The effect of an ion generator on indoor air quality in a residential room

Abstract

Ion generators charge particles with a corona prior to their removal on collector plates or indoor surfaces and also emit ozone, which can react with terpenes to yield secondary organic aerosol, carbonyls, carboxylic acids, and free radicals. This study characterized the indoor air quality implications of operating an ion generator in a 27m3 residential room, with four different test room configurations. Two room configurations had carpet overlaying the original flooring of stained/sealed concrete, and for one configuration with and without carpet, a plug-in air freshener was used as a terpene source. Measurements included airborne sampling of particulate matter (0.015-20μm), terpenes and C1-C4 and C6-C10 aldehydes, ozone concentrations, and air exchange rates. When the heating, ventilating, and air-conditioning system was not operating (room air exchange rate=~0.5/h), the use of the ion generator in the presence of the air freshener led to a net increase in ultrafine particles (<0.1μm). Also, increased concentrations of ozone were observed regardless of air freshener presence, as well as increases in formaldehyde and nonanal, albeit within measurement uncertainty in some cases. Thus, it may be prudent to limit ion generator use indoors until evidence of safety can be ascertained. © 2010 John Wiley & Sons A/S.