Underfloor heating..

[vkurup]

Got some major renovation coming up and we were looking to replace our downstairs radiators with a wet underfloor heating.
1) The cost bit looks prohibitive if we were to go for lifting up all the floor boards and screed it. The builder suggested looking at 'Warmboard' UF heating... where you can lay it on top of existing floor and it will work... We are looking at it now.

However, beyond the cost aspect, my neigbhour who has put UF heating in their new kitchen extension raised a few points
1) UF takes a long time to heat up, so you still need some secondary heating e.g. Radiators, Oil filled heaters etcs. that can help during a cold snap. Our primary reason for UF was to get rid of the downstairs rads, so this was a bit of wasted effort
2) The cost of running a UF system is prohibitive, so some of their friends dont use the UF, but have gone and bought oil filled rads that they use.

Effectively, UF not easy to put in or to run!!! Any forumers having experience of UF?

 

[brendy]

Got some major renovation coming up and we were looking to replace our downstairs radiators with a wet underfloor heating.
1) The cost bit looks prohibitive if we were to go for lifting up all the floor boards and screed it. The builder suggested looking at 'Warmboard' UF heating... where you can lay it on top of existing floor and it will work... We are looking at it now.

However, beyond the cost aspect, my neigbhour who has put UF heating in their new kitchen extension raised a few points
1) UF takes a long time to heat up, so you still need some secondary heating e.g. Radiators, Oil filled heaters etcs. that can help during a cold snap. Our primary reason for UF was to get rid of the downstairs rads, so this was a bit of wasted effort
2) The cost of running a UF system is prohibitive, so some of their friends dont use the UF, but have gone and bought oil filled rads that they use.

Effectively, UF not easy to put in or to run!!! Any forumers having experience of UF?

We have underfloor heated matt rolls fitted to our downstairs and extension. Warms up pretty quickly but doesnt half make the wee clock spin!! If you use decent tiles though, they will maintain heat for quite a while so works out ok.

 

[Sweep]

I have it in my house (already in when I moved in). Personally I wouldn't bother. Can take days to warm up and cool down, unless you open the windows But then if you do that and if it gets too cool you end up taking days to heat up again. For me, it isn't worth it just to do away with wall mounted radiators and there are a lot of really stylish radiators available now.
Where it is good is under ceramics in bathrooms where I guess you can expect to walk in bare feet. Other than that, I don't think its worth bothering with.

 

[Rooter]

I have it in my house (already in when I moved in). Personally I wouldn't bother. Can take days to warm up and cool down, unless you open the windows But then if you do that and if it gets too cool you end up taking days to heat up again. For me, it isn't worth it just to do away with wall mounted radiators and there are a lot of really stylish radiators available now.
Where it is good is under ceramics in bathrooms where I guess you can expect to walk in bare feet. Other than that, I don't think its worth bothering with.

Am surprised reading that, my brother in laws house has it and he says its fantastic, cheap efficient, fast etc etc.

 

[Deleted member 1740]

I fit UFH and to be honest it's a great system but it does have its downside mostly the time it takes to heat up/cool down though it depends on the size of the area it's installed in.

If you're on budget for energy bills then I'd swerve it as it's not cheap to run.

 

[Whereditgo]

Ideal for facilitys such as a creche (little ones crawling around etc) or an area with a very high ceiling owing to the heating zone being right where you want it, and fairly efficient on a wet heating system owing to the low flow and return temperatures meaning a condensing boiler would be running at optimum efficiency, but huge thermal inertia, so very slow to warm up and cool down.

Personally I don't think it's a good solution domestically as too often (Spring and Autumn in particular) we get large changes in weather from day to day, even morning to afternoon, or the odd chilly evening requiring just an hour or two of heat.

 

[Qwerty]

IMO in general It isn't a good idea for a domestic system and really isn't worth the outlay and inconvenience of screeding the floor.
As others have said it takes too long to warm up as typically you would only run the system at Approx 40*c otherwise the screed can crack.
Then due to the latent heat in the floor it takes too long to cool down.

If you were to back up the system with rads they would also have to run at 40*c unless you had a separate Variable Temp circuit for the UF heating only, which for a domestic system is way OTT.

Also, dependant on manufacturer the UF manifold actuators are quite fault prone in my experience.

I'd avoid the cost and hassle and buy some nice Rads.

 

[vkurup]

I fit UFH and to be honest it's a great system but it does have its downside mostly the time it takes to heat up/cool down though it depends on the size of the area it's installed in.

If you're on budget for energy bills then I'd swerve it as it's not cheap to run.

Stuart.. have you come across Warmboards? It is a wet system that you can retro fit it into the house. I was discussing with the company, and they say, you fix an insulation board (no more ply), then warmboard, then cement based board and then tiles/vinyls. This would raise the height by about 300-500mm atleast. The height is not too much of an issue as we have to replace all the internal doors (they are fairly old at the moment).

