Underfloor heating running costs - help

When discussing the merrits of different types of heating systems one should always compare them on the basis that they are correctly installed.

Well of course.

There is no evidence to suggest that a properly installed radiator system is better than a properly installed UFH system.
 
I've seen it commented here so often that an air tight house is essential for UFH. Of all the houses with UFH how many could be considered air tight (or how many have had their house measured for air tightness and passed)? Perhaps 5% be an accurate figure?

If building a cavity wall house for example would it not be pointless using UFH as so many commentators on this site have said it is almost impossible to build an air tight cavity wall house? Just interested.
 
Just a matter of note....
thenew revised Part L regs coming in in july require any floor with UFH to have a uvalue of 0.15....!!!!!!

basically that means that if you have any kind of a dwelling thats not a shoebox you will need at least 125mm of PU (kingspan / xtratherm)......... compare that to what people are currently installing....

and barney... you are completely correct with your last statement.....

and this causes problems like people stating that UFH is crap etc when they dont realise they are living in a sieve....
 
Bear in mind of course that radiators are also not very well suited to heating drafty houses.
 
Bear in mind of course that radiators are also not very well suited to heating drafty houses.

Here's my reading on this....

Yes obviously a draughty house is not desirable for anyone but it just seems that since UFH uses a low heat (an this is where it is economical) it is greatly dependant on air tightness. With this combination (low heat and air tightness) it's very economical.

In non-airtight situations (vast majority of houses) most people turn the heat up to try and compensate for leaking air... low heat scenario is changed to higher heat scenario and becomes more uneconomical.

Perhaps it's better to sum up as UFH really needs air tightness as it's a low heat system and can only work as a low heat system if there is good air tightness. Radiators provide a blast heat so better able to get the room to desired temp even if not air tight. Which one is more economical is the big question. And bigger question for all is perhaps how to acquire air tightness!!
 
if you have UFH, the heat is radiating from the floor up across the floor, so if you do have draughts is this not a better system to have, the only i place i can see air entry into a house is in the wall vents or trickle vents on the windows, which can be controlled aswell..or maybe i haven't seen very draughty houses. I was told that you cam buy wall vents that actually open and close depending on the weather ie winds outside, has anyone come across these?
 
the only i place i can see air entry into a house is in the wall vents or trickle vents on the windows, .....

windows is another obvious place if not properly fitted.

For cavity wall house where else is a source of air leakage? Electrical sockets, cracks in wall, joining walls, walls and floor joins?

Can some sort of "membrane" be used to seal a cavity wall house?
 
BarneyMc
you can use a vapour check as air control barrier. Products such as Tyvek SD2 or Intello can be used to seal inner leaf and prevent air leakage through block wall. these products can be sealed to the ceiling and floor and then taped to ensure air tightness. I am in the process of a self build and I am still investigating the best method to adopt.
However if you employ this method you must remove moisture from the internal air. the only way to achieve this is to use a HRV system whereby all warm moist air is removed from the house.

I do believe that making a house airtight is extremely difficult with tradional cavity block construction. Passive houses are the future and the use of breathable materials such as wood fibre softboards is the way to go. Alas builders in this country are totally ignorant to idea of air tightness in a house
 
but if these are insulated properly, this will eliminate these eaks, i think when you are building a once off you have more control of what is going on and you can take steps to correct it when it appears, my plan is a cavity block built with concrete floors and pumped insulation which should seal up the cavity and eliminated these draughts..
 
but if these are insulated properly, this will eliminate these eaks, i think when you are building a once off you have more control of what is going on and you can take steps to correct it when it appears, my plan is a cavity block built with concrete floors and pumped insulation which should seal up the cavity and eliminated these draughts..

Why bother with a cavity at all if you're going to just fill it up with insulation? Why not consider a solid method, such as Poroton - much simpler.
 
Why bother with a cavity at all if you're going to just fill it up with insulation? Why not consider a solid method, such as Poroton - much simpler.
...cost, Poroton is way too expensive and trying to get some one to use this new method is quite hard !!!!
 
Perhaps you're right about it hard to get a blocklayer to use Poroton. I was faced with this problem a few years ago and in my frustration decided to lay the blocks myself

Now I'd never laid a block in my life before, yet I completed two 2-storey Poroton-built extensions by myself in 15 working days. Yes, the blocks were expensive (about €40 per sq metre) at the time, but I saved a lot of money not having to pay a blocklaying crew.

The results were very pleasing, and the house feels very snug. The Poroton people at FBT in Enniscorthy will give you all the assistance you need. (I have no affiliation.)
 
Does the boiler need to run 24/7 for max efficient underfloor heating. Are there any figures running times.
 
Does the boiler need to run 24/7 for max efficient underfloor heating. Are there any figures running times.

I'd say this is no different for UFH than any heating system. If your house is well insulated and there is minimum heat loss, then why not run the boiler 24/7 at a comfortable room temperature. If your house does not retain heat, it makes no sense to waste heat when you're not there, or you're asleep, no matter which system you use.
 
After going round in cirlces on Wood pellet vs oil and whether to use UFH or rads in my bungalow (approx 2750) . i am considering going for oil condenser with a solid or pellet stove linked to the boiler. I am thinkin of putting UFH in the living areas and then just usings rads in the bedrooms. We would like UFH in the living areas as we have young kids and would like the comfort. I was considering wood pellet but was told that i would be looking at about 20k as opposed to 5k for oil. I will hopefully switch in future when it becomes less costly. I have read that mixing UFH and rads is inefficient but my architect recommended a mixing system which overcomes this. Has anyone any experience of this? or am i going for a bad system? If i am going for this should i also install a buffer tank? Can someone give me a spec for what i should go with? I am putting in extra insulation and a heat recovery system. Thanks
 
Corkcuu,
somebody is obviously, siphoning your tank of oil. This has become a more common crime since the price of oil has been rising so much. Put a lock on your oil tank.
 
Can anybody give me an idea of installation costs for both rads and UFH as opposed to running costs. It is for a house of approximately 200sq meters. I presume rads are somewhat cheaper to install than UFH. I think we are going for an oil condenser as well as solar panels although this will only heat water. Advice appreciated.
 
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