underfloor heating, electric vs gas...

underfloor heating, electric vs gas...

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Discussion

alphonso

Original Poster:

273 posts

195 months

Wednesday 24th February 2010
quotequote all
Hello,

I'm having the floor re-laid in my kitchen with underfloor heating.
It's about 30sq m.

The proj mananger is recommending electric, but has no experience of gas heated water pipes. Surely the normal gas heating is far more efficient and cheaper to run?

Does anyone have any definitive idea, rather than an assumed opinion?

John MacK

3,170 posts

206 months

Wednesday 24th February 2010
quotequote all
I presume he is talking about putting in a thin mesh type elctric heating 'pad', this will be (probably) much cheaper to install than a conventional underfloor system which is designed to replace radiators, and has the warm water pumped through it.


Do you have a boiler and radiator central heating system for the house?


alphonso

Original Poster:

273 posts

195 months

Wednesday 24th February 2010
quotequote all
yes, that's right, she reckons £700 for the electric system. I do have a boiler and central heating.

The thought of putting an electric current through 200m of heating cabling sounds horrendously inefficent and expensive, but I really have no idea.

freecar

4,249 posts

187 months

Wednesday 24th February 2010
quotequote all
I installed electric a couple of years ago. We have no radiator now and it's not up to the job of heating the whole room so we've also got a under unit fan heater.

It's hard to figure out its running costs as my mother also got a kiln not long after fitting so the electric usage went bananas!

During the winter it's really nice underfoot, just warm so it's comfortable to stand on for extended periods but during really cold spells we need to switch on the fan heater to get the air temperature up.

So electric can't replace a radiator if that effects your decision!

garycat

4,398 posts

210 months

Wednesday 24th February 2010
quotequote all
alphonso said:
Hello,

I'm having the floor re-laid in my kitchen with underfloor heating.
It's about 30sq m.

The proj mananger is recommending electric, but has no experience of gas heated water pipes. Surely the normal gas heating is far more efficient and cheaper to run?

Does anyone have any definitive idea, rather than an assumed opinion?
Sounds like a big kitchen... what is it 5m x 6m?

Remember you will only need heating on the exposed areas of floor so take off areas where there are base units, appliances, island etc.

These people were the best value I found and good to deal with. http://www.ambient-ufh.co.uk/

mackg

152 posts

180 months

Wednesday 24th February 2010
quotequote all
Why pay for electricity when you have the central heating running? as a previous post said they are good for taking the chill of the tiles but would cost alot to heat a large room like yours

John MacK

3,170 posts

206 months

Wednesday 24th February 2010
quotequote all
alphonso said:
yes, that's right, she reckons £700 for the electric system. I do have a boiler and central heating.

The thought of putting an electric current through 200m of heating cabling sounds horrendously inefficent and expensive, but I really have no idea.
They should be able to give you running costs for the electric heating.

Can you get a quote for underfloor heating using water pipes run from your existing boiler? Though the underfloor normally runs cooler than your rads, don't know if it can run at the same temp as your rads..?

Solitude

1,902 posts

175 months

Wednesday 24th February 2010
quotequote all
i have installed plenty of electric u/floor in others properties and recently did so in my own bathroom which is relatively small(3m x 3m).
It feels great under foot i can tell you and i'd never be without it.
I have no rad, but installed a (c.h. only) towel rad which is currently not piped up.
Even in this weather i don't need anything else on anyway.
Electric underfloor is fine for bathrooms to take the cold edge off tiles, and actually does a fair job of warming the room up, but i would not use it on such a large area nor as a replacement for heating, your leccy bills will be thru the roof.
The water systems are down to a great price now and you can (via a manifold and seperate pump), hook it up to your system with the use of a valve and a stat, it will work independently.
Do not run it under kitchen units as it dries them out and the joints don't like it.
More and more people install it because it is affordable now, but complaints are on the increase because it really isn't as "variable" (response time wise) as rads.
It just looks better cos you cant see it.
I really would NOT do it in electric (and thats my living)
Good luck

d50cyx

282 posts

249 months

Wednesday 24th February 2010
quotequote all
My entire flat is now entirely heated by electric underfloor heating. It was a gamble I took when doing my loft conversion & refurb. I can honestly say that I am 100% happy with the result and costs don't seem too bad. Haven't had long enough to do a formal evaluation but gas is about £5 per month on the DD (for the hob) and electricity £48 (including water heating). That's for 2.5 bed & large kitchen/diner with vaulted ceiling. That said, there is an enormous amount of insulation in the roof...

Incorrigible

13,668 posts

261 months

Wednesday 24th February 2010
quotequote all
Did my bathroom with devimat, did the kitchen with water

devimat reg blew up in 2 years, no problem with the other so far

I did all the work myself so managed to get the screed on top of the insulation (the pipes run in the screed) as thin as possible, then layed 10mm tiles. Really helps speed up the heating time

RWA28

703 posts

224 months

Wednesday 24th February 2010
quotequote all
We have just built a house and have put UFH in our kitchen and sunroom (one leads to the other) The main reason we went for it was due to the rooms having vaulted ceilings so we were worried a radiator wouldn't be very effective. We put in a polyplumb overlay system.

