ground source heat pump

22 Aug 2004
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United Kingdom
I'm about to extend my house and I am interested in saving fuel (I'm out in the sticks and rely on very expensive oil) and was wondering about installing the pipework in my new floors for the later addition of a GSHP - I can't afford the whole system yet but obviously this would be the time to set out he heating loop.

Is this pipework the same as for conventional underfloor heating?


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Its better to have the pipe spacings much closer in a heat pump installation. Some installations have a maximum spacing of 150mm down to as close as 100mm. Yep. Its a hell of a lot of pipework.
Then the heating flow temperature can be dropped lower and still maintain comfort conditions within the home..
The lower the differential temp between the evaporator and condensing side of the heat pump then the more efficient the machine will perform.

You will find quite a lot of detail here and actual installations and how much they cost.
Flippin heck I 'm nearly in argement with balski :eek:

150mm centers should be more than enough provided the insulation etc is up to scratch, you can always upsize the pipe from 14mm to 17mm if you wanted to.

Avoid areas, under fridge/freezers, kitchen units and wc pans, and limit the length of the loops to 100m ish each.
have you worked out what size pump you require and the cost of electricity to run it and the effects on the enviroment using that power source.
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Thanks for all the advice and the link.

I haven't yet worked out the size but presumably a fairly small one as this is just an extension albeit around 30 square metres and not the whole ground floor.

The pump will be powered by my green tariff electricity and should (according to quoted figures) be around 200 -300% efficient.

Interesting point about not installing heating pipes under units - I know someone who did just that and he can't keep food in any of his base units as it perishes very quickly.

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