of radiation installed, but smaller piping may be used, the same as for a pressure system. The Honeywell system is operated by mercury. This appliance is designated as a " Heat Generator " and is illustrated by Fig. 148. It consists of two pipes, one within the other, the larger pipe termed the " stand pipe," the inner one, the " circulating pipe." The upper end of the stand pipe is screwed into the bot- tom opening of a hollow bulb, termed a " separating chamber," which has also an opening at the top into which the pipe connection to the expansion tank is made. The lower half of the stand pipe is screwed into a bottle-shaped hollow casting, as shown by Fig. 149 (12), terminating in a hol- low cup or " shoe " screwed on the bottom of the pipe. The plug (16) screwed into the bottom of the bottle makes it tight, except for opening (6) on one side near the top of tlie casting, into which expansion pipe from heating system is connected. The lower part of the bottle is termed the " mercury chamber," being filled with mercury to the height of the small plug shown (10), making it approximately 1%" in depth. The principle of the operation of the generator is based on the fact that mercury is thirteen times heavier than water, and the apparatus is really a mercury seal, requiring a pressure of about ten pounds to break the seal and allow the pressure to reach the expansion tank. The various parts of the generator are so arranged as to allow the mercury to circulate under pressure and to be separated from the water (by plate 2) when the mercury HOT-WATER HEATING APPLIANCES 151 seal is broken by excess of pressure on the system. As the mer- cury is heavier than the water, it settles again through space 8, as per sketch, into the mercury chamber at the bottom of the gen- erator. The rapidity of the circulation through small piping and re- duced radiation, under a temperature equal to steam at ten pounds FIG. 148. Honeywell heat generator. 14 16 15 FIG. 149. Sectional view of Honeywell heat generator. pressure, renders the reduced amount of radiation (10$ reduction) effective for cold weather and the wide range of temperature allows of a mild degree of heat in warmer weather. 152 PRACTICAL HEATING AND VENTILATION When installing this system there are a few points to be con- sidered, viz. : (a) The radiation should be figured as for the regular hot- water system, then a deduction of 10$ made. (b) The heater should remain the full size. (c) In proportioning size of mains, allow 1 sq. in. of area for each 100 sq. ft. to be supplied. (d) Make branches and risers of the same size and take branches from side of main. (e) Take branches for second or third floor risers from side of other branches, not from end of the branch to first floor. (f) Radiator tappings should be as follows: For first floor up to 25 sq. ft. ll/o" ; 25 to 60 sq. ft. %" ; over 60 sq. ft. I". For second floor up to 30 sq. ft. %" ; 30 to 100 sq. ft. %" ; over 100 sq. ft. 1". For third floor up to 50 sq. ft. %" ; 50 to 125 sq. ft. %" ; over 125 sq. ft. I". The length of the pipe which screws down into the mercury chamber and connects it with the oval separating chamber is regu- larly 21 inches, which allows of a pressure of ten pounds upon the apparatus. A feature of the generator is that no mercury will be forced out of it and lost through the overflow pipe during the operation of filling the apparatus from the regular water-service pipes. When the water supply valve is opened the mercury is forced up into the separating chamber and held there until the apparatus is filled with water, or until the supply valve is closed, when it falls into the mercury pot and is ready for service. A detailed description of the operation of the generator may be given as follows : When the fire in the heater has warmed the water in the apparatus sufficiently for it to begin to expand, the pressure is exerted downward upon the mercury in the bowl or chamber, forcing it upward through the circulating tube and the space be- tween it and the stand pipe. As soon as sufficient pressure has ac- cumulated to force the mercury to the top of the stand pipe and the circulating tube, the mercury in the bow T l will be lowered un- til its level is at the top of the lower inlet of the circulating tube. HOT-WATER HEATING APPLIANCES The two pipes now stand full of mercury, which, owing to the connection of the two columns at the top of the pipes, begins im- mediately to circulate. Unless the fire in the heater is checked the pressure will continue to increase until the mercury is forced below the inlet of the circulating tube, allowing the water to enter and Expansion Pipe FIG. 150. Phelps heat retainer. pass upward to the tank until the pressure is reduced or removed, the baffle plate in the separating chamber dividing the mercury from the water and preventing it from leaving the generator. Owing to the small size of piping used, it is well to ream the ends of each length or piece of pipe used in the installation of the system and it is well also to test the circulation at as low a tern- 154 PRACTICAL HEATING AND VENTILATION perature as 110 and see that a perfect circulation may be main- tained at this temperature. An appliance quite similar to the Honeywell Generator in the results attained is known as the " Phelps Heat Retainer." How- ever, this has no mercury attachment, but consists of a double-act- ing valve inclosed in a cast-iron box, as illustrated by Fig. 150. A weight rests upon the valve disc that opens toward the expansion tank, so that the pressure on the heating system must lift this weight in order that the water may overflow into the tank. The opposite end of the valve opens into the heating system and as there is no weight upon it, the least condensing of the water in the system, due to a low temperature, will open the valve and allow the water in the expansion tank to feed down into the system, thus preventing a vacuum. The pressure on the system at which the retainer operates is sixteen and one half pounds, allowing of a temperature of 250 degrees before the water can boil. As with other appliances of this kind, a large reduction may be made in the amount of radiation ; also small piping and radia- tor tappings may be used, but the heater capacity should remain unchanged, as it is necessary that this should be of ample size. As a cure for sluggish circulation, due to improper methods of piping on work already installed, or a heating plant with insuffi- cient radiation, it would seem that the use of a " generator " or a " retainer " should remedy the defect. CHAPTER XVI Greenhouse Heating THE earlier methods of heating greenhouses were both crude and unsatisfactory. The improvement over the old forms of green- house heating and greenhouse construction has been such as to result in a complete revolution in building and heating the same. The earliest method of heating a greenhouse, a^l one which for a time was more or less followed in this country, was the brick furnace and flue. This consisted of a brick combustion chamber, which was fitted with a cast-iron front, and the lower part pro- vided with grate bars and an ash pit. The furnace was built in a pit or cellar at one end of the greenhouse, the brick or tile smoke flue connecting with the furnace, rising at a sharp angle to the floor of the house, where it was continued at a slight rise under the bed in the center of the house to the chimney at the opposite end. The hot air radiated by this flue was sufficient to heat a small greenhouse. There were so many objections to the use of this apparatus, such as the overheating and withering of plants, the killing of flowers by escaping gas through the tile or brickwork, etc., that it was discarded in favor of steam or hot water heat, as soon as the latter methods were generally adopted for green- house heating. The original method of hot-water heating in this country, as applied to greenhouse work, consisted of a cast-iron heater of a type similar to that as shown by Figs. 23 and 24. The piping was of cast iron, about 4" in diameter, with a hub or socket on one end. These were fastened together by using iron filings and other ingredients, making a rust joint. The various lines of pipe had an upward pitch to the far end of the house, where they terminated in a hollow cast-iron post with air openings through the top. These were called expansion tanks, 155 156 PRACTICAL HEATING AND VENTILATION though they might more properly have been called " expansion posts." They not only took care of the increase in the volume of water, when heated, but served at the same time to extract the air from the system. We believe Hitchings & Company were the pio- neers in this class of work in the United States. Greenhouses are of two kinds, viz. : the commercial greenhouses in which are grown flowers and vegetables for profit, and the green- houses or conservatories of the wealthier class and as found also in many of our public parks and botanical gardens. In the heating of the latter the first consideration is the efficiency of the ap- paratus, without reference to the matter of economy in the con- sumption of fuel. On the other hand, with the former class (the commercial houses) both efficiency and economy in fuel are a con- stant study with the owner. The increase in the number of com- mercial greenhouses has been such that at the present time there is scarcely a town of any size which does not have one or more greenhouses, and in the towns adjacent to or within easy com- munication of the larger cities, they may be counted by the dozen. It is, therefore, important that the heating contractor become fa- miliar with the modern methods of greenhouse heating how to es- timate the radiation required and in what manner the piping should be erected and the general conditions surrounding the work. Modern Greenhouse Heating The modern methods of greenhouse heating are by steam or hot water. There is a diversity of opinion among florists and garden- ers as to which system of the two is perferable, some florists of large experience advocating steam, while others of equal expe- rience and standing favor hot water. We are inclined to believe that hot water is best adapted for the use of florists for the fol- lowing reasons. (a) Greater economy in fuel consumption. (b) Uniformity of temperature, hot-water heat being more constant and even. Should the fire for any reason get low, the water continues to circulate for hours. (c) Where hot water is used for heating, the atmosphere in the greenhouse is mild and humid, insuring a healthy growth of the plants and flowers. GREENHOUSE HEATING 157 (d) The hot-water apparatus may be put under pressure, if desired, and thus equal low-pressure steam in intensity and quick- ness of action. There are some groups of houses so situated that a steam- heating apparatus is better adapted for heating than would be a hot-water apparatus or where a hot-water apparatus could not be properly installed ; hence it is well that the heating contractor become conversant with each of the two methods. Estimating Radiation A greenhouse structure offers less resistance to cold and frost than any other type of building, and, therefore, requires not only a greater amount of heat but greater care in its distribution in order to insure an even temperature throughout the house. In order to intelligently estimate we must know what tempera- ture is required for each house, as different plants require different degrees of heat. For instance, carnations require a temperature of from 50 to 55 degrees, roses from 60 to 65 degrees, chrysan- themums from 55 to 60 degrees, and houses for ferns, orchids, palms, etc., or, as they are called by florists, " general purpose houses " require from 55 to 70 degrees. Many florists have be- come growers of mushrooms, and these require a temperature of from 51 to 56 degrees. Exposed surface is alone considered in estimating radiation and there are several methods of figuring. Where houses are al- ready erected and it is possible to measure them, the amount of glass and exposed surface may be easily and quickly figured. Where this is not possible, the following rule will be found fairly accurate. For houses not exceeding three or four feet in height at the eaves and when built in groups with no side glass, find the floor area of the house and add one third for ends and pitch of roof. The result will be the amount of exposed glass surface. Example: a house 16' X 100' no glass on sides. 16 X 100 == 1600 -=- J = 533 1600 + 533 = 2133 sq. ft. of glass. For a house 16' X 100' with a belt of glass 2' high under 158 PRACTICAL HEATING AND VENTILATION eaves: Proceed as before, and to the result of 2133 sq. ft. add the side glass 100 X 2 = 200 X 2 = 400 + 2133 = 2533 sq. ft, of glass. To determine the amount of radiation necessary, use the fol- lowing table. This table is based on the temperature of a climate similar to that of New York City, where the temperature is sel- dom at or below zero and then for only a short period of time. TABLE XVI Temperature Required. For Steam. For Water. 45 Divide square feet of glass by 8 5 50 ( 7 4 55 < 6^2 3% 60 < a 6 3^ 65 < < VA &A 70 5 3 It is the custom to build greenhouses in as protected a position as possible and this fact is taken into consideration in formulat- ing the above table. When the houses are in a particularly ex- posed position, to give 70 inside, use the figures " 4 " for steam and " 2% " for hot water as divisors and the same proportionate addition for other temperatures. When estimating for the pressure system (sealed tank) of hot water, use the same divisors as for steam. TABLE XVII Temperature of Air Sq. Ft. of glass and its equivalent proportioned to one sq. ft. of surface in heating pipes or radiator. in House. Temperature of Water in Heating Pipes. 140 160 180 200 40 4.33 5.25 6.66 7.69 45 . 3.63 4.65 5.55 6.66 50 3.07 3.92 4.76 5.71 55 2.63 3.39 4.16 5.00 60 2.19 2.89 3.63 4.33 65 1.86 2 53 3.22 3.84 70 1.58 2.19 2.81 3.44 75 1.37 1.92 2.50 3.07 80 1.16 1.63 2.17 2.73 85 .99 1.42 1.92 2.46 GREENHOUSE HEATING 159 For a greenhouse exposed on all sides (not one of a group) it is well to figure all wall surface, sides and ends, and for each five square feet of wall surface add one sq. ft. to the glass surface. The preceding table will assist in determining the proportion- ate amount qf glass to heating surface for various temperatures in the greenhouse, the outside temperature being at zero. Methods of Greenhouse Piping There has been much discussion among florists as to the relative merits of various styles of piping for greenhouses and we believe the consensus of opinion to be in favor of what is termed the " over- fed system." By this is meant a running of the flow pipes overhead from one end of the house to the other and bringing back a suffi- cient number of return pipes under the benches or beds to give the necessary amount of heating surface in the house. In arrang- ing for the heating of a greenhouse the boiler pit or cellar should, if possible, be placed at the low end of the house in order better to allow for the proper pitch and drainage of the piping, which in a house of considerable length is often a troublesome matter. If the greenhouse is built on level ground the boiler may be placed at either end and in the event of using one boiler to heat a group of houses, the boiler house and cellar should be centrally located in order to facilitate the arrangement of the piping. There are many advantages to be gained by the use of the overfed system, chief of which is the placing of a share of the heating surface in the most exposed portion of the house, thus tempering a large portion of' the cold air which finds entrance through or around the ventilators or through the laps in the glass. In setting the glass in a greenhouse the panes are lapped over each other in much the same manner as shingles or slate are laid on a roof, and the lap made in laying each pane is in many instances not air tight. Again, in securing an even temperature of the air in the house the overhead pipes are of great assistance. We show by Fig. 151 a small hot-water apparatus for heating a single house. The potting shed and cellar for the heater are built against the side of the house at one end. The flow pipe rises from the heater in the most convenient manner to a point well toward the top of the 160 PRACTICAL HEATING AND VENTILATION shed. This is the high point of the system and from this point the connection to the expansion tank is made. The flow is then '). ' I \ ' 1 { N ,/ - iv* >,-;< x*V.Oi ?^!^C5 iiTn'^JM ' 5, .i vi'(,'j.v ~-; ';(;r r j (^-~^)' r i'nV' 1 : >: ''- ' -' taken into and across one end of the greenhouse and supplies two main pipes which are hung overhead on the posts supporting the roof. These have a slight fall to the far end of the house where GREENHOUSE HEATING 161 a drop is made, each flow feeding four return pipes which are hung under the benches. The piping (both flows and returns) have a slight fall from the expansion-tank connection to the connection to main return. Fig. 152 shows a skeleton view of one half of the piping, and illustrates the system very clearly. Valves should be placed on the connections to each group of return pipes; those for hot water may be placed on either the flow or return connection. This will enable the florist to cut out from service any portion of the ap- paratus as desired a very necessary operation in the mild days of the spring and fall months. Down Flow To Heater FIG. 152. Method of piping for greenhouse. The arrangement of the piping for steam is quite similar to that for hot water, the expansion tank and connections, of course, being omitted. When piping a greenhouse for steam, valves must be placed on both supply and return pipes, the air vents being placed on the return end of each group of return pipes and care must be taken to avoid all trapping of pipes and the forming of air pockets in the system. Should the house be a large one and a number of return pipes be placed in each group it is well to use branch tees (see Fig. 52) on the supply and return end of each group of pipes. Where the side walls of a greenhouse are built high from the ground it is sometimes found advisable to place a portion of the piping on the sides. When a number of houses are built side by side it is an excellent plan to build a potting shed or inclosed passage along one end of the houses, and the main supply pipe 162 PRACTICAL HEATING AND VENTILATION of the heating apparatus should be run through this shed, branch mains being taken off as frequently as is found necessary. In de- termining the quantity and size of pipes to obtain a certain amount of heating surface, the table of pipe size and capacities given in Chapter VI will be found of great assistance. For the mains running through the center of the house it is not advisable to use pipe larger than 3" in size. As these mains are usually hung on the center posts supporting the roof, the increased weight of the heavy piping might cause damage from breakage or sagging. CHAPTER XVII Vacuum, Vapor and Vacuum Exhaust Heating VACUUM heating is the operation or running of a steam-heat- ing plant at a less pressure than the atmosphere, which at sea level is 14.7 pounds per square inch. On the ordinary steam-heat- ing plant we are accustomed to say, for instance, that we have two, five or ten pounds pressure. By this we mean, pressure above that of the atmosphere, and therefore the true pressure on such a plant would be 16.7, 19.7, or 24.7 pounds as the case might be. To state this matter in another form : water boils at sea level, atmospheric pressure, at 212 degrees Fahr., in an open vessel or in the ordinary steam apparatus with air vents open to the at- mosphere. Supposing we relieve the apparatus from all atmos- pheric pressure the water in it will boil at a temperature of 98 degrees. The word " vacuum " means empty space, or space void of matter. We are accustomed to speak of a bottle or other ves- sel from which the contents have been drawn off as being empty. This is not true, because as fast as the receptacle is emptied of its visible contents an invisible volume of air or atmosphere takes its place. Steam and air being of different densities will not mix. Close tightly the air valve on a radiator when there is no pressure of steam on the apparatus and the result will be that as the steam pressure is increased the air in the radiator w r ill be compressed, making it impossible for the steam to fill all of the radiator. Open the air vent and the radiator will fill with steam as the air is pushed ahead of the steam and exhausted through the air vent opening. Steam is an elastic gas, or properly, is water turned into gas by expansion due to heating it to a temperature above the boiling point. If unconfined, water thus turned into steam is expanded seventeen hundred times. Therefore, reverting again to the radia- tor, after the steam with which it is filled condenses, it occupies 163 164 PRACTICAL HEATING AND VENTILATION but a very small part of the space within the radiator, the remainder of the space again filling with air, which must repeatedly be ex- hausted before the radiator will fill with steam. Vacuum as applied to steam heating means the use of some form of apparatus, such as an exhauster, pump, or other appliance, to keep the radiators and other parts of the heating apparatus free from air, or under a vacuum in order that the water in the system w r ill boil at a low temperature and be converted into steam, which may then flow un- obstructed through all piping and radiators. The flow of steam in a vacuum attains a velocity of 1,550 feet per second. Thus it will be seen how quickly a circulation in a heating system can be established. With an apparatus capable of producing steam at 98 degrees (complete vacuum) to 240 degrees (10 Ibs. atmospheric pressure), there seems no doubt but what any building may be readily and easily heated no matter how quickly weather conditions and the outside temperature may change, and that a minimum degree of economy in fuel consumption may be attained. With a regular system of steam heating the air in apparatus is never entirely removed from radiators and piping, particu- larly from the radiating surface. When the vacuum system is at- tached to an apparatus of this kind all air in every portion of the radiators and piping is exhausted from the system, rendering the heating surface more efficient. Thus old systems are benefited by the addition of the vacuum appliances and even though but a partial vacuum be maintained, the betterment of the job in effi- ciency and the saving of fuel are quickly noticeable. To this may be added other features which make a system of this character particularly desirable, among which may be men- tioned : (a) The low cost of installation, it averaging much less than for hot water, yet retaining all of the various degrees of tempera- ture regulation possible with a hot -water system. (b) Economy in fuel over either steam or hot water. (c) Less radiation required than for hot water, while still re- taining the range of temperature. (d) No danger from frosts or leaks, which frequently occur in a hot-water heating apparatus. VAPOR AND VACUUM EXHAUST HEATING 165 (e) Long runs of piping which very often cause trouble, ow- ing to inability to drain them properly, can with a vacuum system be entirely freed from the water of condensation. Improved Methods of Exhaust Heating In Chapter XII we briefly called the attention of our readers to the advantages of utilizing the exhaust steam from the engine. We now desire to describe several of the more modern methods of applying this exhaust to the heating of a building. To derive the greatest benefit from a steam-heating apparatus, it is neces- sary to keep the system free of air, and this is particularly true when heating with exhaust steam. Air in a greater or less quantity is always present in water used for boiler-feed purposes. As the water in the boiler is gen- erated into steam, all air collects in the various radiators or coils of the heating system and this accumulation of air obstructs the flow of the incoming steam and prevents it from distributing uni- formly over the heating service, with the result that the radiator or coil is never working at its full efficiency. Vacuum heating when originally used was applied to a system of exhaust heating and for some time was employed in no other manner. The original patents w T ere taken out by Mr. N. P. Williams, in 1882. This was followed by the " Webster System " by Warren Webster & Co., the "Paul System," by Andrew G. Paul, and the vacuum system was applied to all classes of steam work. Fig. 153 shows the application of the Webster System on an exhaust steam-heating apparatus. Reference to the same will show the various appliances and connections necessary for a system of this character. " The operation of the Webster System is based upon the flow of steam and condensation from a pressure slightly above into a pressure slightly below that of the atmos- phere or into a partial vacuum." This is the explanation given of the principles of the Webster System and is, we think, sufficiently clear to be readily understood. With this system a partial vacuum is maintained only on the return pipes and the system is, therefore, applicable only to two- pipe work. At the return end of each radiator or coil, in the place 166 PRACTICAL HEATING AND VENTILATION 0@l 3 > 3 f VAPOR AND VACUUM EXHAUST HEATING 167 of an ordinary valve there is put a motor valve, as shown by Fig. 154* and Fig. 155. The working of this valve is automatic. It prevents the escape of steam from the radiator or coil and at the same time removes all air and all water of condensation from the same, thus making the entire surface of the radiator or coil effective for heating purposes. The pressure of steam in these radiators or coils is not reduced by the vacuum on the returns. This pres- FIG. 154. Exterior of motor valve. FIG. 153A. Webster motor valve at base of riser. sure is dependent on the volume of steam which can enter through the supply valve. At the base of each riser a motor valve is placed as shown by Fig. 153A. The vacuum on a Webster system is produced by the operation of a pump, which pumps the return water and the vapor (air) out of the system and delivers them into a tank which is open to the atmosphere to allow all vapor to escape. The return water is fed from this tank into a feed-water heater, and from this is delivered to the boiler by a feed pump. When a low-pressure boiler is used the vacuum pump is usually driven by a chain-connected electric motor, and the water and air are delivered to a tank placed suffi- 168 PRACTICAL HEATING AND VENTILATION ciently high above the boiler to feed the water into the same by gravity against the low pressure carried on the boiler. With this system smaller flow and return pipes may be used than for the regular two-pipe system of steam heating, and radia- Pc280 FIG. 155. Cross section of motor valve. tors or heating coils may be placed below the line of the main feed or return pipes and work successfully. The Paul System Mr. Andrew G. Paul in seeking a method of keeping a heating apparatus free from air perfected a system which is known as the " Paul System." This is quite different from the other sys- tems of vacuum heating in that it removes the air only, the water of condensation finding its way to the boiler by gravity. It is thus applicable to either low-pressure or high-pressure steam heating, and to either the one or two pipe system. A special apparatus called an exhauster removes all air from the system before the steam is allowed to enter, the automatic or thermostatic air valves on each unit of radiation closing against the steam immediately all air is exhausted and the steam comes in contact with the air valve. This exhausting apparatus is of two kinds, namely, for high pressure and for low pressure. Fig. 156 shows the high-pressure exhauster. It is operated by a jet of steam, and is the kind of appliance used on a system of exhaust VAPOR AND VACUUM EXHAUST HEATING 169 .Outlet FIG. 156. Paul system high-pressure exhauster. FIG. 157. Paul system Low-pressure exhauster. 170 PRACTICAL HEATING AND VENTILATION heating. Fig. 157 shows the low-pressure exhauster, which may be operated by water pressure. The return pipes and drips connect into a receiving tank, from which the condensation is pumped back to the boiler. This receiver is a closed tank and on it is placed a thermos tatic valve for the removal of all air. KEY TO FIG. 158 A. Boiler B. Feed-water Heater C. Engine D. Exhauster F. Feed Pump G. Reducing-pressure Valve H. Back-pressure Valve I. Exhaust from Engine J. Exhaust from Pump K. Compound Gauge L. Vacuum Gauge M. Gate Valves N. Check Valves O. Live Steam to Pump P. Live Steam to Engine Q. Live Steam to Exhauster R. Cold-water Feed S. Feed to Boiler T. Suction to Pump U. Discharge from Exhauster V. Exhaust to Atmosphere W. Radiators X. Air Valves Y. Returns Z. Drips a. Air Pipes b. Supply Heating Pipes d. Blow-off and Overflow e. Relief Pipe f. Angle Valve h. Water Column i. Radiator Valves KEY TO FIG. 159 A. Boiler B. Engine C. Feed-water Heater D. Aut. Return Tank and Pump E. Back-pressure Valve G. Live-steam Separator H. Grease Extractor I. Steam Gauge J. Compound Gauge K. Vacuum Gauge L. Exhauster M. Safety Valve N. Water-relief Valve O. Gate Valve P. Angle Valve Q. Check Valve R. Reducing-pressure Valve S. By-Pass for Red. -pressure Valve T. Automatic Air Valve U. Live Steam to Engine V. Live Steam to Reducing-pressure V. W. Live Steam to Pump X. Live Steam to Exhauster Y. Exhaust from Engine Z. Exhaust to Atmosphere a. Drip from Exhaust Head b. Heating Supply Pipe Drip from Heater Drip from Grease Extractor Drip from Exhaust Pipe Feed -water Pipe Discharge from Exhauster c. d. e. f. g- h. Drip from Separator i. Return Pipe j. Air Pipe Fig. 158 shows the application of the system on a two-pipe system and Fig. 159 shows a single pipe overhead or down-fed VAPOR AND VACUUM EXHAUST HEATING 171 172 PRACTICAL HEATING AND VENTILATION VAPOR AND VACUUM EXHAUST HEATING 173 system. In operating, the exhausting apparatus is first put in operation and all air removed from the system. The steam as it is turned on the system finding no air pressure to impede its prog- ress flows naturally and unobstructed into each radiator and coil, when having completely filled them reaches the thermostatic air valve, which closes as the steam touches it. When the steam is turned off and the radiator cooled, the air valve again opens, all air in it is exhausted, thus leaving the radiator in condition to re- ceive the steam again. There is a constant vacuum on the air line below the air valves. After the air has been sucked out of the radiators, however, these valves close. The Vaa-Auken System In many respects this is similar to the Webster and the Paul systems. An exhausting device known as a " Belvac Thermofier " is used on the return end of each radiator, which works in much the same manner as the Webster Motor Valve. A vacuum pump, receiving tank, together with the usual specialties employed in ex- haust heating, are also used in much the same manner as on the Webster System. In application several styles of piping may be used. For a heating plant with gravity returns a drip tank or receiver is made use of, into which the gravity return discharges. The drops from the various risers discharge to the tank through a trap. The main vacuum return is connected to this tank, which feeds directly to the vacuum pump. Mercury Seal Systems The systems described in the preceding pages are what might be called mechanical systems, that is, they require a pump, ex- hauster, or other device in maintaining a vacuum and removing the condensation from radiators and piping. A system of this kind would scarcely be applicable for heating an ordinary residence, or small-sized building. In order to maintain a vacuum on a heating system it is essen- tial that after having once exhausted or driven the air out of the radiators and piping it be prevented from entering again. It can 174 PRACTICAL HEATING AND VENTILATION be readily comprehended how that any simple method of accom- plishing this would be as productive of results as either one of the larger systems. The success of the larger mechanical heating plants led to much experimenting w r ith the smaller systems. Ow- ing to its density, mercury was brought into use in conducting these experiments, with the result that two systems have been evolved and patented, one by D. F. Morgan, now known as the " K-M-C " system, and the other by Jas. A. Trane, known as the " Mercury Seal " system. Both are similar in principle, employing a mercury device for preventing the air from reentering the system after once having been exhausted. The "K-M-C" System Fig. 160 shows the general arrangement of the piping, boiler connections and special devices of this system. The air is driven from the apparatus by a slight pressure of steam and is prevented from reentering the system by a mercury FIG. 160. "K-M-C" system of vacuum heating. seal. The end of the air line is submerged in mercury to the depth of about one half of an inch. This offers but little resistance in VAPOR AND VACUUM EXHAUST HEATING 175 expelling the air, but effectually prevents it from reentering the system. An accumulating tank is used to prevent any water from entering the mercury seal. Sufficient water is always present in this tank to condense any steam which might enter through the air line. Fig. 161 shows a descriptive cut of the system with the various specialties connected. The damper regulator is a very important part of this ar- rangement ; it effectually controls the fire and prevents overheating. It consists of a drawn copper cylinder with a rubber diaphragm Mercury Seal Accumulating Tank. FIG. 161. "K-M-C" system showing attachment of fixtures. at the bottom. The expansion of air in the copper cylinder, when heated, operates the regulator, which may be set to open or close the dampers either above or below atmospheric pressure. A special type of automatic air valve known as a " retarder " is used on the radiators and coils and to which the air lines are connected. The supply end of the radiator is provided with a Packless Diaphragm radiator valve, which prevents air leaks at 176 PRACTICAL HEATING AND VENTILATION the valve, which would destroy the vacuum on the system. The air lines are run in quite the same manner as described for the following system. The Trane System The Trane System, as designed by Jas. A. Trane, is also known as the " Mercury Seal System " from the fact that all air from the system is discharged through a mercury seal or trap which effec- Mercury FIG. 162. Mercury seal Trane system. tually prevents the air from reentering the system through the air valves, after having been expelled by the steam pressure. Each radiator is provided with an automatic air valve quite similar to the Paul air valve, having a union drip connection. An air-line pipe is run around the basement, convenient to the steam main and the air pipe from each radiator is connected into it. This air line terminates at a point near the boiler and drops down, connecting into the top of the device known as a mercury seal. See Fig. 162. VAPOR AND VACUUM EXHAUST HEATING 177 The steam piping may be either one of the regular systems, and there is nothing special in the way of erecting the same, ex- cept to see that all joints are made tight and that the stuffing boxes of all valves are tightly packed. A safety valve which is air tight should be used, the " pop " spring valve being recom- mended. A compound gauge registering vacuum and steam pres- sure should be placed on the system. The mercury seal device shown by Fig. 162 is constructed some- what on the principle of the ordinary mercury barometer, the end of the air pipe dipping into the mercury, which is held in the cup- FIG. 163. The Trane system of vacuum heating. shaped interior of the hollow base of the seal. While forming a seal preventing air from entering the system, the mercury offers very litle resistance to the expulsion of air from the system, a pres- sure of but one half pound being necessary to accomplish this. A general idea of the application of this system is shown by Fig. 163, which illustrates the air lines and mercury seal at- 178 PRACTICAL HEATING AND VENTILATION tached to a one-pipe circuit system. The operation of it is as follows : After starting a fire in the apparatus, a steam pressure of from two to three pounds should be maintained for a short period, in order to drive all air out of the system and determine whether or not it is free from leaks. The draught door of the boiler is then closed and the temperature at the boiler falls. As the steam pres- sure is removed from the radiators, the automatic air valves open and the air endeavors to enter the system, but is prevented by the mercury seal. However, the mercury will be drawn up into the tube above the seal to a height representing the difference between the pressure within the radiator and the atmospheric pressure without, and this height representing inches of vacuum will be registered by the compound gauge. The apparatus may then be operated at a very low tempera- ture and should any air again enter the system it is easily expelled by raising a slight pressure of steam on the system. The Ryan System The piping for the Ryan system of vacuum heating is installed the same as for the other styles making use of air pipes. An air trap is used instead of mercury for sealing the system. The main air line connects into a side opening in the trap, which is so located that this opening is 27" or more above the water line of the apparatus. A drip pipe from bottom of the trap con- necting into the return below the water line of the boiler, relieves it of all water carried into it through the air line. At the top of the trap is the opening through which the air is exhausted and an equalizing pipe from boiler is also connected into it at this point. A special automatic air valve is used on each radiator, which closes against the steam and opens again as the radiator cools, permitting the exhausting of all air carried into the radiator by the steam. Fig. 164 shows the application of this system. Vapor Heating The Broomell System is distinctly a vapor system, the tempera- ture never exceeding that of water at the boiling point, namely VAPOR AND VACUUM EXHAUST HEATING 179 degrees. The piping for this system while smaller than used for steam has the appearance of the piping of a two-pipe system, the smaller pipe being the drip through which the air and water of condensation are carried back to the boiler through an apparatus FIG. 164. The Ryan system of vacuum heating. which is described as a " combined receiver, relief apparatus and draught regulator." A few loops of indirect radiation termed a condensing coil are located adjacent to and above this receiver and a connection is made from the top of the receiver to the bottom of the coil. From the top of this coil an air pipe is run into the 180 PRACTICAL HEATING AND VENTILATION chimney. The draught in the chimney exerts a pull on the appa- ratus, causing a partial vacuum on the system, which not only exhausts the air, but at the same time accelerates the flow of vapor through the radiators and coils. The pressure on this system is slightly above that of the atmosphere and is registered in ounces on the receiver. See Fig. 165. This receiver is the real heart of the system, regulating the draughts of the boiler by a ball-float attachment and acting as a separator and equalizer in dividing the FIG. 165. Combined receiver, relief, and draught regulator .Broomell system. return water and the air which accumulates in the system, and again acting as a relief from any overpressure at the boiler. It can be so adjusted as a regulator that the draught doors of the boiler will close under the slightest pressure. Hot-water radiators are used with this system. The supply is connected at the top of one end by what is termed a quintuple valve, that is, a valve having four holes or ports through the disc, which engage with similar ports in the bottom or seat of the valve. VAPOR AND VACUUM EXHAUST HEATING 181 Thus it may be entirely closed or opened one, two, three or four ports, thereby fully regulating the amount of heat or vapor de- livered to each radiator. At the bottom of the opposite end of the radiator the return end the air and return pipes are con- FIG. 166. The Broomell system of vapor heating. nected by a specially constructed union elbow, which, while allow- ing all air and water to escape from the radiator, is closed against any pressure on the return line. It is recommended that the same amount of radiation be in- stalled as would be used for hot-water heating. Fig. 166 clearly illustrates the installation of this system. Vacuum- Vapor Systems There are some systems of heating at a pressure below that of the atmosphere, which embody some of the principles of both the vacuum and the vapor systems, and these are aptly called vacuum-vapor heating systems. Representing this style of heating we have the Gorton System and the Vacuum Vapor Company's System. 182 PRACTICAL HEATING AND VENTILATION The Gorton System With the regular system of vacuum heating it is not possible to regulate the heat in any single radiator except by automatic heat control. With the regular vapor system the heat in each in- dividual radiator may be controlled, but it is not possible to attain a temperature on the apparatus of over 212 to 215; therefore the radiators must be larger than would be required for steam. The Gorton System is capable of heating under a vacuum or at ten pounds pressure. The method of piping used is practically the two-pipe system. An ordinary or a special type of a radiator valve is used on the PIG. 167. Cross section of Gorton auto- matic drainage valve. FIG. 168. Cross section of Gorton automatic relief valve. supply end of the radiator. The radiators may be built for steam or hot water. On the return end is placed an automatic drainage valve Fig. 167. When the radiator valve is opened the drainage valve opens sufficiently so that all air and the water of condensation pass into the return pipe and down to the automatic relief vah VAPOR AND VACUUM EXHAUST HEATING 183 Fig. 168 where the air is exhausted and the water returns to the boiler. The relief valve is operated by the difference in pressure between the steam and the return mains. It opens to relieve the air just as soon as the air in the return main increases the pres- sure, when, having relieved the system, it will again close. This system has the advantage of a wide range of temperature, the use of steam or hot-water radiators and the ability to control the heat in any one radiator. It has this disadvantage, however, that it is applicable only to two-pipe work. Fig. 169 shows a view of the correct position of the automatic relief valve and the pipe connections at the boiler. The return Relief PFpe 1 V :r- i e::-n::^: __i i - __ J Return A" HM BOILER ; IT ~~ "^-~ < -i^__ FIG. 169. Gorton system of vacuum-vapor heating. mains may be connected above the water line, as shown, or they may drop as indicated by dotted lines on Fig. 169 and be con- nected below the water line. The lowest point of return mains should be at least 18" above the water line of the boiler, and the relief pipe should be 4" above the return mains. The automatic relief valve is connected to the relief pipe and to the steam main as shown. The Vacuum-Vapor System The vacuum-vapor method may be applied to almost any style of piping. The special appliances necessary are an air trap, a float valve and an ejector. A condensing radiator is used as shown on Fig. 170. The 184 PRACTICAL HEATING AND VENTILATION VAPOR AND VACUUM EXHAUST HEATING 185 air lines containing vapor and more or less water are discharged into the condensing radiator by means of an ejector. This ejector is connected directly to the boiler or steam main, from which it receives the necessary force to operate it. The air and water pass through the return outlet of the condensing radiator, the water of condensation returning to the boiler by gravity. The air passes through the air trap and thence to the float or vacuum valve and into the atmosphere. In other respects this system is similar to those already de- scribed. The Dunham Vacno-Vapor System A method of vacuum heating styled " Vacuo-Vapor " has been developed by Mr. C. A. Dunham, which is in some respects both novel and interesting, mainly in that the appliances employed maintain a constant difference in pressure between the steam or flow pipe and the return pipe without any mechanical means. The maintenance of this difference in pressure proves of great assist- ance to the circulation on the regular gravity system of steam heating. Like many of the vacuum systems, air valves on the radiators are dispensed with, the air and return water of condensation being taken to the basement into a small tank hung 18" or more above the regular water line of the boiler. A drip from this tank drops to the return opening of the boiler, the water of condensation re- turning to the boiler through this drip, which has a horizontal check valve on it near to the boiler. The condensation in entering the tank passes through a horizontal check placed on the return near the tank. The air, separated from the water in the tank, passes through a thermostatic and vacuum air valve to the at- mosphere. An air trap, Fig. 170A, is placed on the return end of each radiator, remaining open when cold and closing as soon as the heated vapor or steam reaches it. The closed trap retards the steam until the water of condensation collects in sufficient quantity to operate the trap, when it, together with the accumulated air, passes through the returns to the separating tank. When the system is working above atmospheric pressure, the 186 PRACTICAL HEATING AND VENTILATION accumulated air passes freely through the air trap or thermostatic air valve and the vacuum air valve above the tank, the water con- tinuing to collect in the tank until such an amount has been evapo- rated from the boiler as will lower the water line below the end of the equalizing pipe. This equalizing pipe forms a loop approxi- mately four feet in length connecting the receiving tank with the boiler, the end of the loop entering the boiler through an opening, tapped for the purpose, and extending below the water line. This permits live steam to enter the loop, equalizing the pres- sure between the tank and the boiler, permitting the water to flow FIG. 170A. Air trap Dunham vacuo-vapor system. down into the return pipes and through the check valves into the boiler. This action again raises the water line above the bottom of the loop or equalizing pipe, effectually sealing it. The partial vacuum created by the condensing of the steam in the tank after the discharging process, relieves the pressure against the check valves on the return pipes, allowing the accu- mulated air and water to enter the tank, and relieving the returns of any pressure, as the partial vacuum reaches to the radiators. To obtain the most economical results from a system of this character, the supply valves on the radiators should be opened only enough to admit sufficient steam to properly heat the room, the pressure at the boiler being slightly above that of the atmosphere and not greater than one pound. The fire should be banked at night and the system operated under a vacuum. Fig. 170B shows the application of this system for ordinary low-pressure work. Smaller piping is employed than that used on VAPOR AND VACUUM EXHAUST HEATING 187 a regular steam job. The return connections from all radiators should be !/>" in size, and the supply end of radiators tapped up to 50 sq. ft. %", 50 to 90 sq. ft. 1", 90 to 185 sq. ft. 1%". A special form of this system is devised for larger jobs, using live or exhaust steam, the regular form of air trap being employed FIG. 170B. Dunham system for low pressure. on all radiators, and an air relief and pump governor or con- troller, which acts as a receiver for all condensation, is placed near the pump and is so connected that the pump may assist the cir- culation by pulling directly on the returns. 188 PRACTICAL HEATING AND VENTILATION The Future of Vacuum Heating But a few years ago (1895) a heating engineer made use of the following expression in discussing the future of the heating business before a trade association : " If you can circulate a system below atmosphere in a large building you can certainly circulate it below atmosphere in a dwelling house. If you can circulate it below, how much below can you circulate it? It is possible that in a few years from now we will be heating houses not by hot water but by steam below atmospheric pressure, of such a low temperature that it gives all of the advantages of hot water without any of its disadvantages." His prediction is now an accepted fact and vacuum and vapor heating, as we may observe by following up the many ideas and the many systems already before us, have by the use of various devices described on the preceding pages become adaptable to any size of residence or building. CHAPTER XVIII MISCELLANEOUS HEATING The Heating of Swimming Pools THE simplest method of heating an open body of water such as a swimming pool or tank is by hot-water circulation. The heater should be placed sufficiently below the level or surface of the water that a natural circulation may be established between the heater and the tank. Fig. 171 shows an apparatus of this kind. The swimming pool illustrated contains approximately 30,000 gal- lons of water when filled to the normal water level. The size of flow pipe leaving the heater should be 6" and this should supply two 4" feed or flow pipes to the pool. These may be connected to it at points about 18" below the water line, the first pipe entering the pool about midway of its length, the last pipe entering well toward the shallow end. The return pipes should be connected from the deep end of the pool at a point about 6" from the bottom. The direction of the circulation of the water is indicated by the arrows shown on the illustration. The heater must be so set that the return open- ings in it are at least 12" below the bottom of the water in the pool. Fig. 172 is an elevation plan of the same apparatus and shows the relative heights at which the circulation enters and leaves the pool. Some engineers favor the method of having the flow pipes enter at the bottom of the shallow end of the pool and the taking of the returns out of the bottom of the deep end. This is not as good a plan as that which we illustrate by Fig. 171. With an apparatus installed in this manner the cross currents in the circulation thoroughly excite and warm all portions of the pool. 189 190 PRACTICAL HEATING AND VENTILATION In estimating heating capacity for work of this character it is safe to assume that each 100 sq. ft. of heater capacity will warm 1,000 gallons of water from 40 degrees to 90 degrees in from six I to eight hours. Thus a 5,000-gallon tank would require a 500-ft. hot-water heater to properly do the work. As the tank capacity MISCELLANEOUS HEATING 191 192 PRACTICAL HEATING AND VENTILATION is increased in size the relative size of heater may be somewhat decreased as shown by the following table: TABLE XVIII Capacity of Pool or Tank Gallons. Rated Capacity of Hot-water Heater Sq. Ft. Capacity of Pool or Tank Gallons. Rated Capacity of Hot- water Heater Sq. Ft. 5,000 500 40,000 3,450 10,000 950 45,000 3,800 15,000 1,350 50,000 4,200 20,000 1,800 55,000 4,600 25,000 2,200 60,000 5,000 30,000 2,550 70,000 6,000 35,000 2,950 80,000 6,800 There are many circumstances which would vary the above figures considerably. However, those given are sufficiently accurate for estimating and represent the gross rating of cast-iron hot- water heaters as listed by any one of the reliable manufacturers and whose named ratings may be accepted as correct. It is a frequent occurrence to find that the necessary depth for heater room cannot be procured, owing to low ground, trouble with drainage, etc. In a case of this kind it is necessary to make use of steam for heating the water and an apparatus of this kind is somewhat more complicated than the one for hot water already described. Where the steam is obtained from pure water, the pool may be heated by blowing live steam into the water through an orifice of the nature of an injector. A large circulating pipe is arranged at the deep end of the pool as shown by Fig. 173. At the top connection a reducing tee is used, as shown, in making the injector. This not only heats the water but causes also a circulation through the large pipe in the manner shown. Where it has been correctly used this arrangement has proven to be very successful. In the event of heating a large body of water, say 40,000 gal- lons or more, it is well to use two circulating pipes and injectors and they should each be placed at the deep end of the pool about from 18" to 20" from each corner. The manner of circulation of the water in the pool is shown on the illustration Fig. 173. When making use of the injector method the greater the pres- sure of the steam the more quickly a circulation may be established MISCELLANEOUS HEATING 193 and the water heated. For this work we recommend a boiler on which a pressure of from 30 to 60 pounds may be maintained. The usual practice is to clean and refill a swimming pool about once in each week or ten days, depending somewhat upon the num- i her of bathers using it. To keep the water as pure as possible during this period there is generally a small stream of fresh water entering the pool constantly, and the overflow openings of the 194 PRACTICAL HEATING AND VENTILATION pool empty the excess water. Therefore, it will be seen that it is but once in a period ranging from six to ten days that the full volume of water in the pool has to be heated. For this reason the steam-injector principle is the most economical as the excess of boiler power may be put to other uses, such as heating a tank of water for domestic uses or for shower baths. In determining the size of boiler power the conditions of the work must be considered. A safe estimate is one-horse power of boiler capacity for each 2,500 gallons of water. Still another method whereby steam can be employed for heat- ing a pool is shown by Fig. 174. Coils of this nature are placed Steam Supply Return FIG. 174. Heating swimming pool with steam coils. in recesses along the sides and end of the pool, the condensation returning to the boiler room, where it is pumped into the boiler or fed to it by an injector or return trap. Owing to the large amount of condensation in coils when used in this manner, it is well to use a header or branch tee coil and to make the runs as short as possible. Heating Water for Domestic Purposes A class of heating now largely practiced is that of heating water for domestic purposes. In the cities and towns of any con- siderable size we find numbers of flat or apartment buildings and it MISCELLANEOUS HEATING 195 is customary in the better class of these buildings to furnish the various apartments with hot water from a central supply tank located in the basement. Such a tank is called a storage tank. There are two methods of heating the water, first by means of a small hot-water heater, called a tank heater, which is directly con- nected to the tank, and second by means of a steam coil within the tank. Such an apparatus becomes a part of the heating speci- fications and the methods as generally adopted should, therefore, be understood by the heating contractor. Storage tanks are made in two styles, namely, horizontal and vertical. The horizontal tank is usually hung from the first-floor FIG. 175. Domestic hot-water supply horizontal tank. joists by means of wrought-iron straps or hangers, or it may rest on brick piers. The vertical tanks are supported by cast-iron legs provided for the purpose. We have found the latter method to be better, as the weight of a large tank full of water is liable to strain the joists from which it is suspended, unless hung very close to a supporting wall. Fig. 175 illustrates the method of hanging a horizontal tank and making the heater connections, and Fig. 176 shows the method of setting and connecting the vertical tank. In making use of the latter method the tank should stand sufficiently high so that the bottom of it is above the return opening of the tank heater, as the return pipe is connected to opening in the bottom of the tank. 196 PRACTICAL HEATING AND VENTILATION When steam boilers are employed in heating the building or when steam is obtained from a central heating plant the water may be heated by means of a steam coil within the tank, as shown by Fig. 177. Black iron or steel pipe should never be used for this purpose, owing to liability of rust or corrosion. The coil should be made of galvanized iron or copper pipe, the latter being Draw-ofl' Tank Heater FiO. 176. Domestic hot-water supply vertical tank. preferable, and it should be well braced or stayed in order that the expansion and contraction will not loosen it. 'The tank may also be double connected, that is, directly con- nected, to a tank heater for use in the summer months and provided with a coil, and connected to the steam boiler in order that steam may be utilized for heating in cold weather. This method makes a very satisfactory arrangement. In determining the size or capacity of tank required several points should be considered. The ordinary tank capacity provided MISCELLANEOUS HEATING 197 when each apartment has its separate supply from water front in range is thirty gallons. When providing for apartments hav- ing but one set of bathroom fixtures, it will be found that an al- lowance of from twenty to twenty-five-gallon-tank capacity for Hot Water Supply Draw-off-JT FIG. 177. Storage tank with steam coil. each apartment will prove sufficient. The tank heater should have a capacity of from 20$ to 25$ greater than that of the tank. The following table shows approximately the sizes of tank and heater necessary for from four to thirty-six apartments. TABLE XIX Number of Apartments. Capacity of Tank. Size of Tank. Heater Capacity Size of Grate. 4 100 gallons 22'xeo* 78 sq. n. 6 120 24*X60* 78 8 180 30^X60* 113 10 215 30 /f X72 /f 132 12 250 30*X84" 176 16 365 36"XS4 /r 254 20 430 42"X72 /r 314 24 575 42*X96" 380 36 720 42* XI 20* 452 Should the tank service be used for other than regular domes- tic purposes, additional capacity must be provided. The manufacturers of storage tanks seldom place coils in them except according to specifications received with the order ; therefore, the heating contractor must specify the length of coil or number 198 PRACTICAL HEATING AND VENTILATION of runs of pipe desired and the size of same. As a basis of what is required the following table will prove useful: TABLE XX Size of Tank. Size of Coil. 100 and 120 gaf. 180 " 215 " 250 " 365 " 430 " 575 " 720 gal. 4 V pipes 6 V 6 1M" " 4 \ys " 6 111" " Steam for Cooking and Manufacturing Purposes While the use of steam for cooking, or rather the adaptation of certain methods for accomplishing this, is in reality no part of a steam fitter's education, we wish in a general way to make men- tion of the subject in this chapter, and at the same time to call attention to the use of steam for manufacturing purposes. No large hotel or restaurant is complete in its equipment with- out a Steam carving table and in most of the hotel and restaurant kitchens all vegetables are cooked by steaming. Meats may be cooked or roasted in ovens made for the purpose, and when pre- pared in this manner, meat will be as tender as would be a pot- roast cooked in the usual way over the fire of a kitchen range, and ;will lose less weight in cooking than when roasted in an oven. Ap- pliances for cooking and baking are marketed by the builders of such apparatus and the steam fitter, as a usual thing, has simply to make certain specified pipe connections to the apparatus. The usages of steam for' manufacturing purposes are many and varied in character. Double-bottomed kettles for the use of dyeing establishments, soap making, etc., and for heating glue, paste and numerous other purposes are in common use. For carpet cleaning, feather renovating and drying, in hat manufac- tories and for numerous other manufacturing purposes, steam is employed in a greater or lesser quantity, and the subject would require a volume to illustrate and describe the various fixtures and fittings. It is quite probable that more than two thirds of our manufactories make use of steam for purposes other than the generation of power. CHAPTER XIX Radiator and Pipe Connections IN those chapters of this book having reference to systems or methods of piping for steam or hot-water circulation we have fre- quently made mention of certain styles of radiator and pipe con- nections. We shall in this chapter illustrate and explain the sev- eral modes of radiator connections and show the method of using swing or expansion joints on piping, together with some special forms of pipe connections which are made desirable by conditions of building construction. Steam Radiator Connections Fig. 178 shows the most simple form of connecting a single steam radiator with the main. The illustration shows the branch connection taken from the top of the main with a 90 elbow. A f\ FIG. 178. Simple form steam radiator connection. FIG. 179. Steam radiator connected from riser. 45 elbow at this point would be preferable. The valve should be used on the end of radiator farthest from the riser or branch in order to provide for expansion. When a radiator is connected 199 200 PRACTICAL HEATING AND VENTILATION from a riser on single-pipe steam work the connection should be made as illustrated by Fig. 179. This is known as a " stiff " con- nection and when used in this manner there should be a " double swing " or expansion connection at the base of the riser. In order Double Swing Joint FIG. 180. Double swing connection at bottom of riser. that this form of radiator connection may be thoroughly under- stood we illustrate by Fig. 180 a riser feeding three radiators, all of which are connected with stiff joints. The radiator on the first floor is connected direct from riser with an offset valve ; the radi- ator on the second floor is connected by a stiff joint, as described RADIATOR AND PIPE CONNECTIONS 201 by Fig. 179, and the third-floor radiator is connected by a valve placed directly on the top of the riser. Note the double swing or FIG. 181. Radiator connected with expansion joints. expansion joints at the base of the riser. When the riser is con- nected to main by a stiff joint on the branch, all radiators fed by it should be connected by expansion joints as shown by Fig. 181. Hot- Water Radiator Connections The regular form of connecting a single hot-water radiator from main and to the return is illustrated by Fig. 182 and needs no further explanation. When the same branch feeds a riser, as well as the first-floor radiator, the connection should be made as shown by Fig. 183. There is always a tendency for hot water in circu- lation to rise quickly to the highest radiator; hence the connec- tion to upper radiator should be taken from the side of the riser as shown. 202 PRACTICAL HEATING AND VENTILATION . FIG. 198. Measuring 45 angles. for each different angle. Fig. 198 illustrates the method. The following constants are the multipliers. TABLE XXI Angle (line B). Constants (Multipliers). III? 1.0196 22 1 /2 1.0824 30 1 . 1547 45 1.4143 60 2.0000 RULE. To determine the dimension C (the hypothenuse), center to center measure, multiply the distance A by the constant opposite the angle B. CHAPTER XX VENTILATION Importance of Ventilation THE need or importance of ventilation has been recognized for many years. Probably the first effort to ventilate a room of any considerable size was made by Dr. J. F. Desaguliers, as briefly referred to in the introductory pages of this book, who in 1723 arranged a ventilating apparatus for the British House of Com- mons. This apparatus was used for upward of eighty years, being replaced early in the nineteenth century by a system of fans propelled by hand. These fans were arranged to exhaust the foul air at the top of the building. Records of ventilation by means of bellows or blowers by the Romans and later by the Germans are to be had. Without doubt, however, the British attempt marked the beginning of ventila- tion as we to-day understand and use the term. The early at- tempts at ventilation were to remove the air vitiated by the exhalations of many people occupying a single room and by the candles or various styles of lamps used for lighting. With the advent of the present-day type of heating apparatus came the greater need of ventilation in order not only to exhaust the foul air but also to provide a supply of fresh air to replace that vitiated by the breath of the persons occupying a building and also the oxygen consumed by lamps or gas burners for illumina- tion. Oxygen is the all-important element or quality of the atmos- phere and without it we can have neither heat nor light. It is required in the chemical process of combustion and without it fuel will not burn. It is necessary to sustain life and without its presence all living beings would die. The atmosphere we breathe is composed principally of about one part oxygen to four parts of nitrogen, together with more or less vapor or water in a gaseous 211 PRACTICAL HEATING AND VENTILATION state or held in suspension and is expressed by the term humidity. Oxygen is the life-sustaining quality of the air, which is diffused or diluted by the nitrogen. The percentage of watery vapor present varies with the temperature and the exposure or proximity to a body of water. There is also present in the atmosphere carbon dioxide or car- bonic-acid gas, which by itself is not particularly harmful. Under certain conditions, however, it is detrimental to health, not from the amount usually present in the air, which ranges but from two to four parts in 10,000, but when present in larger quantities due to the exhalations from the lungs of t several persons con- gregated in a single room. It then produces a feeling of close- ness or stuffiness, causing headaches and is otherwise detrimental to health. The poisonous matter thrown into the air or given off by our bodies is also the source of great danger to health. For example, confine a person in a tight inclosure. That person will liye as long as there is oxygen to breathe, depending upon the size of the inclosure. The oxygen will eventually be con- sumed and the person choke or suffocate, being poisoned by the carbonic-acid gas and impurities exhaled from his own body. If our exhalations are poisonous to ourselves what then may be said of the risk entailed by living in or even temporarily occupying crowded rooms, such as offices, workrooms, or places of amuse- ment where we are breathing the foul air exhaled from the lungs of our neighbors, some of whom may be suffering from tubercu- losis or other diseases and so contaminate the air with the germs of such diseases. Not a very pleasant thought but true never- theless and the fact should be carefully considered by every think- ing person. Ventilation is not a luxury it is a necessity. As another example, enter a residence temporarilv occupied for a social gathering. Entering the building from outside where the air is pure into brilliantly lighted rooms not sufficiently ven- tilated and possibly more or less crowded with people, a feeling of closeness, stuffiness, or suffocation is at once apparent. A person not strongly constituted or in good health may in a short time faint from lack of air, while a stronger individual may perhaps become acclimated and soon fail to notice the oppress- ing effects of the foul atmosphere of the room. VENTILATION The use of electricity for lighting purposes has done much toward maintaining the purity of the atmosphere under conditions as cited above. Dr. Tidy after exhaustive tests compiled the following table showing the air consumed by various modes of artificial lighting and the percentage of carbonic-acid gas given off by the various burners : TABLE XXH Light Producing Material equal to 12 Standard Candles. Cubic Feet of Oxygen Consumed. Cubic Feet of Air Consumed. Cubic Feet of Carbonic Acid given off. Cubic Feet of Air Vitiated. Heat, Equal Parts of, raised to 10 Fahr. Conunon Gas 5 45 17 25 3 21 345 25 278 6 Sperm Oil .... 4.75 23 75 3.33 356 75 233 5 Paraffin 6.81 34 05 4.50 484 05 361 9 Sperm Candles Wax Candles Electric Light. 7.51 8.41 None 37.85 42.05 None 5.77 5.90 None 614.85 632.25 None 351.7 383.1 13 8 That the need of ventilation has long been recognized by physicians, scientists and engineers is shown by the works of such men as Chas. Hood, London, whose writings and book published in 1879 are a fair treatise of the subject. Other works more or less practical were published by Dr. D. B. Reid (1844) and by Chas. Tomlinson (1864). Probably the most authentic Ameri- can work is that from the pen of Dr. John S. Billings, of Wash- ington, D. C., a Surgeon of the United States Navy, whose book on warming and ventilation is accepted as a standard authority. Other publications by Thos. Box, F. Schuman, C.E., Butler, Leeds, and the authorities mentioned in the introduction of this book will repay a careful reading. Air Necessary for Ventilation What amount of air is necessary for ventilation? This ques- tion may be answered by numerous examples. Perfect ventila- tion might be said to be the exhausting of the foul air and the admitting of the fresh air in such quantities that the inhabitants of a room or building would never inhale the same air twice, or, in other words, would breathe air inside the building of the same purity as that on the outside. Such a state, however, is neither PRACTICAL HEATING AND VENTILATION practical nor necessary. With the size and conditions of a build- ing and the probable number of occupants known it is possible to estimate very closely the air supply necessary to maintain a certain standard of purity of the air within the building. Not so many years ago a fresh-air supply of 300 cubic feet per hour per person was considered sufficient. To-day we look upon 30 cubic feet per minute or 1,800 cubic feet per hour per person as being the minimum supply essential. Dr. Billings gives the hourly air supply necessary for certain requirements as follows : TABLE XXIII Cubic Feet per Hour. Hospitals . . .... 3 600 per Bed legislative Assembly Halls 3,600 per Seat Barracks, Bedrooms and Workshops 3 600 per Person Schools and Churches. . . 2 400 per Person Theaters and Ordinary Halls of Audience 2 000 per Seat Office Rooms 1,800 per Person Dining Rooms 1 800 per Person It has been recently stated that within a certain congested district in the City of New York there are 70,000 consumptives. There is no question but that this terrible showing is due to the overcrowded offices, sleeping rooms and workshops, the latter more popularly designated as sweat shops, where the admission of only a very small percentage of air, as per Dr. Billings' schedule, would work wonders in the elimination of disease. The average individual spends one third of his or her life in the bed or sleeping room. Without the necessary amount of fresh air to breathe how much solid rest or physical relaxation may we enjoy? Sleeping rooms should, therefore, be well ven- tilated and this may usually be accomplished by the thorough airing of the sleeping room during the day and the opening of the windows at night. By giving the matter a little thought and attention the bed may be so located that no severe draughts are felt by the occupants. However, to properly ventilate the room it should have its separate pure-air supply, tempered by heating, and a ventilating duct leading from the room to the main ven- tilating stack of the building. VENTILATION 215 Massachusetts was the pioneer among the states to enact laws governing the heating and ventilating of public-school buildings. A fresh-air supply of 30 cubic feet per person per minute is demanded and this commonwealth maintains a Board of Engineers to see that the provisions of the law are fulfilled. The laws are imperative, as the following extracts will show: " 1. The apparatus, with proper management, is to heat all the rooms including the corridors, to 70 Fahr. in any weather." " 2. With the rooms at 70 Fahr. and a difference of not less than 40 Fahr. between the temperature of the outside air and that of the air entering the room at the warm-air inlet, the appa- ratus is to supply at least 30 cubic feet of air per minute for each scholar accommodated." " 3. Such supply of air is to so circulate in the rooms that no uncomfortable draught will be felt, and the difference in tempera- ture between any two points on the breathing plane in the occu- pied portion of a room is not to exceed 3 Fahr." We have italicized such portions of the quotation as will bring them prominently before our readers. Other States have enacted laws quite similar and with the standard as set by Massachusetts as a guide, it is quite an uncommon thing to find at this date a school building of any considerable size which is not provided with some form of a ventilating apparatus in connection with the heat- ing of the building. The result is that, as a rule, our children attending school sit and study in an atmosphere much purer than that within the ma- jority of our own homes. This very desirable condition relating to the ventilation of our public schools is due to two distinct causes. First, the writings of eminent physicians, scientists and heating and ventilating engineers, who having noted the former condition of our schools and other public or semipublic buildings and under- standing what was necessary regarding a pure-air supply, have persistently for years conducted a campaign for pure air. Dis- cussions of the subject by engineering societies, articles in the pub- lic press, books written and published in the interests of better heat- ing and ventilating apparatus all had their weight and all have assisted materially in bringing about the improved conditions. The second cause of the changed conditions may be credited to 216 PRACTICAL HEATING AND VENTILATION those manufacturers of ventilating necessities such as fans, heaters, blowers, etc., who have for several years spread broadcast expen- sive catalogues and much other literature and who maintain a corps of engineers to assist architects and builders in the proper arrangement and equipment of buildings for heating and ventilat- ing. Aside from the monetary considerations and profits accru- ing from such work, there is a satisfaction which all must expe- rience when they are contributing to the health and happiness of thousands of human beings. There is still much to be desired, but with the architects alive to the situation and the public aware of the results possible to be obtained, we shall witness very few school buildings erected without the provision of an adequate heating and ventilating apparatus. All government buildings and practically all theaters and places of amusement now planned and erected are provided with ventilating apparatus and the campaign for the ventilating of shops and factories is well under way. Probably no clearer idea of the air required for ventilation can be had than that given by the B. F. Sturtevant Company, which we reproduce in part. " AMOUNT or AIR REQUIRED FOR VENTILATION. Under the general conditions of outdoor air, namely, 70 temperature and 70 per cent of complete saturation, an average adult man, when sit- ting at rest as in an audience, makes 16 respirations per minute of SO cubic inches each, or 480 cubic inches per minute. Under the previously assumed conditions of 70 temperature and 70 per cent humidity, the air thus inhaled will consist of about J oxygen and J nitrogen, together with about 1^ per cent aqueous vapor and yf0- of a per cent carbonic acid. By the process of respiration the air will, when exhaled, be found to have lost about J of its oxygen by the formation of carbonic acid, which will have increased about one hundredfold, thus forming about 4 per cent, while the water vapor will form about 5 per cent of the volume. In addition, the 'inhaled air will have been warmed from 70 to 90, and, notwith- standing the increased proportion of carbonic acid which is about one and one half times heavier than air will, owing to the increase of temperature and the levity of the water vapor, be about 3 per VENTILATION cent lighter than when inhaled. Thus it will be seen that this vitiated air will not fall to the ground, as has often been presumed, but will naturally rise above the level of the breathing line, and the carbonic acid will immediately diffuse itself into the surrounding air. In addition to the carbonic acid exhaled in the process of res- piration, a small amount is given off by the skin. Furthermore, 11/2 to 2% Ibs. of water are evaporated daily from the surface of the skin of a person in still life. If the air supply at 70 is as- sumed to have a humidity of 70 per cent and to be saturated when it leaves the body at a higher temperature, then at least four cubic feet of air per minute will be required to carry away this vapor. " Taking into consideration these various factors, it becomes evident that at least 4% cubic feet of fresh air will be required per minute for respiration .and for the absorption of moisture and dilution of carbonic-acid gas from the skin. This, however, is only on the assumption that any given quantity of air having ful- filled its office, is immediately removed without contamination of the surrounding atmosphere ; but this condition is impossible, for the spent air from the lungs, containing about 400 parts of car- bonic-acid gas in 10,000, is immediately diffused in the atmos- phere. The carbonic-acid gas does not fall to the floor as a separate gas, but is intimately mixed with the air and equally distributed throughout the apartment. " It must then be evident that ventilation is in effect but a process of dilution and that when the vitiation of the air discharged from the lungs is known and the degree of vitiation to be main- tained in the apartments is decided, the necessary constant supply of fresh air to maintain this standard may be very easily deter- mined. For the purpose of calculation, 0.6 cubic foot per hour is accepted as the aA r erage production of carbonic acid by an adult at rest and the proportion of this gas in the external air as 4 parts in 10,000. If, therefore, the degree of vitiation of the occupied room be maintained at, say, 6 parts in 10,000, there will be per- missible an increment of only 2 parts in 10,000 above that of the normal atmosphere, or 2-10,000 = .0002 of a cubic foot of car- bonic acid in each cubic foot of air. The 0.6 cubic foot of car- bonic acid produced per hour by a single individual will, therefore, 218 PRACTICAL HEATING AND VENTILATION require for its dilution to this degree 0.6 -r- .0002 = 3,000 cubic feet of air per hour. Upon this basis the following table has been calculated : TABLE XXIV CUBIC FEET OF AIR CONTAINING FOUR PARTS OF CARBONIC ACID IN TEN THOUSAND SUPPLIED PER PERSON Per Hour. . . 6,000 4,000 3,000 2,400 2,000 1,800 1,714 1,500 1,200 1,000 525 375 231 Per Min.... 100 66.6 50 40 33.3 30 28.6 25 20 16.6 9.1 6.2 3.8 .DEGREE OF VITIATION OF THE AIR IN THE ROOM Parts of Car- bonic Acid in 10,000. . 5 K K o . o 6 6.5 7 7.33 7.5 8 9 10 15 20 30 " The figures indicate absolute relations under the stated condi- tions, and are generally applicable to the ventilation of schools, churches, halls of audience and the like, where the occupants are reasonably healthy and remain at rest. But the absolute air volume to be supplied cannot be specified with certainty in advance, with- out a thorough knowledge of all the conditions and modifying circumstances in fact, the climate, the construction of the build- ing, the size of the rooms, the number of occupants, their healthful- ness and their activity, together with the time during which the rooms are occupied, all have their direct influences. Under all these considerations, it is readily seen that no standard allowance can be made to suit all circumstances, and results will be satisfac- tory only in so far as the designer understandingly, with the knowl- edge of the various requirements as they have here been given, makes such allowance." Methods of Ventilation A building may be properly ventilated only when adequate provision has been made by the architect and builder of such stacks, flues or ducts as may be necessary for the use of the sys- tem of ventilation to be adopted. There are two general methods of producing ventilation, namely, natural and mechanical. Nat- ural ventilation as expressed and understood is caused by ducts so constructed that the velocity of the outside air or difference VENTILATION in temperatures produces a change of air within a building. This method by itself is quite unsatisfactory, but when assisted by heat- ing surfaces placed within the exhaust flues and warming the en- tering air by passing it over or between the heated surfaces of radiators in a manner commonly styled indirect heating, is pro- ductive of fairly good results. This method is shown by Figs. 96, 97 and 98. These radi- ators are located in the basement of the building and connected to the supply or hot-air register by a galvanized-iron duct, the foul air being exhausted through a ventilating duct which is heated by means of an aspirating coil or other device. The enter- ing air may also be warmed by passing between the surfaces of a direct radiator, the bottom of which rests on or is inclosed in an iron boxing connecting with and receiving air through a duct from outside the building. This air is passed from the boxing upward between the sections of the radiator into the room. An arrangement of this kind is styled a direct-indirect or semidirect radiator. See Fig. 101. By placing gas jets, a pipe coil or small radiator in the ven- tilating flue, the air is expanded, creating an upward current which sucks the foul air from the room into the duct. This sys- tem of ventilating may be so arranged as to be entirely adequate for a small residence or a larger building if sparsely occupied, and may be employed to good advantage for small schools or kindred buildings, although as a usual thing, a school should be provided with a system of mechanical ventilation, of which we shall speak later on. In ventilating the living rooms of a residence a main ventilat- ing shaft should be provided, centrally located, into which foul- air ducts from the various rooms should be connected. In this shaft there should be placed an aspirating coil connected with the house-heating apparatus, steam or hot water, for use during the period when the heating apparatus is operated. For summer use the gas supply should be piped into the shaft and one or more gas burners attached. An opening into the shaft in the basement, fitted with a door, should be provided to gain admit- tance to the gas burners. This is a requirement needed only when the rooms are occupied by an unusual number of persons. Fig. 220 PRACTICAL HEATING AND VENTILATION 199 shows a method of connecting the foul-air duct with the ven- tilating shaft. A register should be set in an inside wall of each living room at a point just above the baseboard and a foul-air duct run as shown by the illustration. Rooms having open fireplaces are easily ventilated in warm weather by gas jets placed within the opening to chimney. The fresh-air supply for a residence may be furnished by indirect or semidirect radiators placed as we have shown by Figs. 96, 97, 98 and 101. When no special provision is made for the admis- sion of pure air to a residence, or where the cost of indirect heat- ing seems to make its use prohibitive, there should be at least one fresh-air inlet. This should be placed in the lower or re- ception hall and as great a volume of air admitted as can be tempered by an indirect radiator placed beneath the floor, the -4 \Stack 'Ventilating Shaft Foul Air Outlet Register ^ Foul Air Due t between Joists FIG. 199. Connecting foul-air duct to ventilating shaft. size of same depending upon existing conditions. The inlet reg- isters for all ventilation of this character should be placed in the wall at a point about two thirds the height of the ceiling and they should be located at a point opposite to the fireplace, if there be one in the room. See Fig. 200. The importance of chimneys as ventilating shafts is not gen- erally recognized. The open fireplace, when in use, provides a VENTILATION 221 most successful means of exhausting the foul air from a room. A chimney or shaft may be successfully used for ventilation by running a smoke flue constructed of boiler iron through the center of the shaft and surrounding it with ventilating ducts of such number and size as may be necessary to accommodate the rooms to be ventilated. When used in this connection a chimney should Fresh Air Inlet Register 3' from Ceiling J FIG. 200. Location of fresh-air inlet. be located in the center of the building and the bottom of the smoke flue should rest on a cast-iron plate supported on a brick or stone foundation, as shown by Fig. 201. The arrangement of ventilating ducts is shown by Fig. 202. These ducts rise to the height of the brickwork of the chimney, on the top of which there should be erected an iron canopy open at the sides. The smoke flue should protrude through the top of the canopy and may have a cowl at the extreme end, if desired. The smoke flue should be anchored to the brick walls by iron clamps, as illustrated by Fig. 203. These anchor clamps should be attached at the line of each floor, at the roof line and at the top of the brick chimney. The smoke flue warms and expands the air in the ventilating ducts, inducing an upward circulation, PRACTICAL HEATING AND VENTILATION which exhausts the foul air from each room and discharges it into the atmosphere under the canopy at the top of the chimney. This method of ventilation, in connection with indirect or semidirect radiators for warming, is quite successful and by slight modifications may be readily adapted for many small build- A. A. Brick Chimney B. B. B, Ventilating Ducts FIG. 202. Ventilating ducts m shaft. Iron Clamp FIG. 203. Iron clamps for support- FIG. 201. Construction of ventilating shaft. ing stack. ings. For residences this method may be employed in place of the ventilating shaft as. previously mentioned. The movement of air in the vertical or main vent flues should not be less than 6 feet per second. With an arrangement of the flues as described above, if properly constructed, this velocity, or even a greater, should be easily obtained. Make the register openings of such sizes that the velocity of the air through them will not be more than one half that in the vertical duct, or in other words, not more than 3 feet per VENTILATION second. If this schedule is adhered to, no perceptible draughts will abound or be felt by the occupants of a room. When semidirect radiators are used for warming the enter- ing air, the dampers may be adjusted to suit the state of the weather. With indirect radiation the registers should equal in size and open area those used for foul air. Definite results as to air volume and velocity may be obtained by properly proportioning the amount of heating surface and the sizes of hot and cold air ducts. This is particularly true in cold weather when the maximum amount of pure air would be supplied to the building. There seems to be no question but that the combination of gravity ventilation and indirect heating is one that gives vary- ing quantities of air dependent on atmospheric conditions. In warmer weather, when the minimum amount of heat is necessary, the resulting temperatures and velocities of the air in the ven- tilating flues are less than in colder weather; consequently the volume of fresh air admitted and the volume of air exhausted are less. With this understanding we should not use the average vol- ume necessary as a basis for estimating, but should so plan the work that the volume of air moved in warmer weather would be adequate for the character of the building in which the appa- ratus is placed. CHAPTER XXI MECHANICAL VENTILATION AND HOT-BLAST HEATING Growth and Improvement THE phenomenal growth of the various systems of hot-blast heating and mechanical ventilation during the past twenty-five years is due largely to the better understanding of those who plan and erect buildings as to the need of a positive system of heating and ventilation. Many excellent works have been pub- lished covering the advantages of this type of apparatus and the application of the various methods employed in performing the work. These books and papers are more or less necessarily tech- nical in character and, therefore, useful principally to experienced engineers and are intelligible only to those who have received the benefit of a higher education. While we may not be able to add to the value of what has already been written on the subject, we hope to so describe and illustrate the various methods employed that the average steam fitter or heating contractor will obtain an intelligent idea of the principles applied and the methods practiced in installing work of this character. Our thanks are due to such representative manufacturers of fans and ventilating apparatus as The Buffalo Forge Company, The B. F. Sturtevant Company, American Blower Company, New York Blower Company and The Massachusetts Fan Com- pany and the engineers employed by them for much valuable assistance and for permission granted to use such tables relating to the movement of air, etc., etc., as appear in the last chapter of this book. Experience has clearly demonstrated that mechanical heating and ventilation should go hand in hand, and in order that the cost of installation and operation may be reduced to a minimum, 224 MECHANICAL VENTILATION 225 they should be considered unitedly, planned for unitedly and in- stalled unitedly. A system of heating and ventilating cannot be perfectly controlled where one part is installed independent of the other and without perfect control the cost of operation must be excessive and the results obtained be intermittent, if not a complete failure. Mechanical systems for heating and ventilating are at this date installed principally in buildings of large size, such as schools, theaters, churches, hospitals, factories, etc., and in com- paratively few residences. This latter condition is due undoubt- edly to the cost, both of apparatus and of maintenance. When as a people we shall have decided that we are willing to pay as much for health and comfort (which result from the breathing of pure, fresh air) as we do for the heating of our homes, then, without question, we shall see mechanical methods of heating and ventilating more generally practiced. Another influence oper- ating against the adoption of methods of mechanical heating and ventilation, which possibly has not been heretofore fully recog- nized, has been the antagonism of the steam-fitting trade in many localities to the approval and acceptance of the blower system. In all likelihood this situation is due to two reasons, namely (1) ignorance of the modes applied and the results obtained, and (2) the question of personal gain arising from the adoption of some one of the old orthodox systems of heating. Methods Employed There are two general methods practiced in supplying a building with heat and fresh air and in exhausting or expelling the foul air. These methods are known as the exhaust and ple- num methods. In arranging the apparatus for an exhaust sys- tem, the fan is placed in the main ventilating shaft or duct and cold or fresh air ducts lead to the heating surfaces supplying each room, as would be the case if indirect radiators were used. The entire heating surface may also be placed within a single chamber (brick or iron) and from this chamber the warm-air supply pipes connect with ducts leading to each room. Again, the heating surface may be direct, that is to say, direct cast-iron radiators 226 PRACTICAL HEATING AND VENTILATION or pipe coils placed under windows or at points where the inward leakage is the greatest. In action the fan produces a partial vacuum within the room. This results in drawing the fresh air from outside the building through the coils or other heating surfaces and from them into the various rooms. At the same time it exhausts the foul air through ducts provided for the purpose, which are connected with the main ventilating shaft. In so far as the heating and ventilating results are concerned, it is possible to thoroughly warm and ventilate a building by this method and there are a great many structures heated in this manner. The objections to this mode are that in operation the partial vacuum created draws all air currents inwardly through the crevices around doors or windows, thus often producing a draught which is dan- gerous to the occupants of the rooms; also, that it is difficult to control a system of this character, particularly in a change- able climate. Again, the locations of the inlet and outlet regis- ters must be arranged with great care, owing to the direct course of the air from the inlets to the outlets, and often the conditions of the building (particularly if previously erected) are such that the ducts and openings cannot be distributed as desired. For these reasons this system is not now generally used; it has been replaced by the so-called " plenum " method. With the plenum method the heated air is forced into each room under a slight pressure and all leaks of air around doors, windows or other openings are outward and no perceptible draughts are felt or experienced by the occupants of the room. As the slight pressure exerted is from the source of the pure- air supply it is impossible for any obnoxious odors or gases to enter into and contaminate the air of the room. With this sys- tem the supply of heated air, as well as the supply of fresh air, or we might say the quality, quantity and temperature of the air are always under perfect control. There are several adaptations of the plenum system of heat- ing and ventilating. The older method employed is where the cold air is supplied to the fan direct from a cold-air chamber or cold-air duct, the fan driving it through the heater or heating coils into the various warm air ducts supplying the rooms of the MECHANICAL VENTILATION 227 building. The air may be sufficiently heated by these coils, or it may be driven through supplementary heaters located at the base of the hot-air flues and be increasingly heated before de- livery to the room or rooms to be warmed. Separate ducts may be arranged to connect the main hot-air supply with the rising flues, or the heated air from the coil may be discharged under a slight pressure into a plenum chamber with which all supply pipes or warm-air ducts are connected. Heat Losses and Heating Capacity Required The proportion of heat losses depends principally upon the construction of the building, whether of frame, stone or brick, the conditions of exposure, that is to say, whether standing alone in an isolated position or protected from chilling winds by sur- rounding buildings, the number and sizes of windows and the amount of exposed wall surface. Brick buildings lose less heat through walls than buildings constructed of wood or stone and of the three classes, the frame structure is usually less compactly erected and correspondingly harder to heat. The percentage of loss through walls of varying thicknesses has been ascertained with sufficient accuracy for estimating purposes, as has also been the percentage of heat transmission through windows (glass), doors, floors and ceilings. The use to which the building is put largely governs the heating capacity required. A schoolhouse or similar structure, built in the open and having a large proportion of exposed glass and wall surface, and where a certain number of changes of air per hour is desired, or a definite amount of fresh air per hour per person required, is proportionately harder to warm than would be a theater with its small glass exposure and usually well protected walls, to say nothing of the animal heat emanating from a large number of people closely assembled. In the latter type of building the matter of furnishing fresh air to replace that vitiated by the breaths of the individuals within the struc- ture, and exhausting the air so contaminated without producing draughts or dangerous air currents, is a problem not easily solved. Assembly halls, churches, hospitals, factories and other types of buildings present conditions of heat losses and air vitiation which 228 PRACTICAL HEATING AND VENTILATION vary according to the diversified uses to which each building is put ; therefore each type of building must be considered separately in planning the heating and ventilating of it. The heating capacity of the apparatus is therefore based on two conditions, namely, the temperature of the air necessary to warm the building and the volume of fresh air necessary to be supplied in order to maintain a given standard of purity of the atmosphere within the building. Reference to the table " Volume of Air Necessary to Maintain a Standard of Purity " given in the last chapter of this book will show the volume of air essential under certain stated conditions. Quality of the Air Supplied When a blower apparatus is placed in a building erected in a location where the purity of the air is unquestioned, it may be supplied in its natural state to the building. As a matter of fact, the large proportion of buildings heated and ventilated by mechanical methods are located in the cities, in congested dis- tricts, or in factory towns where the atmosphere surrounding the structure is contaminated by dust and soot and which, aside from the possibility of being more or less filled with the germs of dis- ease, is unfit to breathe. Again, in all buildings heated by arti- ficial means, the air is deficient in moisture, the dryness being so apparent that it is necessary to heat the rooms to a temperature much higher than would be required were proper attention given to the quality of the air supplied. Proper provision for a desirable degree of moisture in the air supplied to a building is as necessary, indeed we may say, more necessary, for health of its occupants, than the heating of it. Proper protection in the way of clothing will prevent chill- ing in a structure insufficiently warmed, but there is no individual resource whereby a person may prevent the oppressive feeling resulting from the dryness or overheating of a room, causing the evaporation of the moisture from the body to such an extent as to produce irritation of the skin and other unpleasant sensations. One can never feel as comfortable inside a room heated to 70 as in the open and balmy outside air when the temperature is at 70. This fact alone shows conclusively that the nearer we MECHANICAL VENTILATION 229 can come to maintaining a fixed standard of humidity within a building, the richer will be the conditions of health and comfort. With these circumstances provided for it is possible at times to breathe better air within than without an edifice, because the weight of moisture in the outside air is variable, as it de- pends upon the conditions of humidity and temperature and these change daily, often hourly. Prof. Kinealy states that the weight of moisture brought into a room per hour by air which enters from the outside, is equal to the number of cubic feet of air, measured at the outside temperature, which enters per hour, mul- tiplied by the weight in grains of the moisture in one cubic foot of air, and that the amount of moisture in one cubic foot of external air is obtained by multiplying its humidity by the weight of moisture required to saturate it at the outside temperature. Again, the same authority states that as it is customary in this country to keep the air of the rooms at 70, and to assume that the volume of the air supplied for ventilation is measured at 70, the following table has been calculated to show the weight of moisture in one cubic foot of air at 70, when the air is taken in a saturated condition at different outside temperatures and heated to 70. TABLE XX\ 7 Temperature of Saturated Weight of Vapor in One Cubic Foot of Air when Humidity of Air when Heated Outside Air. Temperature is Raised to to 70 Degrees. 70 Degrees. 68 8.5 10 0.98 12.3 20 1.43 17.9 30 2.04 25.5 40 2.92 36.5 50 4.13 51.6 60 5.76 72.0 An Ideal System The ideal system of mechanical heating and ventilation must, therefore, be the system which will not only properly warm a building, but which will at the same time expel the foul air in such quantities as to thoroughly remove all excess carbonic-acid 230 PRACTICAL HEATING AND VENTILATION gas and all poisons of respiration from the atmosphere within the building and replace the air expelled with air which has been washed of its soot, dirt and germs and moistened to such a degree as will insure healthfulness and comfort to the occupants. Fur- ther, the ideal system is one which is always under perfect con- trol, giving certain definite results within a minimum cost of maintenance. Our readers may ask if all this is possible, to which we reply : Yes, not only possible, but further, that systems of this character are now in constant use. Installations of this kind are known as the " double-duct system " or more familiarly as the " hot and cold system." The reason for these appellations is shown in the following descriptions of apparatus. Taking the modern school or public building for illustration, Fig. 204 shows a system of this kind as designed by the Buffalo Forge Company. The fan, heaters and air ducts are arranged in the usual manner. The tempering coils are located nearest to the fresh-air inlet and are of sufficient capacity to maintain any temperature desired up to 70 or 80. The coils are spe- cially constructed to admit of temperature regulation by hand, or the temperature in the spray or humidifying chamber may be automatically controlled by means of a by-pass damper under tempering coils. At one end of the spray chamber are located the spray nozzles. These are made of brass and are of simple construction, practically atomizing the water and distributing it uniformly throughout the chamber, the discharge being par- allel to the air currents. At the opposite end of the chamber is located the eliminator or separator, which removes all free par- ticles of moisture from the air before it enters the fan which draws the air direct from the humidifying chamber through the eliminator. The air thus cleansed and moistened is then dis- charged through the coils of the heater into the plenum chamber from which the various ducts supplying the building are taken. Reference to Fig. 205 (which is an elevation plan of an appa- ratus designed for the Carnegie Library at St. Louis, Mo.) will show that the entire volume of air from the fan may be delivered through the heater, or a portion of it may be passed around the heater through the by-pass shown and mixed with the hot air in such quantities as desired or necessary to maintain a given MECHANICAL VENTILATION 231 PRACTICAL HEATING AND VENTILATION MECHANICAL VENTILATION temperature within the building. Thermostatic control at the mixing dampers for each room is an essential and special feature for a system of this character. It may be well to state that the water for the sprays may be furnished from city pressure. The most economical method, however, is to use the water continuously until it is unfit for further use. This is achieved by draining the water separated from the air by the eliminator into a well, from which it is p IG 206. Wire screen for cleansing air. pumped by a centrifugal pump and delivered again to the spray system. This pump may be direct connected or driven by belt from the fan, or a separate motor. Air cleansing and humidifying may be secured by several methods. For cleaning it of soot and' dust, the air may be passed through a fine wire screen similar to that shown by Fig. 206. Originally cheese cloth stretched over wooden frames was used. These frames were made removable, to be replaced when clogged with dirt. PRACTICAL HEATING AND VENTILATION Coke washing and purifying seems to be a very good method of removing dust and dirt and at the same time moistening the air. The coke is placed on shelving within a wire cage, through _ which the air is passed on its way to the fan. At the top of the cage the water supply is placed. The water is allowed to trickle down over and through the coke, while the air passing through MECHANICAL VENTILATION 235 236 PRACTICAL HEATING AND VENTILATION at right angles is purified and moistened. Fig. 207 shows a per- spective section of a school with heater, fan, coke washer, etc., as installed by the American Blower Company. The fresh air enters the building in the usual manner, through a screened opening in basement wall, passes through tempering coils, or direct through by-pass under the coils, to the coke washer and from here to the fan. MECHANICAL VENTILATION 237 It is delivered to the heater or passed around it in the usual manner and under thermostatic control is admitted to the vari- ous rooms through ducts leading out of the plenum chamber. Quite similar is the apparatus of the New York Blower Com- pany, as illustrated by Fig. 208. As conditions of area, location, etc., largely govern the char- acter of the apparatus installed, each particular building must be separately considered and this fact is responsible in no small degree for the many arrangements and designs of the blower system. One of the many Sturtevant methods is shown by illustration Fig. 209. It is a three-quarter housing pulley fan with blow- through heater for the " hot-and-cold " or " double-duct " sys- tem. An apparatus of this kind is used on work where space is limited, or where the space allotted is in such form as to preclude the placing of apparatus of the ordinary form with moistening chamber and tempering coils. The outlet from the heater may be made to discharge directly outward from the end, or upward or downward in either direction. In fact, the methods of setting and housing of the fan, whether a steam fan or operated by a pulley, are such as may be adapted for any special form of installation. A typical apparatus for heating and ventilating a school is shown by the small basement plan Fig. 210. In this case the fan discharges in opposite directions through separate heaters to the right and to the left into separate plenum chambers, as