Simulation models basing on 2-dimensional finite-difference approach were developed for the steady-state and dynamic analyses of the thermal coupling of leakage airflows and building components. The considered types of leakage flows were crack flow and filtration through porous materials.
Reverberant sound excitation and the sound intensity technique have been used for the measurement of the sound transmission loss of narrow slits in rigid walls. A series of experiments was conducted to determine the transmission loss of slit shaped apertures. The measured transmission loss was in good agreement with existing approximate theories over their accepted ranges of validity. However, the effect of viscosity in small apertures was found to be significant and to vary systematically with the dimensions of the apertures.
Both infiltration and exfiltration has a predominant influence on the space heating requirements in cold climates. Good predictive design methods are required to estimate the air leakage component in buildings. This predictive methods will be useful in implementing the air leakage control strategies for reducing the problems associated with air infiltration in both new and existing high-rise buildings.
Tracergases provide a way to determine airflows in different situations. In some cases it is the only way to get quantitative information. This paper presents two cases in which tracergases are used for measuring the internal leakage in heat recovery units. Internal leakage in heat recovery ventilators (HRV's) for domestic use may cause some problems: - the real quantity of fresh air entering the building is unknown - electrical power for the fans is used inefficiently - smelling air a.g.
A new handbook, describing in details the measurement techniques which could be used to better understand the infiltration and ventilation in buildings is presented. This handbook results from the cooperation between Annex 20 and Annex 5 of the IEA ECB program. It presents the techniques for detecting and measuring as well the air leakages as the air flows in buildings and inventilation systems. Methods related to ventilation efficiency and effectiveness, like the measurement of the age of air, are also described.
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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