Underfloor heating as main source

movilogo

I am thinking of replacing my warm air heating unit. 

Is electric underfloor heating in all rooms good enough as main heating source?

Or I need traditional gas radiator too?

Rodders53

What is the energy source of the warm air unit?  Gas??

Electric heating unless from a Heat Pump is mahoosively expensive. Avoid!!!

Wet heating from a gas(piped natural or bulk LPG) or kerosene heating is OK.  Air to Water ASHP wet may be OK too.  Air to Air ASHP (aka aircon units run in 'reverse' to heat the rooms mode) are also OK.

Look in the Energy boards rather than DIY - lots of threads on heating.

ThisIsWeird

Wet UFH would be the way to go - cheap to run via a gas boiler, and perfect for future-proofing for use with an ASHP when the time comes.

Or, even consider the ASHP now.

Electric UFH? Ouch expensive.

Doozergirl

What's your current insulation situation?  It needs to be good to hold the lower heat produced by UFH.  We have UFH downstairs that heats the whole house but the house is built for that to happen.   

And another voice saying nooooo to electric.  That would be insanely expensive to run.  

Kiran

Unless you have free electricity via solar etc. (and even then you are missing out on the benefit of using that electricity elsewhere) I wouldn't use electric underfloor heating. You can calculate your load if you take the information from the supplier and multiply it up by your floor area. Multiply that by your anticipated hourly usage and my guess is you will get a scary figure out. 

Wet underfloor is great, but can be a bit disruptive to install depending on the floor construction, insulation level etc.

movilogo

Energy source for warm air unit is gas. In fact, I have another new combi gas boiler installed last year. It is a 1960s house extended in 1980s. Newer half of house use traditional central heating (with radiators) and original half of the house use warm air heating. My plan is to get rid of warm air unit completely.

My new boiler is powerful enough to cater for the whole house. 

What is gas underfloor heating? Is it water driven system? I thought that would be lot more expensive. Electric underfloor heating is very easy to lay and no maintenance required.

Regarding insulation, the house has cavity walls but not insulated, I am planning get that insulated too.

ComicGeek

Sensible thing at the moment would be to install radiators in the original half of the house, fed from your new boiler. That would be your lowest running cost.

FreeBear

movilogo said: What is gas underfloor heating? Is it water driven system? I thought that would be lot more expensive. Electric underfloor heating is very easy to lay and no maintenance required.

Gas underfloor heating (UFH) uses gas to heat water which is then circulated through pipes embedded in the floor. To get the best out of it, you need lots of insulation underneath to stop the ground soaking up the heat.

Electric UFH also needs lots of insulation underneath. If you go the quick & cheap route of just plonking the mats on top of a concrete floor, much of the heat will be soaked up by the slab. Running electric UFH in the current economic climate is going to cost you a fortune.

movilogo

How difficult/expensive to install gas underfloor heating in concrete floor? I guess it requires significant amount of digging. 

ComicGeek

movilogo said:

How difficult/expensive to install gas underfloor heating in concrete floor? I guess it requires significant amount of digging. 

No, you would lay a system on top of the concrete floor. 

But you are unlikely to get enough heat output from a wet underfloor heating system in an uninsulated house. 

vacheron

Underfloor heating must be laid on top of an insulated floor to prevent the heat leaking into the ground and the external walls of the house. You then put floorboards above, or pour concrete (screed) over the pipes to create an insulated slab which you can then put flooring on. We did this in a recent extension which uses a wet (gas heated) system. 

The system works well, but you need to allow a significant time for the system to put heat energy into the concrete which then heats the room. You also need to make sure that you don't continue to run the heating until the room is warm (like you would do with a radiator) as the overshoot is very large.  There are however special learning thermostats designed to work with underfloor heating which will manage this for you. So if you are planning to mix underfloor and radiators, I would recommend a 2 zone heating system with independent thermostats for each.

In our case, the flooring needs to be on at least an hour before the room starts to warm up, It will then continue to warm up for at least 2-3 hours after the heating has turned off beore stabiliising at which point it will keep the room at a steady temperature for the remainder of the day. This means the "I'm chilly, i'll just stick the heating on for 15 minutes before I go to bed in an hour" approach favoured by my partner doesn't work! (for our system at least).