An Air/Water heat pump extracts energy from the ambient air by using a fan. This creates noise. Depending on the size, shape and speed of the heat pump’s fan, the more noise is generated.
Noise is typically measured in decibels1, or dB(A), which measures the intensity of the sound and how the ear responds. This kind of scale better represents how changes in sound intensity actually feel to our ears2.
The decibel scale is logarithmic – meaning that an increase of 10 dB(A) doubles the perceived sound. For example, a heat pump with 60 dB(A) sound power is perceived twice as loud than a heat pump with 50 dB(A).
To extract energy from the ambient air, a large volume needs to be moved through the evaporator, which acts as a heat exchanger. A fan is required to move air through the evaporator and the fan’s rotation creates noise. This can be lowered by increasing the evaporator surface and/or the fan diameter, leading to a reduction in rotation speed. However, a larger evaporator and fan size increases the overall dimension of the product.
The good news is that gas absorption heat pumps save energy,
as well as deliver a pleasant experience for the homeowner.