shown. This arrangement of the apparatus is particularly com- mendable owing to the centralizing of the fan and heaters and the direct delivery of the warm air. One engineer summarizes the features of this system as follows: " The entire heating surface is centrally located, inclosed within a fireproof casing, and placed under the control of a single individual, thereby avoiding the possibility of damage by leakage or freezing incident to a scattered system of steam piping and radiators. The heater itself is adapted for the use of either exhaust or live steam, and provision is made for utilizing the exhaust of the fan engine, thereby reducing the cost of operation (of the fan) to practically nothing. At all times ample and 238 PRACTICAL HEATING AND VENTILATION positive ventilation may be provided with air tempered to the desired degree. Absolute control may be had over the quality and quantity of air supplied. It may be -filtered, cleansed, heated "BASEMENT f>URN. FIG. 210. A typical method for schools. or cooled, dried or moistened at will. By means of the hot and cold system, the temperature of the air admitted to any given apartment may be instantly and radically changed without the employment of supplementary heating surface." Fans for Blowing and Exhausting For exhaust ventilation and the removal of smoke, obnoxious gases, etc., from factories or other buildings, the regular forms of fan wheels used are of the disc or the cone type. Fans of this character are lightly constructed, are easily installed and require but little power to operate when run at low speed. The Cone type of peripheral discharge, without any casing MECHANICAL VENTILATION 239 whatever, is thought to give the highest efficiency. They are said to produce better results in volume of air moved than could be secured by the use of the ordinary type of disc fan with straight blades. The fan may be driven by a direct-connected motor, as shown by Fig. 211, or may be pulley driven, as shown by Fig. 212. These illustrations also show the manner of setting or installa- tion. This type of fan is frequently used in the main vent shaft of a church, school or similar building in place of an aspirating coil where " assisted ventilation " is necessary. The centrifugal fan wheel illustrated by Fig. 213 is the type of steel-plate fan as used in all blowers whether the housings are made of steel, brick or wood. There are several adaptations of this type of steel-plate fan, which space will not allow us to illustrate or describe. The blades may be curved or they may be bent backward to avoid noise. Various manufacturers have vary- ing ideas of efficiency and forms of construction. The fans illus- trated may be considered as representative of the several types. The propeller or disc fan, as the name implies, propels the air forward by impact and centrifugal force and is efficient for moving large bodies of air under slight resistance. For driving air through heaters and long pipes or ducts, or delivering a fixed volume of air in a stated period or under great resistance, the type of fan wheel illustrated by Fig. 213 is now almost universally employed. Types of Heaters There are several types of heaters as used for mechanical or hot-blast heating and ventilation. The form of the heater em- ployed depends largely upon the character of work to be per- formed and the space to be occupied for its installation. Different requirements demand different heaters and it would be hard to select one make or type of a heater which could always be adopted. Again, the size and shape of the heater depend upon the extent or number of degrees the air is to be heated, the volume of air passed by the fan and the steam pressure available. As a rule, the heater installed for this class of work takes the form of what might be designated as a " set " or " group " of steam coils made from 240 PRACTICAL HEATING AND VENTILATION FIG. 211. Ventilating fan with direct- connected motor. FIG. 213. Type of steel plate fan. FIG. 212. Pulley-driven ventilating fan. MECHANICAL VENTILATION wrought-iron pipe, usually 1" in diameter and screwed into cast- iron bases of various forms, composing sections, the sections being then assembled in groups of two or more, according to the needs of the work. The Sturtevant mitre type of heater is illustrated by Fig. 214. Steam is admitted at the top of the inlet header or section and the condensation removed at the end of the outlet section, each of the sections having an independent feed and drip. The regular Sturtevant type of heater and the construction of the base are shown by Fig. 215. In this type of heater (made FIG. 214. Sturtevant mitre type of heater. also of V pipe) the pipes are set 2 1 /:}" on centers, providing a free area for passage of air equal to about 40^ of the full area of the face of the section. The arrangement of the interior of the cast-iron base and the division partition or diaphragm are clearly shown by the illustration. The steam enters the upper part of the base and feeds one end of the various pipe loops, pass- ing upward and across the top and down the opposite side of the loop, the condensation entering the lower division of each header, from which it passes to the return drip. The headers or bases are made to accommodate either two or four rows of pipe, and the compactness of the heating surface is shown by the fact that within a space of 6 feet in length, 7 feet in 242 PRACTICAL HEATING AND VENTILATION height, and 7% inches deep, nearly 1,000 lineal feet of pipe may be massed. The Buffalo Manifold Heater is illustrated by Figs. 216 and FIG. 215. Sturtevant heater and base. 217, and the Mitre Coil Heater by Figs. 218 and 219. The Buf- falo Manifold Heater is particularly efficient due to the peculiar form of the heater base. FIG. 216. Buffalo heater showing FIG. 217. Buffalo heater showing connections. base. The heaters of the American Blower Company and of the New York Blower Company take the usual form in construction, but MECHANICAL VENTILATION 243 differ in the arrangement of the heater bases. The A. B. C. heater base is divided lengthwise by a diaphragm, the flow entering from one side of the partition, the return passing through the chamber on the opposite side of the partition. The form of the New York heater base is shown by illustration Fig. 220, which also shows this particular heater with a part of the casing removed. Fig. 221 shows the A. B. C. Heater complete ready for the casing. The regular form of cast-iron indirect sections may be used in connection with the blower system for heating and ventilating schools, churches or buildings where it is not necessary to heat the FIG. 218. Buffalo mitre type of heater. FIG. 219. Assembling of mitre type of heater. air to a very high temperature. A hot-air chamber is provided in the basement and the indirect sections assembled into stacks and arranged in two, three, four or more tiers, as occasion demands. Each tier is supported on I beams or railroad rails. There are also special forms of cast-iron sections available for use with a blower apparatus. The fact of so large a heating surface being contained within a comparatively small space, as with any one of the heaters men- tioned and illustrated, and the further truth that but one fifth of the surface ordinarily required for direct heating is necessary for the hot-blast system, are points of economy worthy of serious con- sideration. To these advantages we may add efficiency of service, PRACTICAL HEATING AND VENTILATION as it is conceded that, owing to the rapid movement of the air over the heating surfaces, they become three times more efficient than heating surfaces in comparatively still air, as in the case of direct radiation. FIG. 220. New York heater showing construction of base. One point in heater construction we wish to make plain. The heater may be so valved and connected that certain sections may be used for live steam, certain sections for exhaust steam from an engine-driven fan or other source, or all of the sections may be used for live or exhaust steam as the case may demand. Methods of Driving Fans The method of driving fans for ventilating or for a combined system of heating and ventilation includes a detail of construction MECHANICAL VENTILATION 245 unnecessary to discuss at length. In so far as efficiency is con- cerned, fans of all types may be driven by electricity (a direct connected or independent motor) or by steam. It frequently happens that fans are installed in positions where electric power is available and where it would be inconvenient to use an engine. In such a situation an electric-driven fan with motor directly attached is without doubt the most suitable and economical. Again, when a fan is used to accelerate the movement of air in a ventilating shaft or duct, it is easy to install an electric- FIG. 221. A. B. C. heater ready for casing. driven fan, which may be started, stopped and controlled from a switch located in a convenient position for the attendant's use. The motor used should be independent, that is, should be used for no other purpose than that of driving the fan. An engine-driven fan in an instance of this kind would not be desirable. For an apparatus used for heating and ventilating, such as described in the preceding pages of this book, an engine-driven fan is no doubt the best and most economical. The heater connections are so arranged that the exhaust from 246 PRACTICAL HEATING AND VENTILATION the engine driving the fan may be employed for heating purposes and as this exhaust has probably 95$ of its original value in heat units, the cost of driving the fan is reduced to practically nothing. The requirements for an engine of this kind are lightness of weight and freedom from noise and vibration when run at high speed. FIG. 222. Type of A. B. C. vertical engine. FIG. 223. Showing A. B. C. self- lubricating device. Simplicity and reliability are at all times essential. Fig. 222 shows one of the many types of the A. B. C. engine. It is for low pres- sure and of the vertical type, inclosed to keep the parts free from dust and dirt, and self-oiling or automatic. An interior view showing the mechanism of the self-lubricating system is shown MECHANICAL VENTILATION 247 FIG. 224. The Sturtevant horizontal engine. FIG. 225. The Sturtevant double upright engine. 248 PRACTICAL HEATING AND VENTILATION by Fig. 223. When used in connection with a heating and ven- tilating apparatus, such as would be required for a school or simi- lar building, it is desirable that a pressure of not more than 30 Ibs. be carried ; therefore the engine must be supplied with large cylin- ders in order that the required power may be produced. Fig. 224 shows a horizontal engine of this kind. When located where there is more or less dust in the atmosphere an engine of the vertical, inclosed type is more desirable. The double-upright or vertical inclosed engine illustrated by Fig. 225 represents another type of engine specially designed for this class of work. Some Details of Construction The following details of Sturtevant methods are typical of those in use on blower system construction. The planning of a mechanical system of heating and ventila- tion, the determining of the size of each portion of the apparatus FIG. 226. Form of elbow for hot-air duct. FIG. 227. Manner of reduc- ing size of air duct. and the ordinary details of construction should be left with an en- gineer whose experience at work of this character qualifies him to handle it accurately and competently. There are some few de- tails of construction with which we should become thoroughly familiar. From illustrations and descriptions given on the preceding MECHANICAL VENTILATION 249 pages we should have a good understanding of the methods of placing the mechanical portion of the apparatus, arrangement of air chambers, moistening apparatus and eliminators. The flues, which should be built in the walls as the construction of the building progresses, should, if possible, be tile-lined. If not tile-lined, they should be plastered smooth. The ducts (the name given to all horizontal air passages) are usually made of galvanized iron, although in many instances it is necessary to run a portion of them underground, in which cases they should be constructed of brick or tiling. Sudden turns or angles in the ducts should be avoided. In making a 90 angle turn, the elbow should FIG. 228. Iron duct construction. be built with as large a sweep as possible. Illustration Fig. 226 shows the proper construction of the elbow. An abrupt reduction in the size of the diameter of the pipe should be avoided ; all unnecessary friction is eliminated by a grad- ual diminution of the pipe size. This is illustrated by Fig. 227, whereby we show the manner in which a small pipe should be taken from a main duct. Fig. 228 shows the method of constructing an iron duct and by Fig. 229 we illustrate the method of constructing a brick duct when it is essential for a portion of the air supply to turn at right angles, the remaining quantit} T continuing in the same direction. The movements of air and water are in many respects quite similar. The same methods employed for the elimination of fric- 250 PRACTICAL HEATING AND VENTILATION tion from the pipes conveying water may be used with good re- sults in conducting air. This is very clearly illustrated by the use of a double elbow when it is necessary to divide the supply, send- ing a portion of it in either direction. The proper arrangement of ducts and dampers has much to do with the success or failure of an apparatus of this character. Two ducts, one conveying the hot air, the other conveying the cold air, are run to the base of the flue supplying a room. It is under- stood that each room should have an independent supply. Mixing dampers are placed where the hot air and cold air enter the flue. fe*. FIG. 229. Brick duct construction. Fig. 230 shows an arrangement of a damper of this character and the method of operating the damper from within the room. While this mode is extensively used, nevertheless it is open to some objec- tions. The air currents strike squarely against the damper plate, causing considerable friction. The Sturtevant method is commend- able and is clearly illustrated by Fig. 231 and Fig. 232. As the damper is cylindrical in form it allows the air to mix in proper MECHANICAL VENTILATION quantities at the will of the operator and without friction. The dial placed within each room and the chain attachment are shown by Fig. 233. These dampers may be manipulated by a thermostat. This arrangement we will show in a later chapter. The screen or register opening for the entering air should be placed at a point about two thirds the height of the ceiling and FIG. 230. Type of mixing damper. in such a part of the room as will insure the complete distribution of the air. Frequently the proper location may not be utilized, due to the particular construction of the building and it, there- fore, becomes necessary to assist the distribution of the air in cer- tain directions. This is accomplished by means of a diffuser placed 252 PRACTICAL HEATING AND VENTILATION over the face of the register, as shown by Fig. 234. This appli- ance breaks up the volume of air admitted, deflecting it into sep- arate currents andJJiereby more effectually warming the room. FIG. 231. Sturtevant mixing damper. FIG. 232. Sturtevant mixing damper showing chain for operating. FIG. 233. Enlarged view of dial and chain. FIG. 234. Diffuser placed over register face. MECHANICAL VENTILATION 253 Factory Heating Before the fan and blower came into general use the problem of satisfactorily heating and ventilating factories of any considerable size, was often a vexatious one and the results as often obtained were far from being efficient or desirable. The use of fans for exhausting the foul air, smoke or gases incident to the manufac- turing of some classes of products, and for forcing the distribution of heated air has revolutionized the methods of factory heating and now definite results and efficiency are assured. The exhaust type of fan as illustrated by Fig. 211 and Fig. 212 may be employed with successful results in the removal of foul air and gases and for heating a blower fan and pipe heater arranged for use of all available exhaust steam may be utilized. Probably the most simple and the easiest type of factory build- ing to heat and ventilate is the one-story building. They are usu- ally sparsely occupied and the amount of floor space devoted to the use of each employe is considerably larger than the space per capita in offices or public buildings ; therefore, the ordinary ven- tilation of the building is not a difficult matter. On the contrary, with regard to heating, the customary factory structure is well lighted by many windows and not only presents large exposed wall surface to the action of the wind and weather, but also from the form of its construction has a very large loss of heat or leak- age through the roof. In a building where the process of manufacturing does not fill the air with poisonous gases, the fan may be supplied with air from within the building. Therefore, the loss of heat is only that wasted by leakage, the air being turned over and over and heated to the necessary degree of temperature to allow for heat losses through windows, walls and roof. The fan and heater should be centrally located in order that an even distribution of the heat may be secured throughout the building. The air is carried around the building in galvanized pipes and distributed through openings located at intervals in the piping. Fig. 235 shows an adaptation of this method and is the type of an apparatus designed by the Sturtevant Company. When a factory building of more than one story in height is 254 PRACTICAL HEATING AND VENTILATION in process of erection, flues for the distribution of the heated air may be built up through the pilasters and thus not engage any. space within the building. The heated air may be supplied to these flues through a brick underground duct or through an iron duct located in the basement. For certain classes of mills or factories this method is preferable above all others. Where a blower system is installed in an old factory structure, the most simple form of air distribution is by a galvanized iron stand pipe, as shown by Fig. 236. The openings for each floor may be made in the manner shown, or the piping on each floor car- ried to a central point, the distribution there taking place. ii FIG. 235. Sturtevant method of factory beating. In one sense the heating of factories in this manner far excels all other methods. The moving belting, shafting and machinery all tend to break up the currents of air and assist in its distribu- tion, and the further fact that the operatives in a large percentage of all factories are on their feet and moving about, are not as susceptible to draughts or air currents as would be the case in a factory where the employes were continually sitting or re- mained inactive. This circumstance renders the location of air outlets and the installation of blower systems a comparatively easy task. The shape and size of the building and the usage to which it is put are factors which largely govern the form of the apparatus and the method of installation. MECHANICAL VENTILATION 255 Relative Cost of Installation and Operation No direct comparison between the cost of installing a fan or blower system and any one of the other methods of heating, viz., FIG. 236. Another form of factory heating. furnaces, steam or hot water, can well be made, as the cost of a blower system increases or decreases according; to the rates of air 256 PRACTICAL HEATING AND VENTILATION change demanded, that is, the number of times per hour, the air within each room shall be changed ; in other words, according to the size of the apparatus and not necessarily according to the size of the building. On the contrary, the cost of a direct or indirect system of heating, steam or hot water, without ventilation, increases in proportion to the size of the building and the added cost for ven- tilation may be much or little, corresponding to the amount of ventilation or air changes secured. It has been suggested that as a people we will not tolerate cold rooms, but that we will tolerate a vitiated atmosphere, to which we would add that such toleration on the part of the owners of many buildings is carried to such an extent that the buildings fre- quently are unsanitary and unhealthy, conditions which are reme- died only when pressure is brought to bear upon the owner. It is probable that the cost of installing an indirect system of heat- ing with " assisted " ventilation is in excess of the cost of the blower system when the volume of air moved is considered. The cost of operation, labor of attention required and expense for fuel for the blower system of heating are not very much in excess of the cost of operating other systems. Our public schools, a class of buildings, many of them quite similar in arrangement and design, the rooms averaging 30' X 36' in size and from 12 to 14 feet high, and provided for the use of from fifty to sixty schol- ars, form a very good basis for comparison as to expense of main- tenance (labor and fuel) for the heating and ventilating appara- tus. Carefully preserved records show some interesting data. The cost for mechanical heating and ventilation for a school building of, say, twenty rooms is less per room than for an eight or ten room school. Where furnaces are used there is very little difference in the cost of labor of attendance, or for fuel per room. The records of one city show a comparison of costs, as fol- lows : For five schools provided with a fan and direct and indirect system the cost per room for attendance averaged $62.00 and for fuel $71.00. For six schools provided with a direct and indirect system (assisted ventilation) the cost per room for attendance averaged $61.00 and for fuel $70.00. For twelve schools with fur- nace heat and ventilation the attendance averaged $52.00 per room and the fuel $72.00. For two schools heated with a direct steam MECHANICAL VENTILATION 257 apparatus (no ventilation) the cost of attendance averaged $58.00 per room and fuel $45.00. Upon comparing the figures we find that the fuel bill for heat without ventilation averaged $45.00, or $27.00 per room less than for furnaces with the amount of ventilation they provided ; $25.00 less than for direct and indirect heating and assisted ventilation and $26.00 less than for the fan system of ventilation with direct and indirect heating. Thus the cost of ventilation approximated $25.00, $26.00 or $27.00 per room for fuel, with attendance cost- ing but a very little more than for direct steam and no ventilation, and there seems to be no question but what those schools equipped with a fan were better ventilated than any of the others. Many other comparisons show the expense for fuel with a me- chanical ventilating apparatus to be less than that incurred with furnaces, while the cost of attendance, due to more skillful labor demanded, was approximately one third greater than for the at- tendance given the furnaces. Another item of interest in the comparison of tests shows that year by year the expense of maintenance for the mechanical sys- tems remained very nearly the same, while the figures furnished for furnaces and other systems vary largely. An average of all records at hand reveals that the actual cost of heating is less for the blower system than for other methods, and that whatever further increase in cost is shown is chargeable to the ventilating portion of the apparatus, this increase being much or little in proportion to the quantity and quality of the air pro- vided for ventilation. Apparatus for Testing Systems of Heating and Ventilation In order to make a test of any mechanical apparatus it is necessary that instruments of absolute and positive accuracy be used in making and recording the test. This is particularly true in testing systems of mechanical heating and ventilation, as re- gards temperature of steam or highly heated air, the velocity and the amount of moisture or humidity in the air under varying conditions. A type of thermometer for conducting a test at high tem- peratures is illustrated by Fig. 237. This consists of a high- 258 PRACTICAL HEATING AND VENTILATION grade thermometer, the tube of which is inclosed in a brass casing. The thread at the bottom is a standard-pipe thread and can be screwed into any ordinary fitting. As shown by the illustration, the bulb extends well down into the opening into which it is FIG. 238. Anemometer. FIG. 237. High-temperature thermometer. screwed in order to insure that the reading on the instrument scale will be accurate. The bulb is protected by a section of thin brass pipe as shown. The movement or velocity of air through ducts or openings may be readily determined by the anemometer, or air meter, as shown by Fig. 238. The indications are obtained by the revo- lution of a series of fans, acting first on a long hand, capable of recording the low velocity of fifty feet per minute on a large dial divided to 100 feet, and then successively by a train of wheels on the indices of five smaller dials, each divided into ten parts, and recording respectively 1,000, 10,000, 100,000 and MECHANICAL VENTILATION 259 10,000,000 feet or 1,894 miles, an amount found to be more than adequate to the most protracted observations. A disconnection is provided on the rim of the instrument, which sets the recording hands in or out of gear without influencing the uniform rotation of the fans. The velocity recorded by the anemometer multiplied FIG. 239. Wet-bulb hygrometer. by the area of the air pipe or orifice through which the air is moving will give the total volume of air passing. An instrument for noting the percentage of saturation of the air (humidity) is called a Hygrometer and is illustrated by Fig. 260 PRACTICAL HEATING AND VENTILATION Various forms of this instrument have been devised; that shown by the illustration is a standard type. The atmosphere surrounding us is seldom dry or completely saturated with moisture and the amount of aqueous vapor held in suspension is very changeable. This fact bears an important part when considering the hygienic qualities of the atmosphere. As we have already noted, a certain amount of moisture in the air is essential to good health and the importance of maintaining the proper proportion of moisture in the atmosphere within our homes and public buildings we have commented upon in a former chapter of this book. Particularly is this true in hospitals or in the sick chamber. In speaking of the humidity in the air we hear much of the " dew point." Dew is formed by the radiation of heat from the surfaces of trees, plants, etc., consequently reducing the tempera- ture of the air near the immediate surfaces of such objects to the point of complete saturation, causing moisture to be deposited. With a complete heating and ventilating apparatus, that is, with an air heating, cleansing and moistening apparatus, any kind of climate may be produced and is registered or recorded by the Hygrometer. The Hygrometer has two thermometers a " dry " thermometer and a " wet " thermometer, as indicated by the illus- tration. These are mounted on the face of the instrument. The bulb of the dry thermometer is exposed to the air; the bulb of the wet thermometer is surrounded by a piece of silk, cotton or wick. As evaporation causes a loss of heat, the thermometer with the wet bulb will read lower than the other, provided there is any degree of dryness in the air. When the air is very dry the difference of register between the two thermometers will be great, the variation lessening according to the degree of moisture in the air, until at complete saturation both will read alike, as then there can be no evaporation. To use the hygrometer the wet bulb and attached wicking should be thoroughly saturated with water. The small reservoir under the wet bulb should be filled with water and the loose end of the wicking should dip into it. As fast as the water evaporates from the wet wicking cover- ing the bulb, it will draw its supply from the reservoir by capil- lary action of the wick and so keep the bulb constantly wet. MECHANICAL VENTILATION 261 Having prepared the hygrometer for work, expose it in the atmosphere to be tested for a period of fifteen or twenty minutes. Then note the readings of both thermometers, the dry and wet bulbs. Ascertain the number of degrees difference by subtraction. In the center of the instrument is a cylinder with a knob at the top for turning by hand, upon which is inscribed a series of col- umns of figures numbered at their headings from 1 to 22. These numbers represent the difference in the readings of the wet bulb and dry bulb thermometers and the columns show the relative humidity or percentage of moisture in the air for every degree of temperature indicated by the thermometers. Having ascer- tained the number of degrees difference in the reading of the thermometers, turn the knob of the cylinder until this number is exposed at the top of the column and opposite the opening in front and in line with the reading of the wet bulb thermometer. On the scale of the cylinder will be found the number representing the percentage of humidity in the atmosphere, absolute saturation being 100. Various forms of siphon gauges for water or mercury are manufactured for indicating vacuum or pressure. These are pro- vided with couplings for attaching to pipe or reservoir, the pres- sure or vacuum being shown by the difference in the level of the liquid in the two arms of the glass siphon. CHAPTER XXII Steam Appliances THE appliances used in connection with a steam boiler for power or heating purposes are many and varied in character. Steam Traps for removing the water of condensation without waste of steam, Separators for removing oil and other impurities from the water within the apparatus, or the water held in sus- pension in saturated steam, Steam Pumps, Inspirators, Injectors, Boiler Feeders and Return Traps for returning the water of condensation or feed water to the boiler against whatever pressure is used, Mechanical Apparatus for automatically controlling the draught, Pump Governors and Feed-water Heaters, etc., all have their separate and several offices to perform. While our work has to do only with boilers as used for heat- ing and ventilation, the same conditions of handling the water of condensation, regulation of pressures and separation of impuri- ties apply as to a boiler used for power purposes. These steam specialties are so numerous and different in char- acter that we can illustrate but few of them, mention the salient features of each and discuss with our readers their work in con- nection with a power or heating apparatus. Steam Traps Steam traps are of two general kinds or classes: Those used to separate the water from and thereby relieve steam pipes or heating surfaces, and those used for returning to the boiler the water of condensation from the steam employed for heating or for mechanical purposes. In the first division there are many kinds : Expansion traps, whose action depends upon the difference in the expansion of two metals, such as the Heintz Trap, Fig. 240 and the Kieley Canti- STEAM APPLIANCES 263 lever Expansion Trap, Fig. 241 : Bucket or " Pot " Traps con- structed with a hollow metal bucket inside the trap, which, when FIG. 240. Heintz trap. FIG. 241. Kieley cantilever expansion trap. filled with the return water, opens a valve, allowing the trap to operate and the bucket to empty. A trap of this character is FIG. 243. Nason bucket trap. FIG. 24-2. Albany bucket trap. shown by Fig. 242, which illustrates the Albany Trap, and Fig. 243 which illustrates a trap of the familiar Xason type. 264 PRACTICAL HEATING AND VENTILATION The Kieley Special Trap, shown by Fig. 244 is not unlike the others in the principle of making use of a metal bucket. It FIG. 244. Kieley special trap. has, however, a special form of valve a balanced or double- seated valve, giving it an extremely large capacity for handling rapid condensation, as in a low-pressure heating apparatus. OUTLET MSB BLOW OFF FIG. 245. Wright emergency trap. The float type of trap has many adherents. The Wright Emergency Trap, as illustrated by Fig. 245, is a particularly STEAM APPLIANCES 265 good representation of this type of trap, the illustration being so clear as to require almost no explanation. The condensation enters the trap through the inlet opening and fills the pot some- what more than half of its height, when the copper float rises, opening the discharge valves (of which there are three) at the top of the trap. Note by the small detail of the valve shown on the left of the illustration that the points of the three valve stems are set at varying heights. The center valve is the one in regular operation. Should a rush of water enter the trap, the float will quickly rise, the arms at the bottom engaging the rods on either side cnnecting with the valve stems, thus allowing the three valves to act in unison while the rush of water continues,. FIG. 246. Standard ball float trap. Another of this type of trap is shown by illustration Fig. 24)6, which is the Standard Ball Float Trap, the operation of which is quite similar to that already described, excepting that it has but one valve. Other traps combining the float principle with the balanced valve, or with the expansion feature are manufactured, as are also others making use of the expansion and contraction of some chemi- cal or sensitive liquid. Those illustrated, however, may be con- sidered as representative types of traps employing the principles described. The open trap discharging into the atmosphere, or against slight pressure was invented by Mr. Joseph Nason, a heating 266 PRACTICAL HEATING AND VENTILATION engineer and contractor of New York, and the original Nason Trap was quite similar to those of the same name in use at the present time. Return Traps The returning of the water of condensation to a boiler on which the pressure is much greater than on the return pipes pre- sents an altogether different problem from that of drawing the water from a system without the loss of steam. To Mr. Jas. H. Blessing, of Albany, is due the credit for the first successful efforts in this direction. Circumstances arising with regard to the heating of the factory of Townsend & Jackson, known as the Townsend Furnace & Machine Works, by whom Mr. Blessing was employed as superintendent, made it necessary to return the water of condensation to the boiler by some other means than gravity. Mr. Blessing tells some interesting facts regarding this. He says: " During the year 1870 the proprietors of the Townsend works deemed it best to remove their establishment down to the river front. As the area of the new works was to be considerably greater than that of the old, it was necessary to make some changes in the heating system. I concluded to. use the exhaust steam for heating the foundry and part of the upper floors, and to heat the offices, machine and pattern shops with direct steam taken from a boiler to be specially installed for that purpose. I intended that the boiler should be set in a pit so that the water of condensation from the heating system of the lower floors would gravitate into it. After having settled on this plan, be- lieving it to be all right, I arranged with a contractor to remove as much as possible of the old heating system and replace it in the new works and to furnish all the extra pipe and fittings neces- sary to complete the system as I had planned