OZONE REMOVAL BY RESIDENTIAL HVAC FILTERS

摘要

HVAC filters have a significant influence on indoor air quality. In addition to removing particulate contaminants,filters accumulate a particle layer that can react with ozone. Ozone-particle cake reactions serve as a sink for ozone and a source of secondary carbonyls. The location of filters in air distribution systems can lead to byproducts being distributed throughout a building. Two experiments were performed to determine the ozone removal efficiency on two residential filters that were loaded with particles for one month (#1) and three months (#2). On both filters, the ozone removal efficiency dropped rapidly during the first 30 minutes and then stayed approximately constant for 4 hours. The steady state values of ozone removal efficiency were 10% for Filter #1and 14% for Filter #2 at a face velocity of 0.81 cm/s. The potential for HVAC filters to affect ozone concentrations in residential buildings was evaluated using a well-mixed reactor model. The tested filters reduced indoor ozone levels slightly when compared to indoor surfaces and an entire HVAC system, although the impact was much smaller than that of the air exchange rate. The influence of continuous particle deposition was not considered here, but would likely increase the impact of ozone interactions on HVAC filters.