How much does a heat pump use?

The consumption of a heat pump installation can be estimated on the basis of the COP, which is an abbreviation from the performance coefficient.

In other words, how many electric kW do I need to produce X kW thermal?
Efficiency describes the ratio between usable energy and energy consumption

Technical processes are always associated with losses, therefore, the performance of the equipment is always less than 1.

With the help of heat pumps, part of the energy is extracted from the environment. This part is not considered as consumed because it is available for free.
For my calculations, I always use the COP, because the seasonal performance factor (SCOP, SEER, etc.) given by many manufacturers can be influenced by an abundant selection of the heat source and distribution system.

From the observation we have cost that the seasonal performance factors have nothing to do with real consumption.

As a general rule, according to EN 14511 performance parameters for water heat pumps are stated at 7, 2 and – 7 degrees Celsius. And the COP is marked as A7 / W35. A is the outside air temperature and W is the flow temperature at the outlet of the heat pump of the thermal water.



For water heat pumps, the declared water temperature is 10 degrees Celsius and W10 / W35 is thus written. pompe de caldur

For ground water heat pumps, ie those with vertical or horizontal boreholes, the COP is declared at the 5, 0, -5 values ​​of the water mixture with glycol from the boreholes. The COP is noted as B5 / W35. B comes from brine, meaning brine in English. In the case of water heat pumps, the drills are always loaded with glycol water.

Now I will compare the COPs declared between the three heat pump types.

Water-to-water heat pump at W10 / W35 COP 5.4 – 5.6

Soil-water heat pump at B5 / W35 COP 5.3 – 5.4

Air to water heat pump at A2 / W35 COP 3.5 – 3.8

If we need 10kW of heat in the winter to warm our house, we divide it at the declared COP, say 5.4, and we get the electric kW we consume at 1.85kWh.

From the point of view of this comparison of COPs, it seems at first sight that water-to-water heat pumps are most effective. That’s how it is.