Running costs of underfloor heating

[Seamus51]

Hi,

I'm refurbishing, and thought I should investigate underfloor heating, excavating the existing floor (40sq.m) to a depth of 150mm and installing 100mm of insulation under the system with a finishing screed of 45mm. I intend covering it with an engineered wooden floor.

The cost is considerable and I have to ask if there is a reduction in the cost of heating sufficient to warrant the investment. Can anyone advise me on the comparable running costs of underfloor heating from a gas-fired boiler?

 

[ianniann]

There are plenty of figures floating about, but the exact amount you save will largely depend on your own use of the system. Some people feel the floor heat much more than others and so run the temperature lower. UFH heats up and cools down more slowly, which may be effective for some people, less so for others. The boiler should operate more efficiently than with conventional radiators but only a few percent at best. You'll probably spend a little more electricity running the pump. You might save 10-20% overall. You'll see higher figures quoted, take them with a pinch of salt.

 

[roguetrader]

youll want minimum of 60mm screed to get the best out of underfloor heating.
if your going to pull up all that floor, its going to take a fair old time for any reduced running costs to balance out your initial outlay. by all means do it because you want it, just dont expect it to be vastly cheaper.

 

[Happyplumber]

Boiler will condense alot more because of the lower running temperatures.also the huge slab will once heated let it out slowly so less topping up of heat will be required

Insulation is the key to all cost savings wether its in the floor or in the loft ,make sure to use reputable installer and decent product and you will have trouble free system which will last for years.

A sytem thats been around since the time of the romans underfloor heating is lovely on cold winter morning

If you are loooking for an immediate return then obviously rads are alot cheaper,but over time then under floor is definetly the way to go if you have the opportunity,this is normally quite cost prohibitive on older homes and if you are lucky enough to have floor boards down stairs then the job is doddle.

 

[ianniann]

Your boiler will always be deep in condensing mode

So there's a 5% gain over a poorly configured steel radiator system

 

[Norcon]

Your boiler will always be deep in condensing mode

So there's a 5% gain over a poorly configured steel radiator system

I would say at least 10%.
You have the WC and condensing effiencies combined working in absolute harmony.

 

[Recrem]

What is the most efficient/cost effective way to run wet UFH ? We have Salus thermostats in g/f rooms. 1 Rad downstairs and 1 heated towel rail/ upstairs same. New build with good insulation. We are retired so are at home most days.
Don't like the house too warm during the night. Interested to know what works for you ? Timings, temps etc ?
Has anyone used an online "smart" system and was there any real benefit ? Salus offers this option.
We find the boiler kicks in regularly at night and this can be quite noticeable for light sleepers. I've started turning thermostats down at night to a temp that the house is unlikely to drop to.. so that the boiler stays off during the night but doing this makes the house colder in the morning.

 

[Exedon]

Underfloor should be run with a back set temperature of no more than 4C below desired room temperature.
Try reducing to backset temperature well before you go to bed bring it back up maybe an hr before you get up .
Which salus stats do you have?

 

[Recrem]

Which salus stats do you have?

There doesn't seem to be anything written on them.
Do the "schedule settings" automatically override the basic settings ?

 

[Exedon]

Picture of said stat please !

 

[Recrem]

Hope this helps

 

[winston1]

Underfrloor heating takes ages to heat up and ages to cool down. This means the house is hot when you don't need it and so wasting energy and money.
It is great for elderly peoples homes where it is on 24/7 but wasteful otherwise.

 

[ericmark]

I agree with @winston1 the idea today is to only heat as and when required, be it manual using some app on your phone, or some set schedule, or geofencing, the idea is to only heat when required.

To do this reheat speed is very important, using fan assisted radiators which store less heat but circulate the air, the other end of scale is the storage radiator, but even as a 70+ I don't like rooms hot over night, so want to be able to reheat room within a couple of hours, and UFH can't do that.