Underfloor heating
Author
Discussion

Sgt Bilko

Original Poster:

1,929 posts

231 months

Monday 12th October 2009
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Anyone experienced with UFH? Got some for the kitchen, but wondering if it is ok to have on top of bitumen (with 8mm ply in between)??

aussiebruce

452 posts

206 months

Tuesday 13th October 2009
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On my concrete floor we had to insulate with some stuff called wediboard or something similar, then laid the heating wire on top of that, then the tiles.

Bloody expencive to run though, after seeing our electric bill we now only use it when people come 'round. I now have a nice pair of slippers though.

Sgt Bilko

Original Poster:

1,929 posts

231 months

Tuesday 13th October 2009
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Just worried about the bitumen as mate says it could soften it and lead the tiles to de-bond?

Harry Flashman

20,677 posts

258 months

Tuesday 13th October 2009
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Er - I've had it installed in bathrooms, but not yet turned it on. I thought that the whole point was that running it constantly on a low setting was more efficient than normal central heating?

Glad I kept the radiators in both bathrooms, then...

At least there's now a nice LCD touchscreen outside each bathroom that looks p0rno, I guess.


Rich135

802 posts

258 months

Tuesday 13th October 2009
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Electric is much more expensive to run than normal heating - water based UFH is cheaper (about 30% of normal central heating).

pits

6,606 posts

206 months

Tuesday 13th October 2009
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We have got UFH that runs through the boiler, in 2 years it has worked properly once

Dupont666

22,150 posts

208 months

Tuesday 13th October 2009
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Harry Flashman said:
Er - I've had it installed in bathrooms, but not yet turned it on. I thought that the whole point was that running it constantly on a low setting was more efficient than normal central heating?

Glad I kept the radiators in both bathrooms, then...

At least there's now a nice LCD touchscreen outside each bathroom that looks p0rno, I guess.
Am I ever going to get the photos and the details to see the work of that has been done so I can think about getting my kitchen and bathroom done?

aussiebruce

452 posts

206 months

Tuesday 13th October 2009
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Sgt Bilko said:
Just worried about the bitumen as mate says it could soften it and lead the tiles to de-bond?
I thinj the answer is to use the wediboard or some other insulation on top of the bitumen

Harry Flashman

20,677 posts

258 months

Tuesday 13th October 2009
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Dupont666 said:
Harry Flashman said:
Er - I've had it installed in bathrooms, but not yet turned it on. I thought that the whole point was that running it constantly on a low setting was more efficient than normal central heating?

Glad I kept the radiators in both bathrooms, then...

At least there's now a nice LCD touchscreen outside each bathroom that looks p0rno, I guess.
Am I ever going to get the photos and the details to see the work of that has been done so I can think about getting my kitchen and bathroom done?
Mate - Hoping to have it done for 1 November. At which point you shall have all the photos of before and after that you can handle!

Haven't gone horribly over budget (a couple of thousand) interestingly - but have gone well over on time...

munky

5,328 posts

264 months

Tuesday 13th October 2009
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I"ve been toying with the idea of UFH as well - only because I've been toying with the idea of ground source heat pumps which, apparently, work a lot better with UFH than with radiators. While I'm sure it could work downstairs (wooden floors, void underneath then bare earth AFAIK), upstairs is a problem, the wood ceilings are the floors of the rooms above - there's no gap. So I guess the only way would be to put suspended floors in? Or is it possible to have ground source heating with radiators? Or I guess keep the boiler for radiators upstairs but that seems daft.

jaybkay

488 posts

236 months

Wednesday 14th October 2009
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The reason that heat pumps, ground or air source, work better with underfloor heating is because the "radiator" is so big, this means lower temperatures which results in high efficiency.
Size radiators for the upstairs sensibly and you can use a hot water heat pump and have high efficiency.
Basically you will need bigger radiators.

Also note with a heat pump it's best not to have one with a high capacity - you really need to be able to balance out the heat input into the house with the heat loss over 24 hours rather than blasting lots of energy in over a short time.

The main item I supply is 12kW output, and runs off standard household wiring. With the low value of the pound this works out about two thousand, and would almost certainly heat a fairly standard UK house with underfloor and radiators.

munky

5,328 posts

264 months

Wednesday 14th October 2009
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jaybkay said:
The reason that heat pumps, ground or air source, work better with underfloor heating is because the "radiator" is so big, this means lower temperatures which results in high efficiency.
Size radiators for the upstairs sensibly and you can use a hot water heat pump and have high efficiency.
Basically you will need bigger radiators.

Also note with a heat pump it's best not to have one with a high capacity - you really need to be able to balance out the heat input into the house with the heat loss over 24 hours rather than blasting lots of energy in over a short time.

The main item I supply is 12kW output, and runs off standard household wiring. With the low value of the pound this works out about two thousand, and would almost certainly heat a fairly standard UK house with underfloor and radiators.
That is incredibly useful - thanks! Heat loss at the moment is very high, being a 1920 wooden house with no insulation. At the moment we're renting it to try before we buy - and the heating bill is astronomical but if we know we can solve this with insulation and ground source heat, we'll buy it. I thought the difficulty of upstairs UFH would kill the ground source idea, so I'm happy to hear this isn't the case.

How much gap under the floor do we need to install UFH downstairs? The property is on a gentle slope so there's a lot of space under the house at the front, but less at the back.

Thanks smile

ETA: sorry to do a mini-hijack of your thread SgtB - I'll stop it now!

Edited by munky on Friday 16th October 02:44

Sgt Bilko

Original Poster:

1,929 posts

231 months

Thursday 15th October 2009
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After a bit more digging, looks like i will have to put down some insulated tile backer boards. Anyone with experience on installing these?