Ideal for facilitys such as a creche (little ones crawling around etc) or an area with a very high ceiling owing to the heating zone being right where you want it, and fairly efficient on a wet heating system owing to the low flow and return temperatures meaning a condensing boiler would be running at optimum efficiency, but huge thermal inertia, so very slow to warm up and cool down.

Personally I don't think it's a good solution domestically as too often (Spring and Autumn in particular) we get large changes in weather from day to day, even morning to afternoon, or the odd chilly evening requiring just an hour or two of heat.

The temprature variation is my chief concern. If this takes too much time to warm up then it is no good. If we have to keep rads then it defeats the purpose too..

The other benefit I can think of is that the warm air rising thru will also help provide some warmth upstairs.

That is my worry... we have already switched on the rads a couple of times this month..

 

[sawtooth]

We had an extension to the kitchen done this year, roughly 3m x 6m added with a vaulted ceiling. Thought long and hard about whether to have underfloor heating and in the end opted against it this time around.

Instead we installed a couple of designer column rads, quite narrow but tall and we could put them on walls that would otherwise not be used so to maximise the wall space for furniture. Not had a winter yet so fingers crossed there's enough BTU in the room!

 

[Deleted member 1740]

Stuart.. have you come across Warmboards? It is a wet system that you can retro fit it into the house. I was discussing with the company, and they say, you fix an insulation board (no more ply), then warmboard, then cement based board and then tiles/vinyls. This would raise the height by about 300-500mm atleast. The height is not too much of an issue as we have to replace all the internal doors (they are fairly old at the moment).



The temprature variation is my chief concern. If this takes too much time to warm up then it is no good. If we have to keep rads then it defeats the purpose too..

The other benefit I can think of is that the warm air rising thru will also help provide some warmth upstairs.

That is my worry... we have already switched on the rads a couple of times this month..

I've used a brand called John Guest and it's basically insulation board with pre made channels in it and the pipe fits into that, you then fit either the floor covering over it or a 65mm screed then lay your floor covering on top.

Have a look on their website and it'll give you a better idea.

I suggest trying to get a few local installers out to quote and talk you through it. I honestly don't think it's worth the expense unless you're doing a large area.

 

[Whereditgo]

The other benefit I can think of is that the warm air rising thru will also help provide some warmth upstairs.

The effective heating zone with UFH is 0 - 2m from FFL, so there would be little contribution, if any, from the UFH to the rooms on the level above.

 

[Whereditgo]

IMO in general It isn't a good idea for a domestic system and really isn't worth the outlay and inconvenience of screeding the floor.
As others have said it takes too long to warm up as typically you would only run the system at Approx 40*c otherwise the screed can crack.
Then due to the latent heat in the floor it takes too long to cool down.

If you were to back up the system with rads they would also have to run at 40*c unless you had a separate Variable Temp circuit for the UF heating only, which for a domestic system is way OTT.

Also, dependant on manufacturer the UF manifold actuators are quite fault prone in my experience.

I'd avoid the cost and hassle and buy some nice Rads.

It's not latent heat though.......

 

[Lord Tyrion]

Hugely disappointed by this. I have been in houses, visited and stayed over, with UFH and I have found them marvellous. The heat is spread evenly throughout the room / house in a very gentle but comfortable fashion. A tiled bathroom floor that is heated suddenly becomes a wonderful place.

You don't need to blast heat out in the way radiators do so I had hoped it would be cheap to run and I much prefer the way the heat is given out in comparison to radiators. After reading this thread maybe it is not the future after all. Very useful but ultimately dismaying thread.

 

[vkurup]

Hugely disappointed by this. I have been in houses, visited and stayed over, with UFH and I have found them marvellous. The heat is spread evenly throughout the room / house in a very gentle but comfortable fashion. A tiled bathroom floor that is heated suddenly becomes a wonderful place.

You don't need to blast heat out in the way radiators do so I had hoped it would be cheap to run and I much prefer the way the heat is given out in comparison to radiators. After reading this thread maybe it is not the future after all. Very useful but ultimately dismaying thread.

I am gutted too.. but in a different way, i m happy that I might have saved money by not putting it in the first place!! But the Mrs is thinking about it and we are waiting to hear from the Builder... so never say never..

 

[Rooter]

I should have said after my post saying my BIL says its cheap to run, his runs off solar panels that just heat water for the underfloor heating! Thats why his is cheap to run!

 

[vkurup]

I should have said after my post saying my BIL says its cheap to run, his runs off solar panels that just heat water for the underfloor heating! Thats why his is cheap to run!

Does he get enuf sun during the winter to heat it?

 

[Deleted member 1740]

Does he get enuf sun during the winter to heat it?

I think it's the amount of daylight and not sunshine that creates the energy in the solar panels.

 

[Rooter]

Does he get enuf sun during the winter to heat it?

Pretty much, any extra supplied by gas fired boiler I think. His was fitted as new to a new build, doubt it to be commercially viable as a retrofit.

 

[Qwerty]

It's not latent heat though.......

I'm old skool...Is residual the new latent??