Building air-infiltration quantification based on sound transmission loss calculated using nearfield acoustic holography

This talk will demonstrate the abilities of nearfield acoustic holography (NAH) to detect and quantify leakages in building envelopes. A tonal sound source was placed inside a building model which has known leakages and microphone array measurements were obtained from the outside. Equivalent sources model based NAH was applied on the measured data to reconstruct the sound pressure field on the wall of the building model. Present results show that the NAH method was able to successfully locate the major leakages. A single microphone was used to measure the sound pressure level inside the building model which was used as a reference for quantification calculations. The difference between the inner and outer sound pressure levels was related to the area of the leakage. Various sizes of pinholes and rectangular cracks were investigated, and the detection limits of the current method were explored.