Wet underfloor heating

[shovetheholly]

Forgive me Mumsnet, for I am having a wobble.

How warm is wet underfloor heating? I went to a demo at the weekend, and the floors on the sales stand seemed barely warm to the touch. Will that really be enough to keep me toasty through the winter? I will be using it to heat an exceptionally high room on the north-facing side of the house.

[Wrinklytights]

The floor doesn't need to be so warm as it's such a large surface area. Two of my friends have it. One under tiles and carpet and one under wood. The wood and carpet don't feel particularly warm - think the feeling of a floor that's been warmed by sun through a window - but the tiles feel absolutely lovely when you just have socks on. Both their houses are plenty warm enough in terms of air temp. We are considering it for our extension - probably under polished concrete.

[shovetheholly]

Thanks wrinkly. I'm just worried about all the air moving upwards and leaving me freezing near the floor! Reassuring to know that your friends who have it have warm houses...

[LemonEmmaP]

We have this in our kitchen extension. It's a large area - about 11m by 5m at its widest, and the floor is tiled. If anything, it gets too warm out there! It's regularly 23 degrees, and 24 by the end of an evening. While it takes a while to warm up the room initially, it's very effective at keeping it toasty. Fwiw our room is also north facing, and has reasonably high ceilings.

[CatCoriander]

We have just had it fitted in our lounge in order to get rid of very ugly old radiators. It's under laminate and it's great - the floor feels slightly warm when you are bare foot and the room just heats up gradually to whatever you set on the thermostat. We also have a wall mounted gas fire to top it up if needed but not sure how much we'll use that.

[shovetheholly]

Thanks - that's really reassuring! Especially with the high ceilings. I have a fear that the heat will rise so it will be 35 degrees near the ceiling and 10 degrees near the floor!

I have persistently cold feet, so the idea of being able to put them on a warm surface is a lovely one!

[cantpickusername]

The floor will be 27-29C.

As a PP said, you don't need a higher temperature than this as the surface area is larger, so you get the same output as with radiators.

Underfloor heating work by radiant heat whilst radiators work by convection heat. This basically means that radiators heat up the air but underfloor heating heat up objects (like the sun does).

As underfloor heating doesn't drive natural convection you don't get the same air movement in the room either so you won't have a problem with hot air rising to the ceilings like it does with radiators.

[shovetheholly]

cantpick - if you were right here in front of me, I would give you a MASSIVE hug! That is exactly what I needed to know! Thank you so much.

[pdunne]

Underfloor heating does cause convection as the warm air that's just been heated still rises and then falls back as it cools (think water heating in a saucepan), however as the heat source is actually at the floor and is much larger than a radiator you aren't left with cold air at the bottom or cold spots away from the heat source like you get with radiators.

My wife used to get very cold feet before we had underfloor heating, but doesn't anymore.

[pdunne]

Underfloor heating does cause convection as the warm air that's just been heated still rises and then falls back as it cools (think water heating in a saucepan), however as the heat source is actually at the floor and is much larger than a radiator you aren't left with cold air at the bottom or cold spots away from the heat source like you get with radiators.

My wife used to get very cold feet before we had underfloor heating, but doesn't anymore.

[ZedWoman]

We have wet underfloor heating in our family room. It's lovely and warm underfoot but not too warm that it gives you sweaty and uncomfortable feet (it was at first until we turned the temperature down). It's perfect. Trust me, I grew up in warm houses and really hate the cold. If anyone would not find a heating system warm enough, I am that person.

If the rest of the house is on radiators (as ours is) then make sure that you have a separate control circuit and different timer. The heating needs to come on earlier and go off earlier in a room with UFH as it takes longer to warm the room and it stays warming for a long time after the heating goes off.