Fig. 3: Performance of a typical modern heat pump in a wide range of conditions.
From: Replacing gas boilers with heat pumps is the fastest way to cut German gas consumption
The coefficient of performance (COP) of a widely sold air-to-water heat pump for various water supply temperatures to the heating circuit, as a function of the temperature difference at which the heat pump operates (i.e., water supply temperature minus outdoor intake air temperature)33. Bold line: Our conservative estimate with a quadratic polynomial34, given in Supplementary Note 6.
