key: cord-0950354-mj3s7dyo
authors: Zhao, By Bin; Liu, Yumeng; Chen, Chen
title: Air purifiers: A supplementary measure to remove airborne SARS-CoV-2
date: 2020-04-24
journal: Build Environ
DOI: 10.1016/j.buildenv.2020.106918
sha: 88f9d28eea1c6d8fb3db649f32218b5bb14f36c9
doc_id: 950354
cord_uid: mj3s7dyo

nan

Although the transmission of COVID-19 occurs mainly via droplets during close contact or 20 contaminated surfaces, a recent study showed that SARS-CoV-2 remains viable in aerosols 21 for multiple hours [1] , and the World Health Organization (WHO) is considering "airborne 22

precautions" for medical staff [2] . China even issued the airborne precaution in the "Chinese 23

Government's New Coronavirus Pneumonia Diagnosis and Treatment Plan" [3] . aerosols. According to our previous measurements, the efficiencies of HEPA are more than 53 95% for aerosols of diameter between 0.25 to 1.0 μm and nearly 100% for those with 54 diameter larger than 2.5 μm [10]. The air purifiers are affordable with enough clean air 55 delivery rate (CADR, a figure of merit that is the cubic meter per hour of air that has had all 56 the particles of a given size distribution removed) and low electric power: the median CADR 57 is 361 m 3 /h and the median electric power per CADR is only 0.15 W/(m 3 /h), according to our 58 survey of 100 best-selling air purifiers on China's major online-shopping sites ( Table 1) . waste or disinfected thoroughly to prevent secondary contamination. As there is still lack of 68

proper guidance of handling the filters for such an application, the frequency to replace or 69 clean the filters may should be higher than that for ordinary use. Furthermore, the air purifiers 70 with disinfection capability may be more effective for combating the virus, and could be 71 considered for use if necessary. Such air purifiers would cost more and consume more energy, 72 but this is perhaps of a less concern under the current pandemic situation. 

We declare no competing interests. 97

Aerosol and Surface Stability of

National Health Commission of the People's Republic of China. Chinese Government's

New Coronavirus Pneumonia Diagnosis and Treatment Plan (Trial Version 7

Aerodynamic Characteristics and RNA Concentration of

Aerosol in Wuhan Hospitals during COVID-19 Outbreak

Surface Environmental, 123 and Personal Protective Equipment Contamination by Severe Acute Respiratory Syndrome 124

SARS-CoV-2) From a Symptomatic Patient

Aerosol and Surface Distribution of Severe Acute 127

Respiratory Syndrome Coronavirus 2 in Hospital Wards

Bioaerosol Spread of SARS-CoV-2 for the COVID-19 Pandemic

Natural ventilation for infection control in health-care settings

Declaration of interests ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work

The authors are grateful for Dr. Bin Zhou's edits. 106

All authors have made substantial contributions to all of the following: 100(1) BZ designed the conception, and drafted the manuscript. 101(2) YL analysed the data and helped to draft the manuscript.