geothermal

[stevewilliams]

Having successfully installed a DIY solar hot water system for under two grand and been impressed with the results I am keen to investigate geothermal DIY.

Does such a thing as a DIY geothermal kit exist? Any advice appreciated

Steve

 

[breezer]

if it does it wont work in the UK, but very good in iceland (the country, not the shop)

 

[ZenStalinist]

Actually, on some parts of the south coast it should work very well.

The red is the part where geothermal is possible in the UK, however, a sizeable amount of this geothermal activity is not suitable for home set ups. You need quite a high amount of geothermal heat, and quite shallow for a home geothermal system, but such areas certainly do exist, I'd say about in a half of that red area. If you're outside the red area, you have about no chance.

 

[breezer]

ther is always hope, Bob, and no

 

[shaggy]

You must understand the difference between direct geothermal energy and a geothermal heat pump. The heat pump will work anywhere in this country. There is an oak framed house being built near me(East Midlands) and the guy is really into efficient use of energy. It will have a heat pump.

 

[kevplumb]

there is a kit available

big shovel loads of steel pipe and a big hammer

 

[stevewilliams]

yes it was the heat pump I was interested in - works like a reverse refrigeration unit so only needs a few degrees temp diffeence. Saw a guy on Grand Designs installing one on a converted church in Ireland. I believe it works best as underfloor heating rather than radiators?

Steve

 

[shaggy]

I think you know as much as me Steve, but that's right about reverse fridge. I've been talking to the guy building the house near me and I think for a ground temp of about 10°C at a depth of 1.5m you can get the water to about 45°C and his will be underfloor. A boiler and radiator system would be getting the water to more like 80°C.
Kev, I think they used a JCB and plastic pipe?

 

[kevplumb]

explain this guys i understand the heat pump the post was a laugh now youve got me biting

 

[salem2000]

Do you mean THIS

 

[AdamW]

The best way to understand the heat pumps is to look at it in a bit more detail than just saying "reverse fridge".

If you imagine how your fridge works it is taking heat energy from a cold part (i.e. inside the fridge), and dumps that heat in a warmer part (i.e. your kitchen. For every 1 joule of heat energy you move, you will require say 2 joules of electricity. However, those 2 joules of electricity provide you with 3 joules of heat. Hence the "free heat" part of it. The smaller the temperature drop you give to the "source", the more efficiently the system runs (why a fridge requires less power than a freezer). This is why it is best to do it with a large area,

They are not magical devices, but are a very cool idea. I think there is an opera house by the Thames heated in winter and cooled in summer by a two-way system.

 

[AdamW]

Do you mean THIS

Wow, that is a lot more efficient than I would have imagined! 400% efficient electric heating

 

[salem2000]

Do you mean THIS

Wow, that is a lot more efficient than I would have imagined! 400% efficient electric heating

I agree, sounds too good to be true. But what are the hidden costs, servicing etc.

 

[ZenStalinist]

It's a closed loop system, so I'd imagine there is very little servicing. Especially considering you should have your gas boiler serviced every year...

I can't see a geothermal pump requiring the sort of servicing gas or oil needs.

 

[stevewilliams]

Thanks everybody for all your info on this. I've just started researching it but a common figure quoted for the kind of area you would need for your heat source is about 1.2 square metres of ground source (horizontal system) for every square metre of floor space to be warmed. Figures for the kinds of temperatures expected are not so easy to pin down and seem to vary widely (although I understand an underfloor system works at around half the temp of a radiator to give comfortable background heating whether geothermal heat pump or conventional boiler).

Also would like to understand the science behind using 10 to 12 degrees input from the ground to achieve three times that amount?

Steve