Ground source heat pumps use pipes which are buried in the garden to extract heat from the ground. This heat can then be used to heat radiators, under floor or warm air heating systems and hot water in your home.
A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe – called a ground loop – which is buried in your garden. Heat from the ground is absorbed into the fluid and then passes through a heat exchanger into the heat pump.
The ground stays at a fairly constant temperature under the surface, so the heat pump can be used throughout the year – even in the middle of winter.
The length of the ground loop depends on the size of your home 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.
The benefits of ground source heat pumps
Ground source heat pumps (also known as GSHPs):
- Could lower your fuel bills, especially if you replace conventional electric heating
- Could provide you with an income through the government’s Renewable Heat Incentive (RHI)
- Could lower your home’s carbon emissions, depending on which fuel you are replacing
- Don’t need fuel deliveries
- Can heat your home and provide hot water
- Need little maintenance – they’re called ‘fit and forget’ technology.
- Unlike gas and oil boilers, heat pumps deliver heat at lower temperatures over much longer periods. During the winter they may need to be on constantly to heat your home efficiently. You will also notice that radiators won’t feel as hot to the touch as they might do when you are using a gas or oil boiler.
- Air source heat pumps are usually easier to install than ground source as they don’t need any trenches or drilling, but they are often less efficiency than GSHPs. Water source heat pumps can be used to provide heating in homes near to rivers, streams and lakes.