it. After arrang- ing with the contractor I paid very little attention to the matter as we had over a hundred men employed in the different shops and my time and attention were fully occupied with the details of the business and the removal of the works. Therefore, I did not discover the gross error I had made until after nearly all the work was done, with the exception of the setting of the boiler. STEAM APPLIANCES 267 You can imagine my position, after explaining to my employers what a simple and effective plan I had devised for the return of the water of condensation back to the boiler, when I learned how impracticable it was to place the boiler low enough to have the water from the lower floors gravitate into it, owing to the fact that each tide caused the level of the water in the river to rise higher than the fire box of the boiler. In order to overcome this condition it would be necessary to set the boiler in a tank anchored to prevent its floating. " This would have been very expensive and, under the circum- stances, impossible. " After having discovered the character of the problem that confronted me, my first thought was to secure a trap that would FIG. 247. Early type of Albany return trap. return the water of condensation to the boiler without the aid of pumps. After making a thorough inquiry, I failed to learn of any such device. " In an effort to solve the problem presented, my mind turned naturally to the thought of returning the water of condensation to the boiler by gravity, and my first experiments were all in that direction. My first return-steam traps, invented during the year 1871, Fig. 247, were placed above the water level in the boiler, the steam being taken from the steam space of the boiler and acting upon the upper side of a diaphragm contained within the 268 PRACTICAL HEATING AND VENTILATION trap and intended for equalizing the pressures. This diaphragm acted simply as a dividing wall between the water on the one side and the steam on the other. The steam used for each discharge of water from the trap was, as in the case of a steam pump, ex- hausted to the atmosphere. Although the diaphragm trap was successful in its operation, yet it failed to return all of the water and did not make up for the error I had made. " In my experiments with the diaphragm trap several inter- esting facts came to light. Among other things, I discovered that the inlet pipe for conveying the water of condensation to the trap receiver from the coils contained steam and water, for, after the first condensation, due to the extra amount of steam condensed when steam was first let into the heating apparatus* was worked off by a few rapid discharges of the trap, it would require several minutes to collect water enough to again fill the trap. While this was filling up one could hear the inlet check valve on the inlet pipe rattling on its seat, caused by the water and steam passing through it. As a result of this observation and the experiments I had been making, it occurred to me that after all the coils and radiators were only a part of the direct steam pipe that conveyed the steam from the boiler through them and finally terminated in the small pipes used for collecting the water of condensation. " If this smaller return pipe were connected, so I reasoned, to the top of a vessel of proper size placed a certain distance above the water level of the boiler, the water and steam would pass over into such receiver, the water falling to the bottom and sepa- rating itself from the steam. The steam pressure in the receiving vessel would be about the same as the pressure in the system at its farthest point from the boiler. If this pressure were near enough to that in the boiler and the receiver were placed at a height sufficient above the water level in the boiler so that the solid water column \vould make up for the difference in the pres- sures, the water would gravitate back into the boiler through a return pipe extending from the bottom of the receiver. With this understanding of the conditions, I prepared a spherical vessel twelve inches in diameter as the receiver to be used in the system with which I was experimenting. I believed that a receiver of STEAM APPLIANCES 269 the size mentioned would be ample for the purpose as the capacity was less than one gallon per minute. The receiver was placed on the floor above the boiler where the coils were situated and about nine feet above the water level in the boiler. After the receiver was connected up and steam turned on and the first water and air removed by blowing to the atmosphere, circulation began and was perfectly maintained. This, I believe, was the first steam loop ever made to return the water of condensation from a steam sys- tem situated below the water level of the boiler whence the water issued in the form of steam, all without in any way opening to the atmosphere. " After the steam loop had been in successful operation for some time in the Townsend & Jackson works I thought I would test it in another place. Accordingly, I selected the plant of Mess. Weed & Parsons, printers, of Albany, where a modern heat- Ing system, using steam direct from the boiler, had just been installed. On investigation, I found a place about ten feet above the water level in the boiler where the receiver could be placed. After getting the system connected up and making several at- tempts to start a circulation, I met only with failure. I next concluded to try the steam pressures and found a difference of about eight pounds between that of the boiler and the coils. This explained to me the reason for the failure to get up a circulation, for it would require for the height of the return column of water about twenty-four feet, or over twice the space available. Owing to the conditions under which the system was installed I could not get a place sufficiently high for the receiver and could not without great expense enlarge the main steam-supply pipe so as to make the pressures more nearly equal. I then made a change by taking the receiver and suspending it on one end of a counter- balanced lever and added a steam valve for admitting steam direct from the boiler into the top of the receiver for the purpose of equalizing the pressure with that in the boiler. This steam valve was caused to open and close automatically by the rising and falling of the receiver. In the form here shown in the cut, Fig. 5248, this trap was known as the Albany Gravity Return-steam Trap." During the period following the introduction of this trap, 270 PRACTICAL HEATING AND VENTILATION improvements were added and the Albany Return Trap as used at the present time has all valves and other mechanism inclosed within the body of the Trap itself. As will be seen by the illus- FIG. 248. Albany gravity return trap. tration, Fig. 249, the bucket of the Trap rests on a hinged pivot at one side of the bucket. As the return water enters the space between the bucket and the outer wall of the Trap, the bucket is FIG. 249. The Albany return trap. tilted slightly, allowing the ball weight " C " to slide to the oppo- site side of the Trap, giving a sudden impetus to the tilting move- ment, which seats the equalizing steam valve and at the same time STEAM APPLIANCES 271 opens the exhaust valve. The bucket is held in this position until the "water flows over the top edge and fills it, when it again tilts downward under the impetus of the preponderance of weight and the movement of the ball weight returning to its original posi- tion. This movement opens the equalizing valve, admitting steam direct from the boiler into the trap, thus equalizing the pressure between the boiler and the trap, whereupon the water in the bucket will feed through the siphon-pipe connection down and into the boiler. As the bucket is again tilted it closes the equal- FIG. 250. Method of connecting Albany return trap. izing valve against the steam pressure, the Trap refilling as before. The Return Trap should be located at least three feet above the water line of the boiler. We illustrate by Fig. 250 the general method of connecting the trap. The condensation collects in the cast-iron pot or re- ceiver. The pressure on this receiver from the heating system raises the water to the trap, which returns it to the boiler. There are several kinds of return traps, the same general principle of equalizing pressures being employed, although the methods of operating the traps differ widely. The Champion and the Pratt & Cady Traps work by balanced weights. The Bundy Return Trap differs from all of the others in that no 272 PRACTICAL HEATING AND VENTILATION movable or balanced weights are used. Fig. 251 shows the form of this trap and the method of making connections. The trap consists of a cast-iron bowl which swings on trunnions, moving in a vertical travel. When the trap is empty the bowl rests against the top of the frame surrounding it, the weight of the ball on the overhanging lever holding it in this position when empty or while filling. When the bowl fills with water to a point where the weight of the water combined with the weight of the FIG. 251. Bundy return trap and method of connecting. bowl overbalances the weight of the ball, the trap drops until it rests on the under side of the frame already alluded to. In making this movement it closes the air valve and opens the equal- izing valve, allowing the steam at boiler pressure to enter the bowl on top of the water, through the curved equalizing pipe shown in the bowl of the trap. Thus the pressures on the trap and the boiler are equalized. The water in the bowl now runs unob- structed out of the opening through which it entered the bowl and drops by gravity through the check valve on the return pipe STEAM APPLIANCES 273 and into the boiler. In returning to its first position the bowl closes the equalizing valve and opens the air valve and is again in readiness to receive the returning condensation. There must always be sufficient pressure on the returns or receiver to lift the water to the trap. Where this pressure (one pound for each two feet of lift) is not available, the duplex system, or use of two traps, is necessary. The office of the lower or secondary trap is to receive the water of condensation from the heating coils, or other source, by gravity and in turn lift or deliver it to the upper trap, which returns it to the boiler. It is claimed for return traps that they will handle water much hotter than a pump and with less loss in heat units. Separators Separators for removing moisture from steam and oil, or other impurities from feed water, are made in various forms. The nature of all of them is to receive the steam through the inlet FIG. 252. Kieley separator. opening of the separator, directing it against a series of baffle plates. This action removes the oil or water and delivers the purified steam without loss of pressure into the supply main of the heating system. The oil or water so extracted drips into the 274 PRACTICAL HEATING AND VENTILATION lower chamber of the separator, from which it is removed through a drip pipe. On an exhaust heating system the separator is in- dispensable. When used to extract oil or other impurities from the exhaust it is placed on the exhaust pipe with the baffle plates facing toward the engine. When employed to remove the moist- ure from steam it is placed on the main steam pipe with the plates facing toward the boiler. Many separators are in satisfactory use. An Austin, Bundy, FIG. 253. Bundy separator. FIG. 254. Bundy separator bailie or separating plate. Kieley, or other make, may be found in the boiler room of nearly every power or heating plant. As representative of the separators having stationary cast- iron bafflle plates in the chamber of the separator, we illustrate the Kieley design, Fig. 252. The Bundy Separator, Fig. 253, is illustrative of the type of separator with removable baffle plates and shows clearly the character of it. A nest of six or more baffle plates, or more prop- STEAM APPLIANCES 275 erly, separating plates, as shown by Fig. 254, are grouped in the upper chamber of the separator. The pillars of these plates are staggered, the steam passing through and around them. Each pillar or column is channeled its entire length, the small openings through the face of each column communicating with the vertical channel through which the water or oil passes by gravity to the receiving chamber below. The plates may be easily removed for cleaning, a very neces- sary factor when the separator is employed to remove oil or other impurities from the exhaust. Feed-water Heaters When the hot water from the condensed steam is used for other purposes and it is necessary to feed the boiler with fresh water, or, again, when the return water, trapped or pumped to the boiler, has lost the bulk of heat units contained in it, a very great saving may be effected by reheating this water before sup- plying it to the boiler. Engineers are agreed that for each 10 degrees this water is heated, a saving of 1 per cent of the fuel is realized. Before the closed type of feed-water heater came into use it was customary to run the water of condensation or the fresh water into an open tank or hot well, heating it by steam coils or by turning the exhaust into it, whence it was pumped into the boiler. Frequentlv the water supplied to the feed-water heater is partially heated by coils in drip tanks, thereby making use of heat units which otherwise might be wasted. Progress along the lines of steam engineering has shown the advisability of saving all heat units possible, being conducive to economy in the con- sumption of fuel. The fact has been demonstrated that the feed- ing of cold water direct to the boiler creates a straining, due to expansion and contraction, which must necessarily shorten the life of the boiler. When the temperature of the feed water is raised from an average of 60 degrees to a temperature of from 200 to 212 de- grees, a saving of about 15 per cent of the fuel is effected. With- out entering; into a discussion of the relative merits of various 276 PRACTICAL HEATING AND VENTILATION types of feed-water heaters we may say that a good heater to adopt is one which is so constructed as to admit of easy cleaning, one whose area for the passage of the exhaust is sufficiently great FIG. 255. Bundy type of feed-water heater. to show no back pressure, and one in which the expansion and contraction of the inner tubes are fully provided for. Fig. 255 illustrates one type of a feed-water heater of this character. Steam Pumps One method of returning water to a boiler is by the use of a boiler feed pump. It is entirely probable that no branch of steam engineering has received more attention than that of pump- ing machinery. Steam pumps are manufactured in a multitude of designs and sizes for regular and special purposes, the evolu- tion of the pump having been carried to such an extent that all liquids, including chemicals, may be pumped from one receptacle and delivered to another under all sorts of conditions. Air or gas may be pumped and where steam power is not available, electrically operated pumps may be employed. Our use of pumps has only to do with pumping the water supply to the boiler or in removing the condensation from a heating system and creating and maintaining a vacuum on the heating system. STEAM APPLIANCES 277 Boiler Feed Pumps For this purpose many standard makes are in evidence, among which may be mentioned the Knowles, Marsh, Blake and Deane Pumps. Fig. 256 illustrates the Knowles Direct-acting Steam Pump. This pump has many features to recommend it, chief of which is the simplicity of its construction. An auxiliary piston working in the steam chest drives the main valve, pre- venting what is known to engineers as a " dead center." The meaning conveyed by this expression is that there is a dead point which would stop and prevent the operation of the pump. FIG. 256. Knowles direct-acting steam pump. This piston driven backward and forward by the steam carries with it the main valve, which in turn supplies the steam to the main piston operating the pump, there being no point in the stroke at which either of the pistons is not open to direct steam pressure. The Marsh Boiler Feed Pump, Fig. 257, is the style used of this particular make for low pressure as with a heating appa- ratus. It is essential that a pump employed for this purpose shall be of sufficient size to allow of slow running. While reducing its pumping capacity this is best for low-pressure work. The motion 278 PRACTICAL HEATING AND VENTILATION FIG. 257. Marsh boiler feed pump. FIG. "258. Blake boiler feed pump. STEAM APPLIANCES 279 is less, requiring increased difference between the steam and water pistons. The Blake Pump used for boiler feed purposes in connection with a heating system is shown by Fig. 258. It has large direct water passages, conducive to the reducing of water friction and its operation is continuous at slow speed. Vacuum Pumps Certain mechanical work such as sugar making, etc., demand a " dry " vacuum pump. For vacuum systems of heating where FIG. 259. Marsh vacuum pump. FIG. 260. Knowles vacuum pump. the water of condensation and the air are handled together, the radiators and piping act as a condensing system. For tlu's 280 PRACTICAL HEATING AND VENTILATION purpose pumps with large cylinders must be employed and the valve areas must be sufficiently large to insure the filling of the pump cylinder. It is customary to pump the water and air to a separating tank from which the water, at a high temperature, is delivered to the boiler, the air being delivered to the atmos- phere. Fig. 259 shows the Marsh type of vacuum pump and Fig. 260 the Knowles Vacuum Pump. Each of these types has a horizontal stroke; other styles have a vertical stroke and one, two or more cylinders. Pump Governors and Regulators To give the best of service steam pumps should be operated automatically. This is accomplished by a pump governor or regulator which controls the steam to the pump, thereby reducing Steam from Boiler FIG. 261. Kieley pump governor. or increasing the speed of the pump, according to the amount of condensation to be handled. On heating systems the establishing of a fixed water line, as may be accomplished with a pump gov- ernor, is a distinct advantage and a material help to the appa- ratus. There are two general types of pump governors, the first operating quite similar to a trap with a bucket or float. The Kieley Pump Governor, Fig. 261, has a ball float inside the cast- iron chamber, which rises and falls according to the amount of water delivered through the return pipe. This float connects with an arm or lever outside the casting, which operates the steam STEAM APPLIANCES 281 supply valve to the pump. The suction pipe to pump is connected at the bottom of the receiving chamber of the pump governor. The Blessing Pump Governor operates the steam valve by the rise and fall of an iron bucket within the receiving chamber of the governor, the general principle employed being quite similar to that already described. Quite different in style and operation are the pump regulators of the Knowles, Blake and Worthington types. These consist of a cast-iron receiver placed just above the pump. The drips or return pipes from the heating apparatus drain by gravity into .Cold Water Connection Discharge FIG. 262. Knowles pump and receiver. these receivers. In the interior of each one is placed a float and balance valve. The return water enters the receiver through an opening in the top and falls to the bottom of the receiver. When it accumulates in sufficient quantity to raise the float, the pump is started, which immediately takes the accumulation from the receiver and delivers it to the boiler. When the float falls again the steam supply to the pump is shut off and the pump ceases to work, the speed of it being regulated entirely by the amount of water entering the receiver. Fig. 262 shows the arrangement of a pump, receiver, and regulator of this character. PRACTICAL HEATING AND VENTILATION Back-Pressure Valves On exhaust-heating work there must be sufficient pressure to circulate the steam to all portions of the heating surfaces. The piping supplying the exhaust mains of the heating system should be plenty large in area in order to avoid an increase of back pres- sure on the engine. As has heretofore been stated, the exhaust from the engine is intermittent, the pressure on the exhaust pipe being greater or less, varying with the stroke of the engine. The heating system, acting as a condensing apparatus, does not al- ways use or condense all of the exhaust steam and there must es- sentially be a relief provided. This is accomplished by placing a special form of valve on the exhaust between the exhaust opening from the engine and the exhaust head, acting as a check on the FIG. 263. Back-pressure valve. steam in its forward motion toward the opening to the atmosphere. At the same time it provides a preventive to the backward motion of the steam. When the excess of pressure occurs the valve opens and relieves the pressure through the exhaust pipe to the atmos- phere. It is virtually an adjustable check valve with a lever and weight attachment for balancing the pressure. The unequal pres- sure from the engine causes a throbbing or vibration, which in many of the back-pressure valves is objectionable, owing to the noise. While there are many excellent makes of back-pressure valves, STEAM APPLIANCES 283 practically the same methods of operation are employed in each and every one, and for this reason we illustrate but the one type as shown by Fig. 263. Pressure-Reducing Valves When live steam is turned into the piping of a heating system it is at a high pressure, the same varying with the initial pressure at the boiler. Such a pressure must be reduced or checked before admission to the heating system. In order to accomplish this many styles of valves are used, which may be set to regulate the pressure to any amount desired. As the regulation is from the low-pressure side of the valve, the reduced pressure remains con- stant, regardless of its fluctuation on the high-pressure side. In heating practice, gate valves are usually placed on the piping on either side of the reducing-pressure valve in order that the steam may be cut off from it to make adjustment or repairs. Injectors An injector is a device used for forcing feed water into a boiler against boiler pressure, that is to say, against whatever pres- sure may be carried on it. There are two distinct types of injec- tors, positive and automatic. The injector performs two offices. It lifts the water from whatever source of supply is provided and it also tempers it and delivers it into the boiler. The positive or double-tube injector has an overflow which closes mechanically and has two sets of jets, one for lifting the water, the other for forcing it into the boiler. The automatic injector has an overflow which opens and closes through the action of the injector itself and, as a usual thing, has but one set of jets. The operation of the injector is such that the steam at boiler pressure is passed into a vacuum through a very small opening. As this jet of steam strikes the water it is quickly condensed, creat- ing a velocity or forward movement of the water. All of the energy of the steam is imparted to the water warming it and forcing it into the boiler. Owing to these features the range of the injector depends upon the temperature of the feed water, it having a greater range, lift 284 PRACTICAL HEATING AND VENTILATION and pressure, with water at a low temperature. The best results are obtained with the feed water at from 60 to 100 degrees Fahr.> FIG. 265. U. S. injector (interior). FIG. 264. U. S. injector. FIG. 266. Method of connecting injector. although the injector will satisfactorily handle water at a tem- perature up to 140 degrees. STEAM APPLIANCES 285 The double-tube injector is a German invention. There are several styles of injectors, one of which we illustrate by Fig. 264, showing an interior view of the same by Fig. 265. In order to show the method of connecting the steam supply, suction pipe and delivery to boiler, we illustrate one method of connection, Fig. 266. When the boiler feed water is supplied from a tank above the boiler, the suction pipe should be connected as shown by dotted lines. Gate or globe valves should be placed on steam supply and suction pipes and a check valve on a hori- zontal portion of the boiler feed pipe. The nearer the boiler and the farther from the injector this check valve is located, the better. A stopcock should be placed on the pipe between this check valve and the boiler. Inspirators This is a type of injector and operates along the same lines as the injector above described. That used for feeding boilers of the stationary type, as used for heating or power, is shown by Fig. 267 and the interior mechanism of it by Fig. 268. The name " inspirator " was given to it by Mr. John Hancock under conditions as follows: " In the year 1868, John Hancock, a civil engineer, began ex- periments having in view the entraining of air and compressing it to a certain extent, to be used as a blast for forges and fur- naces. These experiments led to the exhausting of air by means of a jet apparatus, which is now known commercially as an ejector. He found it possible by this method to create a vacuum to the extent of twenty-five or twenty-six inches mercury column; also that water could be lifted from a depth of twenty-five feet and elevated into a tank. Later he found that he could make a jet apparatus which would, with its own steam pressure, force water into a boiler when the water flowed to it from an overhead tank or under pressure. This type of apparatus is now called a non- lifting injector. He therefore applied these two methods, using the ejector to lift the water from a well and deliver it into a tank located above the injector. The water then flowed to the injector and was forced into the boiler. This combination was placed in successful operation in several instances, 286 PRACTICAL HEATING AND VENTILATION " Following up this idea, Mr. Hancock became convinced that the tank could be eliminated and the ejector or lifting apparatus be attached direct to the injector or forcing apparatus. He ac- complished this arrangement and the two connected were emi- nently satisfactory ; in fact, much more so than the first arrange- 5TEAM FIG. 267. Hancock inspirator. FIG. 268. Interior mechanism of Hancock inspirator. nient, as the ejector varied its quantity of water as the steam pressure varied, which was just what the injector required to ob- tain a good working range. He considered this idea in the nature of an inspiration and thereupon called the apparatus the Han- cock Inspirator." STEAM APPLIANCES 287 Automatic Water Feeders Automatic water feeders, or devices for feeding water to the boiler in order to maintain a certain definite water line in the same, FIG. 269. Automatic water feeder Xason type. are manufactured in a great variety of styles. The action of the valves is controlled by a copper-ball float, the water raising this float until the normal level of the water line has been reached, when the valve to the water supply is closed. The pressure of the water supply must ex- ceed the pressure carried on the boiler. The Nason type of boiler feeder is shown by Fig. 269. The Lawler type of water feeder is shown by Fig. 270. As will be noted by the illustration, this feeder is used in place of the regu- lation water column and is provided with a water gauge. Water feeders are now manufactured which, when used on heating boilers, not only keep the boiler supplied to its normal water line, but also prevent the flooding of the boiler by reason of the sudden return to the boiler of any water of condensa- tion which might have become en- FIG. 270.-Lawler automatic trained in piping or radiators. water feeder. CHAPTER XXIII District Heating THIS type, if it may be so termed, of steam and hot-water heating owes its inception to an eminent engineer, Mr. Birdsall Holly, of Lockport, N. Y., who, in the year 1877, introduced the system of underground steam distribution which bears his name. The original plant, with about one mile of underground mains, was installed at Lockport, N. Y., then a city of about 20,000 inhabitants, and the first buildings connected with and heated by the same were five stores, seven residences and two churches, and the original system, with extensions and improve- ments, is now in operation. Mr. Holly's first idea in the construction of this plant was to make use of live steam, the main object being to relieve the users from the necessity of the care and attention essential where individual heating apparatus was used, and to eliminate the dirt and other unpleasant features unavoidably present in connection with the operation of a heating apparatus. Mr. Holly reasoned that those persons owning and operating such plants would pay well to be freed of such care and attention and the trouble oc- casioned by the purchasing and handling of fuel. In using steam from a district plant there would also be a freedom from the danger of fire consequent to the operation of a heating plant within each separate building. That the inventor reasoned along correct lines is clearly demon- strated by the fact that this original plant has been added to from time to time until some three hundred and fifty consumers are customers of the company operating it, the plant at the present time having in successful operation some six miles of street mains. Many obstacles, which had to be met or eliminated altogether, 288 DISTRICT HEATING 289 were encountered in the operation of such a plant and years of effort and experimenting were required to perfect it. The proper insulation of the pipes to prevent loss of heat by radiation from the street mains and service connections, the con- struction of devices for providing for expansion and contraction, anchorage, etc., together with other features of construction, were tested exhaustively in a practical manner, with the result that the Holly System is to-day free from the defects prevalent in its original form. The fact that steam can be manufactured in an isolated posi- tion, from cheap fuel at small expense and delivered without any considerable loss in temperature through ten miles or more of street mains, and the further circumstance that special devices regulate and register the amount of steam used by each consumer, all these, together with other incident conditions, have made this class of heating a paying investment and at this period there are hundreds of district systems in successful operation. The early methods of district heating were such that the water of condensation was returned to the central station through a system of piping separate from the steam mains. This has now been generally abandoned and the surplus of heat available in the water of condensation is fed through a trap to an economizing coil (made usually of several sections of indirect radiation), where the remaining heat units are extracted and delivered to a room above through a register in the same manner as from an indirect radiator on an ordinary job of heating. The water of condensa- tion is then carried to a special condensation meter, where it is weighed and quantities registered and is finally emptied into the sewer. The system of piping in the building to be heated may be of either the one-pipe or two-pipe style, and, if hot-water heat is em- ployed, a special type of hot-water heater is used, through which the steam passes in much the same manner as through a feed-water heater. In this event steam rather than coal or other fuel, is used to heat the water. Probably the best adaptation of district steam heating is by the method of piping known as the " Atmospheric System." The hot-water type of radiator is used and the steam is supplied to each radiator at the top of one end through a 290 PRACTICAL HEATING AND VENTILATION special form of valve with small ports or openings in the seat. Thus a valve may be opened one, two, three or four ports, supply- ing a greater or lesser amount of heat to a radiator, or such an amount as may be required to maintain a uniform temperature within the room to be heated. This system is operated under a few ounces of pressure above that of the atmosphere and such heat units as are contained in the steam or water are extracted before the water of condensation enters the returns. A finely adjusted regulating pressure valve is used on the supply from the street main and as the condensation is metered and weighed the consumer pays only for such heat as he has used. As stated before, the. first idea of central-station heating was that of the production and sale of live steam. At the present time this class of enterprise has found favor with the management of large electric lighting and railway plants, as it gives an oppor- tunity to increase their revenues by providing a profitable method for disposing of their exhaust steam. There are several systems of central-station steam heating now in use. The different systems vary somewhat in the manner of constructing the piping or underground mains and also in the method of handling the steam supply after it has been introduced to the building to be heated. We would divide the methods of central-station or district steam heating into two classes, the first, where the steam is manufactured only for the purpose of heating; the second, where the steam generated is used for power and the " by-product," if so it may be termed, is used for heating pur- poses. It is the latter method w r hich is more generally used, and a wonderful saving is effected by the company which disposes of their exhaust in this manner. It is customary to divide the boiler power of each station into units of 150 or 200 H. P. each. A one-thousand H. P. plant would have five 200 H. P. boilers, one of them held in reserve, the other four in daily operation. It has been shown that after allowing this one-fifth, or 20^, boiler reserve, a further allowance of 15^ for heating feed water and a 5^ loss for leakage and deterioration from condensation, each of the 1,000 H. P. capacity of the plant can supply 80 sq. ft. of radiation with the necessary units of heat, or 80,000 sq. ft. of ordinary cast-iron radiation. During periods of intense cold DISTRICT HEATING 291 weather the reserve boiler may be employed to prevent overwork on the part of those in regular use. It is worth noting that in many instances the revenue from the steam sold for heating has been sufficient to pay the fuel bill for the entire plant for the full twelve months of the year. Central-Station Hot- Water Heating Heating by hot water supplied from a central station has during the past ten years resulted in the installation of over one hundred plants of this nature. While the process of heating sev- eral buildings from a single plant is not new, it having been more or less used for fifty years or more, the improvements in methods of installation and control have advanced materially during the last decade. The systems of Evans-Almiral Company, H. T. Yar- yan and also Schott's balanced column system have been largely used and to-day there are over one hundred of them in operation. This work includes some features which will prove of interest to the fitter. The matter of estimating the amount of radiation required to heat a building depends upon the system employed and the manner of operating the plant. Some systems deliver water at 140 at freezing and raise or lower the temperature one degree for each degree of variation of the outside temperature. Provided the service or street mains are large and there is a suffi- cient amount of radiation installed, this plan works out nicely. We would prefer seeing the water at 155 or 160 at freezing and then vary the temperature according to the weather. TABLE XXVI Outside Temperature. Water Temperature. 