Sound Power Determination of Automotive A/C-Compressors

Dominating sound sources of vehicles (like the combustion engine and the powertrain) have been significantly improved in terms of sound emission during the last decades. Therefore the acoustic performance of A/C-compressors becomes more important for passenger comfort. At engine idling and at extreme temperatures the A/C-compressor can be audible as the significant sound source. Compressor's air borne noise radiation can be quantified by the sound power. The reverberation chamber method is a suitable procedure for the determination of sound power levels. A small reverberation chamber was designed at Visteon for this technique. Acoustic characteristics of the sound field inside the chamber were determined. Objective evaluation of the air borne sound emission of five different refrigerant compressors was performed. The reverberation chamber method was then compared to the sound intensity method for sound power determination.