Heat Pump Dictionary

Ground water has a comparatively constant temperature that remains relatively high even in winter. This enables the heat pumps to achieve high COPs.

However, ground water systems are subject to authorisation. Tapping of ground water with extraction and absorption wells is costly. Additionally, a test drilling must confirm adherence to the required limit values for water quality.

The energy that can be extracted from the ground is dependent on the condition of the ground and thus determines the size and type of the heat source system to be implemented.

To tap the heat source, brine pipes must be installed either horizontally (ground heat collectors) or vertically (borehole heat exchangers) in the ground. However, there is often not enough space available in the garden to install a ground heat collector system. Borehole heat exchangers are subject to authorisation by local water authorities. The costs for the necessary deep drilling are equivalent to those of a well system.

Air is available everywhere as a heat source and can be used at any time and requires no authorisation. However, the annual performance factors which are to be expected are lower than is the case when either water or geothermal systems are implemented. At the same time though, the costs for tapping the heat source system are lower.

In summer, there is no better heat source for DHW preparation than the air. If DHW preparation in summer is taken into account, the annual performance factor of air-to-water heat pumps almost equals that of brine-to-water heat pumps.