Air Infiltration Rates in Pre- and Post-Weatherized Houses

Abstract

Air infiltration rates were measured via a tracer dilution method in 10 eastern Washington houses before and after the houses were weatherized in order to determine the effectiveness of weatherization procedures. Infiltration rates during typical meteorological conditions ranged from 0.3 to 1.0 air exchanges per hour (ex/h) among the houses. Reduction in these infiltration rates due to weatherization also varied considerably from essentially no change to 40% reduction in the air exchange rate. The average reduction in the air infiltration rate was approximately 16%. Infiltration rates were measured continuously in one house during several weeks and the results showed that the extended use of doors can cause infiltration rates to increase from less than 1 ex/h for a closed house to more than 3 ex/h. Limited air pollution measurements conducted during the study indicated that formaldehyde and radon concentrations were quite low indoors while individual hydrocarbon concentrations indoors were much higher than those measured outdoors.