I'd like to hear your experience of underfloor heating - Worth it?

[Mr_JM]

We are currently planning a renovation of a 1920's semi. We need to decide on heating options for downstairs.

Standard central heating vs underfloor. The open-plan room is going to end up being quite large around 12m x 5m.

What's been your experience of underfloor heating, and did you opt for Electric vs Water, and why?

Thanks!

 

[Swwils]

Great.

Water.

Cost.

 

[Murdochcat]

Electric underfloor heating ?

are you mad?

 

[Andy165]

Underfloor heating is great for the newer technologies of heat pumps because of its lower working temperature. But it has to be designed and installed correctly , alongside excellent insulation of your property. Hence the initial high costs of implementing it.

 

[Mr_JM]

Underfloor heating is great for the newer technologies of heat pumps because of its lower working temperature. But it has to be designed and installed correctly , alongside excellent insulation of your property. Hence the initial high costs of implementing it.

So in our situation we are ready to make these decisions - we have the choice between an air-source heat pump and a conventional boiler.

 

[Mr Chibs]

I've got wet UFH in a single room kit (kitchen/dining), and rads through the rest of the house, linked to a combi (£700 intergas job)

If I knew the UFH was going to be as good as it is, I would have done the whole ground floor, and possibly upstairs too.

 

[Mr_JM]

I've got wet UFH in a single room kit (kitchen/dining), and rads through the rest of the house, linked to a combi (£700 intergas job)

If I knew the UFH was going to be as good as it is, I would have done the whole ground floor, and possibly upstairs too.

Nice to hear your experience thanks! How long does it take for the room to go from feeling cold, to feeling comfortable?

 

[Mr Chibs]

Difficult to say, but probably an hour, maybe more from cold.

You have to think differently to radiators, once you've gone through the learning curve, I have mine set to stay at 18°c, it stays in an 'on' position 24/7.
In winter it may come on once/twice a day, I set it a few degrees lower after 10pm but at 5am it's back to 18.
The room always feels comfortable.

Another benefit is free wall space!

 

[SpecialK]

Its great if you want an even temp in the house all day. Not so great if you expect to heat the house a bit in the morning when you get up, go to work with the heating off and pop the heating back on 15 mins before you return. It is however lovely under foot with a hard floor and does provide a nice even temp. Assuming you are upgrading all the insulation in the house during the refurb you wont suffer too much heat loss.

 

[DIYer Damo]

I did my entire ground floor (80m2). I tore up the original suspended timber floor (Which was knackered and needed replacing). Had concrete poured, then 100mm insulation. Laid UFH pipes on top of this and then 60mm Anhydrite screed. This method gives a faster response to demand for heating. You can opt for insulation down first then concrete then screed. This method takes much longer to heat up but kicks the heat out for much longer after the heating switches off. It's so nice in winter and the system only requires the water to run at 45 deg instead of your typical 75 deg+ for central heating. I'd never consider electric for anything bigger than a bathroom. I knew a couple who did this in an old kitchen extension where they'd gone over the original concrete (uninsulated) floor and it was costing them a fortune, and this was back in 2018 before the energy prices went crazy. Wet UFH is expensive up front but will pay for itself over the long term. It's so nice having warm feet without shoes on in the winter time + everything on the floor such as sofas, tables, etc effectively become radiators. You also don't have rads on any walls giving a cleaner look. If you don't want to pull the floor up you could just insulate between the joists or even get low profile systems that sit on top of the floor boards but you might have to raise the height of all the doors. You must have insulation under it though otherwise it'd be wasting too much energy. Only downside is if you come in and want instant heat you're not going to get it within the first hour. To solve thi issue i installed a WIFI controlled thermostat so i can turn the heating on and off via my mobile phone so if i'm travelling home from work i can switch it on before i set off. I also put a wood burner in the living room so i can get that lit for some instant heat. Hope this helps

 

[robinbanks]

How long does it take for the room to go from feeling cold, to feeling comfortable?

Hmm, sounds like you're setting yourself up for a fail here. You don't blast UFH on and off like you do with rads, you insulate your house well and use thermostats that keep it the same temperature all the time. Rooms don't "feel cold".

60mm Anhydrite screed.

That's probably 50 percent thicker than it needs to be, btw

the system only requires the water to run at 45 deg

Hmm. With a heat pump I think I'd be targeting the floor to run at more like 25 than 45. 45 is a big ask that will hammer the efficiency of the pump


Mr_JM, I implore you, get someone in who knows what they're doing with this endeavour, otherwise I think you may be sorely disappointed. Upgrading a house to be suitable for a heat pump needs doing holistically by careful heat loss modelling