A ground source heat pump is a heating/cooling system for buildings that takes advantage of the relative constancy of temperatures of the earth through the seasons and uses it to transfer heat to or from the ground. Whilst ground source heat pumps require larger capital investment, the constant temperatures below ground and high levels of efficiency make them ideal for organisations looking to maximise decarbonisation on their journey to net zero.
A GSHP utilises the latent heat which is found in the ground and use one of two heat collection methods. One can be a horizontal coil collector which is pipe buried 1-2m below ground. Another is to utilise vertical coil collectors placed in a borehole ~100m deep depending on ground conditions. In both of these the pipe holds an antifreeze solution which exchanges heat with the ground.
Ground source heat pumps fall into two main categories. The first utilizes a horizontal coil collector buried between 1-2m underground, whilst the second uses a vertical coiler collected placed at depths of up to 100m. Both of these systems harness geothermal energy and convert it into low-temperature-hot-water at temperatures of up to 85°C which can be used for space heating and hot water.
We are currently delivering the cutting-edge ground source heat pump installation for Southwark Council which will serve 2,175 homes. The project will take the latent, subterranean heat via three locally drilled bore holes and distribute it to homes on the Consort, Newington and Wyndham Estates.
Whilst ground source heat pumps tend to be the most efficient types of heat pump, due to the stable temperatures below ground, they can also incur large capital investments, with boreholes up to 200m needed. This combined with the space needed for the abstraction and injection points and dedicated plant and equipment makes water source heat pumps a complex project, but capable of delivering large carbon reductions.
It should also be stated that not all areas are suitable for supporting a ground source heat pump project and the proposed grounds require an in-depth investigation to ensure they are suitable.
