I realise that this may be slightly off topic - but with the present cost of fuel - I believe that they are going to become more and more relevant - does anyone have one ?

How do they actually work - apart from the earth being a constant temperature 10 metres down (10-14 degrees centigrade) - I am unable to find out how this translates to 50 degrees plus required by central heating radiators ?

I realise that an explanation may take up a lot of space - so how about a link ?

Rough idea Twee, you could do with some Geyser fitting it for you for free. !

http://www.autonopedia.org.uk/renewable_energy/Geo-Exchange/GeoExchange_Systems.html

Hi,

Ground source heat pumps, as you say, take latent heat from the ground by pumping liquid thru pipes you lay underground either horizontally, or for best results at more cost, vertically.

The small amount of electricity you need to put in the system runs something like an air con unit in reverse and compresses the liquid to release and intensify the heat. You need either specialist radiators to use this system which look more like old fashioned ones, big with thick pipes, so as to give a larger surface are for heat to be released into the rooms, or under floor heating.

Its a very efficient way of heating your home, and will reduce your heating bill by a whole lot but it is also very costly to install.. you may well be looking at £10k - £15k plus. If your going to be in your home for years you may see the benefit, it would also make quite a selling point for your house in future and perhaps add something to the value, (Tiny bills? I'd buy it!)

You also get air source heating which is a cheaper, but still very efficient option. You can find more details and a better explaination on both options by following the links below.

As a footnote, you require pumps with the ground source to run it. Although they do not need much electricity to operate, the need quite a large load to start. You would need to find out what you will require in your own application and contact your electricity provider to ensure you have sufficient load available thru your existing service cable. You may not and need an upgrade, which will also cost you. (budget about £2k initially, but your provider should be able to arrange for a inspection and free quote if your starting to think seriously about it)

I also put a link at the bottom for solar water heating.

Hope this helps

http://www.heatpumps.co.uk/

http://en.wikipedia.org/wiki/Geo-exchange

http://www.ecoheatpumps.co.uk/ground_source_heat_pumps.htm?gclid=CNKd-O_QjZYCFQEq1AodKgmOFA

http://www.ecoheatpumps.co.uk/air_source_heat_pumps.htm?gclid=CP77mdjUjZYCFQuH1QodZgMFFg

http://www.energysavingtrust.org.uk/generate_your_own_energy/types_of_renewables/air_source_heat_pumps

http://www.energysavingtrust.org.uk/generate_your_own_energy/types_of_renewables/solar_water_heating