NOISE LEVEL IN RELATION TO ENERGY PERFORMANCE OF AIR-TO-AIR HEAT PUMPS

With increased use of air source heat pumps, a possible barrier for further market growth and customer acceptance is their noise level. The disturbance is both an issue for the owner of the heat pump and the neighbors since both the indoor and the outdoor units radiate sound. The purpose of this study is to create an understanding of the noise generation of air-to-air heat pumps and relate this to their energy performance. This knowledge is then to be used in continued work when describing the total disturbance of a heat pump. Two heat pumps, both of inverter type and with different noise performance were selected for measurements. Energy performance, in the form of Coefficient of Performance (COP), was evaluated at different operating conditions. Measurements of the sound power level were performed on both the outdoor and the indoor units. Results show that the sound level from the indoor units is independent of the outdoor conditions. The noise from the outdoor units varies with different climates and the variation is particularly large at part load conditions