ground-to-water heat pump – borehole draws energy (heat) from deep below the earth’s surface.
When installing this type of heat pump, it is necessary to construct deep borehole, from which the earth’s energy will be extracted. The borehole houses a heat exchanger filled with an antifreeze mixture, which transfers heat between the ground and the heat pump.
Depending on the size of the heated building, one or more boreholes are drilled. Boreholes for heat pumps can only be carried out on the basis of the relevant permits.
When considering the choice of the ground-to-water heat pump – borehole, you also need to bear in mind that boreholes can only be drilled in certain subsoil, which should be sufficiently hard. In areas with gravel or sandy subsoil, drilling is difficult, so a heat pump with a horizontal ground collector is the more suitable option.
Features of a ground-to-water heat pump – borehole
Pros
- Stable output and a high heating coefficient (COP) even at very low temperatures.
- Lower electricity consumption than air-source heat pumps.
- Long service life of both the heat pump and the borehole.
- A maintenance-free, silent solution.
Cons
- Boreholes require a building permit.
- Higher investment costs for drilling the boreholes.
How deep a borehole do I need and where can it be drilled
Ground-to-water and water-to-water heat pumps are more demanding in terms of space. It is generally stated that around 12 m of borehole depth is needed per 1 kW of output.
Depending on the building’s heating needs, one or more boreholes with a diameter of 12 – 16 cm are drilled. A typical family home needs a borehole around 100 to 150 m deep.
The boreholes themselves are drilled around the heated building in areas with hard subsoil. Professional drilling companies with modern equipment can drill in the immediate vicinity of the building without major damage to the plot.
Take a look at our heat pump references.
