Electric UFH options

[Ben100]

hi all,

 

I've looking to install electric UFH in my loft rooms / home offices. As it's not a massive space, 2 rooms around 28m2 in total, and is in a difficult location to run plumbing, I'm looking at installing electric UFH.

 

What do you guys think of the kits you can get online? Are there any which are seen as better than others?

 

Cheers!

[Temp]

Don't get me wrong, I like UFH but I'd have to be desperate to install electric UFH. Id only use it to warm tiles in a bathroom rather than for heating..

 

All direct electric heating (UFH, Fan heaters, Radiant etc) is practically 100% efficient, which sounds good, but electricity is about the most expensive fuel per kWH you can buy. Three to four times the cost of mains gas. Three times current cost of oil etc. I would try really hard to extend your heating system.

 

If the rooms are small and have office furniture etc the actual floor area available to dissipate heat into the room might be quite low. So if the rooms aren't well insulated it might not be possible to get enough power out of any form of UFH (bit like having too small a radiator). 

 

They say heat rises but that's convection. First the heat has to escape the heating element by conduction and it goes in all directions including downwards. So UFH needs at least 100mm of insulation below the floor. 

 

UFH also takes quite a long time to warm up the room. Fine if you are going to be in there most of the day but not so good if its just for short periods say first and last thing in the day. 

 

I can't really comment on makes of electric UFH we have UFH but its oil fired.

[Bitpipe]

We have electric UFH in the bathrooms to warm the tiles, apart from a wet towel rad per bathroom that's the only heating upstairs as the house is passive standard.

 

It's really a comfort measure, as tiles are good conductors of heat they will always feel cold underfoot unless warmed.

 

I got a cheap 100w wire mat kit from eBay, Warmstar and it worked fine. I ditched the very cheap controllers that came with it and got some fancier ones from the Under Floor super store. You get expected resistance values for each mat and test them with a multimeter rolled, unrolled and installed.

 

You need to specify the area to be covered as the mats are pre wired - you can tweak the shape covered by cutting through the webbing. There is also a temp probe that needs to go down alongside the mat for the controller.

 

The build up was structural OSB, 6mm insulated tile backer board (screwed to floor), heating mat (stuck to floor with primer and tape), self levelling compound, adhesive & tiles - total build up was 25mm.

 

The tiler took care of it all and I used a little tester unit that you clip to the mat while its being laid and it beeps if there is a short between L/N/E - you've no other option to bin the mat in that case but saves ripping up tiles.

 

As above - these kits work fine with tiles as the layers above the element are very conductive vs those below. You can get 150W and 200W systems but again, need to think carefully about what is above the element - wood or carpet will be effective insulators.

 

 

[Ben100]

Thanks for the advice.

 

The rooms are small, with low sloped ceilings, and are built to modern standards (new roof this year), so I'd expect the heat given off by the UFH would be ok. In fact I spend +8h a day in my roof office and only have to put on the electric heater a couple of hours a day (first thing in the morning and last thing in the afternoon/evening). I know it's more expensive than oil (we don't have gas), but it is a small, well insulated space...

 

I might see if we can get some radiators up here, but I can see it being a pain to run. I also don't like the look of radiators ?