[HappyHippy]

My dad's friend is thinking about putting one in to run a central heating system and my dad's considering it too (madness since we've got all this wood, but what can I say ? )
So, what are your thoughts ? Has anyone fitted one, how expensive and effective are they, can you give me any links to good companies or just any kind of input would be really helpful.
Thanks folks 
Karen

[Hermit]

I would say they are only any good on a modern house that is built with super insulation as they are only background heating. Watch the leccy as well, again only a modern house built around them will have suitable leccy standards.No good for older houses. If you have a modern house thats diferent.

[Rosemary]

Sorry to disagree, Hermit. We have a GSHP in our house built in 1887. We have underfloor heating downstairs and radiators upstairs. To be fair, we did a major renovation which involved improving all insulation because the heating runs at a low temperature. If Dan comes on, he'll comment on the technical stuff. We haven't got it running right yet but will do.

Contact the Energy Saving Trust for impartial advice.

[Hermit]

If you did a major restoration that is what it needs, not as simple as just buying the system. A modern house or a modernised house I should have said. Some folk up here have also had to get planning permission first as well, one lady I know was refused.Not trying to put people off but there is more to to Ground Source than meets the eye. It is not that much cheaper to run either as leccy bills go up. The pros and cons need to be weighed up for each property, some systems work well others have been a waste of time.

[Anke]

You would have tp be able to put in under-floor heating (and have suitable flooring for it, solid wooden floors are not possible) and it would need serious re-jigging of all your water/heating pipes. You would also need a generator for back-up in case of power cuts.

We did consider it when we built our house, but the cost of installing did put us off.

[Rosemary]

Yes, ours was part of a major refurbishment and we have PV cells to generate the electricity. The underfloor heating is wonderful though 

[doganjo]

You would have tp be able to put in under-floor heating (and have suitable flooring for it, solid wooden floors are not possible) and it would need serious re-jigging of all your water/heating pipes. You would also need a generator for back-up in case of power cuts.

We did consider it when we built our house, but the cost of installing did put us off.

Sorry but none of that is true.  You don't need underfloor heating just because you have a GSHP - I have friends who use normal rads with theirs, with great success.  Also you CAN have wooden floors with U/f heating - I did just that in the house I built with no problems at all.  You do need to use shorter cleats and at a steeper angle though.

[HappyHippy]

All very useful info and points of view folks, much appreciated 
Keep it coming 
Karen x

[Rosemary]

Yes, we run radiators from ours, but I think you need to boost the heat using an immersion. The GSHP only heats the water to a lower temp than is needed by radiators.

Actually, the underfloor in our house is under terracotta, encaustic and engineered oak. We also have u/f, but electric, under slate in the bathroom. I think it's better under the tiles than the wood. It actually feels warm underfoot, where it's not so obvious under the wood.

You can put u/f under solid wood, but it has to be properly fitted, as Annie says.

We've got a wood burner in the living room as backup heating.

[digit]

We put a GSHP in 3 years ago, with u/f heating up stairs and down, the ground floor is slate and takes less energy to heat than up stairs which is wood. It costs us about £600 ayear to heat 240sq mtr and thats on 24/7. And with the govements renewable heat incentive, for a 3 bedroom terrace house you could get a £1000 ayear for the next 23 years

[Norfolk Newby]

Just to cover a few basic points. The ground source heat pump idea has been around for more than 50 years. It's like a refrigerator working in reverse. Instead of using a compressor to cool the inside of a box with the extracted heat going to a finned pipe on the outside, the heat is inside and the cool bit is outside.

This all works by compressing a special gas. The gas gets hot when compressed and cools when it is allowed to expand. Hence the system's ability to 'pump' heat by using a compressor.

The compressor - like a fridge - is normally driven by an electric motor but it could be driven by a car engine, windmill or steam engine if that happened to be the best source of power. Staying with the electric motor, the system effectiveness is measured by how much heat is delivered compared tot he amount of electricity used to drive the motor. So if you have a performance of 4, the system delivers 4Kw for each Kw used by the motor. This measure is called the  'Coefficient of Performance' look this up with Google if you want more information.

The important point is that this measure can be increased if you have a local source of heat like a stream. So you don't have to get the heat from the ground. Water is a good source of heat.