This is a wet system running off our oil fired boiler, whilst it works very well indeed warmth wise it doesn't seem to be very efficient. The control side doesn't have an on/off it has an occupied/set back temp.
This is so the floor always stays just below your occupied temp so the recovery time to get back to temp is shorter.
I don't know what the running cost would've been for the electric but I'd be interested to know any one else's experiences of both systems smile . For info (pics on my housebuild blog) the floor space is 55m squared and the max height will be about 5m in the kitchen, so a pretty big area to heat I guess.

hairyben

8,516 posts

183 months

Wednesday 24th February 2010
quotequote all
Electrics easier to install, 2mm wire rather than 15mm pipes then screed. A wet system would be the best long-term solution though, in terms of running cost. If height is indeed the issue, have they allowed for insulation underneath? If not I simply wouldn't bother, get a rad or a kickboard heater.


blade runner

1,029 posts

212 months

Friday 26th February 2010
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We are soon to get planning approval for our kitchen/diner extension which will be 11m long x 3.5m deep (38.5sqm). All but one side of the extension will be glass, so no room to put a radiator anywhere. Was thinking that electric would be the way to go, but having read the above posts am now a bit less convinced. Has anyone got any experience of using trench heating as this could be another option although it does seem to be prohibitively expensive?

hairyben

8,516 posts

183 months

Friday 26th February 2010
quotequote all
blade runner said:
We are soon to get planning approval for our kitchen/diner extension which will be 11m long x 3.5m deep (38.5sqm). All but one side of the extension will be glass, so no room to put a radiator anywhere. Was thinking that electric would be the way to go, but having read the above posts am now a bit less convinced. Has anyone got any experience of using trench heating as this could be another option although it does seem to be prohibitively expensive?
Nothing "wrong" with it per se, apart from being a bit of a dust/st trap, I would have an engineer or specialist at least spec the system rather than rely on the builders to get it right.

Any reason why with a new build extension you can't go underfloor piping though?

Bill

52,749 posts

255 months

Friday 26th February 2010
quotequote all
We have devimat in our (65sqM) living area and have no problems. I've got no idea of before and after fuel bills but our electricity bill isn't horrendous.

Ranger 6

7,052 posts

249 months

Friday 26th February 2010
quotequote all
Did our kitchen using water pipes (Polypipe overlay I think) 55 sq m and has been one of the best investments. I don't know price as it was part of a total refurb. Good temperature, stable and warm. I certainly would never have considered electric for something the size of ours - we did put it into our en-suite but that is only 6 sq m smile

The best advice we were given was to use Ditramat on top of the pipework to minimise thermal shock going through the stone tiles and cracking them.

blade runner

1,029 posts

212 months

Friday 26th February 2010
quotequote all
hairyben said:
Any reason why with a new build extension you can't go underfloor piping though?
I just preferred the idea of electric as it seems far simpler to fit and less involved than a wet system in our case. Our existing kitchen will also form part of the new open-plan kitchen/diner and seeing as we have concrete floors here already, it's going to be a pain to have to dig up the existing kitchen floor to install a wet system that will cover the entire area. I suppose we could have an electric system to heat the existing kitchen area and put a wet system in the new extension, but I thought it would be easier to have the same system throughout.

Given the amount of insulation required with today's building regs I was rather hoping that an electric system would be good enough for the new space. The glass panels we will use are all made from the highest rated E glass and argon filled + roof and floor will be insulated to the max.

Ranger 6

7,052 posts

249 months

Friday 26th February 2010
quotequote all
blade runner said:
...it's going to be a pain to have to dig up the existing kitchen floor to install a wet system that will cover the entire area...
The polypipe system is a 'slim' one which doesn't need to old floor dug up. we had the same issue with exisiting and new floor levels.

ChrisnChris

1,423 posts

222 months

Saturday 27th February 2010
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Just a quick point re under floor heating, & I have no idea how widespread this might be. I built a kitchen for a new build house. Kitchen was 12mx6m so.... big! (house was on 5 levels) There was underfloor heating which was fine....except that the heat also transfered to the cold water pipes under the floor.

Result was that the cold taps had to be run for at least 30 secs before cold water appeared. I'm not sure how the problem was or even if it was ever resolved.

No, I wasn't responsible for the plumbing!

So make sure your cold water pipes are insulated..... from the heat!

Ferg

15,242 posts

257 months

Saturday 27th February 2010
quotequote all
ChrisnChris said:
...cold water pipes under the floor.
Is it in a screed? I wasn't aware that any water authorities allowed domestic supplies in screeds anymore.