Abstract: The running noise of the wall mounted integral heat pump water heater is large, about 49 dB(A) before the improvement. The main noise sources are compressor and fan running noise, piping vibration, and so on. The wall mounted integral heat pump water heater is installed usually in the toilet, and the running noise affects people's daily life. Through the improvement of the compressor anti-vibration pad and fixing method, fan speed and blade twist angle, piping vibration reduction and noise propagation path etc., the noise of the machine can be reduced by about 10 dB(A), and the noise reduction effect is obvious.

Key words: Wall mounted heat pump water heater, Fan blade twist angle, Piping vibration reduction, Noise propagation path