Variability in residential air leakage.

Air leakage is the single most important quantity in the determination of air infiltration in residential structures. Air leakage is most commonly measured using the fan pressurization technique (ASTM standard E779): the data gathered with this method is often used to determine a leakage constant and a flow exponent. In this report, data gathered from measurements in the USA and Canada is compiled into a list of leakage constants and flow exponents, and the variability of these values over climate and housing types is examined.