Is an air source heat pump sufficient for a harsh winter in the Black Forest?

**Heating capacity and power consumption of the heating element

As a rule, in the small to medium power range, such as for heating single-family homes, an air/water heat pump is designed monoenergetically. This means that from a certain outdoor temperature, an electric heating element supports the heat pump or completely takes over the heating. Thus, air/water heat pumps can be used up to outdoor temperatures of -20 °C.

An air/water heat pump is therefore not designed according to the standard design point (e.g., at a maximum outdoor temperature of -16 °C) but according to the bivalence point (e.g., -5 °C). This reduces the required heating capacity of the air/water heat pump, but also increases the power consumption of the air heat pump due to the electric auxiliary heating. The required power of the heating element results from the difference between the heating demand and the heating capacity of the heat pump at the standard design point.

As a rule, the heating element capacity amounts to around 50 - 60 percent of the necessary heating capacity. Although the power share of the electric heating element is relatively large, the operating share of the heating element is only about 2 - 7 percent of the total annual heating work, since the outdoor temperature falls below the bivalence point on only a few days per year.

**Source: Energy Experts

Rhineland regards

There is up to 8.8 kW heating rod power (but it must be set accordingly, i.e. the heating rod can also be limited or turned off). That should be sufficient for a house of normal size, even at -25 degrees.