Beneath the surface the ground stays at an almost constant temperature, ground source heat pumps are buried in the ground and extract this heat. The ground source heat pump circulates a mixture of water and antifreeze around a ground loop, heat from this fluid is pumped through a heat exchanger. This heat can be used to heat radiators or underfloor heating systems and even hot water.
The loop is coiled or laid flat in trenches 2m deep, the length of the loop would depend on how much heat was needed, longer loops can draw more heat from the ground but need more space.
Benefits of ground source heat pumps
- Can reduce your carbon footprint: heat pumps can lower your home’s carbon emissions, depending on which fuel you are replacing.
- Can provide space heating and hot water.
- Can lower fuel bills, especially if you are currently using conventional electric heating.
- It’s often classed as a ‘fit and forget’ technology because it needs little maintenance
Costs and Savings
The cost of installing a system can range from £9,000 to £17,000 and running costs will depend on the size of your home and how well insulated it is.
Savings are hard to specify it all depends on the previous system that was installed, how high your temperature settings are and the fuel that is used to power the pump. There are grater savings if a heat source pump is used for underfloor heating than radiators as the water does not have to be heated to such high temperatures, also if using it to heat water as well as heating this can lower the system efficiency.
To see how efficient these systems are there is a report on the Energy Savings Trust that tested the systems in a range of environments, Getting warmer: a field trial of heat pumps.