Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Ultrafine particle removal and generation by portable air cleaners
AbstractPortable air cleaners can both remove and generate pollutants indoors. To investigate these phenomena, we conducted a two-phase investigation in a 14.75m3 stainless steel chamber. In the first phase, particle size-resolved (12.6–514nm diameter) clean air delivery rates (CADR) and efficiencies were determined, as were ozone emission rates, for two high-efficiency particle arresting (HEPA) filters, one electrostatic precipitator with a fan, and two ion generators without fans. The two HEPA air cleaners had count average CADR (standard deviation) of 188 (30) and 324 (44)m3h−1; the electrostatic precipitator 284 (62)m3h−1; and the two ion generators 41 (11) and 35 (13)m3h−1. The electrostatic precipitator emitted ozone at a rate of 3.8±0.2mgh−1, and the two ion generators 3.3±0.2 and 4.3±0.2mgh−1. Ozone initiates reactions with certain unsaturated organic compounds that produce ultrafine and fine particles, carbonyls, other oxidized products, and free radicals. During the second phase, five different ion generators were operated separately in the presence of a plug-in liquid or solid air freshener, representing a strong terpene source. For air exchange rates of between 0.49 and 0.96h−1, three ion generators acted as steady-state net particle generators in the entire measured range of 4.61–157nm, and two generated particles in the range of approximately 10 to 39–55nm. Terpene and aldehyde concentrations were also sampled for one ion generator, and concentrations of terpenes decreased and formaldehyde increased. Given these results, the pollutant removal benefits of ozone-generating air cleaners may be outweighed by the generation of indoor pollution.
Ultrafine particle removal and generation by portable air cleaners
AbstractPortable air cleaners can both remove and generate pollutants indoors. To investigate these phenomena, we conducted a two-phase investigation in a 14.75m3 stainless steel chamber. In the first phase, particle size-resolved (12.6–514nm diameter) clean air delivery rates (CADR) and efficiencies were determined, as were ozone emission rates, for two high-efficiency particle arresting (HEPA) filters, one electrostatic precipitator with a fan, and two ion generators without fans. The two HEPA air cleaners had count average CADR (standard deviation) of 188 (30) and 324 (44)m3h−1; the electrostatic precipitator 284 (62)m3h−1; and the two ion generators 41 (11) and 35 (13)m3h−1. The electrostatic precipitator emitted ozone at a rate of 3.8±0.2mgh−1, and the two ion generators 3.3±0.2 and 4.3±0.2mgh−1. Ozone initiates reactions with certain unsaturated organic compounds that produce ultrafine and fine particles, carbonyls, other oxidized products, and free radicals. During the second phase, five different ion generators were operated separately in the presence of a plug-in liquid or solid air freshener, representing a strong terpene source. For air exchange rates of between 0.49 and 0.96h−1, three ion generators acted as steady-state net particle generators in the entire measured range of 4.61–157nm, and two generated particles in the range of approximately 10 to 39–55nm. Terpene and aldehyde concentrations were also sampled for one ion generator, and concentrations of terpenes decreased and formaldehyde increased. Given these results, the pollutant removal benefits of ozone-generating air cleaners may be outweighed by the generation of indoor pollution.
Ultrafine particle removal and generation by portable air cleaners
Waring, Michael S. (Autor:in) / Siegel, Jeffrey A. (Autor:in) / Corsi, Richard L. (Autor:in)
Atmospheric Environment ; 42 ; 5003-5014
10.02.2008
12 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Sensory Testing on Portable Indoor Air Cleaners
| British Library Conference Proceedings | 1994
| British Library Online Contents | 2018
| British Library Online Contents | 2018