Acoustical impacts of operating air-cooled chillers as heat pumps

With the increased application of heat pumps across wider geographic regions, it is useful to understand how the operating point of an air-cooled chiller shifts when functioning as a heat pump and what impact this has on its acoustics. This paper will review how compressor and fan operating points change when in heating mode and the trends in sound power level with these changes. Measured reverberant room results of compressors at typical heating and cooling conditions will be presented. The impact of unit control strategies in the different modes will be discussed and their impact on sound will be summarized.