60 120 50 140 40 150 30 160 An estimated loss 20 180 of 3 in tempera- 10 190 ture for each mile Zero 200 delivered. -10 210 -20 220 - 30 230 292 PRACTICAL HEATING AND VENTILATION In estimating radiation one square foot of radiating surface for each square foot of glass surface and its equivalent in exposed wall and cubical contents will, as a rule, prove a sufficient ratio in figuring work. Schott advises a schedule of temperatures, as shown on page 291. As to which system is preferable steam or hot water it would be a hard matter to decide, as each one seems to have par- ticular and individual advantages peculiar to itself and not pos- sessed by the other. CHAPTER XXIV Pipe and Boiler Covering THE insulating of exposed boiler or heater surfaces and pipe for conveying hot air, steam or hot water and the value of so doing are matters which ofttimes do not receive proper attention from the steam fitter or heating contractor. Many steam fitters doing work in a small way, installing but few jobs in the course of a season, look upon the subject of covering as an increased expenditure for material which, added to the cost of the work, is apt to destroy all their chances for securing the contracts for the jobs, and this especially if competition be close. An argu- ment of this kind is wrong in its entirety, and steam fitters gen- erally who are contracting for heating work should understand the benefits accruing from thoroughly covering the boiler and such exposed piping as is not used for radiating surface, and should become so familiar with the subject and so versed in its application that the owner may be enlightened as to the saving effected and thus be made to feel willing to pay whatever sum may be necessary for the work. Just as heat is conveyed by three distinct methods, viz., by radiation, by conduction and by convection, as explained in Chapter II, just so is heat lost or dissipated from the bare sur- faces of boilers, heaters and piping for conveying steam or hot water. What this loss is has been quite accurately determined by various authorities. One authority states that a square foot of uncovered pipe, filled with steam at 100 Ibs. pressure, will radiate and dissipate in a year the heat put into 3,716 pounds of steam by the economic combustion of 398 pounds of coal: thus 10 square feet of bare steam pipe (steam at 100 Ibs. pressure) corresponds approximately to the waste or loss of two tons of coal per annum. 293 294 PRACTICAL HEATING AND VENTILATION Some tests reported in Volume XXIII of the proceedings of the American Society of Mechanical Engineers (tests made in 1901) show that on 100 lineal feet of 2-inch pipe, carrying steam at 80 Ibs. pressure, tests based on 300 working days of 10 hours each, with temperature of room about 65 Fahr., a very ma- terial saving was effected. The following table shows the results of the test : TABLE XXVII Net Tons Name of Pipe Covering. Condensa- tion per Hour Lbs. Net Tons of Coal consumed per Year. of Coal saved per Year by use of Cost of Coal per Net Ton. Net Saving in Cost of Coal per Annum by use of Covering. Approxi- mate Cost of Cover- ings. Covering. Bare Pipe 59.16 7.76 $4.00 $31.04 loss Asbestocel 13.47 1.83 5.93 4.00 23 . 72 saving $16.20 Asbetos Molded 14.35 1.9G 5.80 4.00 23.20 " 15.95 Air Cell 14.60 1.99 5.77 4.00 23 . 08 " 15 90 When we consider that there are about 64 square feet of heat- ing surface in 100 lineal feet of 2" pipe, the annual saving amounts practically to 35 cents per square foot, which will pay the entire cost of the covering, leaving the saving of future years as a clear profit on the investment. While the above tests were made at a comparatively high pressure, with 1 Ib. of coal evaporating about 11 Ibs. of water, the same proportionate showing may be made with steam at one or two Ibs. pressure or on hot-water piping where the temperature of water averages 160 degrees. Stated in a different manner, the saving effected by the use of covering on low-pressure steam or hot-water work averages from 10$ to 30$ of the entire yearly expense for fuel, dependent on the character and quality of the covering used. Asbestos, magnesia, mineral wool, cork, wood and felt paper are the materials principally employed in the manufacture of pipe covering, although for underground piping, ashes, charcoal and sawdust have been used. The thermal conductivity of the material used governs the ef- fective character of a covering applied to prevent loss of heat, the efficiency of asbestos, magnesia, hair felt or cork being greater than all other materials in this respect. PIPE AND BOILER COVERING 295 Asbestos is a fibrous rock, Fig. 271, found in many parts of the world. It lies in thin strata or layers and, when broken, separates in long silky fibers, which may be spun into threads FIG. 271. Asbestos rock. or woven into wicking or sheets. This material is not only fire- proof, but acid-proof as well and serves as an insulation for electric currents. Cork, as used for covering, is ground or granulated and then pressed into the desired shape. In places where the covering is m FIG. 2T-2. Method of fastening sectional pipe covering. affected by dampness or water, cork covering is, no doubt, su- perior to all others on account of its non-absorbent and odorless qualities. Pressed cork, magnesia, asbestos and, in fact, all coverings of 296 PRACTICAL HEATING AND VENTILATION this nature are manufactured in three-foot lengths and split lengthwise for easy adjustment on the piping. The different varieties have an outer covering of muslin or light canvas, glued or pasted on them, to give a finish. Covering is secured to the pipe by japanned tin or brass bands, as shown by Fig. 272. Air when confined within a space to prevent circulation is a non-conductor of heat and provides good insulation. A cover- ing which has met with much favor for low-pressure work and FIG. 273. Asbestos air-cell pipe covering. for hot-water piping is known as the " air-cell " covering. It is made of corrugated asbestos paper of various thicknesses. A cross section of this covering is illustrated by Fig. 273. As a rule, on ordinary heating work, the exposed boiler and heater surfaces and the pipe fittings are covered with a magnesia- asbestos plastic cement, mixed with water to the desired consist- ency and applied with a trowel. However, molded fittings may be obtained for use with all sectional covering. See Fig. 274. These are secured to the fittings by bands of tin or brass, as shown by illustration. For underground piping or for steam pipes run in the open there is probably no better type of covering than the Wyckoff wood covering, as illustrated by Fig. 275. It is constructed of PIPE AND BOILER COVERING 297 eight thoroughly seasoned white pine staves, one inch thick, closely jointed together and wound with heavy galvanized steel wire, as shown by the illustration. It is then wrapped with two FIG. 274. Molded fittings. layers of heavy corrugated paper and again surrounded by a pine wood casing one inch in thickness, jointed and wire wound as before. When used underground, the exterior of the covering is FIG. 275. Wyckoff wood covering. completely coated with asphaltum pitch. A covering of this kind for such service will undoubtedly outlast all others and is thor- oughly effective as an insulator. There are now so many different varieties and grades of cov- erings on the market that it would be next to impossible to illus- 298 PRACTICAL HEATING AND VENTILATION trate and describe them, nor can we discuss the merits of the vari- ous makes. It is sufficient to state that in the same manner as the thickness and texture of clothing retain the heat 'of the human body so does insulation retain the heat within the steam or hot- water heating system, the quality of the covering governing the amount of heat retained and the saving made. CHAPTER XXV Temperature Regulation and Heat Control AUTOMATIC government of pressures and temperatures is one of the most important adjuncts to an artificial heating apparatus. We have shown in Chapter IV by illustration Fig. 35, a simple automatic 'steam damper regulator for regulating steam pres- sures, and by Figs. 36, 37 and 38, the application of it to the draught and check damper doors of a steam boiler. For the draught regulation of a high-pressure boiler, the damper regulator is heavier and more powerful, the rubber dia- phragm larger and the lever longer. A better regulator is one in which a compound lever is employed. A very slight movement of the rubber and the plunger resting against it will give a movement of from four to eight inches at the end of the lever where the chain to draught door is connected. In this style of regulator the rubber diaphragm is less apt to get strained or broken. Probably the best high-pressure damper regulator is one where a piston working in a cylinder is used, the piston being operated by water pressure. The employment of a compound lever on this type of regulator makes it extremely sensitive and will successfully operate the dampers at less than one-pound pres- sure. The Lock and Climax Regulators are of this character, that illustrated by Fig. 276 being the Imperial Climax. The successful and economical working of a steam boiler, either high or low pressure, depends largely upon the methods employed in regulating the pressure by means of the draught and check damper doors. All methods formerly applied depended upon the power furnished by the boiler itself. During the last -twenty years such rapid strides have been made in temperature regulation that we now have regulators for controlling tempera- tures of air, water and steam, as well as other liquids and gases, and it would require a volume to adequately describe, illustrate 300 PRACTICAL HEATING AND VENTILATION and comment upon the various makes of regulators. We shall, therefore, select some regulators and systems representative of the various styles in use, and endeavor to give the reader an idea of the scope and character of this important industry. The automatic temperature regulator consists of three parts : (a) The thermostat, which by reason of the changes in the FIG. 276. Climax high-pressure regulator. temperatures of the room, furnishes the primary motor power for operating the damper-controlling device. (b) The means of transmitting this energy to the damper- controlling mechanism. (c) The damper-controlling mechanism, or device for open- ing or closing the dampers. The thermostat is placed within the room or at a point where the temperature is to be controlled. This is the primary motor TEMPERATURE REGULATION 301 operating the apparatus by means of certain mechanism employed for opening and closing the draught doors, check draught doors or dampers. The Powers Thermostat, Fig. 277, operates on the vapor prin- ciple. This disc is composed of two metal plates spun in cor- FIG. 277. The Powers' thermostat. rugations to give flexibility. Fastened together at the outside edges these plates form a hollow disc. A volatile liquid is placed within the disc. This liquid will boil and vaporize at a tem- perature below that of the water in the apparatus, or at a tem- FJG. "278. Regulator for hot-water heater or furnace. FIG. 279. Regulator for low-pressure steam boiler. perature of 50 degrees Fahr., generating a pressure which ex- pands the disc. At a temperature of 70 degrees a pressure of about six pounds to the square inch is exerted and this amount of pressure is sufficient to operate the valves controlling the com- pressed air. PRACTICAL HEATING AND VENTILATION For the regulation of the ordinary house-heating apparatus, this regulator is made in three styles, the same disc as shown by Fig. 277 furnishing the primary motor power : (a) which controls the temperature of the rooms by operat- ing the draught and check doors of the hot-water heater or hot- air furnace by a diaphragm motor as shown by Fig. 278 ; (b) which controls the draught and check doors of a low- pressure steam heater by a diaphragm motor of double construc- tion, as shown by Fig. 279, which also takes the place of the ordinary pressure diaphragm regulator usually furnished with steam boilers; (c) which regulates the temperature of the room by regu- lating the temperature of the water in a hot-water heater by means of a generator in connection with the diaphragm motor FIG. 280. Hot-water regulator. Fig. 280. This generator is attached directly to the heater and one of the flow pipes from the heater is connected to it. The diaphragm motor consists of two castings, slightly oval, bolted together, with an elastic material between. The reverse action of the plunger is accelerated by a steel spring placed around the plunger under the lever connection. The generator is a hol- low casting having a double shell or wall. The inner chamber is filled with cold water. The hot water passing from the heater into the flow pipe flows through the space between the inner and outer shells of the generator, thus surrounding the chamber into which the cold water has been placed. As the water in this inner chamber is under less pressure than that in the heater, it will TEMPERATURE REGULATION boil quicker, producing a pressure which is exerted against the under side of the diaphragm through a pipe connected directly to it. This pressure is sufficient to operate the dampers of the heater and prevent the boiling of the water in the system. In order to obtain the best results from a regulator of this kind, it is essential that very light or counterbalanced check and FIG. 281. Counterbalanced check door. FIG. 282. Counterbalanced draught door. draught doors be used. Fig. 281 shows a very good style of check damper and Fig. 282 an excellent draught damper. The exertion of a very slight force will open or close either of these doors. The Powers System of controlling the temperature of a large building provides for the control of the valves admitting the FIG. 283. Powers' diaphragm radiator valve. FIG. 284. Thermostat for control- ling radiator valve. steam, or regulating the flow of hot water to the radiators. We know that an occupant of a room, by watching the thermometer and attending constantly to the operation of the radiator valves, 304 PRACTICAL HEATING AND VENTILATION may control the temperature of the room in a very satisfactory manner. The Powers System accomplishes this work automati- cally by means of diaphragm radiator valves, Fig. 283, w r hich are placed on all radiators and operated by compressed air regulated by a thermostat, which is placed in each room and may be adjusted with a key to operate the valves at any temperature from 60 to 80 Fahr. This thermostat is shown by Fig. 284, without the cover. The cover is composed of metal, plated to correspond with the decoration of the room, and has a tested thermometer attached to its face. For controlling the mixing dampers of a blower system of heating, or the by-pass dampers of the air supply, the same type of thermostat as that already described is used, the dampers being operated by a diaphragm motor, Fig. 285. Compressed-air pipes lead from the storage tank to each of the thermostats and from the thermostat to each motor. The variation of temperature at the thermostat causes it to operate FIG. 285. Powers' diaphragm motor. as the primary force for releasing or retaining the air pressure upon the motor. With the air pressure removed the springs of the motor operate the dampers in a motion opposite to that ef- fected by the compressed air. Possibly a clearer conception of this arrangement may be had from Fig. 286, which shows an elevation of a fan apparatus as used in a school building. " A " shows the location of the thermostats in the school rooms ; " B " the motor ; " C " the mixing dampers controlled by them. " D " shows the location of the thermostat for controlling the temperature of the tempered air before admission to the fan ; " E " the motor which operates this damper. TEMPERATURE REGULATION 305 " F " shows the reservoir or storage tank for the compressed air. A pressure of air at fifteen pounds is automatically main- tained in this tank. The air compressor may be operated by steam, electric or hydraulic pressure. 306 PRACTICAL HEATING AND VENTILATION The operation of the National Regulator for the above class of work is quite similar to that already described. For control of a direct-heating apparatus a diaphragm valve is used on the radiators, and for a fan system a diaphragm or damper motor is used and compressed air is employed to operate each -of these. FIG. 287. National regulator thermostat. FIG. 288. National regulator ther- mostat interior mechanism. The thermostat, however, is entirely different from all others, a vulcanized rubber tube being the element made use of in con- trolling the compressed-air force which operates the system. Fig. 287 shows the thermostat and the ornamental thermometer used in connection with it. Contained within the rubber tube are the air valve and the valves for operating the compressed air. Vul- canized rubber is very sensitive to changes of temperature, ex- panding or contracting instantly with the varying temperatures TEMPERATURE REGULATION 307 of the room, and when such expansion or contraction occurs it results in the opening or closing of the compressed air valves. The interior of this thermostat is shown by Fig. 288. Two air pipes are used, one from the air reservoir to the thermostat and the other from the thermostat to the valve or motor. The expansion or lengthening, or the contraction or shorten- ing of the rubber tube A raises or sets the point of the rod K upon the seat M, opening or closing the valves of the air supply. For the regulation of the temperature of water in storage tanks we show the D. & R. (Davis & Roesch) regulator. Fig. FIG. 289. D. & R. tank regulator. 289 shows the application of it to a tank heated by a steam coil. The motor employed is a diaphragm valve, using the rubber dia- phragm against which water or air pressure is exerted to close the valve, a spring on the stem of the under side of the valve holding it open until the pressure upon the diaphragm is suffi- cient to close it. The primary motive power is obtained from a regulator with an expansion post or plug screwed into an 308 PRACTICAL HEATING AND VENTILATION opening of the tank and extending into the same, as shown on the illustration. The mechanism is such that the expansion of the post pushes a spring which opens a valve, allowing the pres- sure of the water supply, or compressed air, to close the diaphragm valve by exerting a pressure upon the diaphragm. When the temperature of the water cools sufficiently to allow the post within the regulator to contract, this pressure is removed, the diaphragm valve opening by the spring, and steam is allowed to enter the heating coil. In a slightly different form this regulator is made to use on tanks supplied directly from a hot-water heater and adapted for FIG. 290. The Howard thermostat. FIG. 291. Motor for Howard thermostat. domestic hot-water supply, pasteurizing or sterilizing, and is also employed for directly controlling the draught and check dampers of a hot-water heater. It is best known as a device to prevent the overheating of water in a storage-tank supply system. Of the regulators operated by expansion we show the Howard and the Minneapolis as representing two distinct types. Each of these regulators makes use of a motor having a strong spring mechanism which furnishes power to operate the dampers. The Howard thermostat is composed of a sensitive plate, tri- TEMPERATURE REGULATION 309 angular in form, as shown by Fig. 290, attached to the side wall of the room. As the temperature rises, the plate curves or warps toward the wall. A wire and chain connection concealed within the partition leads from the top of the plate, over frictionless pulleys, to a weight within the motor box. The relaxing of this wire and chain allows the weight to drop sufficiently to release the motor, which makes one half turn of the crank arbor, when it stops automatically. The crank connecting with chain to the check damper, points down, holding the check damper door open ; the crank connecting with the draught door, points up, slacking the FIG. 292. Method of attaching Howard thermostat. chain connection to the draught door, which closes by its own weight, or, if this be insufficient, by a weight attached to the bot- tom of it. As the temperature of the room cools below the degree of heat desired, this action is reversed, the check door being closed and the draught door opened. This is better illustrated by Fig. 291 which shows the mechanism of the motor, a thermo- static plate being attached to show the operation of the weight due to the curving of the plate. The operation of the motor and the method of attaching the chains to draught and check doors are clearly illustrated by Fig. . The spring of the motor is occasionally wound with a key. 310 PRACTICAL HEATING AND VENTILATION The motor of the Minneapolis regulator and the method of attaching the chain connections to the draught and check doors are quite similar to that already described. Otherwise the regulator consists of a thermostat and two cells of open circuit battery. The thermostat, Fig. 293, is operated by the expansion and con- traction of a curved metal blade, imparting a side motion to a suspended arm, as illustrated by Fig. 294, which shows the ther- mostat with the screen removed. The wires from the battery are connected to the two posts shown just above the indicator of the FIG. 293. Minneapolis thermostat. FIG. 294. Interior of Min- neapolis thermostat. thermostat. Needle-pointed adjustable set screws pass through these posts, the pendant blade hanging between them. As the temperature of the room rises, the side motion of the pendant moves it against the point of one set screw, forming a contact, which closes the electric circuit. As the circuit is closed an electric current flows through the magnets of the motor, releas- ing the brake, and the driving shaft of the motor makes a half revolution. As the temperature of the room lowers, the project- ing arm or pendant is, by contraction of the circular blade, TEMPERATURE REGULATION 311 thrown against the opposite pin, when the operation above de- scribed is reversed. The releasing feature of the motor consists of a pair of magnets, which become energized and attract an armature. The movement of the armature releases the motor, and when it starts, the armature is secured until the driving shaft of the motor makes a half revolution, when it resumes its normal position. Temperature controlling devices of the Howard and Min- neapolis types are best adapted for operating the dampers of the boiler or heater of a low-pressure heating apparatus. The Lawler thermostatic regulator shown by Fig. 295 is of another type. The expansion of the metal used is multiplied by a FIG. 295. The Lawler thermostat. series of levers to a range or force sufficient to operate the dam- pers of a steam or hot-water heating apparatus. It is also used, with a slight variation of the adjustment of the levers, to control the temperature of water in a storage tank for domestic or other use, the mixing of water to a certain temperature for baths, or for the controlling of the air supply of an indirect heating system. The Johnson System is one of the oldest of the systems of automatic control of temperatures. The motive force employed is compressed air, which is supplied by an automatic air com- pressor and stored in a tank. For ordinary service a hydraulic 312 PRACTICAL HEATING AND VENTILATION air compressor, Fig. 296, is used. This is connected to the water supply to the building and to some convenient waste pipe. It is noiseless in operation and automatically keeps up a pressure of FIG. 297. Johnson thermostat. FIG. 298. Mechanism of Johnson thermostat. FIG. 296. Johnson hy- draulic air compressor. from ten to fifteen pounds. Compressors are also furnished which operate by electric power and by steam. A thermostat is placed on the wall of each room in which the heat is to be regulated. The external appearance of this thermo- stat is shown by Fig. 297 ; the interior mechanism is shown by Fig. 298. The strip E is composed of two metals, soldered to- gether. Observe that the top of this strip is fastened to D ; TEMPERATURE REGULATION the bottom, forming a hook, is fastened to the frame of the ther- mostat. A variation of but two degrees in the temperature of a room will cause this little tongue to expand, moving D and operating the valve of the air pipe. Two air pipes are connected to the upper part of the thermostat, one of them being the direct connection from the air main from the storage tank. The other connects the thermostat with the air motor of the valve at the radiator or with the damper to be operated, thus directly oper- ating the valve and limiting the steam supply at each radiator or the flow of hot water to it, if it be a hot-water system, or the air-mixing dampers should it be a blower system. In order that the operation of the diaphragm valve may be clearly understood we show by Fig. 299 a sectional view of E FIG. 300. Exterior of dia- phragm radiator valve. FIG. 299. Interior of diaphragm radiator valve. it. D and E show the openings for supply pipe and radi- ator connections. C is the seat of the valve and B the disc. Up to this point the body of the valve is built the same as an ordinary radiator valve. The frame supporting the dia- phragm is adjusted to the valve immediately below the stuff- ing box. A spring is slipped on the valve spindle and an oval shell, with air opening A, is fastened to the saddle or frame. 314 PRACTICAL HEATING AND VENTILATION To the under side of this shell is placed a rubber diaphragm. Note that in place of the valve wheel on the top of the valve spindle is a curved top fitting against the rubber diaphragm. The spring G keeps the valve open until the temperature of the room is sufficiently high for the thermostat to open the air valve and admit the compressed air to the chamber F, which presses down on the diaphragm, closing the valve and holding it in this position as long as the temperature of the room is above FIG. 301. Double damper for round flue. FIG. 302. Double damper for square flue. the point desired. When the temperature cools to such a degree as to cause the thermostat to act, the air pressure is removed and the spring G opens the valve. Fig. 300 shows an exterior view of the valve. The action of the thermostat is positive and quick in moving the valves. When impelling the dampers of a fan or hot-air system, that is, the air supply, another form of the thermostat is used, which operates gradually. This is also employed on a hot-water heating apparatus. TEMPERATURE REGULATION 315 Special forms of thermostats for air ducts, hot-water tank supply, etc., etc., are applied in connection with the Johnson pneu- matic system, and a system for handling the valves of a vapor system of heating is one of their achievements of later date. When handling air or controlling the temperature in the air ducts of a " hot and cold " or fan system the air motor is attached to the dampers as shown by Fig. 301, which shows a double dam- per for a round flue, or by Fig. 302, which shows a double square damper. The value of a successful system of heat control is not meas- ured entirely by the saving in fuel, which is variously estimated from 20^ to 35^; the fact of having an apparatus which without any thought or action from the occupants of a room or building, will automatically maintain the temperature at any desired degree, is something on which a value cannot very readily be placed. In schools, the teachers are relieved from the time lost and attention given the heating apparatus, in hospitals the value of an even temperature cannot be calculated, while for our homes, churches and offices the results from temperature regulation cannot be measured. CHAPTER XXVI Business Methods THERE are certain business methods in connection with the estimating on, the contracting for and the installing of an appa- ratus for heating and ventilation, which should be adopted by those already engaged in or about to enter into the business of contracting for work of this character. Quite frequently the owner of a building will let his heating work to the contractor whose bid for the job may not be the lowest, but who has de- scribed his proposition and appliances in a clear and concise manner, who has submitted a bid or proposal itemizing and enu- merating the various portions of the apparatus and the com- mendatory features of whose proposition are reinforced by a care- fully worded guaranty, covering the character of materials and class of workmanship to be furnished on the work. Such a business method cannot fail to be compared with that of the contractor who, in submitting his figure, simply notes a few words upon a letterhead bearing his business title. The owner is justified in expecting a higher class of work from that heating man who approaches him in a business way and with business methods, and undoubtedly is willing to pay more for it. Estimating In this, as in nearly every other business, competition is apt to be close and consequently the estimate covering any heating work should be carefully prepared, diligence and caution being exercised that no important items are omitted. For this purpose an estimate book or a carefully arranged sheet should be em- ployed. Various large jobs require special items. The ordinary job of steam or hot-water heating may be thoroughly covered by the sample estimate sheet shown on the following pages. The 316 DIM KXSIONS AND DATA iJ.ll 1 ft i h i S J i : ' i j i Jl j ~A C '7. ' ~ -S: ! "~^ ; II Ih 1" 1 -J 1 . ~ g2 i Steam. Jl. W. Total heater capacity required 970 1 ,075 Heater No. 20 Success. r .. ( Steam, 1,000'. Capacity j JIot Wa ^ ^^ 2oo= o =====0 o==o * 5 1 = I i I HADIATOU8. 8TIOAM. qSijj fe ^ % 5; % % ft % % % fe fe * 5: j. - !kx^ * ^fetX2& ^"t% z> i ^oaaipuj i : ?, . . . . '-' ^ . ... i -i }D8Jl(J }j bg cc i O -^ U5 *--; 3 15 15 S ^ S K 1 * i{3ijj ? 22SS2U S x x | A g r Steam. H. W. 1 )iivct Uadiation 595 940 Indirect limitation 120 200 Add 50 JUT cent of Indirect for Boiler capacity . CO 100 Add radiation in Mains and Risers 195 435 jowipu! ; ; ; ; i nTTTTf ! 1 ! i|8 -E3g O -: '0 ; C -; '-1 ^ t-1 t-^ O O O x s: x ?: i> x rs t- M -: c s < ^ jj a-itmbg SS3i ? S^^I?^t32 ^S^S jj ainnbg oooo o r:c:o;s;**o? oot'- aoBjjng \[e& 5>5>4*4- c^ ^^-4>5<^ oJSrZ c"" 1 iSii 3 S335S3S S^ii _^^^ ^^^^^ ^ _ i ? -^oo X X X X *n -1X^O tO 5 5 5*5 -* S> O tt -f" X apLVi 1' -^ O' ^ * G> O 5> O> ^> X X O ^ O ^ i j : _"^ : o .'s* J^ : : : '^ 5"s t : 1 : s s ^ N - a ^"^ : c -I "= * "i - 317 B :88 : :8 "2 8 21 I s ifiil^jIJi*!^ " IK*B8.I *.*-' 5 . in *?, : -5 : : Jill,,, Si- 12 lill : : : 8 i-ii-iO : : :| i i i(S |. l u$ X * g^v^ 1 rSP NF 92 * fMSWXIk % "^"^i N fcU r c I I ^) CO I-H fi 318 BUSINESS METHODS detail represents an estimate for both steam and hot water for A brick three-story dwelling. The rule " 2 20 200 is used in estimating the amcmnt of radiation required; the prices inserted are fictitious, being given for the sole purpose of instructing our readers in the right course to pursue in correctly Ming out the blanks on estimate sheet. Haying estimated carefully the requirements of the work, size of heater, square feet of radiation, etc,, etc,, and checked over the cost figures to insure accuracy, the next step is to prepare A proposal and bid to submit to the owner. Proposal and Bid Printed forms arranged with spaces left blank for filling in with a pen may be procured for this purpose. It is our belief, however, that a typewritten form of proposal and bid is better suited to the purpose, as the printed forms must necessarily con- tain much matter which has to be crossed off or eliminated to cover certain work, but which, if excluded from the printed form, would for certain other work have to be inserted with a pen. We submit the following form of proposal as covering such detail as is necessary, and the bid attach**! becomes A legal contract after the signatures of both the contractor and the owner are add**! to it. The usual practice is to make two copies, the contractor signing both of them before submitting to the owner, who, if he accept* the proposition submitted, signs the acceptance clause and returns one copy to the heating contractor, As no one style of proposal can cover both steam and hot water work, we give separate forms for each. Where the dotted horizontal line ", " occurs it denotes space in which the name of the boiler, radiator or other goods to be used, should be inserted. nd Bid to Steam- Heating Apparatus General. These specifications are intended to cover a com- plete low-pressure stem-heating apparatus and it is understood that the ome will be placed exactly as specified, 1, KOOC5O5-'5C5OMi i < i *f i-i 5 ^f< 4 O9 ft & ^ 99 O# Oft ^ 0* 9 O9 60 ^ Q 09 IM mra 55 uira 55 mra ; 55 jj* i^ji^|| || * p|S|||iii|^i4i55i4||^5 s - ^fflMuduOQO^Jh2^S^Sc2c2^^aQ^SaHu 356 RULES, TABLES, AND OTHER INFORMATION 357 TABLE XXXV COMPARISON OF THERMOMETRIC SCALES Fahr- enheit. Centi- grade. Reaumur. Fahr- enheit. Centi- grade. Reaumur. - 40 - 40.00 - 32.00 + 125 + 51.67 + 41.33 " 35 " 37.22 " 29.78 "130 " 54.44 " 43.56 " 30 " 34.44 " 27.56 "135 " 57.22 " 45.78 " 25 " 31.67 " 25.33 "140 " 60.00 " 48.00 " 20 " 28.89 " 23.11 "145 " 62.78 " 50.22 " 15 " 26.11 " 20.89 "150 " 65.55 " 52.44 " 10 " 23.33 " 18.67 "155 " 68.33 " 54.67 5 " 20.55 " 16.44 "160 " 71.11 " 56.89 " 17.78 " 14.22 "165 " 73.89 " 59.11 + 5 " 15.00 " 12.00 "170 " 76.67 " 61.33 " 10 " 12.22 " 9.78 " 175 " 79.44 " 63.56 " 15 " 9.44 " 7.56 "180 " 82.22 " 65.78 " 20 " 6.67 " 5.33 "185 " 85.00 " 68.00 " 25 " 3.89 " 3.11 "190 " 87.78 " 70.22 " 30 " 1.11 " 0.89 "195 " 90.55 " 72.44 " 32 0.0 0.00 "200 " 93.33 " 74.67 " 35 + 1.67 + 1.33 "205 " 96.11 " 76.89 " 40 " 4.44 " 3.56 "210 " 98.89 " 79.11 " 45 " 7.22 " 5.78 "212 "100.00 " 80.00 " 50 " 10.00 " 8.00 "250 "121.10 " 96.90 " 55 " 12.78 " 10.22 "300 "148.89 "119.20 " 60 " 15.55 " 12.44 "302 "150.00 "120.00 " 65 " 18.33 " 14.67 "350 "176.66 "141.40 " 70 " 21.11 " 16.89 "392 "200.00 "160.00 " 75 " 23.89 " 19.11 "464 "240.00 "192.00 " 80 " 26.67 " 21.33 "500 "260.00 "208.00 " 85 " 29 . 44 " 23.56 "572 "300.00 "240.00 " 90 " 32.22 " 25.78 "600 "315.06 "252.40 " 95 " 35.00 " 28.00 "662 "350.00 "280.00 " 100 " 37.78 " 30.22 "700 "371.11 "296.90 "105 " 40.55 " 32.44 "752 "400.00 "320.00 "110 " 43.33 " 34.67 "800 "426.66 "341.30 " 115 " 46.11 " 36.89 "932 "500.00 "400.00 (f 120 " 48.89 " 39.11 358 PRACTICAL HEATING AND VENTILATION TABLE XXXVI TABLE OF THE AREAS OF CIRCLES AND OF THE SIDES OF SQUARES OF THE SAME AREA Diam- eter of Circle in inches. Area of Circle in square inches. Sides of Sq. of same area in square inches. Diam- eter of Circle in inches. Area of Circle in square inches. Sides of Sq. of same area in square inches. Diam- eter of Circle in inches. Area of Circle in square inches. Sides of Sq. of same area in square inches. 1 .785 .89 21 346.36 | 18.61 41 1,320.26 36.34 y* 1.767 1.33 y 2 363.05 19.05 H 1,352.66 36.78 2 3.142 1.77 22 380.13 19.50 42 1,385.45 37.22 M 4.909 2.22 y 2 397.61 19.94 H 1,418.63 37.66 3 7.069 2.66 23 415.48 20.38 43 1,452.20 38.11 y 2 9.621 3.10 H 433.74 20.83 1 A 1,486 . 