Would you replace your radiators with underfloor heating?

i love this idea it really brings out your eyes, i also love these nuts`

I too have a 1960’s house with huge amounts of window. But it has a wet radiator system. I’m guessing converting to an air system would be prohibitively expense – we have concrete floors downstairs. Any thoughts?

Very unlikely that you could reasonably retro-fit a hot air system to a property. Having said that all calculations really should be based on how long do you intend to stay at the property and how much are you willing to spend.

There are a couple of things to consider. The forthcoming generation of CHP boilers where you can create your own electricity whilst burning gas that heats water/house. There are three systems that I know of all undergoing trials in houses. There may be more companies and they all have slightly differnt technologies and strengths. Some rate electricity generation higher than heating etc.

Heat-pumps are a technology i like and have been improving quite quickly in performance. As I am not currently buying I only keep half-an-eye on the market but you can get blown air, heated water, heat boosted water ………

An interesting technology much adopted in countries other than the most of the English speaking world. A big hit in Japan where the Government put some serious muscle into making it a very common system. Also used on the continent,

I also only have a hazy idea on the various solar offerings whether electrical generating or water heating. Here again apart from buying an immersion heater already fitted with additional pipe-work if I Invest I only take a passing interest,

There are more uncommon ways to heat property such as painting walls black to harvest the heat from the sun etc, but this only make sense if you intend to stay at a location for a long time – 10 years plus.

Anyway a lot of information is here:
http://www.energysavingtrust.org.uk/About-us/About-us

Whilst on technologies ignored by the

they are not deluding themselves, and no breach of the laws of physics is needed.

A radiator system set to keep your feeling warm when sat in front of the tele will have the ceiling temperature up around 30 Celsius or more. Underfloor heating inserts the heat where you want it.

Hi, How did u get on, we are about to buy a wet under floor system love to know how u did it?

Andy & Lesley

I agree with IanW regarding the heating up time delay with wet underfloor heating. During Spring and Autumn, when the mornings are a little chilly and the days are still relatively warm, the room thermostat cuts-in early morning to trigger the underfloor heating. This then takes four or five hours for the heat to come through into the room, by which time it is not required: Result – gas used for no reason! One way around this would be to set the room thermostat to a lower temperature,

Upstairs in the bedrooms, we have a wet radiator system with room thermostat, which gives almost instantaneous heat-up and cool-down properties such that the problems IanW relates do not occur.

No point being sick about it – take a tablet!
I left my UFH on all summer with just the thermostat controlling when it came on. That’s when I really found the problem with the slow response time of UFH – by the time it takes effect it’s either bedtime, or a the weather has changed and it’s not needed. So now it is manually set to off until the cold spell takes a hold, and I rely on a wood burner until then for short burst of heating.

Like you I have the heating on when it is cold and if it happens to freeze in May or even August, then it comes on. The only difference is that as I am out during the day a lot more in summer, I tend to have it only on the morning evening setting but as soon as it gets colder or the days get less inviting, I have it on all day. I have started dropping the temperature a bit if I am out all day but not so much that the house is cold whenever I get home.

I cannot see the sense in holding off until November or whenever. If I could cope with extra jumpers until then, why not simply cope with extra jumpers all winter. If it is a matter of not being able to afford it then I would use the extra jumpers and thick socks all the way through winter.

Yep but no better than mains gas with rads, perhaps even not as good.
But against LPG or Oil then yes go for a heat pump with underfloor, if you can afford it.

Think your savings came from the extra insulation associated with the underfloor heating installation and control system rather than from it simply being an underfloor system. A kilowatt hour of energy is a kilowatt hour of energy, the delivery system makes no difference. Savings come from insulation and/or the difference in price of the energy source, mains gas, electricity, oil, LPG or solid fuel.

Heat pumps work like a fridge in reverse and you can get out as much as 3 kilowatt hours of heat from a one kilowatt hour input of electricity, sounds great but a kilowatt hour of electricity costs about three times that of mains gas. Still better than oil or LPG of course but no real advantage over mains gas and the heat pump (and floor insulation) installation ain’t cheap.

