Infiltration and indoor air quality in energy efficient houses in Eugene, Oregon

Measurements of infiltration rates and indoor pollutant levels in houses incorporating energy-conserving measures can provide important information about the effectiveness and health effects of such measures. Twelve energy-efficient houses in Eugene, Oregon were measured for effective leakage area using blower door fan pressurization. Air exchange rates over a period of several hours were determined by tracer gas decay analysis. The results of these measurements were used in conjunction with the LBL infiltration model to predict average annual and heating season infiltration rates. Measured leakage areas and infiltration rates were found to be quite low in comparison to other groups of test houses in North America. Average specific leakage areas for the 12 houses was 2.8 cm/sup 2//m/sup 2/ as compared to 6.4 cm/sup 2//m/sup 2/ for post-1975 California housing. The average heating season infiltration rate was calculated to be 0.34 air changes per hour. Infiltration rates measured from tracer gas decay ranged from 0.08 to 0.27 air changes per hour. Indoor concentrations of radon, formaldehyde, and nitrogen dioxide were measured in four of the twelve houses. Radon levels were found to be insignificant. Nitrogen dioxide concentrations were low in all four houses, although levels in the two houses where occupantsmore » smoked were slightly elevated by comparison to the two houses without smokers. Levels of formaldehyde comparable to or half of the most restrictive existing guideline were found in all four houses. Furniture and/or building materials are believed to be the source of this pollutant.« less