Heat pump, the heating technology of the future

The decision for a new heating system is a decision for the future. It applies for at least the next 15 years. Which heating system suits the house best: a heat pump, a pellet boiler or a new gas heating system again? This is the question many homeowners are currently asking themselves.

Stiftung Warentest has tested air-to-water heat pumps for the first time. This technology is most commonly used in Germany; the pumps draw their thermal energy from the outside air.

All six models tested can heat a single-family house. The difference lies in the efficiency, i.e. how much electricity the pumps need in operation. In an averagely insulated house with 140 square metres of living space, the most efficient pump requires less than 5,000 kilowatt hours per year, while the last pump requires more than 6,500 kilowatt hours. Four of the six heat pumps tested scored well in the noise test, two satisfactorily. The heat pump test can be read in the October issue of the magazine test and at www.test.de/waermepumpen.

Old houses lose a lot of heat energy because they are usually poorly insulated. To compensate for these heat losses, the heating system requires higher flow temperatures and consumes more energy. Then a heat pump with a higher connected load must be selected, which consumes correspondingly more electricity. How high the electricity costs are per year for heating with the heat pump can be estimated with the so-called annual performance factor (APF).

The analysis and consulting company Prognos has examined the influence of subsidy options on the economic viability of heat pumps. According to the study, the installation of an air-source heat pump is slightly more expensive than the installation of a new gas boiler, taking into account all costs including the measures on the building without subsidies. Taking into account the basic subsidy of 30 percent, the annual costs of a heat pump are already slightly lower than those of a gas boiler. If, in addition to the basic subsidy, the climate bonus and/or the income bonus are claimed, the economic efficiency is improved even further. Depending on the amount of the subsidy, the heat pump pays for itself after three to twelve years, and with an additional PV system even after one to nine years.

(Photo: © Br_LW_WPaussen-Schnee1_2022_c_Brunner / waermepumpe.de)