How good is underfloor heating in a large room

[BeeDee]

Morning all,

I'm about to embark on some home renovation and the kitchen is the first target. We are looking at making it bigger, all in the room would be 32m2. I have read that electric underfloor heating systems are better and more efficient for smaller rooms, but that they can take a while to heat the room and are more expensive to run than wet underfloor heating systems. I'd prefer electric however, ideally throughout the house as I'd like to get away from gas entirely and move towards renewables.

So my question is, how practical is it to have electric underfloor heating in a room of this size? Could it be the sole heating source in the room (bare in mind just last week we had temperatures of -10C)? And would it be prohibitively expensive to run (I realise this is subjective but given it's one room in the house I'd hope it would be no more than a £5-£10 a month in running costs)?

Thanks,

 

[James]

For an open room like that you are looking at 100 to 200w per sq m
Therefore 3 to 6kw

At 15p per kwh
This is roughly
45 to 90 pence per hour.

I think £5 to £10 is a realistic cost to run PER DAY during the winter.

 

[pc1966]

I would imagine a ground or air source heat pump would be your best long-term option as you don't need (or want!) too hot a floor and the running costs would be much lower (by 2-3 times) than normal electric heating.

However, the installation cost of that would need consideration, and any practical issues of where it can be located.

 

[DPG]

This is the problem when people want to go 'eco' and use renewables. But then end up using 6 kilowatts of power just to heat the kitchen!

No offence intended to the OP.

 

[littlespark]

is your area calculated by the room size, or the floor area AFTER the kitchen units have been put in? No point heating under the units.

 

[MJPD29]

5 quid or slightly more per day is more realistic in a room that size

 

[Wilko]

Hi - it’s good to think this through before you build. So well done .
If you do choose to go electric underfloor heating can it can work very well. It has very few moving parts and it is easy to install. But, if the mat gets damaged it just stops working. This can happen during tiling and it can be quite difficult to fix, ie tiles up. Meanwhile you’ve no heating. So perhaps make sure the responsibility to install and commission is clearly linked to ‘significant’ payments.

It takes power to increase the room temperature and the more insulation you have the less power is required. So perhaps spend more on this aspect .

Unless you generate your own power, gas is going to be the cheapest per kW but that too may change in future.

 

[Mike Johnson]

Wet underfloor heating can be accommodated with an electric boiler if you are dead against gas, essential to insulate under the floor to ensure heat always goes where you want it and as above don't heat under the units or fixed furniture, but I am sure you have identified that in your research.

 

[Mike Johnson]

I would imagine a ground or air source heat pump would be your best long-term option as you don't need (or want!) too hot a floor and the running costs would be much lower (by 2-3 times) than normal electric heating.

However, the installation cost of that would need consideration, and any practical issues of where it can be located.

And the noise from the external compressor can be considerable if you live in a Rural environment, mine are very noticeable if you are near them.

 

[HappyHippyDad]

I put 160w P/sqM electric underfloor heating in my 12m2 conservatory. It is absolutely wonderful! I walk in, in the morning in my bare feet and it just feels lovely ?. It stays on all day in the winter keeping my feet lovely and warm. It also costs a bloody fortune!!!!! I wish I'd bought a pair of slippers!

It is lovely, but it feels extravagant and is very expensive to run. My electric bill is usually around £40 p/month and it went up to around £130. The install was done properly with good insulation below. Also, it's not just the winter months you use it. The tiles are cold throughout spring and autumn so it is used (albeit less) in those months too.

I don't know much about wet underfloor heating, but if I had the choice I would go with that, as I assume it is far less to run. I'm sure it most be quite a bit more to install, but I bet you make that back over a few years with the reduced running costs.