Residential Air Exchange Rates in the United States: Empirical and Estimated Parametric Distributions by Season and Climatic Region

Abstract

The purpose of this paper is to undertake a statistical analysis to specify empirical distributions and to estimate univariate parametric probability distributions for air exchange rates for residential structures in the United States. To achieve this goal, we used data compiled by the Brookhaven National Laboratory using a method known as the perfluorocarbon tracer (PFT) technique. While these data are not fully representative of all areas of the country or all housing types, they are judged to be by far the best available. The analysis is characterized by four key points: the use of data for 2,844 households; a four-region breakdown based on heating degree days, a best available measure of climatic factors affecting air exchange rates; estimation of lognormal distributions as well as provision of empirical (frequency) distributions; and provision of these distributions for all of the data, for the data segmented by the four regions, for the data segmented by the four seasons, and for the data segmented by a 16 region by season breakdown. Except in a few cases, primarily for small sample sizes, air exchange rates were found to be well fit by lognormal distributions (adjusted R2 > 0.95). The empirical or lognormal distributions may be used in indoor air models or as input variables for probabilistic human health risk assessments.

Evaluating methods for predicting indoor residential volatile organic compound concentration distributions

“…The size of the residences in the BEAM study were similar to the national average of 369 m 3 (U.S. Environmental Protection Agency, 1997) and larger, on average, than the residences in the TEACH LA study. The estimated air exchange rates were greater in the TEACH LA residences than in the BEAM study, both of which are higher than the mean values in earlier-derived regional distributions (Murray and Burmaster, 1995).…”

“…Although this poses some challenges, it is theoretically feasible to develop distributions of air exchange and volume using data in the literature or using publicly available data. For example, Murray and Burmaster have established air exchange distributions for different regions of the country; however, we note that for both of our study populations, the measured air exchange rates were at the upper end of the distributions of values estimated by Murray and Burmaster (Murray and Burmaster, 1995). Residence sizes could be obtained from local property assessment offices or real-estate websites.…”

Ozone in Indoor Environments: Concentration and Chemistry

“…Residential air exchange rates vary from a seasonal average of ∂ 0.2 ach for tightly constructed housing to as high as 2 ach for loosely constructed housing (ASHRAE, 1997). Based on a statistical analysis of data from 2,844 households, Murray and Burmaster (1995) report a mean air exchange rate of 0.76 ach. Their analysis illustrates the influence of the season on air exchange.…”

Continuous measurements of air change rates in an occupied house for 1 year: The effect of temperature, wind, fans, and windows

“…Air change rates have been measured in several thousand homes in the US (Murray and Burmaster, 1995 ), but most of these were one-time measurements made over short periods of 12 h to several weeks, making it impossible to determine the effects on air change rates of weather conditions and homeowner behavior such as windowopening habits and use of exhaust fans. Some attempts to determine temperature and wind effects have been made in unoccupied test houses (Emmerich and Nabinger, 2000 ), but these efforts omit homeowner behavior effects, which may be more important than the effects of temperature and wind.…”