See all of our Eco Solutions available
What are ground source heat pumps?
A groundwater heat pump heats your home by transferring naturally renewed heat from the ground outside to heat your radiators or underfloor heating. It can also heat water stored in a hot water cylinder for your hot taps and showers.
How do ground source heat pumps work?
A few metres beneath the surface, the ground keeps a constant temperature of about 11 degrees centigrade. Ground source heat pumps (GSHPs) take advantage of this constant temperature to extract the geothermal heat they need.
Loops of pipework are buried underground, either in long or coiled pipes in trenches (1-1.5 metres deep) or a long loop inserted into a vertical borehole (typically between 100-250 metres).
The pipes contain fluid which absorbs geothermal heat and passes it to a refrigerant which is then compressed to raise its temperature. A heat exchanger then extracts the heat and transfers it to central heating and hot water systems.
The ground stays at a constant temperature ensuring the heat pump can be used throughout the year.
Are ground source heat pumps expensive to run?
A well-designed geothermal heating system delivers up to four units of heat for each unit of electricity consumed.
Because of this, it also emits 70 to 80 per cent fewer carbon dioxide emissions than an equivalent oil boiler.
Maintenance costs are low and the pipework can be expected to last 50 years, with other parts of the system lasting up to 25 years if well maintained.
Things to consider
- Geothermal heat pumps operate most efficiently and effectively in energy-efficient buildings such as new builds. To minimise heat demand, older properties may need to increase their insulation levels.
- The size of the heat pump and ground loop will need to reflect the building’s heat requirements.
- The area of available land, the type of ground and good access are also important.