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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - How efficiently can HEPA purifiers remove priority fine and ultrafine particles from indoor air?
AU - Lowther, Scott
AU - Deng, W.
AU - Fang, Z
AU - Booker, Douglas
AU - Whyatt, Duncan
AU - Wild, Oliver
AU - Wang, Xinming
AU - Jones, Kevin
PY - 2020/11/1
Y1 - 2020/11/1
N2 - More than 1 million premature deaths in Asia annually are estimated to be associated with indoor air quality. HEPA (high-efficiency particulate air) filter air purifiers (APs) are widely used in urban Chinese residences by the growing middle class, as public awareness of air pollution increases. Currently, understanding of how particle size affects particle removal is inconsistent, and the rate at which different particle types are removed remains largely unknown. Therefore, this investigation aimed to determine the relationship between particle size and the removal efficiency of particles, and how efficiently ambient air is filtered compared to standard particle types which are typically used for such tests (tobacco smoke, dust and pollen). Three of the most popular AP models in China were tested in China’s largest indoor controlled chamber laboratory and the removal efficiencies of particles in the 18-514nm range were identified. Each AP had a distinct profile of removal efficiency against particle size, but the three APs shared similarities in performance, with removal efficiency consistently lowest at 200-250nm. This size fraction is important in an exposure context as these particles are abundant in ambient air in mega-cities, can penetrate through building shells effectively, remain airborne for long periods of time and can penetrate the deepest areas of the lungs. Ambient air particles were removed at a similar rate to test particles; this confirms that the Association of Home Appliance Manufacturers’ (AHAM) standards are a suitable proxy for “real world” performance.
AB - More than 1 million premature deaths in Asia annually are estimated to be associated with indoor air quality. HEPA (high-efficiency particulate air) filter air purifiers (APs) are widely used in urban Chinese residences by the growing middle class, as public awareness of air pollution increases. Currently, understanding of how particle size affects particle removal is inconsistent, and the rate at which different particle types are removed remains largely unknown. Therefore, this investigation aimed to determine the relationship between particle size and the removal efficiency of particles, and how efficiently ambient air is filtered compared to standard particle types which are typically used for such tests (tobacco smoke, dust and pollen). Three of the most popular AP models in China were tested in China’s largest indoor controlled chamber laboratory and the removal efficiencies of particles in the 18-514nm range were identified. Each AP had a distinct profile of removal efficiency against particle size, but the three APs shared similarities in performance, with removal efficiency consistently lowest at 200-250nm. This size fraction is important in an exposure context as these particles are abundant in ambient air in mega-cities, can penetrate through building shells effectively, remain airborne for long periods of time and can penetrate the deepest areas of the lungs. Ambient air particles were removed at a similar rate to test particles; this confirms that the Association of Home Appliance Manufacturers’ (AHAM) standards are a suitable proxy for “real world” performance.
KW - HEPA
KW - Air Purifiers
KW - Air Filtration
KW - Particulate Matter
KW - Ambient PM
U2 - 10.1016/j.envint.2020.106001
DO - 10.1016/j.envint.2020.106001
M3 - Journal article
VL - 144
JO - Environment International
JF - Environment International
SN - 0160-4120
M1 - 106001
ER -