secondary underfloor heating, how long to warm up tile?

[cornasdf]

Hi all,
I am remodelling a mid sized bath (2x3m). Our primary heat is through radiators but I am considering installing electric underfloor heating in the bathroom. This will be in conjunction w/ a rad so won't be the primary heat, more a luxury to walk on when we are taking a shower/bath.

The question i have is how long will it take to warm up a limestone tile floor? I know the room can take hours but I am just looking for the time until the tiles are warm to the touch. Can anybody w/ electric underfloor heating on tile or stone (or even wood) comment?

Thanks

 

[mattysupra]

Underfloor heating should not be turned on and off. It should not change its temperature by more than 2-3c over a 24hr period.

Floorcoverings fail when it is turned on and off.

So the answer to your question, it should take no time to heat as it should always be running at a low temperature.

So next im sure you will ask " that sounds expensive to run" well no. Heating something cold takes a lot of power and will take a while. If maintained at a sensible temperature (say 21c) the heating will be switching on and off and using small amounts to power rather than trying to heat up a mass in one go. As it will be a second heat source you might want to set the underfloor heating to drop down to say 18c at night and then heat to 20-21c in the morning and evening. You house will rarely drop below 18c i would guess so it will take minimal power to keep the floor heated.

 

[texasholden]

Time taken for the tiles to heat up depends upon the heating output (150 w/sqm? etc) and the thermal conductivity of the tiles and subfloor.

Warmup claim using their insulation boards reduced heat up time to 20 mins - and there's a simple graph on their website (although I'd take that with a pinch of salt).

If I was looking for the fastest heat up time then I would ensure a relatively high heat output from the element, insulation below the element and relatively thin but dense tiles (high thermal conductivity) to ensure they absorb the vast majority of the energy from the element. With this set-up I would expect to be able to feel the effect on the tiles in approx 30 mins.

FWIW, I would try to find a porcelain tile which replicated limestone as these are usually more dense, thinner and less likely to stain or wear in unwanted or unexpected ways. Maybe they don't have the kudos that the 'real thing' has but possible something to consider nevertheless.

I disagree with the previous advice - you should have no issues turning the element on and off as you require and you can always check with the manufacturer if you want confirmation.

 

[Tipper]

Electric underfloor heating is usually connected using an in-floor thermostat. This turns the heating on & off!

I had a wetroom, with a Hot Tub in it, with the above and it took about 12 hours for the room as a whole to get up to heat. I never measured the floor surface temperature during this period but the heat in the floor surface felt nice and warm to my cold tootsies.

 

[texasholden]

Using a programmer to provide warm tiles at specific times is absolutely fine.

You do not need to keep the floor warm.

 

[Agile]

Its usually expected that to heat up a floor with underfloor heating from cold can take up to about TWO hours!

Tony

 

[texasholden]

http://www.thegreenhome.co.uk/heati...long-does-underfloor-heating-take-to-warm-up/

 

[mattysupra]

Using a programmer to provide warm tiles at specific times is absolutely fine.

You do not need to keep the floor warm.

Thats correct, providing you dont expect to be able to heat the flooring up by more than a few degrees.

 

[mattysupra]

Its usually expected that to heat up a floor with underfloor heating from cold can take up to about TWO hours!

Tony

the consumer expects this as miss sold . However as my above post you should not raise temperatures up and down fast.