Geo thermal heating

[topogigo]

Has anyone any relevant knowledge of geothermal heating that i may want to install in houses i am building in the uk? The type that has pipes buried underground and has merely a pump to run to heat the property?

[gen2]

What you seem to be describing is NOT geothermal energy. Geothermal energy is obtaned from hot rocks hundreds of feet below the surface and commonly found in volcanic regions such as Iceland. In the UK there are a few places where geothermal energy heats underground water that then rises as warm springs - eg at Bath.

When you place pipes just below the ground surface of a garden, The heat source is the atmosphere and solar radiation warming the soil. The heat pump works in the same way as the pump in your fridge which pumps heat from the inside (cooling it) and radiates it from a radiator grille at the back which warms the room.

Here is a website with some information that might be useful:
http://www.iceenergy.co.uk/faq.asp

[Clanad]

It must be more popular here in the U.S. But Geothermal heating/cooling is being installed in more and more new construction homes since the laying of the pipes in the soil should be done when the earth is already disturbed from the building process. It can be retrofitted to older homes, but usually isn't.
Here in the U.S., the soil maintains a 50�F temperature beginning approximately four feet down, well past the winter frost line. Polypropylene pipes are layed in trenches, usually about six to ten feet below the surface. The number of pipes is determined by the square footage of the house. The pipes are filled with an antifreeze solution and then pumped through a heat exchanger in the home. This is used for both heating and cooling. It's extremely inexpensive but the initial construction cost are high.
Geothermal heating systems, also called ground-source heat pumps, "capture" the steady supply of heat energy and "move" it from the Earth and through a home or building.
Alternate methods of achieving the same efficiency without disturbing as much square footage in trenching is to drill a number of holes about 200 feet deep. The same types pipes are then cemented in and the rest is the same process as described above....

[heathfield]

'Geothermal' just means 'ground heat'. You don't have to encounter hot rocks to obtain it. There's a good illustrated summary to back up Clanad's explanation here