Unlike gas and oil boilers, heat pumps deliver heat at lower temperatures over longer periods. Radiators will not feel as hot to the touch as they might when using a Gas or Oil boiler, and they will be bigger to deliver the required heat. Air source heat pumps are generally easier to install than ground source as they do not need any trenching or drilling but they are less efficient.

Ground source heat pumps (GSHP) work in a similar way to air source heat pumps but heat from the ground provides the energy for the refrigeration cycle. This is collected by pipes which are buried in the garden called the ground loop, and filled with a mixture of water and antifreeze. The ground source heat pump circulates this mixture around the ground loop where heat from the ground is absorbed into the fluid. The ground stays a fairly constant temperature under the surface and so the heat pump can be used all year through. The length and type of ground loop depends on the size of property to be heated and the space available to install the ground loop. These can be vertically drilled holes, known as bore holes if space is restricted.

AS Renewables have installed many ground source heat pumps in and around the Devon and Cornwall areas including a working model with bore holes here on display in our show room at Sisna Park.