Strategy for measuring infiltration rates in large, multicelled and naturally ventilated buildings using a single tracer gas.

Large, multicelled and naturally ventilated buildings pose many inherent problems for the measurement of overall infiltration rates using tracer gases. Considering a single tracer gas decay technique, the most obvious problems are: (a) local variations in infiltration, (b) imperfect internal mixing of the air, and (c) practical difficulties in distributing (ie, seeding) the tracer gas and subsequently obtaining air samples. This paper proposes a relatively simple technique which avoids these problems and which, if successful, makes a breakthrough in the measurement of infiltration rates in large and complex buildings. By considering a multicell model, it is shown that it can be sufficient to seed part of a building with a single tracer gasin order to measure the overall infiltration rate to a good approximation.