Measurement of seasonal air flow rates in an unoccupied single family house.

For more than four years air infiltration measurements have been made on two nearly identical side-by-side test houses in Gaithersburg, Maryland, USA. This testing of the complete seasonal weather influence on air infiltration has, in the past two years, included constant concentration tracer gas measurements (CCTG). These multizone air infiltration measurements have added further detail on the response of air infiltration into the house to weather changes and the variation of air infiltration between different house locations. Time series data point out the minimal infiltration rates that occur during certain periods. Seasonal data displayed in frequency and three-dimensional plots illustrate the regularity of air infiltration and its relation to delta temperature and windspeed. Regression analysis is then applied to the data sets to reveal the influence of individual parameters such as delta temperature, windspeed and direction. The results show that a simple additive model of delta temperature and windspeed explains most of the air infiltration variations (r² ~ 0.75) and that more sophisticated models add little to the accuracy of the prediction.