Ground Source Heat Pumps

Ground Source Heat Pumps (GSHP) use heat from the sun’s rays, which is then stored in the ground, to power your home’s heating and hot water system.

The ground loops or bore hole loops are buried into the ground, either in boreholes drilled with piling rigs or a series of horizontal trenches. The in-ground pipes are a closed circuit filled with a mixture of water and glycol solution, which is then pumped round the pipe, absorbing the natural heat from the ground.

In the colder months the ground is warmer than the air and buildings above. The glycol mixture absorbs the heat from the ground, which is then concentrated and transferred to the buildings from the heat pump inside the property. This heat can be used to heat domestic water and a low temperature heating system such as underfloor heating.

The efficiency of a ground source heat pump is measured in Coefficient of Performance (CoP). This is the ratio of units of heat output for each unit of electricity used to drive the compressor and pump for the ground loop. A CoP of 4 means that for every kilowatt of electricity put in, you get 4 kilowatts of energy in the form of warm water. The flow temperature of the warm water is typically between 35 degrees Centigrade and 45 degrees Centigrade, ideal for low surface temperature heating systems and then raised for heating the domestic hot water cylinder.

There are government funding initiatives available, like the Renewable Heat Incentive (RHI) to help with the cost of Ground Source Heat Pump installations.

For up to date information simply visit www.energysavingtrust.org.uk