Air is the main transport medium for contaminants in buildings. Minimizing source strengths has first priority, second is to control air flow rates, supply and exhaust, and directions between zones in buildings. Computer simulation models forventilation and pollutant spread in buildings have been proven to give useful predictions. Large measurement campaigns for optimizing ventilation and pollutant problems are complex and expensive. They are often jammed by too many vague parameters influencing the result. The computer models are an alternative and form a supplement to measurements.
Accurate measurement of the positions of windows, skylights, vents, dampers, etc. has always been a problem for researchers. Often open/closed switches are used which do not indicate the degree of opening which has occurred. The use of Hall-Effect sensors to measure such positions was first proposed for monitoring residential passive air inlets.
The sound intensity technique and reverberant sound excitation have been used for the measurement of sound transmission loss through narrow slits in rigid walls. As predicted by theory, the dimensions of the apertures determine the magnitudes andresonant frequencies of the sound transmission loss curves. It should thus be possible in principle to size air leakage cracksusing the technique described in this paper.
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