Ground source heat pump systems collect heat through a pipe loop buried in the ground or immersed in water. The loop, acting as a heat exchanger, collects heat and transfers it, through the heat pump system, into buildings. This provides underfloor heating, space heating and hot water. Some ground source heat systems use coils of high density polyethylene pipe buried horizontally at around 4-6 feet underground, this is called a "slinky" system. However, where space is at a premium, or the geology proves beneficial, boreholes can be used. These are usually drilled to depths ranging from 100 feet to 400 feet and water is circulated through pipework inserted into these boreholes in a closed loop system, or water can be extracted directly in an open loop system.

The benefits of a ground source heat pump system are multi-fold. The earth is a huge source of heat energy and by tapping this source the benefit is not only for the user, but also the environment.

Benefits:

• A secure, local and inexhaustible resource
• Lower fuel bills and heating running costs
• Less carbon dioxide and other greenhouse gases
• Cleaner air
• Reduction of dependence on fossil fuels

Ground source heat pumps are highly efficient and can return up to four times the energy used to power the system. To put that into perspective, for every 1kW of energy used, the system will return up to 4kWs of energy in the form of heat, a huge saving in running costs and in the Co2 created, this works out to approximately 7 tonnes of Co2 per household, very eco-friendly!

Where the geology is suitable, or where there is a lack of space for burying the heat exchanger loop piping, boreholes can be used. The pipe goes down vertically rather than being buried horizontally. Boreholes usually extend from 100 to 400 feet, depending on the heating requirements.