One of the first big heat pump installations in the UK was the then newly opened South Bank complex in London (c. 1950). The pump was a Merlin engine (as used in the Spitfire and Lancaster) using the supercharger as the compressor. The heat source was the river Thames. It had a Coefficient of Performance of 6 so it was a very good system. However, it was noisy and required a lot of maintenance so it was replace with a conventional boiler system.

With a domestic system, it would be a good idea to regard the compressor as requiring replacement every 10 years, like a fridge they don't last forever. Also, the special gas would need to be checked, topped up or replaced every year. This all adds to the overall cost of the system

If you happen to want to run your own generator driven by an engine burning LPG, red diesel or old cooking oil, you can recover a lot of heat from the engine without the need for a heat pump. But you have to consider the noise and maintenance questions as well as the cost. If you need 10Kw of electricity (continuously) it would be easy to recover 10Kw of heat, enough for a small house from the engine's cooling system. If you collect heat from the engine exhaust by putting a water jacket on the exhaust pipe, you could increase this to 15Kw of heat for 10Kw of electricity.

[mab]

If it's a choice between electric heating (conventional) and a heat pump then the heat pump is definately the best option.

If it's a choice between the heat pump and other central heating systems it's harder to call.

If you've got plenty of wood I would suggest you'd be better off sticking with wood based heating and spending the money on improving insulation, double glazing, etc.

[Rosemary]

The Energy Saving Trust will send out an adviser, who will look at first of all reducing energy use, which should be the starting point, then will look at enegy generation. We found them to be very helpful.

[waterhouse]

I'd echo the major refurbishment or rebuild point. 

Our 1870's property was restored by an imbecile with a fondness for gas boilers.  When we embarked on the replacement of the four boilers and the Rayburn we got really keen on heat pumps but we'd have had to rip too much of the house apart to put them in.  And the insulation wasn't done to a high standard either.

We saw someone selling low temperature wall mounted radiators intended to be plastered in last year.  That would possibly involve less disruption.

[egbert]

We have an air source heat pump- just to put in a slightly different option. I can't tell you technical details but this is how it worked from my untechie wife point of view. . .

OH spent hours/weeks/months researching online.
We live in a 30's house that is twice as large downstairs as upstairs, half single brick, half cavity walls, barely any insulation. . .
The OH had the cavity walls filled with insulation, and because he couldnt put more insulation in the roof, something to do with sloping ceilings, he took off the ceilings and put insulation board in between the rafters from the underneath, then boarded and replastered. He has so far done 2 bedrooms and the hall upstairs.

SO back to the pump - we couldnt have a ground source pump because I believe option 1 is deep bore holes drilled downwards, which was ridiculously expensive, or option 2 is rows of tubing under the ground and we would have to rip up the whole garden to get the amount of tubing required for our house (incidentally the large school next door (think private in old manor house) has had it done and dug furrows down most of the sides of a hill to get their tubing in).

So, we have the air source pump in the garden which is fairly ugly but is going to be disguised this summer, and produces a fantastic fridge effect on the one side for cooling beer and us in the summer - a big pipe underground into the garage and a large tank and some extra system boxes all in the garage with the fuse boxes. OH also had new radiators put through the house but I think this was for efficiency and not necessary for the heat pump. And I no longer have a tank in the airing cupboard so more storage room! The heat pump heats the water in the tank which has an inner tank and outer tank. The water in the outer tank  is used in the radiators and keeps the inner tank warm for the shower.

All together it took a week I think for the installers to put in the pump, tank etc - during which time we had no heating/water. But I now have a fantastically warm house, hot water on tap all the time, a new shower which runs off the tank in the garage (water is apparently pushed round the house under the cold pressure - dont ask me how, which means the shower is more powerful now). Over this very cold winter (our first year with the pump) the old oil boiler comes on when the temp outside drops below minus 3 I think to give it a boost. And I also now have a heater blowing hot air in the kitchen connected to the radiators, which was always freezing before. The kids bedroom is always warm (mine is still to be insulated!) but we still have a log fire in the lounge cos we like it! 

Cost wise, it was expensive to put in but has already saved us more in oil than cost in elec this winter so we are money up bill wise. Which means we expect it to pay itself off long before we retire! 

I have just read the pertinent points to the OH who is now laughing hysterically at my inability to explain the techie bits and who keeps naming things like buffer vessels (the tank in the garage), compressor and evaporator (the thing in the garden) to make me look really stupid.