17 38.55 4 12.566 3.54 24 452.39 21.27 44 1,520.53 38.99 y 2 15.904 3.99 y 2 471.44 21.71 1 A 1,555.29 39.44 5 19.635 4.43 25 490.88 22.16 45 1,590.43 39.88 y 2 23.758 4.87 y 2 510.71 22.60 H 1,625.97 40.32 6 28.274 5.32 26 530.93 23.04 46 1,661.91 40.77 l /2 33.183 5.76 H 551.55 23.49 y 2 1,698.23 41.21 7 38.485 6.20 27 572.56 23.93 47 1,734.95 41.65 y 2 44.179 6.65 y 2 593.96 24.37 y 2 1,772.06 42.10 8 50.266 7.09 28 615.75 24.81 48 1,809.56 42.58 y 2 56.745 7.53 H 637.94 25.26 H 1,847.46 42.98 9 63.617 7.98 29 660.52 25.70 49 1,885.75 43.43 H 70.882 8.42 H 683.49 26.14 y 2 1,924.43 43.87 10 78.540 8.86 30 706.86 26.59 50 1,963.50 44.31 H 86.590 9.30 y 2 730.62 27.03 y 2 2,002.97 44.75 11 95.03 9.75 31 754.77 27.47 51 2,042.83 45.20 H 103.87 10.19 y 2 779.31 27.92 y 2 2,083.08 45.64 12 113.10 10.63 32 804.25 28.36 52 2,123.72 46.08 H 122.72 11.08 y 2 829.58 28.80 y 2 2,164.76 46.53 13 132.73 11.52 33 855.30 29.25 53 2,206.19 46.97 y 2 143.14 11.96 y 2 881.41 29.69 y 2 2,248.01 47.41 14 153.94 12.41 34 907.92 30.13 54 2,290.23 47.86 y 2 165.13 12.85 y 2 934.82 30.57 y 2 2,332.83 48.30 15 176.72 13.29 35 962.11 31.02 55 2,375.83 48.74 y 2 188.69 13.74 1 A 989.80 31.46 y 2 2,419.23 49.19 16 201.06 14.18 36 1,017.88 31.90 56 2,463.01 49.63 H 213.83 14.62 1 A 1,046.35 32.35 y 2 2,507.19 50.07 17 226.98 15.07 37 1,075.21 32.79 57 2,551.76 50.51 H 240.53 15.51 y 2 1,104.47 33.23 y 2 2,596.73 50.96 18 254.47 15.95 38 1,134.12 33.68 58 2,642.09 51.40 y 2 268.80 16.40 y 2 1,164.16 34.12 y 2 2,687.84 51.84 19 283.53 16.84 39 1,194.59 34.56 59 2,733.98 52.29 H 298.65 17.28 y 2 1,225.42 35.01 y 2 2,780.51 52.73 20 314.16 17.72 40 1,256.64 35.45 60 2,827.74 53.17 H 330.06 18.17 H 1,288.25 35.89 y 2 2,874.76 53.62 RULES, TABLES, AND OTHER INFORMATION 359 TABLE XXXVH TEMPERATURE OF STEAM AT VARIOUS PRESSURES ABOVE THAT OF THE ATMOSPHERE (14.7 LBS.) Pounds Pressure. Degrees Fahrenheit. Pounds Pressure. Degrees Fahrenheit. Pounds Pressure. Degrees Fahrenheit. 212 18 254.5 100 337.5 1 215.5 19 256 105 341 2 219 20 257.5 115 347 3 222 25 265 125 353 4 225 30 272.5 135 358 5 227.5 35 279.5 145 363 6 230 40 285.5 155 ' 368 7 232.5 45 291 165 373 8 235 50 297 175 377 9 237.5 55 302 185 381 10 240 60 307 235 401 11 242 65 311 285 417 12 244 70 315 335 430 13 246 75 320 385 445 14 248 80 323 435 456 15 250 85 327 485 467 16 252 90 331 585 487 17 253.5 95 334 685 504 TABLE XXXVIII PROPERTIES OF SATURATED STEAM Pres- sure. Abso- lute Pres- sure. Tem- perature Fahren- heit. Total Heat above 32 degrees. Latent Heat. Relative Volume 39 =1. Volume C. F. in 1 Ib. Steam. Weight 1 cubic foot Steam. Lbs. Heat Units in the Water. Heat Units in the Steam. 0.0 14.7 212.0 180.9 1,146.6 965.7 1,646.0 26.36 .03794 1.3 16.0 216.3 185.3 ,147.9 962 . 7 1,519.0 24.33 .04110 2.3 17.0 219.4 188.4 ,148.9 960.5 1,434.0 22.98 .04352 3.3 18.0 222.4 191.4 ,149.8 958.3 1,359.0 21.78 .04592 4.3 19.0 225.2 194.3 ,150.6 956.3 1,292.0 20.70 .04831 5.3 20.0 227.9 197.0 ,151.5 954.4 1,231.0 19.72 .05070 10.3 25.0 240.0 209.3 ,155.1 945.8 998.4 15.99 .06253 15.3 30.0 250.2 219.7 ,158.3 938.9 841.3 13.48 .07420 20.3 35.0 259.2 228.8 ,161.0 932.2 727.9 11.66 .08576 25.3 40.0 267.1 236.9 ,163.4 926.5 642.0 10.28 .09721 30.3 45.0 274.3 244.3 1,165.6 921.3 574.7 9.21 .1086 40.3 55.0 286.9 257.2 1,169.4 912.3 475.9 7.63 .1311 50.3 65.0 297.8 268.3 1,172.8 904.5 406.6 6.53 .1533 60.3 75.0 307.4 278.2 1,175.7 897.5 355.5 5.71 .1753 70.3 85.0 316.0 287.0 1,178.3 891.3 315.9 5.07 .1971 80.3 95.0 323.9 295.1 1,180.7 885.6 284.5 4.57 .2188 90.3 105.0 331.1 302.6 1,182.9 880.3 258.9 i 4.16 .2403 100.3 115.0 337.8 309.5 1,185.0 875 .5 237.6 3.82 .2617 125.3 140.0 352.8 325.0 1,189.5 864.6 197.3 3.18 .3147 150.3 165.0 365.7 338.4 1,193.5 855.1 169.0 2.72 .3671 200.3 215.0 387.7 361.3 1,200.2 838.9 131.5 2.12 .4707 360 PRACTICAL HEATING AND VENTILATION TABLE XXXIX MATERIALS FOR BRICKWORK OF TUBULAR BOILERS Boilers. Common Brick. Fire Brick. Sand, Bushels. Cement, Barrels. Fire Clay, Pounds. Lime, Barrels. Single Setting 30in.x 8ft. 5,200 320 42 5 192 2 30 in. x 10 ft. 5,800 320 46 5 1 A 192 2% 36in.x 8ft. 6,200 480 50 6 288 *% 36in.x 9ft. 6,600 480 53 6 1 A 288 2% 36 in. x 10 ft. 7,000 480 56 7 288 3 36 in. x 12 ft. 7,800 480 62 8 288 3% 42 in. x 10 ft. 10,000 720 80 10 432 4 42 in. x 12 ft. 10,800 720 86 11 432 414 42 in. x 14 ft. 11,600 720 92 11% 432 4^2 42 in. x 16 ft. 12,400 720 99 12^ 432 5 48 in. x 10 ft. 12,500 980 100 1H 590 SH 48 in. x 12 ft. 13,200 980 108 1SH 590 5 1 A 48 in. x 14 ft. 14,200 980 116 14^ 590 5% 48 in. x 16 ft. 15,200 980 124 15H 590 6 54 in. x 12 ft. 13,800 1,150 108 13% 690 5 1 A 54 in. x 14 ft. 14,900 ,150 117 15 690 6 54 in. x 16 ft. 16,000 ,150 126 16 690 6% 60 in. xlOft. 13,500 ,280 108 1SH 768 &A 60 in. x 12 ft. 14,800 ,280 118 14% 768 6 60 in. x 14 ft. 16,100 ,280 128 16 768 &A 60 in. x 16 ft. 17,400 ,280 140 17H 768 60 in. x 18 ft. 66 in. x 16 ft. 18,700 19,700 ,280 ,400 148 157 18% 19% 768 840 VA 8 66 in. x 18 ft. 21,000 ,400 168 21 840 8^ 72 in. x 16 ft. 20,800 ,550 166 20% 930 8^ 72 in. x 18 ft. 22,000 ,550 175 22 930 9 Two Boilers in a Battery 30 in. x 8ft. 8,900 640 70 9 384 3^ 30 in. x 10ft. 9,600 640 76 9^ 384 4 36in.x 8ft. 10,500 960 84 wy 2 576 4% 36in.x 9ft. 11,100 960 88 11 576 4^ 36 in. x 10 ft. 11,800 960 95 12 576 4% 36 in. x 12 ft. 13,000 960 104 13 576 5% 42 in. x 10 ft. 17,500 1,440 140 17H 864 7 42 in. x 12 ft. 18,600 1,440 148 isy 2 864 7^ 42 in. x 14 ft. 19,900 1,440 159 20 864 8 42 in. x 16 ft. 21,200 1,440 168 21 864 8^ 48 in. x 10 ft. 21,400 1,960 170 21H 1,180 8% 48 in. x 12 ft. 22,300 1,960 178 22% 1,180 9 48 in. x 14 ft. 23,900 1,960 190 24 1,180 VA 48 in. x 16 ft. 25,100 1,960 200 25 1,180 10 54 in. x 12 ft. 23,300 2,300 186 23% 1,380 9% 54 in. x 14 ft. 24,800 2,300 198 25 1,380 10 54 in. x 16 ft. 26,300 2,300 210 26% 1,380 10^ 60 in. x 10 ft. 22,600 2,560 180 22V 1,536 9 " 60 in. x 12 ft. 24,800 2,560 198 25 1,536 10 60 in. x 14 ft. 26,800 2,560 214 27 1,536 10% 60 in. x 16 ft. 28,900 2,560 230 29 ,536 11} 2 60 in. x 18 ft. 31,000 2,560 248 31 ,536 12^ 66 in. x 16 ft. 33,100 2,800 264 33 ,680 13% 66 in. x 18 ft. 36,500 2,800 276 35 ,680 14 72 in. x 16 ft. 34,000 3,100 272 34 ,860 13% 72 in. x 18 ft. 38,000 3,100 282 36 1,860 15 RULES, TABLES, AND OTHER INFORMATION 361 TABLE XL STANDARD PIPE Extra Strong Actual Nominal Nominal Size, Inches. Price per Foot. Outside Diameter, Inside Diameter, Thickness, Inches. Weight, per Foot, Inches. Inches. Pounds. X .11 .405 .205 .100 .29 M .11 .540 .294 .123 .54 ^ .11 .675 .421 .127 .74 1^ .12 .840 .542 .149 1.09 M .15 1.05 .736 .157 1.39 i .22 1.315 .951 .182 2.17 i^ .30 1.66 1.272 .194 3.00 ij/o .36 1.900 1.494 .203 3.63 2 " .50 2.375 1.933 .221 5.02 2V4 .81 2.875 2.315 .280 7.67 3 1.05 3.500 2.892 .304 10.25 3V 1.33 4.000 3.358 .321 12.47 4' 1.50 4.500 3.818 .341 14.97 4^ 1.95 5.000 4.280 .360 18.22 5 2.16 5.563 4.813 .375 20.54 6 2.90 6.625 5 750 .437 28.58 7 3.80 7.625 6.625 .500 37.67 8 4.30 8.625 7.625 .500 43.00 Double Extra Strong Actual Nominal Nominal Size, Price Outside Inside Thickness, Weight Inches. per Foot. Diameter, Diameter, Inches. per Foot, Inches. Inches. Pounds. M .25 .84 .244 .298 1.70 M .30 1.05 .422 .314 2.44 1 .37 1.315 .587 .364 3:65 IK .52 1.66 .885 .388 5.20 1M .65 1.90 1.088 .406 6.40 2 95 2.375 1.491 .442 9.02 2^o 1.37 2.875 1.755 .560 13.68 3 1.92 3.50 2.284 .608 18.56 33^> 2.45 4.00 2.716 .642 22.75 4 " 2.85 4.50 3.136 .682 27.48 4/"2 3.30 5.00 3.564 .718 32.53 5 ~ 3.80 5.563 4.063 .750 38.12 6 5.30 6.625 4.875 .875 53.11 7 6.25 7.625 5.875 .875 62.38 8 7.20 8.625 6.875 .875 71.62 O O1> OOOOOOOO OOOOOO^O OTOO<3^l>^-OOO r-T r-T of Of CS 1 i $ i s 8 i 8 i ; 8 8 8 ^ ^ _ r-T rn" r-T i-T of of of 8a JO 8 - i i i i O l~ 0*3 1> C5 O O i-ri-ri-ri-Tofofofof PH W ' XXOO- i O t t MS >- rJ " 4" rH~ Qf Of Of Of CO Q^ GC Oi G3 CO QC Ct ^ ^r ,_r _r _r of of of O MS * O 1-1 OJ C5 t> X O r-i r-T rS Of Of .... rH r-l rH rH rH ri O* *a . -OtMO-ii iOMOOtiS-5 PH XOC^COC5C^ OOO*"*XO^ ^j i i r-i i ii "OtM^MSOt-XC 55 nu^i-iaoflOO>atoQoerHOtt ^0<^Oi>OO^^Xr-.C5trl>l> P K 363 PRACTICAL HEATING AND VENTILATION TABLE XLIII RELATION BETWEEN TEMPERATURE OF FEED WATER AND EVAPORATIVE CAPACITY OF BOILER Temperature of Feed Water, Degrees Fahr. Steam Pressure, Pounds. Feed Water per Horse Power per Hour, Pounds. Gallons per Minute per 100 Horse Power. 100 70 *30.00 6. 02+ 10 per cent. = 6.62 70 100 29.04 5.79+10 ' =6.36 100 100 29.82 5.98+10 ' =6.57 150 100 31.22 6.34+10 ' =6.97 180 100 32.14 6.61+10 ' = 7.27 200 100 32.77 6.65+10 = 7.31 212 100 33.17 6.94+10 " = 7.63 * This is the standard adopted by the American Society of Mechanical Engineers, and is the generally accepted commercial standard by boiler makers and users. The evaporative capacity of a boiler depends, among other things, upon the steam pressure and temperature of the feed water. The pressure makes so little difference that it has been estimated for 100 pounds as practically correct for all pressures. The difference between making steam at atmospheric pressure and 100 pounds pressure is only Sy 2 per cent. Changing the tem- perature of the feed water from 100 degrees to 212 degrees will vary the evaporative capacity of a boiler over 11 per cent. TABLE XLIV QUANTITY OF FEED WATER REQUIRED TO SUPPLY BOILER Horse Power of Boiler. Quantity of Feed Water Required. Temperature of Feed Water. Degrees Fahr. Gallons per Minute. Pounds per Hour. 50 3. 60 to 4.20 1,599 to 2,029 100 to 212 100 6. 57 to 7.63 3,285 to 3,815 100 to 212 200 13. 14 to 15.26 6,590 to 7,630 100 to 212 250 16. 43 to 19.07 8,215 to 9,535 100 to 212 300 19 . 71 to 22 . 89 9,855 to 11,445 100 to 212 400 26. 28 to 30.52 13,140 to 15,260 100 to 212 500 32. 85 to 38.15 16,425 to 19,075 100 to 212 600 39. 42 to 45.78 19,710 to 22,890 100 to 212 800 52. 26 to 61.04 26,280 to 30,520 100 to 212 1,000 65. 70 to 76.30 32,350 to 38,150 100 to 212 1,200 78. 84 to 91.56 39,420 to 45,780 100 to 212 1,500 98.55 to 114.45 49,275 to 57,225 100 to 212 1,800 118.26 to 137.34 59,130 to 68,670 100 to 212 2,200 144. 50 to 167.80 71,290 to 83,930 100 to 212 3,000 197.10 to 228.90 98,500 to 114,500 100 to 21 2 3,500 229.95 to 267. 05 114,975 to 133,525 100 to 212 4,500 295.65 to 343. 35 147,825 to 171,675 100 to 212 6,000 394. 20 to 457. 80 197,100 to 228,900 100 to 212 7,000 459 . 90 to 534 . 10 229,950 to 267,050 100 to 212 RULES, TABLES, AND OTHER INFORMATION 365 TABLE XLV VACUUM, PRESSURE AND TEMPERATURE, ETC. Vacuum measured in inches of Mercury. Absolute pressure in inches of Mercury. Absolute pressure in Ibs. per square inch. Temperature of boiling point. Fahr. Latent heat of evaporation in B. T. U. Sensible heat of Evaporation. 29^2 Y2 .245 59.1 1072.8 27.1 29 1 .490 79.3 1058.8 47.3 28^ iy 2 .735 92.0 1049.9 60.1 28 2 .980 101.4 1044.4 69.5 27 3 1.470 115.3 1033.7 83.4 26 4 1.960 125.6 1026.5 93.8 25 5 2.450 134.0 1020.6 102.2 24 6 2.940 141.0 1015.7 109.3 23 7 3.430 147.0 1011.5 115.3 22 8 3.9-20 152.3 1007.8 120.5 21 9 4.410 157.0 1004.5 125.4 20 10 4.900 161.5 1001.3 129 . 9 19 11 5.390 165.6 998.4 134.1 18 12 5.880 169.2 995.9 137.7 17 13 6.370 172.8 993.4 140.3 16 14 6.860 176.0 991.1 144.5 15 15 7.350 179.1 988.8 147.7 14 16 7.840 182.0 986.9 150.6 12 17 8.820 187.4 983.1 156.0 10 20 9.800 192.3 979.6 161.0 5 25 12.25 203.0 972.1 171.8 30 14.70 212.0 965.7 180.9 366 PRACTICAL HEATING AND VENTILATION TABLE XLVI PUMP DIAMETERS AND CAPACITIES IN GALLONS Diameter. Area Inches. Displacement in Gals, per Ft. of Travel. Diameter. Area Inches. Displacement in Gals, per Ft. of Travel. M .0129 .0006 8 50.26 2.548 % .0490 .0025 8% 53.45 2,. 7739 8 .1104 .0056 A 56.74 2.944 1^3 .1963 .0101 8% 60.13 3.0105 ^ .3068 .0135 9 63.61 3.2505 % .4417 .0228 9/4 67.20 3.407 % .6018 .0311 $ 1 A 70.88 3.678 i .7854 .0407 9% 74.66 3.874 \y% .9940 .0505 10 78.54 3.997 1% 1.227 .0624 10% 82.51 4.281 IT'S 1.484 .0629 lOVo 86.59 4.493 l/^ 1.767 .0896 10% 90.76 4.708 1^1 2.073 .1073 11 95.03 4.931 18 2.405 2.761 .1237 .1432 "$ 99.40 103.8 5.158 5.386 2 3.141 .1639 11% 108.4 5.634 2/ / 8 3.546 .1839 12 113.0 5.852 2% 3.970 .2063 12% 117.8 6.015 4.430 .2296 12Mj 122.7 6.366 2^2 4.908 .2545 12% 127.6 6.620 g^| 5.411 .2807 13 132.7 6.884 2% 5.939 .2948 13% 137.8 7.149 6.491 .3411 18j| 143.1 7.254 3 7.068 .3667 13% 148.4 7.688 3/ / 8 7.669 .3979 14 153.9 7.966 3% 8.295 .4304 14% 159.4 8.270 3^8 8.946 .4641 14;M> 165.1 8.565 8^8 9.621 .4992 14% 170.8 8.874 35^ 10.32 .5355 15 176.7 9.167 3% 11.04 .5728 15% 182.6 9.474 3j| 11.79 .5953 188.6 9.785 4 12.56 .6522 15% 194.8 10.098 4% 14.18 .7356 16 201.0 10.435 15.90 .8250 16% 207.3 10.720 4% 17.72 .9194 16^2 213.8 11.079 5 19.63 .9954 16% 220.3 11.43 5% 21.54 1 . 123 17 226.9 11.775 5% 23.75 25.96 1.2035 1.346 17% ml 233.7 240.5 12.125 12.172 6 28.27 1.433 17% 247.4 12.838 6^ 30.67 1.5915 18 254.4 13.208 6% 33.18 35.78 1.6817 1.8137 18i| 261.5 268.8 13.57 13.975 7 38.48 1 . 9965 18% 276.1 14.375 7% 41.28 2.1416 19 283.5 14.711 7^ 44.17 2.2958 19% 291.0 15.10 7% 47.17 2.4465 19^2 298.6 15.55 RULES, TABLES, AND OTHER INFORMATION 367 TABLE XLVH TABLE OF DECIMAL EQUIVALENTS OF AN INCH By 64ths; from l-64ih to 1 Inch Fraction. Decimal. Fraction. Decimal. A .015625 ft .515625 & .031250 H .531250 A .046875 it .546875 I 1 * .062500 9 It) .562500 A .078125 H .578125 & .093750 & .593750 9< .109375 If .609375 * . 125000 5. 8 .625000 & .140625 li .640625 & . 156250 H .656250 H . 171875 H .671875 A . 187500 H .687500 if .203125 t* .703125 - 3 V .218750 H .718750 H .234375 .734375 1 .250000 1 .750000 tt .265625 .765625 A .281250 If .781250 3 .296875 tt .796875 -1% .312500 if .812500 li .328125 if .828125 & ' .343750 i 3^ .843750 M .359375 H .859375 3 .375000 .875000 If .390625 fi .890625 H .406250 If .906250 Il- .421875 H .921875 l's .437500 it .937500 it .453125 H .953125 H .468750 ft .968750 o7 .484375 fi .984375 i .500000 i 1.000000 368 PRACTICAL HEATING AND VENTILATION Belting Horse power of a belt velocity in feet per minute, multiplied by the width the product divided by 1,000. 1 in. single belt moving at 1,000 feet per minute, 1 H. P. 1 in. double " " " 700 " " " 1 H. P. It is desirable that the angle of the belt with the floor should not exceed 45. It is also desirable to locate the shafting and ma- chinery so that the belts should run off from each shaft in op- posite directions, as this arrangement will relieve the bearings from the friction that would result when the belts all pull one way on the shaft. The diameter of the pulleys should be as large as can be ad- mitted. The pulleys should be a little wider than the belt required for the work. Belts should be kept soft and pliable. For this purpose blood- warm tallow, dried in by the heat of fire or the sun, is advised. Castor-oil dressing is also good. TABLE XLVIII HORSE POWER OF A LEATHER BELT ONE INCH WIDE Velocity in Feet per Second. LACED BELTS THICKNESS IN INCHES. 1 .143 t .167 A .187 & .219 i .250 A .312 * .333 10 .51 .59 .63 .73 .84 1.05 1.18 15 .75 .88 1.00 1.16 1.32 1.66 1.77 20 1.00 1.17 1.32 1.54 1.75 2.19 2.34 25 1.23 1.43 1.61 1.88 2 16 2.69 2.86 30 1.47 1.72 1.93 2.25 2.58 3.22 3.44 35 1.69 1.97 2.22 2.59 2.96 3.70 3.94 40 1.90 2.22 2.49 2.90 3.32 4.15 4.44 45 2.09 2.45 2.75 3.21 3.67 4.58 4.89 50 2.27 2.65 2.98 3.48 3.98 4.97 5.30 55 2.44 2.84 3.19 3.72 4.26 5.32 5.69 60 2.58 3.01 3.38 3.95 4.51 5.64 6.02 65 2.71 3.16 3.55 4.14 4.74 5.92 6.32 70 2.81 3.27 3.68 4.29 4.91 6.14 6.54 75 2.89 3.37 3.79 4.42 5.05 6.31 6.73 80 2.94 3.43 3.86 4.50 5.15 6.44 6.86 85 2.97 3.47 3.90 4.55 5.20 6.50 6.93 90 2.97 3.47 3.90 4.55 5.20 6.50 6.93 The horse power becomes a maximum at 87.41 feet per second, 5,245 per minute. RULES, TABLES, AND OTHER INFORMATION 369 If possible to avoid it, connected shafts should never be placed one directly over the other, as in such case the belt must be kept very tight to do the work. For this purpose belts should be care- fully selected of well-stretched leather. RULE FOR FINDING LENGTH OF BELTS Add the diameter of the two pulleys together, multiply by 3%, divide the product by two, add to the quotient twice the dis- tance between the centers of the shafts, and product will be the required length. THE TABLES ON THE FOLLOWING PAGES HAVE TO DO WITH THE TEMPERATURES AND MOVE- MENTS OF AIR, VOLUMES AND VELOCI- TIES, SIZES OF DUCTS, ETC., AS USED IN COMPUTATIONS FOR THE BLOWER SYSTEM OF HEATING AND VENTILATION RULES, TABLES, AND OTHER INFORMATION 873 TABLE XLIX NUMBER OF SQUARE INCHES OF FLUE AREA REQUIRED PER 1,000 CUBIC FEET OF CONTEXTS FOR GIVEN VELOCITY AND AIR CHANGE No. Minutes to Change Air. VELOCITY OP AIR IN FLUE IN FEET PER MINUTE. 300 400 500 600 700 800 900 1,000 1,100 1,200 1,300 1,400 1,500 4 120. 90. 72. 60. 51.6 45. 40. 36. 32.2 30. 27.6 25.6 21.4 5 96. 72.2 57.6 48. 41.1 36.1 32. 28.8 26.2 24. 22.2 20.5 19.2 6 80. 60. 48. 40. 34. 3 1 30. 26.6 24. 21.8 20. 18.5 17.1 16. 7 68.6 51.4 41.1 34.3 29.4 25.7 22.9 20.6 18.7 17.2 15.7 14.713.7 8 60. 45. 36. 30. |25.8 22.5 20. 18. 16.1 15. 13.8 12.812. 9 53.3 40. 32. 26.6 22.9 20. 17.8 16. 14.5 13.3 12.3 11.410.7 10 48. 36. 28.8 24. 20.6 18. 16. 14.4 13.1 12. 11.1 10.3' 9.6 11 43.6 32.2 26.2 21.8 18.7 16.1 14.5 13.1 11.9 10.9 10.1 9.5 8.7 12 40. 30. 24. 20. 17.2 15. 13.3 12. 10.9 10. 9.2 8.6 8. 13 36.9 27.7 22.2 18.5 15.7 13.8 12.3 11.1 10.1 9.2 8.5 7.9 7.4 14 34.3 25.7 20.6 17.2 14.7 12.8 11.4 10.3 9.5 8.6 7.9 7.4 6.9 15 32. 24. 19.2 16. 13.7 12. 10.7 9.6 8.7 8. 7.4 6.9 6.4 16 30. 22.5 18. 15. 12.9 11.2 10. 9. 8.2 7.5 6.9 6.4 6. 17 28.2 21.2 16.9 14.1 12.1 10.6 9.4 8.5 7.7 7. 6.5 6.1 5.6 18 26.6 20. 16. 13.3 11.5 10. 8.9 8. 7.3 6.6 6.2 5.7 5.3 19 25.3 18.9 15.2 12.6 10.8 9.5 8.4 7.6 6.9 6.3 5.8 5.4 5.1 20 24. 18. 14. 4 12. 10.3 9 8. 7.2 6.5 6. 5.5 5.1 4.8 To facilitate calculation of flue areas for different requirements in heating, ventila- tion and the general movement of air, the table above and that upon the three suc- ceeding pages have been prepared. The former is to be employed when in a ventilating system the area of the flue is to be based upon the time required to change the air within the room and upon the permissible velocity in the flue. The latter table indicates the flue area necessary for the passage of a predetermined volume of air at stated velocity. Values for volumes below 100 or above 1,000 cubic feet may be readily determined from the latter table by reading for the multiple of the given volume, and then pointing off the requisite number of places. Thus, if a volume of 8,750 cubic feet of air is required to pass through a flue at a velocity of 900 feet per minute, the cross sectional area of that must be 1,400 square inches. 374 PRACTICAL HEATING AND VENTILATION TABLE L FLUE AREA REQUIRED FOR THE PASSAGE OF A GIVEN VOLUME OF AIR AT A GIVEN VELOCITY Volume in Cubic Feet per Minute. VELOCITY IN FEET PER MINUTE. 300 400 500 600 700 800 900 1,000 1,100 100 48 36 29 24 21 18 16 14 13 125 60 45 36 30 26 23 20 18 16 150 72' 54 43 36 31 27 24 22 20 175 84 63 50 42 36 32 28 25 23 200 96 72 58 48 41 36 32 29 26 225 108 81 65 54 46 41 36 32 29 250 '120 90 72 60 51 45 40 36 33 275 132 99 79 66 57 50 44 40 36 300 144 108 86 72 62 54 48 43 39 325 156 117 94 78 67 59 52 47 43 350 168 126 101 84 72 63 56 50 46 375 180 135 108 90 77 68 60 54 49 400 192 144 115 96 82 72 64 58 52 425 204 153 122 102 87 77 68 61 56 450 216 162 130 108 93 81 72 65 59 475 228 171 137 114 98 86 76 68 62 500 240 180 144 120 103 90 80 72 65 525 252 189 151 126 108 95 84 76 69 550 264 198 158 132 113 99 88 79 72 575 276 207 166 138 118 104 92 83 75 600 288 216 173 144 123 108 96 86 79 625 300 225 180 150 129 113 100 90 82 650 312 234 187 156 134 117 104 94 85 675 324 243 194 162 139 122 108 97 88 700 336 252 202 168 144 126 112 101 92 725 348 261 209 174 149 131 116 104 95 750 360 270 216 180 154 135 120 108 98 775 372 279 223 186 159 140 124 112 101 800 384 288 230 192 165 144 128 115 105 825 396 297 238 198 170 149 132 119 108 850 408 306 245 204 175 153 136 122 111 875 420 315 252 210 180 158 140 126 115 900 432 324 259 216 185 162 144 130 118 925 444 333 266 222 190 167 148 133 121 950 456 342 274 228 195 171 152 137 124 975 468 351 281 234 201 176 156 140 128 1,000 480 360 288 240 206 180 160 144 131 RULES, TABLES, AND OTHER INFORMATION 375 TABLE LI FLUE AREA REQUIRED FOR THE PASSAGE OF A GIVEN VOLUME OF Am AT A GIVEN VELOCITY ( Continued } Volume in Cubic Feet per Minute. VELOCITY IN FEET PER MINUTE. 1,200 1,300 1,400 1,500 1,600 1,700 1,800 1,900 2,000 100 12 11 10 9.6 9. 8.5 8 7.6 7.2 125 15 14 13 12. 11.3 10.6 10 9.5 9. 150 18 16 15 14.4 13.5 12.7 12 11.4 10.8 175 21 19 18 16.8 15.8 14.8 14 13.3 12.6 200 24 22 21 19.2 18. 16.9 16 15.2 14.4 225 27 25 23 21.6 20.3 19.1 18 17.1 16.2 250 30 28 26 24. 22.5 21.2 20 19. 18. 275 33 30 28 26.4 24.8 23.3 22 21.8 19.8 300 36 33 31 28.8 27. 25.4 24 22.7 21.6 325 39 36 33 31.2 29.3 27.5 26 24.6 23.4 350 375 42 45 39 42 36 39 33.6 36. 31.5 33.8 29.6 31.8 28 30 26.5 28.4 25.2 27. 400 48 44 41 38.4 36. 33.9 32 30.3 28.8 425 51 47 44 40.8 38.3 36. 34 32.2 30.6 450 54 50 46 43.2 40.5 38.1 36 34.1 32.4 475 57 53 49 45.6 42.8 40.2 38 36. 34.2 500 60 55 51 48. 45. 42.4 40 37 9 36. 525 63 58 54 50.4 47.3 44.5 42 39.8 37.8 550 66 61 57 52.8 49.5 46.6 44 41.7 38.6 575 69 64 59 55.2 51.8 48.7 46 43.6 41.4 600 72 66 62 57.6 54. 50.8 48 45.5 43 2 625 75 69 64 60. 56.3 52.9 50 47.4 45. 650 675 78 81 72 75 67 69 62.4 64.8 58.5 55.1 60.8 57.2 52 54 49.3 46.8 51.2 48.6 700 84 78 72 67.2 63. 59.3 56 53.1 50.4 725 87 80 75 69.6 65.3 61.4 58 55. 52.2 750 90 83 77 72. 67.5 63.5 60 56.9 54. 775 93 86 80 74.4 69.8 65.6 62 58.8 56.3 800 96 89 82 76.8 72. 67.8 64 60.6 57.6 825 99 91 85 79.2 74.3 69.9 66 62.5 59.4 850 102 94 87 81.6 76.5 72. 68 64.4 61.2 875 105 97 90 84. 78.8 74. 70 67.3 63. 900 108 100 93 86.4 81. 76.2 72 68.2 64.8 925 111 103 95 88.8 83.3 78.4 74 70.1 66.6 950 114 105 98 91.2 85.5 80.5 76 72. 68.4 975 117 108 100 93.6 87.8 82.6 78 73.9 70.2 1,000 120 111 103 96. 90. 84.7 80 75.8 72. 376 PRACTICAL HEATING AND VENTILATION TABLE LII FLUE AREA REQUIRED FOR THE PASSAGE OF A GIVEN VOLUME OF Am AT A GIVEN VELOCITY (Continued} Volume in Cubic Feet per Minute. VELOCITY IN FEET PER MINXJTE. 2,100 2,200 2,300 2,400 2,600 2,700 2,800 2,900 3,000 3,100 100 6.9 6.6 6.3 6. 5.5 5.3 5.1 5. 4.8 4.6 125 8.6 8.2 7.8 7.5 6.9 6.7 6.4 6.2 6. 5.8 150 10.3 9.8 9.4 9. 8. 8. 7.7 7.5 7.2 7. 175 12. 11.5 11. 10.5 9.7 9.3 9. 8.7 8.4 8.1 200 13.7 13.1 12.5 12. 11.1 10.7 10.3 9.9 9.6 9.3 225 15.6 14.7 14.1 13.5 12.5 12. 11.6 11.2 10.8 10.4 250 17.1 16.4 15.7 15. 13.9 13.3 12.9 12.4 12. 11.6 275 18.9 18. 17.2 16.5 15.2 14.7 14.1 13.7 13.2 12.8 300 20.6 19.6 18.8 18. 16.6 16. 15.4 14.9 14.4 13.9 325 22.3* 21.3 20.6 19.5 18. 17.3 16.7 16.1 15.6 15.1 350 24. 22.9 21.9 21. 19.4 18.7 18. 17.4 16.8 16.3 375 25.7 24.5 23.5 22.5 20.8 20. 19.3 18.6 18. 17.4 400 27.4 26.2 25. 24. 22.2 21.3 20.6 19.8 19.2 18.6 425 29.1 27.8 26.6 25.5 23.5 22.7 21.9 21.1 20.4 19.7 450 30.9 29.5 28.2 27. 24.9 24. 23.1 22.3 21.6 20.9 475 32.6 31.1 29.7 28.5 26.3 25.3 24.4 23.6 22.8 22.1 500 34.3 32.7 31.3 30. 27.7 26.7 25.7 24.8 24. 23.2 525 36. 34.4 32.9 31.5 29.1 28. 26.9 25. 25.2 24.4 550 37.7 36. 34.4 33. 30.5 29.3 28.3 27.3 26.4 25.5 575 39.4 37.6 36. 34.5 31.9 30.7 29.6 28.5 27.6 26.7 600 41.1 39.3 37.6 36. 33.2 32. 30.8 29.8 28.8 27.8 625 42.9 40.9 39.1 37.5 34.6 ' 33.3 32.1 31. 30. 29. 650 44.6 42.5 40.7 39. 36. 34.7 33.4 32.2 31.2 30.2 675 46.3 44.1 42.3 40.5 37.5 36. 34.7 33.5 32.4 31.3 700 48. 45.8 43.8 42. 38.8 37.3 36. 34.7 33.6 32.5 725 49.7 47.4 45.4 43.5 40.2 38.7 37.3 36. 34.8 33.6 750 51.4 49.1 47. 45. 41.5 40. 38.6 37.2 36. 34.8 775 53.1 50.7 48.5 46.5 42.9 41.3 39.9 38.5 37.2 36. 800 54.9 52.4 50.1 48. 44.3 42.7 41.2 39.7 38.4 37.1 825 56.6 54. 51.7 49.5 45.7 44. 42.4 40.9 39.6 38.3 850 58.4 55.6 53.2 51. 47.1 45.3 43.7 42.2 40.8 39.4 875 60. 57.3 54.8 52.5 48.5 46.7 45. 43.4 42. 40.6 900 61.7 58.9 56.3 54. 49.9 48. 46.3 44.6 43.2 41.8 925 63.4 60.5 57.9 55.5 51.3 49.3 47.6 46. 44.4 42.9 950 65.1 62.2 59.5 57. 52.6 50.7 48.8 47.1 45.6 44.1 975 66.8 63.8 61.0 58.5 54. 52. 50.2 48.4 46.8 45.3 1,000 68.7 66. 62.6 60. 55.4 53.3 51.4 49.6 48. 46.4 RULES, TABLES, AND OTHER INFORMATION 377 TABLE Lm WEIGHT OF ROUND GALVANIZED IRON PIPE AND ELBOWS, OF THE PROPER GAUGES FOR HEATING AND VENTILATING SYSTEMS Gauge and Weight per Sq. Ft. Diam. of Pipe. Area in Sq. Ins. Weight Run- ning Foot. Weight of Full Elbow. Gauge and Weight per Sq. Ft. Diam. of Pipe. Area in Sq. Ins. Weight R P un- ning Foot. Weight of Full Elbow. 3 7.1 0.7 0.4 36 1,017.9 17.2 124.4 4 12.6 1.1 0.9 37 1,075.2 17.8 131.4 No. 28 5 19.6 1.2 1.2 38 1,134.1 18.2 139.4 0.78 6 7 28.3 38.5 1.4 1.7 1.7 2.3 No. 20 39 40 ,194.6 ,256.6 18.7 19.1 146.0 152.9 8 50.3 1.9 2.9 1.66 41 ,320.3 19.6 160.7 42 ,385.4 20.1 168.6 43 ,452.2 20.6 176.7 9 63.6 2.4 4.3 44 ,520.5 21.0 185.0 10 78.5 2.7 5.3 45 ,590.4 21.5 193.4 Xo. 26 11 95.0 2.9 6.4 46 1,661.9 22.0 202.2 0.91 12 113.1 3.2 7.6 13 132.7 3.4 8.9 14 153.9 3.7 10.4 47 1,734.9 29.2 274.3 48 1,809.6 29.8 286.6 49 1,885.7 30.4 298.8 15 176.7 4.5 13.5 50 1,963.5 31.0 309.9 16 201.1 4.7 15.1 51 2,042.8 31.6 322.5 Xo. 25 17 227.0 5.0 17.0 52 2,123.7 32.2 335.1 1.03 18 254.5 5.3 19.1 No. 18 53 2,206.2 33.0 349.7 19 283.5 5.6 21.4 2.16 54 2,290.2 33.6 363.4 20 314.2 6.0 23.9 55 2,375.8 34.4 377.2 56 2,463.0 34.9 390.7 57 2,551.8 35.6 405.1 21 346.4 7.0 29.6 58 2,642.1 36.1 418.8 22 380.1 7.3 32.3 59 2,734.0 36.7 433.1 Xo. 24 23 415.5 7.7 35.6 60 2,827.4 37.4 448.6 1.16 24 452.4 8.0 38.6 25 490.9 8.3 41.7 26 530.9 8.7 45.1 61 2,922.5 46.7 569.7 62 3,019.1 47.5 589.0 63 3,117.3 48.3 608.6 27 572.6 10.9 59.1 64 3,217.0 49.1 628.5 28 615.7 11.4 64.2 65 3,318.3 49.8 647.4 29 660.5 11.8 68.6 Xo. 16 66 3,421.2 50.5 666.6 Xo. 22 30 706.9 12 2 73.4 P 66 67 3,525.7 51.3 687.4 31 754.8 12.6 78.3 ** . Uvl 68 3,631.7 52.1 708.6 1.41 32 804.3 13.0 83.4 69 3,739.3 52.8 728.6 33 855.3 13.5 88.9 70 3,848.5 53.6 750.4 34 907.9 13.9 94.3 71 3,959.2 54.3 771.0 35 962 . 1 14.3 99.9 72 4,071.5 55.1 793.4 RULES, TABLES, AND OTHER INFORMATION 379 TABLE LV AIR Loss of Pressure in Ounces per Square Inch for Varying Velocities and Varying Diameters of Pipes Velocity of Air, Feet per Minute. DIAMETER OF PIPE IN INCHES. 1 2 3 4 5 6 LOSS OF PRESSURE IN OUNCES. 600 1,200 1,800 2,400 3,000 3,600 4,200 4,800 6,000 600 1,200 1,800 2,400 3,000 3,600 4,200 4,800 6,000 600 1,200 1,800 2,400 3,600 4.200 4,800 6,000 600 1,200 1,800 2,400 3,600 4,200 4,800 6,000 .400 1.600 3.600 6.400 10.000 14.400 .200 .800 1.800 3.200 5.000 7.200 9.800 12.800 20.000 .133 .533 1.200 2.133 3.333 4.800 6.553 8.533 13.333 .100 .400 .900 1.600 2.500 3.600 4.900 6.400 10.000 .080 .320 .720 1.280 2.000 2.880 3.920 5 . 120 8.000 .067 .267 .600 1.067 1.667 2.400 3.267 4.267 6.667 DIAMETER OF PIPE IN INCHES. j 8 9 10 11 12 LOSS OF PRESSURE IN OUNCES. .057 .229 .514 .914 1.429 2.057 2.800 3.657 5.714 .050 .200 .450 .800 1.250 1.800 2.450 3.200 5.000 .044 .040 .178 .160 .400 .360 .711 .640 1.111 1.000 1.600 1.440 2 178 1.960 2.844 2.560 4.444 4.000 .036 .145 .327 .582 .909 1.309 1.782 2.327 3.636 .033 .133 .300 .533 .833 1.200 1.633 2.133 3.333 DIAMETER OF PIPE IN INCHES. 14 16 18 20 22 24 LOSS OF PRESSURE IN OUNCES. .029 .114 .257 .457 1.029 1.400 1.829 2.857 .026 .100 .225 .400 .900 1 . 225 1.600 2.500 .022 .089 .200 .356 .800 1.089 1.422 2.222 .020 .080 .180 .320 .720 .980 1.280 2.000 .018 .073 .164 .291 .655 .891 1.164 1.818 .017 .067 .156 .267 .600 .817 1.067 1.667 DIAMETER OF PIPE IN INCHES. 28 32 36 40 44 48 LOSS OF PRESSURE IN OUNCES. .014 .057 .129 .239 .514 .700 .914 1.429 .012 .050 .112 .200 .450 .612 .800 1.250 .011 .044 .100 .178 .400 .544 .711 1.111 .010 .040 .090 .160 .360 .490 .640 1.000 .009 .036 .082 .145 .327 .445 .582 .909 .008 .033 .075 .133 .300 .408 .533 .833 380 PRACTICAL HEATING AND VENTILATION Ss > 15 Ij co 5 I-H I-H 00 t* CO OS CO O O**> 8 . i | h * a * * s- 8 V* 3 I fc sal . I. -3 "8 i 1 i i a - I g ii RULES, TABLES, AND OTHER INFORMATION 381 TABLE LVII OF THE NUMBER OF THERMAL UNITS CONTAINED IN ONE POUND OF WATER Temper- ature. Number of Thermal Units. In- crease. Temper- ature. Number of Thermal Units. In- i Temper- crease, jj ature. Number of Thermal Units. In- crease. 35 35.000 15*5 155.339 5.034 275 276.985 5.107 40 40.001 5.001 160 160.374 5.035 280 282.095 5.110 45 45.002 5.001 165 165.413 5.039 285 | 287.210 5.115 50 50.003 5.001 170 170.453 5.040 290 292.329 5.119 55 55.006 5.003 175 175.497 5.044 1 295 297.452 5.123 60 60.009 5.003 180 180.542 5.045 300 302.580 5.128 65 65.014 5.005 185 185.591 5.049 305 307.712 5.132 70 70.020 5.006 190 190.643 5.052 310 312.848 5.136 75 75.027 5.007 195 195.697 5.054 315 317.988 5.140 80 80.036 5.009 200 200.753 5.056 320 323.134 5.146 85 85.045 5.009 205 205.813 5.060 325 328.284 5.150 90 90.055 5.010 210 210.874 5.061 330 333.438 5.154 95 95.067 5.012 215 215.939 5.065 335 338.596 5.158 100 100.080 5.013 220 221.007 5.068 340 343.759 5.163 105 105.095 5.015 225 226.078 5.071 345 348.927 5.168 110 110.110 5.015 230 231.153 5.075 350 354.101 5.174 115 115.129 5.019 235 236.232 5.079 355 359.280 5.179 120 120.149 5.020 240 241.313 5.081 360 364.464 5.184 125 125.169 5.020 245 246.398 5.085 365 369.653 5.189 130 130.192 5.023 250 251.487 5.089 370 374.846 5.193 135 135.217 5.025 255 256.579 5.092 375 380.044 5.198 140 140.245 5.028 260 261.674 5.095 380 385.247 5.203 145 145.175 5.030 265 266.774 5.100 385 390.456 5.209 150 150.305 5.030 270 271.878 5.104 390 395.672 5.216 382 PRACTICAL HEATING AND VENTILATION TABLE LVHI VOLUME AND DENSITY OF AIR AT VARIOUS TEMPERATURES Temperature. Degrees. Volume of 1 Ib. of Air at Atmospheric Presssure of 14.7 Ibs. Cubic Feet. Density or Weight of 1 Cubic foot of Air at 14.7 Ibs. Lbs. 11.583 .086331 32 12.387 .080728 40 12.586 .079439 50 12.84 .077884 62 13.141 .076097 70 13.342 .07495 80 13.593 .073565 90 13.845 .07223 100 14.096 .070942 120 14.592 .0685 140 15.1 .066221 160 15.603 .064088 180 16 . 106 .06209 200 16.606 .06021 210 16.86 .059313 212 16.91 .059135 220 17.111 .058442 240 17.612 .056774 260 18.116 .0552 280 18.621 .05371 300 19.121 .052297 320 19.624 . 050959 340 20.126 .049686 360 20.63 .048476 380 21.131 .047323 400 21.634 .046223 425 22.262 .04492 450 22.89 .043686 475 23.518 .04252 500 24 . 146 .041414 525 24.775 .040364 550 25.403 .039365 575 26.031 .038415 600 26.659 .03751 650 27.915 .035822 700 29.171 .03428 750 30.428 .032865 800 31.684 .031561 850 32.941 .030358 900 34 . 197 .029242 950 35.454 .028206 1,000 36.811 .027241 1,500 49.375 .020295 2,000 61.94 .016172 2,500 74.565 .013441 3,000 87.13 .011499 RULES, TABLES, AND OTHER INFORMATION TABLE LIX INFLUENCE OF THE TEMPERATURE OF AIR UPON THE CONDITIONS OF ITS MOVEMENT Temper- ature in Degrees, Fahr. Relative Velocity Due to the Same Pressure. Relative Pressure Necessary to Pro- duce the Same Velocity. Relative Weight of Air Moved at the Same Velocity. Relative Velocity Necessary to Move the Same Weight of Air. Relative Pressure Necessary to Produce the Velocity to Move the Same Weight of Air. Relative Power Necessary to Move the Same Volume of Air at the Same Velocity. Relative Power Necessary to Move the Same Weight of Air at the Velocity in Column 5 and the Pressure in Column 6. 1 2 3 4 5 6 7 8 30 0.98 1.04 1.04 0.96 0.96 1.04 0.92 40 0.99 1.02 1.02 0.98 0.98 1.02 0.96 50 1.00 1.00 1.00 .00 1.00 1.00 .00 60 1.01 0.98 0.98 .02 1.02 0.98 .04 70 1.02 0.96 0.96 .04 1.04 0.96 .08 80 1.03 0.94 0.94 .06 1.06 0.94 .12 90 1.04 0.93 0.93 .08 1.08 0.93 .17 100 1.05 0.91 0.91 .10 1.10 0.91 .21 125 1.07 0.87 0.87 1.15 1.15 0.87 .32 150 .09 0.84 0.84 1.20 1.20 0.84 .43 175 .11 0.81 0.81 1.24 1.24 0.81 .55 200 .14 0.78 0.78 1.29 1.29 0.78 .67 225 .16 0.75 0.75 1.34 1.34 0.75 .80 250 .18 0.72 0.72 1.39 1.39 0.72 .93 275 .20 0.69 0.69 1.44 1.44 0.69 2.07 300 .22 0.67 0.67 1.49 1.49 0.67 2.22 325 .24 0.65 0.65 1.54 1.54 0.65 2.36 350 .26 0.63 0.63 .59 1.59 0.63 2.51 375 .28 0.61 0.61 .63 1.63 0.61 2.66 400 .30 0.59 0.59 .68 1.68 0.59 2.82 425 .32 0.58 0.58 .73 1.73 0.58 2.99 450 .34 0.56 0.56 .78 1.78 0.56 3.17 475 .35 0.55 0.55 .83 1.83 0.55 3.35 500 .37 0.53 0.53 .88 1.88 0.53 3.53 525 .39 0.52 0.52 .93 1.93 0.52 3.72 550 .41 0.51 0.51 .98 1.98 0.51 3.92 575 .43 0.49 0.49 2.03 2.03 0.49 4.12 600 .44 0.48 0.48 2.08 2.08 0.48 4.33 625 .46 0.47 0.47 2.13 2.13 0.47 4.54 650 .48 0.46 0.46 2.18 2.18 0.46 4.75 675 .49 0.45 0.45 2.22 2.22 0.45 4.93 700 .51 0.44 0.44 2.27 2.27 0.44 5.15 725 .52 0.43 0.43 2.32 2.32 0.43 5.38 750 .54 0.42 0.42 2.37 2.37 0.42 5.62 775 .56 0.41 0.41 2.42 2.42 0.41 5.86 800 .57 0.40 0.40 2.47 2.47 0.40 6.10 384 PRACTICAL HEATING AND VENTILATION TABLE LX VELOCITY CREATED, VOLUME DISCHARGED AND HORSE POWER REQUIRED WHEN AIR UNDER A GIVEN PRESSURE IN OUNCES PER SQUARE INCH is ALLOWED TO ESCAPE INTO THE ATMOSPHERE In the following table the volume is proportional to the velocity. The power varies as the cube of the velocity. " Blast area " generally means the maximum area over which the velocity of the air will equal the velocity of the pipes at the tips of the floats. If this area is decreased the volume will be decreased, but the pressure will remain constant. If this area is increased the pressure is lowered, but the volume somewhat increased. This table is calculated for 50 F. temperature. Different temperature will effect the result. The movement of air through pipes will also change results. Pressure Ounces per Square Inch. VELOCITY OF AIR ESCAPING INTO ATMOSPHERE. Volume Dis- charged in One Minute Through Effective Area of One Square Inch, in Cubic Feet. Horse Power of Air Blast. In Feet per Second. In Feet per Minute. l /S 30.47 1,828 12.69 . 0004 X 43.08 2,585 17.95 001 y* 52.75 3,165 21.98 0.002 H 60.90 3,654 25.37 003 5 /s 68.07 4,084 28.36 0.005 H 74.54 4,473 31.06 0.006 7 /s 80.50 4,830 33.54 0.008 I 86.03 5,162 35.85 0.01 Vi 96.13 5,768 40.06 0.014 iy 2 105.25 6,315 43.86 0.02 w 113.64 6,818 47.34 0.023 2 121.41 7,284 50.59 0.028 2^ 128.70 7,722 53.63 0.033 &A 135.59 8,136 56.50 0.039 *H 142 . 14 8,528 59.22 0.044 3 148.38 8,903 61.83 0.05 3^ 160.10 9,606 66.71 0.06 4 170.98 10,259 71.24 0.08 4^ 181 . 16 10,870 75.48 0.09 5 190.76 11,446 79.48 0.11 VA 199.86 11,992 83.24 0.12 6 208.53 12,512 86.89 0.14 7 224.77 13,486 93.66 0.18 8 239.80 14,388 99.92 0.22 9 253.83 15,230 105.76 0.26 10 267.00 16,020 111.25 0.30 11 279.70 16,768 116.45 0.35 12 291.30 17,478 121.38 0.40 13 302.59 18,155 126.06 0.45 14 313.38 18,803 130.57 0.50 15 323 . 73 19,424 134.89 0.55 16 333.68 20,021 139.03 0.61 17 343.26 20,596 143 . 03 0.66 18 352.52 21,151 146.88 0.72 19 361.46 21,688 150.61 0.78 20 370.13 22,208 154.22 0.84 RULES, TABLES, AND OTHER INFORMATION 385 TABLE LXI MOISTURE ABSORBED BY Am The Quantity of Water Which Air is Capable of Absorbing to the Point of Maximum Saturation, in Grains per Cubic Foot for Various Temperatures Degrees. Grains in a Degrees Fahrenheit. Cubic Foot. Fahrenheit. Grains in a Cubic Foot. 10 1.1 85 12.43 15 1.31 90 14.38 20 1.56 95 16.60 25 1.85 100 19.12 30 2.19 105 22.0 32 2.35 110 25.5 35 2.59 115 30.0 40 3.06 130 42.5 45 3.61 141 58.0 50 4.24 157 85.0 55 4.97 170 112.5 60 5.82 179 138.0 65 6.81 188 166.0 70 7.94 195 194.0 75 9.24 212 265.0 80 10.73 PRACTICAL HEATING AND VENTILATION a : i 3 g I S g I g g % I 3 : : : : 8 3 $ S : : : : 8 i ?3 : : : : i T-4 (N : : : : i $ % s ** GO 1-1 -ft G* O* CO CO 0) "5 05 i-l O O CO O .' ' o* co co co o s S : : : i g 3 8 H ja t- 1-1 g 5 O ^ X i-< (X CO CO CO * ! s M .S l> O* O O CO (X CO CO "* * 2 10 H i d O O Oi O 5 CO CO CO * * J S | s 1> CO GO O* 5 1> 0< CO CO *** | CO TH 1 02 O O -i C O CO CO * * -* 5 1 M H I CO OS * 00 -H CO CO CO "J * 5 1-1 i-l W CO O^ l> r-4 -^ <& CO * * 5 "5 5 S B O O O rji l> Oi * * O 5 5 i 1 OJ 1 * O * 1> S ' * AO 5 H "8 00 05 * 00 i-" ^ -0 * O 5 O O O 8 I c- O * CO CO <0 J> t- 10 C5 0* * CO J> o o i> J> i> J> Tt< * xft l> O5 O < t- t- t- 1> 00 GO w oo o a* * o -o J> X GO x co oo GO o a rH l> <3* CO * -^ O *O X C5 C5 05 05 C5 OS Temperature of the Air, Degrees Fahrenheit. (N G< O* * G< .18170 2,204 . 16 m .8721 4,836.06 H .21804 2,414.70 m 1.0174 5,224.98 1 A .29072 2,788.74 2 1 . 