Although we may not realise it heat pumps are very familiar to us, fridges and air conditioners are two examples. Ground source heat pumps (GSHP) transfer heat from the ground into a building to provide space heating and, in some cases, to pre-heat domestic hot water.
For every unit of electricity used to pump the heat, 3 to 4 units of heat are produced. As well as ground source heat pumps, air source and water source heat pumps are also available.
Lengths of pipe are buried in the ground, either in a borehole or a horizontal trench. The pipe is usually a closed circuit and is filled with a mixture of water and antifreeze, which is pumped round the pipe absorbing heat from the ground.
The heat pump (via an evaporator, a compressor and a condenser) transfers the heat to a hot water tank which feeds the heating distribution system.
For more on how heat pumps work, options, costs and other important considerations see the Energy Saving Trust information page.
The Carbon Trust offers advice on many aspects on low carbon buildings.
View information on the planning and building regulations regimes covering heat pumps in our common projects section: