UFH and foot-feel?

[puntloos]

As I understand it, tiles and stone feel cold, because they conduct heat easily and therefore if they are 20C, they will happily pull heat out of your feet (@37C). 

 

Am I correct that to avoid this effect, you will have to permanently heat your tiles to something like 25C, whilst perhaps engineered wood or carpet need no heating? If so:

 

- 1/ Wouldn't this source of heat not be problematic in summer? Should I always walk around with socks/shoes on to avoid this?

- 2/ Cost? Do you keep your UFH at 'feet-friendly' setting and if so how much extra  cost per yr is this?

- 3/ Using engineered wood might feel better for feet, but then you will lose more heat if you actually want to heat your place, because it isolates the heat away from your house (more)?

 

What's the right balance here? 

 

[puntloos]

Anyone with tiles? Do you heat them? When? Or just wear socks? (so pragmatic..)

[JohnMo]

Our heating come once per day for a few hours, heating been off for the last few days, our tiled floor doesn't feel cold under foot, it is cool, but not so as you would notice or is uncomfortable.

 

 1 if your house is hot, having a cool floor will be nice in my opinion.

2.  Tried a few things but once up to temp heating goes off, but floors stay warmer than cool

3 choose a floor finish you like for t room, everything else is over thinking it.

[ProDave]

Socks and slippers

 

The only place we routinely walk bare foot is the en-suite sand then only when you are going for a shower.  The bathrooms are the only place upstairs that has UFH, just to take the chill off the tiles in the winter.

[joe90]

Cool/cold tiled floors is the reason we went LVT in the bathrooms (with electric UFH in the en suite which is rarely used). We have a no shoes policy upstairs (all carpet apart from bathrooms) tiles and Oak flooring downstairs with slippers (mostly). I think it works well.

[joth]

Textured porcelain (e.g. wood effect) feels a little warmer to touch IMO than smooth polished tiles, as you don't have such a large contact area .

That said yes it's a bit cooler feel than the wood floors, except when the UFH is on, but not cold. We tend to be slippers or socks indoors which hides most of it

[Bitpipe]

11 minutes ago, joe90 said:

Cool/cold tiled floors is the reason we went LVT in the bathrooms (with electric UFH in the en suite which is rarely used). We have a no shoes policy upstairs (all carpet apart from bathrooms) tiles and Oak flooring downstairs with slippers (mostly). I think it works well.

 

We have no shoes policy in whole house.

 

Have resin on GF which is non conductive underfoot so always feels warm irrespective of whether UFH is active (only comes on during winter).

 

Engineered wood upstairs and karndean in basement, both behave similarly.

 

Bathrooms have ceramic tile and we have low power (150w) electric UFH there to warm it in mornings, just to take the cold feet feeling away.

 

[Radian]

Since I turned off the UFH in our garden room extension a couple of days ago I really miss the nice cosy feel from the floor. Although we wear footwear in the room, it still had a 'feel' about it that's no longer there. Admittedly it's not an issue when the sun is blasting in like it is now but in the evening, even though it's still around 21 degrees, it just feels like something's missing. 😞

[jack]

On 23/03/2022 at 00:18, puntloos said:

As I understand it, tiles and stone feel cold, because they conduct heat easily and therefore if they are 20C, they will happily pull heat out of your feet (@37C). 

 

Am I correct that to avoid this effect, you will have to permanently heat your tiles to something like 25C, whilst perhaps engineered wood or carpet need no heating? If so:

 

- 1/ Wouldn't this source of heat not be problematic in summer? Should I always walk around with socks/shoes on to avoid this?

- 2/ Cost? Do you keep your UFH at 'feet-friendly' setting and if so how much extra  cost per yr is this?

- 3/ Using engineered wood might feel better for feet, but then you will lose more heat if you actually want to heat your place, because it isolates the heat away from your house (more)?

Most of our downstairs floor area is polished concrete.

 

While we have Passivhaus levels of airtightness and insulation, we don't have huge amounts of solar gain, and our house does tend to have a longer heating period than other Passivhaus-class houses I'm aware of.

 

I turned off the heating last week. The floor temperature has been fluctuating between 18 and 19 degrees over the last couple of days. It definitely feels cold underfoot. I tend to walk around in socks, so isn't really an issue. 

 

So to answer your questions:

 

Quote

- 1/ Wouldn't this source of heat not be problematic in summer? Should I always walk around with socks/shoes on to avoid this?

 

We don't heat the floor in summer, and it feels perfectly comfortable. In fact, we cool ours during hot periods, and it feels amazing.

 

Quote

- 2/ Cost? Do you keep your UFH at 'feet-friendly' setting and if so how much extra  cost per yr is this?

 

No. We run UFH only when the house needs heating or cooling.

 

I can't answer question 3, as we don't have wooden floors. I will say that the one carpeted room downstairs is the coldest room in the house during winter, presumably because the carpet reduces energy transfer from the UFH.

[TerryE]

We have UFH in the slab and slate tiling throughout the ground floor.  We just walk around in bare feet; never had any problems with feet feeling cold.

[markocosic]

Yes. 

 

Tiles suck the heat our of your feet. Even in summer. 

 

If you have real summers, the room is too warm, and the perceived coolth is good.

 

Else if you have "sprautumn" summers I think you'll end up with rugs in the living spaces. And socks.

 

 

Yes.

 

Your wife will want to warm the tiles outside of a real summer, and it should be as good as free because you're using your PV and a heat pump to do so at an exceedingly high COP due to the low temperature increase. Right?

 

The Thermia unit I've got has a "summer mode" that ensures the return from the heating system is at least X degC at all times, where X is set to 25 degC by default. I'd probably run this...whilst using the source side (ground source brine loop) to cool the intake air...if the floors were tiled.

 

 

Timber may be better.

 

The perceived temperature of timbers floors is much higher than than of tile, lino, laminate or indeed engineered wood. If your heating system can tolerate the compromise.

 

Likewise carpet.

 

 

UK house has:

 

- Tile to the porch (with UFH)

- Engineered timber downstairs (with radiators) - plus a rug where you're sat on the sofa / lying on the floor

- Softwood stairs (bare)

- Engineered timber upstairs bathroom (with towel radiator) - plus a bath/sink rug where you might stand for more than a minute

- Carpet to bedrooms

 

The tiled area with UFH is decidedly unpleasant underfoot outside the heating season compared with the engineered timber. I wear socks until the floor is about 22C. My wife wears slippers even then. 18C isn't pleasant even with socks.

 

 

Next house will likely have:

 

- Tile to bathrooms with UFH that has "summer mode" running on a heat pump 

- Timber everywhere else

- Rugs (or low tog carpets with trimmed edges) in key areas over that timber (easier to clean than wall to wall carpet imo)

 

[AliG]

I can feel when the tiles aren't heated but it is not uncomfortable.

 

If the floor wasn't heated in the winter you would really feel it, but in the summer it is just cooler, not really cold. We don't have any carpets, only tiles or wood. The upstairs tiles feel a little warmer I would say, so in particular I don't notice any issue at all in our en suite.

 

I have never heard of anyone running the UFH just to have the floor feel warmer. I guess @markocosic is right in that it would use less energy, but it still seems wasteful. It would almost certainly warm the house up to a temperature that would feel uncomfortable 23+

 

[markocosic]

I think loads of people have direct electric underfloor in bathrooms...and 25C in those probably isn't too hot.

 

COP of an air to water heat pump with ambient air 12C and flow temp 25C will be 7+ vs 1 for direct electric. Not that it makes much odds if you have any PV.

 

Perception depends on genetics. Women operate at higher body temperatures and are more likely to have Raynaud's than men. 

 

https://en.wikipedia.org/wiki/Raynaud_syndrome

https://pubmed.ncbi.nlm.nih.gov/3425973

[AliG]

The main issue is warming the house up. In a very well insulated house, it would warm up running water at 25C. Some people have had issues in near passive houses due to hot water tanks or the inability to run their UFH cold enough (most equipment was not made with this kind of flow temp in mind).

 

You would maybe get away with it in a bathroom as the heat would dissipate into the rest of the house. I suspect that most people with tile warmers have a wooden subfloor so it won't store heat like UFH in screed would. By the time you have heated up a tile and screed floor it would continue to pump heat out into the house for hours.

 

As you say it wouldn't really use much energy.

[Russdl]

On 24/03/2022 at 23:57, puntloos said:

Anyone with tiles?

Yep, the majority of our ground floor is porcelain tiles. 
 

On 24/03/2022 at 23:57, puntloos said:

Do you heat them?

Yep, infrequently with wet UFH

 

On 24/03/2022 at 23:57, puntloos said:

When?

Overnight between 00:30 and 04:30. 
 

On 24/03/2022 at 23:57, puntloos said:

Or just wear socks?

Occasionally. 
 

Over the winter the house has never felt cold (passive standard) equally the tiles have never felt cold.
 

The house has generally felt ‘just right’ and in bare feet the tiles have felt a bit cooler than ‘just right’ but never felt cold. 
 

Socks would probably help but not necessary. 
 

Completely unconnected with your questions but the main benefit of having porcelain tiles downstairs is that they are pretty much indestructible so there is no requirement to remove outside shoes/boots etc when you wander in (useful down the end of the muddy lane where we live) and they are very easy to clean. 
 

 

[Newbie1]

Hi I have very heat sensitive feet. I have lived in numerous apartments with wet UFH system with mix of engineered wood and porcelain tiles. I hate tiles as they always feel cold unless you have the heating higher than what you actually need it. For wood I find it comfortable underfoot as long as the room is a comfortable temperature. If you live somewhere hot, you might like the cool tile in summer, which is when you tend to notice the temperature difference the most:) 

[puntloos]

On 10/04/2022 at 21:49, Newbie1 said:

Hi I have very heat sensitive feet. I have lived in numerous apartments with wet UFH system with mix of engineered wood and porcelain tiles. I hate tiles as they always feel cold unless you have the heating higher than what you actually need it. For wood I find it comfortable underfoot as long as the room is a comfortable temperature. If you live somewhere hot, you might like the cool tile in summer, which is when you tend to notice the temperature difference the most:) 

 

This is a great point. While I don't have sensitive feet (or perhaps I should say 'I don't care if my feet are somewhat cold') I can certainly appreciate the point that for average comfort you need to turn up the heat too much. An important point to consider.

[Temp]

We have a mix of stone, engineered wood and carpet over UFH. It's nice having cool floors in summer and warm in winter. Particularly in bathrooms.

 

I suppose there are days in spring when the heating is off that the floor feels a bit cold in bare feet. But socks are enough to prevent that. We certainly don't heat the floor.

 

Mostly we walk around in bare feet all year round. I'm sitting with my bare feet on the stone floor as I write this.