1628 5,587.58 TABLE LXV PRESSURE IN OUNCES PER SQUARE INCH WITH VELOCITIES OF AIR DUE TO PRESSURES Pressure in Ounces per Square Velocity Due to the Pres- sure in Feet per Minute. Pressure in Ounces per Square Inch. Velocity Due to the Pres- sure in Feet per Minute. Pressure in Ounces per Square inch. Velocity Due to the Pres- sure in Feet per Minute. .25 2,582 2.75 8,618 7.50 14,374 .50 3,658 3.00 9,006 8.00 14,861 .75 4,482 3.50 9,739 9.00 15,795 1.00 5,178 4.00 10,421 10.00 16,684 1.25 5,792 4.50 11,065 11.00 17,534 1.50 6,349 5.00 11,676 12.00 18,350 1.75 6,861 5.50 12,259 13.00 19,138 2.00 7,338 6.00 12,817 14.00 19,901 2.25 7,787 6.50 13,354 15.00 20,641 2.50 8,213 7.00 13,873 16.00 21,360 RULES, TABLES, AND OTHER INFORMATION 389 TABLE LXVI WEIGHTS OF GALVANIZED IRON PIPE PER LINEAL FOOT Diameter of Pipe in Inches. GAUGE OF IRON NUMBERS. 18 20 22 24 26 3 2^~ 1% ix 1 4 2% 1% l/^ 1% 5 6 3% 3% 2% 3 2 2% 1% 2 IM 7 3^2 2% 2% 2 8 &/A. 4 3 2% 2% 9 5% 4/^ 3% 3 2/^ 10 gix/ 4% 3% 23^ 11 12 6% 5% 5% 3% 4% 3% 2% 3 13 8 2 6% 4/^ 4 3% 14 15 16 9% 9% 6% 7% 4% 5% 4% 4% 5 3% 17 8 6 5% 4% 18 19 10% 9 2 6% 6% 5% 4% 20 12 2 7 6 5% 21 22 13% 9% 10% ?% 6% 5% 23 14 11 8% 7 6 24 14% H/^ 8% 7/^ 6^ 26 15% 123^ 9% 7% 6^ 28 16% 13Vi 9% 8^A 7 30 18 14 10}/^ 9 7^/2 32 19% 15 11% 9% 8 34 36 20% 15% 16% 12 10% 10% 9 38 22% 18 133^ ll/^ 9/^j . 40 42 24 25 18% 1H 14 " 14% 12 10 44 26% 15i/o * 13 11 46 271-1 21% 16 13% H/^2 48 28i/ 22% 16% 14% 12 50 29% 23 VV& 15 123^ 52 31% 24% 18% 54 25 18% 56 33% 26 19 58 60 35 36% 26% 271^ 20% 20% 63 38% 29 21% 66 40 30% 22% 69 72 41% 32% 33% 23% 25 The figures in bold-faced type represent weight of round piping ordinarily used in heating work. INDEX Advantages of steam heating, 114. Angles, measurements for, 209, 210, Air, circulation of, by direct radia- tion, 98. Air, circulation of, by indirect radia- tion,.^. Air cleansing, 233, 234. Air compressor, Johnson, 312. Air, conditions of its movement, 383. Air ducts for ventilating, 248, 250. Air ducts, indirect heating, 94. Air, expansion of, 349. Air, humidity of, 259, 260. Air, influence of the temperature, 383. Air, loss of pressure in pipes, 379. Air, method of measuring velocity, 258. Air, moisture absorbed by, 385. Air necessary for ventilation, 213, 218. Air required to burn coal, 349. Air, table of velocities due to pressure, 388. Air valve, 77. Air valve, compression, 77. Air valves, automatic, 78, 79. Air, velocity at furnace register, 349. Air, velocity, volume, and horse power required, 384. Air, volume and density at various pressures, 382. Air, volume necessary to maintain given standard of purity, 387. Air, wire screen for cleansing, 233. Altitude gauge, 146. Anemometer, description of, 258. 349. Angle valve, 74. Apparatus for testing blower systems, 257, 261. Area of circle, 350. Areas of circles, table of, 358. Artificial heating apparatus, evolu- tion of, 22. Artificial heating, methods of, 23. Artificial water line, 205, 206. Asbestos, 295. Aspirating coil, to determine size of, 349. Atmosphere, moisture in the, 386. Attention to boilers, 330, 331. Automatic damper regulator, 50, 53, 300. Automatic water feeders, 287. Back-pressure valves, 282. Belting, horse power of, 368. Belting, rule for finding length, 369. Blow-off cock, 53, 54. Boiler, All Right, 33. Boiler, Bundy, 33. Boiler, common type of upright tubu- lar, 28. Boiler covering, 293. Boilers, cross-connecting, 206, 209. Boiler, Dunning, 29. Boilers, early types of, 26. Boiler explosions, 340, 341. Boilers, feed water required, 364. 391 392 INDEX Boiler, Florida, 32. Boiler, Gold, 30. Boiler, Gorton, 34. Boilers, grate surface of, 41. Boiler, Haxtun, 29. Boiler, locomotive fire-box, 31. Boiler, manner of bricking locomo- tive fire-box, 43, 44. Boiler, Mills, 30. Boiler, original type of Furman, 32. Boiler, Page Safety Sectional, 32. Boilers, proper attention to, 330, 331. Boilers, removing oil and dirt from, 331, 332. Boiler setting, 42. Boiler, shell of Dunning, 28. Boiler, standard type of horizontal tubular, 27. Boiler surfaces and settings, 40. Boiler, volunteer, 32. Boilers, water surface of, 41. Boiler, what constitutes a good one, 38. Boiling point of water, 347. Boiling point of water, table, 142. Boiling points of fluids, 353. Box base for direct-indirect radiator, 96. Boxing indirect radiators, 92, 93. Brass, to clean, 351. Branch tees, 69, 71. Bricking tubular boilers, materials required, 360. Brick setting tubular boilers with full fronts, 46. Brick setting tubular boilers with half fronts, 48. British thermal heat unit (B. T. U.), 19. Bronzing, painting, and decoration, 335, 336. Broomell vapor-heating system, 178, 181. Bucket traps, 263, 264. Business methods, 316, 328. Capacities of pumps, 366. Capacity of stacks, 363. Care of heating apparatus, 329, 330. Care of tools, 333, 334. Casing indirect radiators, 92, 93. Cast-iron fittings, 69. Cast iron, to harden, 352. Cast-iron fittings, types of, 70. Cast-iron flanges, 71. Cast-iron flanges, schedule of, 71. Cement for leaky boilers, 350. Cement for steam boilers, 350. Central - station hot -water heating, 291, 292. Check valve, 76. Chimney flue, 56. Chimney flue, capacity of, 59. Chimney flue, elements of, 59. Chimney flue, proper construction of, 56, 58. Chimney flue, table of sizes, 58. Chimneys, tables of heights and area, 61. Circles, table of areas, 358. Circle, to find area of, 350. Circle, to find circumference of, 349. Circle, to find diameter of, 350. Circulation of air by direct radiator, 98. Circulation of air by indirect radiator, 99. Circumference of circle, 349. Coal, air necessary to burn, 349. Coal, heat units in, 348. Coal, weight of anthracite, 348. Coal, weight of bituminous, 348. INDEX 393 Coil stands and hook plates, 90. Coils for tanks, sizes of, 198. Comparison of thermometric scales, 357. Condensing engines, water required, 349. Contracts, special features of, 328. Contracts, specifications of, 319, 328. Cost, manner of estimating, 317, 318. Cost of coal for steam power, 362. Cost of mechanical heating and ven- tilation, 255, 257. Couplings, wrought-iron, malleable, 68. Covering, pipe and boiler, 293, 298. Cross-connecting boilers, 206, 209. Cylindrical tank, to find capacity of, 348, 351. Damper, double, for round flue, 314. Damper, double, for square flue, 314. Damper regulator, automatic, 50, 53, 300. Damper regulator, low-pressure, 51. Damper regulator, manner of con- necting, 52. Decimal equivalents of an inch, table of, 367. Density of air at various tempera- tures, 382. Diameter of circle, 350. Diameter of pipes, table for equal- izing, 378. Diaphragm motor, powers, 304. Diaphragm radiator valve, 303, 313. D. & R. regulator, 307, 308. Direct-indirect radiators, 95, 96. Dirt, removing from boilers, 331, 332. District heating, 288, 292. Domestic water heating, 194, 198. Ducts, sizes of, for indirect heating, 94. Dunham vacuo-vapor system, 183, 187. Early history of heating, 15. Early history of ventilation, 16. Early types of boilers, 26. Eccentric fittings, use of, 114. Efficiency determined by summer tests, 332, 333. Engines for blower systems, types of, 245, 248. Equalizing diameter of pipes, 378. Estimate, form of, 317, 318. Estimating, 316, 319. Estimating radiation, 97, 102. Estimating radiation for greenhouses, 157, 158. Estimating radiation, rules for, 100, 102. Evolution of artificial heating ap- paratus, 22. Exhaust steam, heating capacity of, 118. Exhaust-steam heating, 115, 119. Exhaust-steam heating, necessary fixtures, 116. Exhaust-steam heating, plan of, 117. Exhaust-vacuum systems, 165, 173. Expansion of air, 349. Expansion of pipe, to find, 351. Expansion of water, 347. Expansion tank, 125, 127. Expansion tank, automatic, 127. Expansion-tank connections, 126, 127, 134, 135, 142, 143. Expansion tank, table of sizes, 128. Expansion tank, to determine size, 349. Expansion traps, 263. 394 INDEX Explosion of boilers, 340, 341. Explosions, prevention of, 341, 342. Factory heating and ventilating, 253, 255. Fan engines for blower systems, 245, 248. Fans for blowing and exhausting, 238, 240. Features of contracts, 328. Feed-water heaters, 275, 276. Feed-water required by boilers, 364. Firing tools and brushes, 54. Fittings, cast-iron, 69. Fittings, eccentric, 114. Flanges, cast-iron, 70, 71. Float traps, 264, 265. Floor and ceiling plates, 149. Flues, area required for ventilation, 373, 376. Fluids, boiling points of, 353. Forms of radiating surfaces, 81. Fuel, consumption of, 348. Fusible plug, 54. Future of vacuum heating, 187, 188. Galvanized iron pipe, weight of, 377, 389. Gate valve, 74, 75, 76. Gauge, altitude, 146. Gauge glass and water column, 53, 54. Gauges and their fractional equiva- lents, 351. Globe valve, 74, 75, 76. Gorton system vacuum heating, 181, 183. Governor for pump, 280, 281. Grate surface in boilers, 41. Greenhouse heating, 155, 162. Greenhouse piping, methods of, 159, 162. Guaranty, bad features of, 337, 340. Guaranty, forms of, 337, 340. Healthfulness of furnace heating vs. steam or hot water, 25. Heart of the heating system, 26. Heat absorbed by bodies, 21. Heat, how measured, 19. Heat, how transferred, 18, 20. Heat, nature of, 18. Heat unit, British thermal unit, 19. Heat units in anthracite coal, 348. Heat, utilizing waste, 342, 346. Heaters, feed-water, 275, 276. Heaters for blower systems, types of, 239, 245. Heating apparatus, average life and cost, 24. Heating apparatus, care of, 329, 330. Heating, artificial methods of, 23. Heating by exhaust steam, 115, 119. Heating by hot water, 120, 141. Heating by steam, 103, 114. Heating capacity of exhaust steam, 118. Heating capacity of tubular boilers, 349. Heating, district method, 288, 292. Heating, early history of, 15. Heating greenhouses, 155, 162. Heating, miscellaneous, 189, 198. Heating of swimming pools, 189, 194. Heating system, Broomell vapor, 178, 181. Heating system, Dunham, 183, 187. Heating system, Gorton, 181, 183. . Heating system, K-M-C (Morgan), 174, 175. Heating system, Paul, 168, 173. Heating system, Ryan, 178, 179. INDEX 395 Heating system, Trane mercury seal, 175, 178. Heating systems, vacuum-exhaust, 165, 173. Heating system, vacuum-vapor, 183. Heating system, Vacuum Vapor Com- pany, 181. Heating system, Van Auken, 173. Heating system, vapor, 178, 180. Heating system, Webster, 165, 168. Heating, vacuum systems, 163, 188. Heating and ventilating factories, 253, 255. Heating and ventilating, relative cost, 255, 257. Heating water for domestic purposes, 194, 198. High temperature thermometer, 258. Honeywell heat generator, 150, 152. Hook plates and coil stands, 90. Horse power, definition of, 19. Horse power of belting, 368. Hot-blast heating and ventilation, 224, 261. Hot-blast heating, growth and im- provement, 224, 225. Hot-water heaters, 35. Hot-water heater, Carton, 37. Hot-water heater, early type of Gur- ney, 35. Hot-water heater, Hitchings, 36. Hot-water heater, improved Gurney, 36. Hot-water heater, perfect, 36. Hot-water heater, Spence, 35. Hot-water heater, thermo, 38. Hot-water heating, 120, 140. Hot-water heating appliances, 146, 154. Hot-water heating, central - station method, 291, 292. Hot- water heating, methods, 121. Hot-water heating, modified over- head system, 135. Hot-water heating, pipe connections, 132. Hot-water heating, pressure systems, 141, 145. Hot-water heating, size of main for one pipe, 139. Hot-water heating, sizes of mains two-pipe system, 124. Hot-water heating, special fittings, 138. Hot-water heating, specifications and bid, 324, 328. Hot-water heating, the circuit sys- tem, 136, 139. Hot-water heating, the overhead sys- tem, 128, 136. Hot-water heating, the two-pipe sys- tem, 121, 128. Hot- water heating, why water circu- lates, 139, 140. Hot-water radiator connections, 201, 203. Hot-water thermometer, 147, 148. Hot-water thermometer, method of attaching, 148. Howard regulator, 308, 309. Hygrometer, wet and dry bulb, 259, 261. Importance of ventilation, 211, 213. Improper use of tees, 203. Indirect heating, location of regis- ters, 91, 93. Indirect heating, sizes of air ducts and registers, 94. Indirect heating, surface required, 100, 102. Indirect radiators, 84, 92, 93. 396 INDEX Indirect radiators, casing of, 92, 93. Indirect radiators, method of sup- porting, 95. Injectors, 283, 285. Inlets, location of those for fresh air, 221. Inspirators, 285, 286. Johnson air compressor, 312. Johnson regulator, 312, 313. Johnson system of temperature reg- ulation, 311, 315. K-M-C (Morgan) system, vacuum heating, 174, 175. Labor-saving suggestions, 334, 335. Latent heat of steam at various pressures, 359. Lawler regulator, 311. Leaky boilers, cement for, 350. Length of belts, rule for determining, 369. Location of fresh-air inlets, 221. Location of registers, indirect heat- ing, 91, 93. Locating radiating surfaces, 91. Loss of pressure of air delivery through pipes, 379. Machinery, to prevent rusting, 352. Marble, to remove stains from, 352. Measurement of offsets, 349. Measurements for 45 and other an- gles, 209, 210. Measurements for setting tubular boilers with full fronts, 45. Measurements for setting tubular boilers with half fronts, 47. Measuring pipe and fittings, 72. Mechanical heating and ventilation, an ideal system, 229, 238. Mechanical heating and ventilation, capacity required, 227, 228. Mechanical heating and ventilation, methods employed, 225, 227. Mechanical ventilating apparatus, details of, 248, 252. Mechanical ventilation, American Blower Co.'s method, 234. Mechanical ventilation and hot blast heating, 224, 261. Mechanical ventilation, Buffalo Forge Co.'s method, 230, 233. Mechanical ventilation, growth and improvement, 224, 225. Mechanical ventilation, New York Blower Co.'s method, 235. Mechanical ventilation, quality of air supplied, 228, 229. Mechanical ventilation, Sturtevant method, 236. Mechanical ventilation, typical meth- od for schools, 238. Melting points of metals, 353. Metals, melting points of, 353. Metal, to inscribe, 352. Methods of artificial heating, 23. Methods of greenhouse piping, 159, 162. Methods of heating business, 316, 328. Methods of pipe construction, 203, 205. Methods of ventilation, 218, 223. Metric system, table of, 355. Minneapolis regulator, 310. Miscellaneous, 329, 346. Miscellaneous heating, 189, 198. Mitre pipe coil, 86. Mixing dampers, 250, 252. Moisture absorbed by air, 385. Moisture in the atmosphere, 386. INDEX 397 National regulator, 306, 307. Nature of heat, 18. Nipples, table of sizes, 68. Nipples, wrought-iron, 67. Offset, measurement of, 349. Oil, removing from boilers, 331, 332. Oil separators, 273, 275. One-pipe system, hot-water, 137, 139. One-pipe system, steam, 103, 111. O. S. hot-water fitting, 131. Oxygen, necessity and importance of, 211, 212. Painting, bronzing, and decoration, 335, 336. Paul system, exhaust-steam heating, 168, 173. Phelps heat retainer, 153, 154. Pipe, 63. Pipe and fittings, method of measur- ing, 72. Pipe and radiator connections, 199, 210. Pipe, bending, 64. Pipe coils, 86, 88. Pipe coils, method of building, 89. Pipe construction, methods of, 203, 205. Pipe covering, 293, 298. Pipe covering, tests, 294. Pipe, expansion of, 64, 65, 351. Pipe hangers, 65. Pipe, table of extra strong, 361. Pipe, table of double extra strong, 361. Pipe, table of standard wrought-iron, 63. Pipe, threading, 64. Pipe, to ascertain whether wrought- iron or steel, 66. Pipe, wrought-iron or steel, 66. Plates, floor and ceiling, 149. Powers system heat regulation, 303, 305. Pressure appliances, 150, 154. Pressure of water, 348. Prevention of explosions, 341, 342. Properties of saturated steam, 359. Proposal and bid, 319, 328. Pulleys, size and speed of, 350. Pump, diameters and capacities, 366. Pump governors and regulators, 280, 281. Pumps, steam, 276, 279. Pumps, vacuum, 279, 280. Radiating power of bodies, 20. Radiating surfaces, forms of, 81. Radiating surfaces, pipe coils, 86, 88. Radiating surfaces, proper location, 91. Radiation for greenhouses, 157, 158. Radiation, rules for estimating, 100, 102. Radiator and pipe connections, 199, 210. Radiator connections, hot-water, 201, 203. Radiator connections, steam, 199, 201. Radiators, decoration of, 335, 336. Radiators, direct-indirect, 95, 96. Radiators, indirect, 84, 92, 93. Radiators, types of, 81, 85. Radiator valves, 74. Radiators, wall, 85. Radiators, window, 85. Reducing pressure valves, 283. Registers for indirect heating, sizes of, 94. Regulator, D. & R., 307, 308. 398 INDEX Regulator, Howard, 308, 309. Regulator, Imperial Climax, 300. Regulator, Johnson, 312, 313. Regulator, Lawler, 311. Regulator, Minneapolis, 310. Regulator, National, 306, 307. Regulator, Powers, 301, 302. Regulators, pump, 280, 281. Relation between temperature of feed water and evaporative capac- ity of boiler, 364. Relative pressure, velocity and weight of air, 383. Removing grease stains from mar- ble, 352. Removing oil and dirt from boilers, 331, 332. Removing rust from steel, 352. Required flue area for given velocity and air change, 373. Required flue area for passage of air, 374, 375, 376. Required quantity of feed water to supply boiler, 364. Return bend pipe coil, 87. Return branch tee coil, 87. Revolutions of pulleys, to find, 350. Round galvanized iron pipe and el- bows, weight of, 377. Rule for calculating size and speed of pulleys, 350. Rules for estimating radiation for greenhouses, 157, 158. Rules, tables, and other information, 347, 389. Ryan system, vacuum heating, 178, 179. Safety valves, 49. Safety valves on expansion tanks, 143, 144. Saturated steam, properties of, 359. Schoolhouse heating and ventilating,, typical methods, 230, 238. Schoolhouse ventilation, cost of, 256, 257. Schoolhouse ventilation, Massachu- setts laws for, 215. Separators, steam and oil, 273, 275. Setting direct-indirect radiators, 95. Setting tubular boilers, 45, 48. Shell of Dunning boiler, 28. Sizes of steam mains, 114. Special features of contracts, 328. Specific gravity of steam, 349. Specifications for hot-water heating, 324, 328. Specifications, for steam heating, 319, 323. Stacks, capacity of, 363. Standard flanges, schedule of, 71. Standard type of tubular boilers, 27. Standard pipe, table of, 63, 361. Steam appliances, 262, 287. Steam for cooking and manufactur- ing, 198. Steam gauge, 50. Steam gauge, low-pressure, 51. Steam heating, advantages of, 114. Steam-heating apparatus, 103, 114. Steam heating, exhaust, 115, 119. Steam heating, methods of, 103, 104. Steam heating, specifications and bid^ 319, 323. Steam heating, the circuit system,, 104. Steam heating, the divided circuit system, 107, 109. Steam heating, the one-pipe system with dry returns, 108, 110. Steam heating, the overhead system,. 108, 111. INDEX 399 Steam heating, the two-pipe system, 112, 113. Steam mains, sizes of, 114. Steam power, cost of coal, 362. Steam pumps, 276, 279. Steam-radiator connections, 199, 201. Steam regulator, Imperial Climax, 300. Steam separators, 273, 275. Steam, specific gravity of, 349. Steam, table of temperatures, 359. Steam traps, 262, 266. Steam, value of exhaust, 115. Steel, to remove rust from, 352. Suggestions for saving labor, 334, 335. Summer care of heating apparatus, 329, 330. Summer tests to determine efficiency, 332, 333. Supporting indirect radiators, 95. Swimming pools, heating of, 189, 194. Table I. Radiating power of bodies, 20. Table II. Measurements for setting tubular boilers with full fronts, 45. Table III. Measurements for setting tubular boilers with half fronts, 47. Table IV. Sizes of chimneys, 58. Table V. Heights of chimneys, 61. Table VI. Measurements of stand- ard and wrought-iron pipe, 63. Table VII. Expansion of wrought- iron pipe, 65. Table VIII. Length and size of wrought-iron nipples, 69. Table IX. Schedule of standard flanges, 71. Table X. Indirect work: sizes cold and hot air ducts, 94. Table XI. Sizes of steam mains, 114. Table XII. Sizes of mains two- pipe hot-water system, 124. Table XIII. Expansion tank sizes, 128. Table XIV. Sizes of mains for one- pipe hot w r ater, 139. Table XV. Boiling temperatures of water at various pressures, 142. Table XVI. Temperatures green- house heating, 158. Table XVII. Schedule of water temperatures greenhouse heating, 158. Table XVIII. Capacities of hot- water heaters for swimming pools, 192. Table XIX. Sizes of tanks and heaters domestic hot-water sup- ply, 197. Table XX. Sizes of steam coils for storage tanks, 198. Table XXI. Measuring 45 and other angles, 210. Table XXII. Consumption of air by various modes of artificial light- ing, 213. Table XXIII. Air supply necessary for various buildings, 214. Table XXIV. Cubic feet of air con- taining four parts of carbonic acid in ten thousand supplied per per- son, 218. Table XXV. Temperature, weight, and humidity of air, 229. Table XXVI. Temperature table, Schott's balanced column system, 291. Table XXVII. Tests of pipe cover- ing, 294. Table XX VIII .Tests to determine efficiency, 333. 400 INDEX Table XXIX. Gauges and their equivalents, 351. Table XXX. Melting points of met- als, 353. Table XXXI. Boiling points of fluids, 353. Table XXXII. Weights and meas- ures, 354. Table XXXIII. Metric system of weights and measures, 355. Table XXXIV. Minimum and mean temperatures of various cities, 356. Table XXXV. Comparison of ther- mometric scales, 357. Table XXXVI. Area of circles and sides of squares, 358. Table XXXVII. Temperature of steam at various pressures, 359. Table XXXVIII. Properties of sat- urated steam, 359. Table XXXIX. Materials for brick- work of tubular boilers, 360. Table XL. Standard pipe, 361. Table XLI. Cost of coal for steam power, 362. Table XLIL Capacities of stacks, 363. Table XLIIL Relation between temperature of feed water and evaporative capacity of boiler, 364. Table XLIV. Feed water required by boiler, 364. Table XLV. Vacuum, pressure and temperature, etc., 365. Table XLVI. Pump diameters and capacities in gallons, 366. Table XL VII. Decimal equivalents of an inch, 367. Table XLVIII. Horse power of a leather belt one inch wide, 368. Table XLIX. Number of square inches of flue area required per 1,000 cubic feet of contents for given velocity and air change, 373. Table L. Flue area required for the passage of a given volume of air at a given velocity, 374. Table LI. Flue area required for the passage of a given volume of air at a given velocity (continued), 375. Table LII. Flue area required for the passage of a given volume of air at a given velocity (continued), 376. Table LIIL Weight of round gal- vanized iron pipe and elbows, of the proper gauges for heating and ventilating systems, 377. Table LIV. Equalizing the diam- eters of pipes, 378. Table LV. Air: Loss of pressure in ounces per square inch for varying velocities and varying diameters of pipes, 379. Table LVL Number of cubic feet of dry air that may be heated through 1 (F.) by the condensation of one pound of steam, 380. Table LVII. Number of thermal units contained in one pound of water, 381. Table LVIII. Volume and density of air at various temperatures, 382. Table LIX. Influence of the tem- perature of air upon the conditions of its movement, 383. Table LX. Velocity created, volume discharged and horse power re- quired when air under a given pressure in ounces per square inch INDEX 401 is allowed to escape in the atmos- phere, 384. Table LXI. Moisture absorbed by air, 385. Table LXII. Moisture in the atmos- phere, 386. Table LXIII. Volume of air neces- sary to maintain a standard of pur- ity, 387. Table LXIV. Pressure in inches of water and corresponding pressure in ounces, with velocities of air due to pressures, 388. Table LXV. Pressure in ounces per square inch with velocities of air due to pressures, 388. Table LX VI. Weights of galvan- ized iron pipe per lineal foot, 389. Table of weights and measures, 354. Tables, rules and other information, 347, 389. Tank capacities, domestic water heat- ing, 197. Tees, improper use of, 203. Temperature of steam, table of, 359. Temperature regulation and heat control, 299, 315. Temperatures of various cities in the United States, 356. Thermal units in one pound of water, 381. Thermometer, high temperature, 258. Thermometer, hot-water, 147, 148. Thermometric scales, comparison of, 357. Thermostat, Howard, 308. Thermostat, Johnson, 312. Thermostat, Lawler, 311. Thermostat, Minneapolis, 310. Thermostat, National, 306. Thermostat, Powers, 301. To clean brass, 351. To harden cast iron, 352. To prevent machinery from rusting, 352. To remove rust from steel, 352. To remove stains from marble, 352. Tools, care of, 333, 334. Trane mercury seal system, vacuum heating, 175, 178. Traps, bucket, 263, 264. Traps, expansion, 263. Traps, float, 264, 265. Traps, return, 266, 273. Tubular boilers, heating capacity of, 349. Tubular boilers, materials for brick- ing, 360. Tubular boilers, measurements for setting, 45, 47. Tubular boilers, plan of brick setting, 46, 48. Underground pipe, covering for, 296, 297. Useful information, 347, 389. Utilizing waste heat, 342, 346. Vacuum exhaust systems, 165, 173. Vacuum heating, future of, 187, 188. Vacuum heating systems, 163, 188. Vacuum, pressure and temperature, table of, 365. Vacuum pumps, 279, 280. Vacuum, relief on expansion tank, 143, 144. Vacuum Vapor Company's system, 181. Vacuum- vapor heating system, 183. Valves, 73. Valves, angle, 74. Valves, back-pressure, 282. 402 INDEX Valve, check, 76. Valve, diaphragm radiator, 303, 313. Valves, gate, 74, 75, 76. Valves, radiator, 74. Valves, reducing pressure, 283. Valves, safety, 49. Valve, straightway hot-water, 131. Value of exhaust steam, 115. Van Auken system, vacuum heating, 173. Vapor heating system, 178, 180. Velocity of air due to pressures, 388. Ventilation, 211, 223. Ventilation, air necessary for, 213, 218. Ventilation, early history of, 16. Ventilation, importance of, 211, 213. Ventilation, mechanical, 224, 261. Ventilation, methods of, 218, 223. Ventilation, required area of flues, 373, 376. Volume of air at various tempera- tures, 382. Wall boxes for direct-indirect radia- tors, 95. Waste-heat utilizing, 342, 346. Water, boiling point of, 142, 347. Water column and gauge glass, 53, 54. Water, expansion of, 347. Water feeders, automatic, 287. Water, gallons in cylindrical tank, 348, 351. W r ater-line, artificial, 205, 206. Water, pressure of, 348. Water, pressure in inches, 388. Water, pressure in ounces, 388. W'ater required by condensing en- gines, 349. Water required by tubular boilers, 348. Water surface in boilers, 41. Water, thermal units in one pound, 381. Water, weight of, 347. Weight of anthracite coal, 348. Weight of bituminous coal, 348. Weight of galvanized iron pipe, 377, 389. Weight of water, 347. Weights and measures, table of, 354. Weights and measures, the metric system, 355. Webster system, exhaust-steam heat- ing, 165, 168. W^hy hot water circulates, 139, 140. OF THE UNIVERSITY OF RAINBOW PACKING Makes Steam Flange and Hot Water Joints Instantly THE COLOR OF RAINBOW PACKING IS RED See that our Trade Mark, the word "Rainbow" in a diamond, in three rows of diamonds in black, connected, extends throughout the entire length of each yard or roll. 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ENDORSED BY ALL BOILER MANUFACTURERS More than six thousand systems installed in all classes of buildings in the United States and Canada during 1907. For full particulars regarding this eminently successful system and how to install it, write the HONEYWELL HEATING SPECIALTY CO. WABASH, INDIANA The BUNDY LINE of manufacture consists of Bundy Steam and Water Boilers Bundy Steam and Water Radiators Bundy Steam and Oil Separators Bundy Steam Traps Bundy Feed Water Heaters These goods are partially described within the pages of this book for complete details send name and address for latest published Catalogs. A. A. GRIPPING IRON COMPANY Jersey City, N. J. Boston, Mass. Philadelphia, Pa. THE ALBANY STEAM TRAP CO ESTABLISHED 1870 ALBANY, N. Y. MANUFACTURERS OF RETURN STEAM TRAPS NON-RETURN STEAM TRAPS PUMPS, PUMP GOVERNORS AND HIGH GRADE STEAM VALVES JAMES H. BLESSING THOMAS F. RYAN PRESIDENT TREASURER STEAM, WATER AND AIR SPECIALTIES Up to Date and Guaranteed Reducing Valves for all purposes Back Pressure Valves for all purposes Atmospheric Relief Valves Steam Traps for all purposes Damper Regulators Hot Water Temperature Controllers Water Pressure Regulators Steam Separators Grease Extractors Pump Regulators Water Feeders Trap Purifiers and Feed Water Heaters Feed Water Regulators High Pressure Boiler Feeders Water Arches. Emergency Valves. High and Low Water Alarms Strainer Connections Drip Tank Controllers Float Valves Pump Governors and Receivers Combination Muffler and Grease Extractor Tanks, Receivers, Pump Governor, Pump and Feed Water Heater Grease Extractor and Purifier Feed Water Heaters Waste Heat Utilizers, etc. MANUFACTURED BY Grease and Oil TrapH Low Water Alarms Tank Pump Controllers ~tT" Special 98 Valve KIELEY & MUELLER, 34 West 13th Street, New York City SCIENTIFIC AND PRACTICAL BOOKS PUBLISHED BY The Norman W. 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Standard Electrical Dictionary A practical handbook of reference, containing definitions of about 5,000 distinct words, terms, and phrases. An entirely new edition, brought up to date and greatly enlarged. Complete, concise, convenient. 682 pages. 393 illustrations. Handsomely bound in cloth. 8vo. $3.00. STARBUCK. Modern Plumbing Illustrated A comprehensive and up-to-date work illustrating and describing the Drainage and Ventilation of dwellings, apartments, and public buildings, etc. The very latest and most approved methods in all branches of sanitary installation are given. Adopted by the United States Government in its sanitary work in Cuba, Porto Rico, and the Philippines, and by the principal boards of health of the United States and Canada. The standard book for master plumbers, architects, builders, plumbing inspectors, boards of health, boards of plumbing examiners, and for the property owner, as well as for the workman and his apprentice. 300 pages. 50 full-page illustrations. $4.00. USHER. The Modern Machinist A practical treatise embracing the most approved methods of modern machine-shop practice, and the applications of recent improved appliances, tools, and devices for facili- tating, duplicating, and expediting the construction of machines and their parts. A new book from cover to cover. Fifth edition. 257 engravings. 322 pages. Cloth, $2.50. Publications of The Norman W. Henley Publishing Co. VAN DERVOORT. Modern Machine Shop Tools ; Their Construction, Operation, and Manipulation, Including Both Hand and Machine Tools An entirely new and fully illustrated work of 555 pages and 673 illustrations, describ- ing in every detail the construction, operation, and manipulation of both Hand and Machine Tools; being a work of practical instruction in all classes of machine-shop practice. In- cluding chapters on filing, fitting, and scraping surfaces; on drills, reamers, taps, and dies; the lathe and its tools; planers, shapers, and their tools; milling machines and cutters; gear cutters and gear cutting; drilling machines and drill work; grinding machines and their work; hardening and tempering; gearing, belting, and transmission machinery ; useful data and tables. Fourth edition. $4.00. WALLIS- TAYLOR. Pocket Book of Refrigeration and Ice Making This is one of the latest and most comprehensive reference books published on the sub- ject of refrigeration and cold storage. It explains the properties and refrigerating effect of the different fluids in use, the management of refrigerating machinery and the construc- tion and insulation of cold rooms, with their required pipe surface for different degrees of cold; freezing mixtures and non-freezing brines, temperatures of cold rooms for all kinds of provisions; cold-storage charges for all classes of goods, ice-making and storage of ice, data and memoranda for constant reference by refrigerating engineers, with nearly one hundred tables containing valuable references to every fact and condition required in the instalment and operation of a refrigerating plant. $1.50. WOOD. Walschaert Locomotive Valve Gear The only work issued treating of this subject of valve motion. 150 pages, illustrated. Cloth $1.50. WOODWORTH. American Tool Making and Interchangeable Manu- facturing A practical treatise of 560 pages, containing 600 illustrations on the designing, con- structing, use, and installation of tools, jigs, fixtures, devices, special appliances, sheet-metal working processes, automatic mechanisms, and labor-saving contrivances; together with their use in the lathe, milling machine, turret lathe, screw machine, boring mill, power press, drill, subpress, drop hammer, etc., for the working of metals, the production of in- terchangeable machine parts, and the manufacture of repetition articles of metal. $4.00 WOODWORTH. Dies, Their Construction and Use for the Modem Working of Sheet Metals A complete treatise of 384 pages and 505 illustrations upon the designing, constructing, and use of tools, fixtures, and devices, together with the manner in which they should be used in the power press, for the cheap and rapid production of the great variety of sheet- metal articles now in use. It is designed as a guide to the production of sheet-metal parts at the minimum of cost with the maximum of output. The hardening and tempering of Press tools and the classes of work which may be produced to the best advantage by the use of dies in the Power press are fully treated. The engravings show dies, press fixtures, and sheet-metal working devices, from the simplest to the most intricate, and the descriptions are so clear and practical that all metal- working mechanics will be able to understand how to design, construct and use them. $3.00. WOODWORTH. Hardening, Tempering, Annealing, and Forging of Steel A new book containing special directions for the successful hardening and tempering of all steel tools. Milling cutters, taps, thread dies, reamers, both solid and shell, hollow mills, punches and dies, and all kinds of sheet-metal working tools, shear blades, saws, fine cutlery and metal-cutting tools of all descriptions, as well as for all implements of steel, both large and small, the simplest and most satisfactory hardening and tempering processes are presented. The uses to which the leading brands of steel may be adapted are con- cisely presented, and their treatment for working under different conditions explained, as are also the special methods for the hardening and tempering of special brands. 320 pages. 250 illustrations. $2.50. WOODWORTH. Punches, Dies and Tools for Manufacturing in Presses A work of 500 pages, and illustrated by nearly 700 engravings, being an encyclopaedia of die-making, punch-making, die-sinking, sheet-metal working, and making of special tools, subpresses, devices and mechanical combinations for punching, cutting, bending, forming, piercing, drawing, compressing, and assembling sheet-metal parts and also articles of other materials in machine tools. $4.00. WRIGHT. Electric Furnaces and Their Industrial Application This is a book which will prove of interest to many classes of people ; the manufacturer who desires to know what product can be manufactured successfully in the electric furnace, the chemist who wishes to post himself on electro-chemistry, and the student of science -who merely looks into the subject from curiosity. The book is not so scientific as to be of use only to the technologist, nor so unscientific as to suit only the tyro in electro-chemistry; it is a practical treatise of what has been done, and of what is being done, both experi- mentally and commercially, with the electric furnace. 288 pages. $3.00. 37-7 UNIVERSITY OF CALIFORNIA LIBRARY BERKELEY THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW 00 1926 50m-8,'26 I U