Ground source heat pumps use pipes that are buried underground to extract heat from the ground, which is then further heated and moved to the heating and hot water circuits of your property.
A mixture of water and antifreeze is circulated around a loop of pipe which is buried outside. Heat from the ground is absorbed into the fluid and then passes through a heat exchanger into the heat pump. Since the earth absorbs energy released from the sun, underground temperatures are constant. In the UK, the temperature of the earth a few metres below our feet remains at around 11°C.
The length of the pipe in the ground depends on the size of your property and the amount of heat you need. Longer loops can draw more heat from the ground, but need more space to be buried in. If space is limited, a vertical borehole can be drilled instead.
If you’re considering installing a ground source heat pump you’ll need to seek advice on whether your property is suitable. You need to check if you have enough outdoor space to support the underground pipes and pump, and access for digging machinery.
According to the Energy Saving Trust, installing a ground source heat pump costs between £24,000 to £49,000, depending on the size of your property.
Next steps on your renewable energy heating journey
Here's where to go for more advice on installing a heat pump in your home or business.