So you may well have saved on your bills a bit but not simply because it’s underfloor heating. It will be the other associated factors like insulation and fuel type coming into play to give the saving.

But as said before underfloor heating is nice and I’m not knocking it, but in itself an energy saving measure? – no.

Oh the smugness of someone on gas!
For GSHP you do need lots of land or expensive drilling of bore holes. But if you have the land it is probably a better bet than ASHP.
ASHPs are not all noisy – I have one (Hitachi) producing around 12KW and the noise is quite tolerable, barely noticeable except when it needs to be on full blast (which is, unfortunately, when it’s dark and cold outside – so it is at its least efficient.) It does not require much by way of maintenance – mostly keeping leaves clear of the cooling fins, and a service less often than a gas boiler.
My ASHP drives wet UFH – seer my other comments regarding the time delay in it being effective – but it’s OK once it is.

who visits you – elephants?

People at rest give off about 100 watts each, not a kilowatt. Dancing may get them up to 200 watts.

OK. so I was using the same guestimate that comment number 4 was using hers: http://cosmoquest.org/forum/showthread.php?97274-How-much-heat-does-the-human-body-produce

But I can assure you that in a well insulated room, even one that is over 5 metres by 5 metres with 4 metre ceiling 3 or 4 extra people sends the temperature soaring during the course of an evening, even more so if we play on the Wii sports.

Interesting experience. My extension was around 8 mtrs by 5 mtrs AFAIR with a central pitched glulam beam with a ceiling of structural insulated panels with multiple external glazing and three Velux windows. We never suffered a heat build-up but possibly that is because we had two openings of 6ft by 8ft into the main house which provided circulation to the rest of the house.

As I said we used it as a giant heat sink leaving it running on a relatively low water temperature all the time.and only in the coldest weather would we use the radiators to heat the house or particular rooms.

Response to post of 7th Oct re extension with folding doors/ glass celing .
We recently extended and also put in a 5 meter by 4m glazed extension – 2 walls glass with 5m opening glass bifold and 50% roof fully glazed. Extended underfloor into that room from main house under stone tile. Underfloor works brilliantly and as per an earlier post – this is in main due to fact each zone has its own thermostat. So what is effectively a conservatory has its own stat placed out of the sun, whilst the adjoining kitchen has it’s own thermostat. We set conservatory slightly lower temp. We never overheat or chill – just let the system run itself.
Note – initially as with any underfloor system you live with it and gently tweak the temperature on stats until you get the temp that works for you – then leave it alone. It is a totally different heat to a radiator system and generally you are more comfortable at a lower temp than a radiator system which gives a lot of heat higher in the room – a real temp gradient vs down where you are sitting. Underfloor keeps your legs warm for instance when sitting at a table – with radiators open might feel cold and have to run the heating up. We did make sure that all furniture in conservatory is elevated – ie with good air space beneath to allow the underfloor heating to work fully.

The best way to run underfloor is keeping rooms at base temp of say 16 degrees and not using it like a radiator system – switching it on an hr before needed as it simply will not work. If this is done then it is likely that the floor (slab) will heat up and with the “lag” in transference – you get a lot of heat later than you need it. The floor does not need to be many degrees above the desired heat in the room as the area compared to a radiator is huge.

Extremely important and as if not more important than underfloor heating will be to select glazing that has treatements to refelect heat in summer whilst retaining it in winter and as geed an insulation value as you can afford, Expensive but very good are SUNFOLD based in Norfolk. You can also add roof vents which will open automatically on those too rare days of extreme summer heat 🙂

Good luck

Re: Aileen Mckenzie and MW’s posts.
We too are planing an extension into which we wanted to incorporate a lot of glazing for light. The design of the new kitchen uses part of the existing 1920’s house plus a small new build and does not leave wall space for radiators. We had not realised initially that fitting underfloor heating would involve digging out the slab of the existing floor nor had we fully understood the potential insulation problems that the glazing could cause. A lot of internet trawling and talking to builders, installers and suppliers later and I must confess that we are getting cold feet (pardon the pun).
So I was very interested to read your posts.
MW, is your glazed extension separated from the house by a closable door? and have you experienced a harsh winter with it yet?
Ours would ideally be a continuation out from the existing room (5mx2m extension) with lots of glass in the sides and roof plus bifold doors at the front. Underfloor heating would heat the area. We are worried that it may look great but be uninhabitable for parts of the year.

