Low sound level source path contribution on a HVAC

For compliance test purposes, the noise level of a HVAC is usually measured with a pressure microphone positioned at a certain distance. This measurement is normally performed in an anechoic room.

However, this method doesn't provide the engineer any insight on what noise sources do contribute to the overall noise level measured. A new Microflown based low sound level source path contribution analysis measurement approach is presented to pinpoint the various noise sources that vary in time, frequency and place. The new method shows all place and time dependent noise sources, and allows assessment of the extent that they contribute to the overall noise level determined for the compliance test using the sound pressure microphone. Furthermore, the new method can be used in a normal room, eliminating the need to use an anechoic room.