Measurement of infiltration rates in building spaces with blower-door and tracer gas methods
This DRP focuses on the air tightness of buildings and its effect on Indoor Air Quality (IAQ) and energy use. The objective is to measure the infiltration rates by blower-door and tracer gas methods and finding a correlation between the two. Tracer gas method gives air change rate due to infiltration under atmospheric conditions. The blower-door method on the other hand estimates the infiltration rate at a pressure of 50 Pa (above or below the atmospheric pressure). The blower-door method is not affected by atmospheric conditions and its results are reproducible. Also, it can be carried out in a period of 1-2 hours unlike tracer decay which needs considerable time. Currently, for converting infiltration rates of the blower-door to atmospheric conditions the following equation is employed: Where Q50 is the measured air leakage at a pressure of 50 Pa (m3s-1) and V is the internal volume of the building (m3). The leakage-infiltration ratio, N=20, used in the equation is based on tests conducted on dwellings in the United States. Literature suggests that division by such a factor for conversion of infiltration rates could be climate dependent and may not be generic. Therefore, the objective of this DRP is to measure infiltration rates with both tracer gas and blower-door methods for 50 building spaces in Ahmedabad, India and find out the correlation between the two methods. Estimation of infiltration rates is necessary in the context of energy efficiency and indoor air quality. Such a study would throw light on the current building stock, their envelope characteristics and associated infiltration rates.