Hi Aileen,
I understand your predicament having “been there”. No – we do not have any door between glazed area and kitchen – it is a fabulous opening – 11ft width letting in all the light we wanted through into kitchen. Added to this we have a further wide opening at side to dining room – more bifold doors and retrofitted underfloor. main lounge remains radiators and actually most ineffective at heating vs underfloor. Wish we had continued through!

We have had one winter living with this – and our 1 year old played every day on the stone floor throughout – when snow on glass roof and icicles hanging down gutters and minus 10. We stayed warm, underfloor had no problem at all. I do think had we used radiators floor we would have been cold, space up at glass ceiling hot and room too cool. I never had a doubt about using u/floor and it proved the right choice for glazed area. (aside from fact little space for rads) As you point out though also key is the glazing insulation.

Happy to share specs. more info if helps as we also spent months researching both glazing/ door systems and very importantly underfloor controls.

You can solve this problem by using Heatmiser smart thermostats, I use the slimline series. You just set the temperature you want at the time you want it and after a day or so of learning it will turn on early enough to achieve the set temperature at the set time.
It then continually adjusts as the weather and conditions change, it can occasionally be caught out by a very sudden change in the weather but that is quite rare.

Well I disagree with this mornings perfection idea! One thing you normally get with Victorian property is excellent suspended floors and the idea of putting something on top which is less giving needs some thinking about.

During the night I was pondering the problem and my thoughts leapt to a wood-pellet boiler. This may be able to use the existing pipework and minimise expense.

On the expense front we are given no size or budget but it occurred to me that if the land area is big enough the sale or a very long lease of a building plot could realise a very large chunk of cash that could be allocated to the hall as a sinking fund once the work was done.

You can go for a wet system or possibly more flexibly a space heater such as Fabbri. This site here allows you to spec the size of burner needed.
http://www.euroheat.co.uk/contlit1.php

I believe you will need to have very large LST rads to get sufficient heat. Check carefully – you lose a lot of wall space which may be ok in your design. Having put underfloor in with new condensing boiler, decent controls and a weather compensator unit I would not want to move anywhere without u/f heating again.

Low surface temperature radiators are used in hospitals and buildings where the occupants are under 5 years old or over 60. They are basically a natural convector or a radiator in a cabinet which is warm to the touch even if the water circulating is hot (80C)

Sure that’s the traditional place for them. There was a paragraph or two in a renovation magazine a few months ago about LSTs specifically designed for use with heat pumps – from http://www.jaga.co.uk/

Hi Joanne.
We did a self build house and installed a wet UFH system throughout powered by an oil boiler. It was made by a company called Robbens. You can google them up if interested. The ground floor is solid screed and the first floor similar to as you describe. It is a great system and thoroughly warms the bones of the house. The first floor runs at a higher water temp (60 degrees I think) than the ground floor (45?) due to the different construction but this is all set up for you on installation. All you need to do is set the room thermostat for the temp you want and leave it. We set the room temps we want and then leave the system on all the time and it’s electronic brain does the rest. There are radiators in the bathrooms to warm towels etc but underfloor as well so great when you get out of the bath a step on the warm tiled floor. It is quite a bit more complicated than radiators but I wouldn’t be put off. The only down side is the slow time it takes to make any difference to the temp and it’s no good coming in in the evening and switching it on as you won’t notice much heat until you go to bed. It is a bit quicker to react upstairs without the solid screed mass to heat up. That’s why we leave it on all the time which seems highly efficient and the best way to run it. The lack of radiators in the main rooms and the extra wall space for furniture is really noticeable. Give Robbens a call if you want to take it further. They were very helpful and even sent an engineer to the house to brief my plumber and electrician on how to instal the system.