Ground source heat pumps (GSHPs) use pipes which are buried in the garden to extract heat from the ground. This heat can then be used to heat radiators, underfloor 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.
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 a Ground Source Heat Pump
Low Running Costs
Ground source heat pumps are very efficient, typically operating anywhere between 350% to 500% efficiency. This means that for every £1 spent on electricity, you’ll receive up to £5 worth of heat back.
Lower Carbon Emissions
The energy retrieved from the ground is solar energy which has been absorbed by the surface of the earth. It is 100% renewable, sustainable and carbon free, meaning you could lower your carbon footprint by over 75% compared to burning fossil fuels.
No Fuel Deliveries
Unlike oil or LPG, there are no fuel deliveries required, and no ugly tanks or bottle to hide. This also eliminates the environmental and fire hazards associated with fuel storage or cost of future replacement.
Heat Your Home & Hot Water
Correctly specified ground source heat pump systems will provide 100% of your heating and hot water needs, all year round. There is usually no need to retain any form of auxiliary heat source unless the system has been designed to work in this way.
Eligible for Financial Support
Most ground source heat pump installations are eligible for Renewable Heat Incentive Payments, currently 19.52p per kWh of renewable heat production. The scheme, which was released in 2014, rewards adopters of renewable heating technologies which save energy and helps towards the reduction of UK carbon emissions. Successful applicants will receive a quarterly payment for 7 years, based on an estimation of the amount of renewable heat generated by their system.
Ground Source Heat Pumps are a proven, reliable form of heating for you or your property. Very little in the way of maintenance required for ground source systems. It is recommended that the system is examined on an annual basis, ensuring that any filters or strainers are clear and that the ground loop is performing as it should.
Things to Consider
Horizontal ground collectors require outdoor space to install so you’ll need a reasonably large garden or field. Boreholes need much less space, although can be costly and access for a drilling rig.
Underfloor heating is an ideal combination due to the lower operating temperatures associated with heat pumps. Although heat pumps also work very well with radiators, you may need to replace some for larger ones in order for the system to operate as efficiently as possible.
Heat pumps require DNO approval to ensure that the electricity grid is capable of providing the electricity you need to run a heat pump. This is rarely a problem but if you have a large house in a remote location, it is worth considering at an early stage.
The typical cost of a ground source heat pump installation with horizontal collectors is between £10,000 – £18,000. Vertical boreholes are more expensive and can add between £3,000 – £15,000+