Underfloor Heating Questions Water

This is obviously crucial with UFH because the heat you get is based on the metrage of tube you lay and very obviously you can't alter that afterwards and you can't rely on some kit that says it does 15 m2 as much of a guide.

Le métrage c'est un mot que n'est pas utilise en Anglais.

"Métrage" means the size or length!

Tony

 
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My initial thoughts for heating were to put a radiator in one corner, either a smallish (width wise) double rad, or a low long single rad against one of the dwarf walls.

Then if it wasn't enough the aircon split unit was the idea for the other end of the room.

At this point now I'm slightly unsure whether I should be more worried about the heating or cooling of the conservatory!


Just to add - I'm asking all these questions now whilst it's still in the design phase, we've nearly got to the point of signing off the actuall layout ect of the conservatory, but I'd be sorting any heating etc out myself
 
Bravo Francophone Tony !

I started to write meterage, then thought that can't be right because of the "metre" and "meter" meanings and did the other.

What do you say ? ( or do you opt out and say length ) ?


BTW , you next to the R4 ? Ah ! Magnification shows an ARGI T-shirt so I guess so. Your international HQ , no doubt :D

@ sotal

I don't know rads very well, but thinking back to a house I had with a similar-sized but normal brick/insulated room, I can't see those sizes doing much more than take the chill off in a 15 m2 connie.
 
http://www.uk-plumbing.com/brochure/hepworth/UFHConservatoryPack.pdf

The above link seems to show how the simple cheap system works, would it be any use at all? It has no pumps etc and just relies on the main system.

It's cheap and would be easy to install and would provide 1500W

I found a calculator tool online into which you put the conservatory specifics. For standard double glazing it estimates that I would need 2940W

Low E glass would require 2300W
Low E glass with argon would require 1897W
 
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I've been reading more about the 'better' wet UFH systems, and it appears they connect up to the Boiler Flow and Return. The return from the main ciruit in the house feeds into the UFH, and a sensor detects when the temp drops too low and adds freshly heated water from the flow.

First off is that correct?
Second what happens when you have H/W only on, does it heat the UFH?
Third is this a good way of doing it? The boiler is right next to the conservatory so would be idealy placed to do this.
 
Bravo Francophone Tony !

I started to write meterage, then thought that can't be right because of the "metre" and "meter" meanings and did the other.

What do you say ? ( or do you opt out and say length ) ?

In relation to UFH I think the only way to correctly describe what you want to say would be "amount" as that would take into account the length, width and spacing.

Tony
 
After reading all night, my research suggests that my original plan may well be more economical.

A split A/C unit which uses a air source heat pump, will be more econimical than the underfloor heating and will be more suited to the size of the room.

A radiator in the room could also keep the chill off the room without costing a fortune.

So the plan would be to use the rad to keep the chill off, and the a/c to cool / heat for short periods of time when required. From my workings out this will be slightly more expensive to run than just underfloor heating alone, but should have suffucient power to heat the room, wheras the underfloor heating would need additional heating to complement it.

The A/C unit also has the advantage of cooling if required.

I do still like the idea of hidden heating using UFH but it seems pointless if I need additional heating.


I don't really want the additional noise of a couple of fan heaters!

My other option is to fit another rad at the other end so I have two rads in the conservatory but I am concerned about just pumping heat out through the windows and roof!

I've also read that condensing boilers work well with UFH (not sure on the reasons) but I've read a few sources which say they are most effecient with UFH. The new bolier will be condensing
 
OK

If we are down to keeping the "chill off", you could look at a bit of UFH in a really cheap method.

Basically all you would do is simply divert the return rad flow through a few coils of UFH pipe laid in the floor.

This isn't scientific, not strictly in accordance with regs because of the surface temp issues I mentioned before but I have friends who have done it and for "keeping the chill off" but not real heating it is ok IMHO.

All you need are two fittings to join ( above floor) to the return pipe and the chosen length of pipe which is usually sold in 100/120 m rolls but can also be got in 25 and 50 m at a much higher per m price.

You could do the same for your other room(s) if your rad piping layout allows it.

If you wanted , this would also allow you to see if you needed a rad by taking the pipes to where the rad would be , but not installing it until after you had tried the UFH and found more heating necessary if that were the case.

Forgot to mention that 16 mm UFH pipe is a real pain to handle and you need a method of holding it in place on the floor. The best method for me was panels of 3 mm welded steel mesh to which the pipe was wired/tied ( but leave a few mm of play pipe/mesh)

You should talk to your heating engineer to work out the effect of "x" metres of extra pipe on a rad circuit as I don't have any mixed circuits and cannot comment.
 
A reversible A/C unit is quite expensive, perhaps about £5000 ?

Thats a big capital cost! But you say you dont want any noise but that will also make a noise!

If you must have expensive cooling then get teh a/c but for a conservatory with no special need to sit there its a big luxury.

I would just go out into the shade outside!

If I wanted to mend my bike in the cons then I would use the £9.99 fan heater.

For me big money should be kept for important things which are going to be used most days in the year like a car etc.

Tony
 
This is from another current thread. You will see that he is going to do what I suggested of having a fanned radiator!


Hi all,
I'm hoping to buy a fan convector heater to be fitted in my conservatory (a Myson Hi-Line) and the installation manual I've found online says that I should flush my central heating system before fitting the unit to the existing pipes (there used to be an old Myson unit where I am hoping to fit the new one).
A) is this absolutely necessary?
B) if so, do I need to get somebody in to do it, or can I do it myself?

My central heating is run off of a combi boiler, which was fitted last summer. The radiators in my house are all fairly old, but in good working order.

Grateful for any help you can give.
 
Thanks for the replies again, I've got to say the A/C unis I was looking at were no where near £5k, more like £500. They claimed to be 'proper' air pump heaters rather than the cheaper units which just have a heater element, and claimed upto 4 times effeciency - ie you put 1kw of power in and get 4kw of heat output. How true or how good these units are is unknown, A friend has one in the conservatory which they only use for heating and say it is really good, they say the noise of the internal unit is barely noticeable, obviously the main noise is outside.

The conservatory will be more of a living area, I won't be 'allowed' to fix my bike in there! But I've got a garage for that.

I'll have a word with the heating guy and see what he says now that I have a bit more of an insight. I'm thinking if I do go for it, it's probably best to go for the cheap option as a way of having it, I don't think I'd do the just connecting it to the return pipe bit.
 
Sotal, these small heat pump/AC units are as cheap as chips & they have a COP of 3-4, but when trying to heat your conservatory with -10*C outside temperatures they are useless, and you would be better with Telly Tony's £9.99 fan heater. However, for the most of the year they're great.

UFH is a radiant heat, so the heat will always go to a cold surface(ie Glass), so unless you have good U values in the fabric of your construction, it's unfortunately a waste of time. UFH is one of the best forms of heating, if you lived in a house with it installed, you'd agree.

The HP/AC units are cheap, easy to install & quite cheap to run. However, it's blow heat, as soon as the unit goes off, you are cold, unlike a radiator or UFH.
 
Something that no one has pointed out is that a heat pump even with a COP of 3-4 is not saving anything for you compared with gas heating.

A unit of electricity is about 13p for a kWh. That can power a heat pump to give 3-4 kWh.

BUT burn gas to give 3-4 kWh and that costs about 9.6p to 12.8p so there is no monetary saving.

Furthermore the cost of the reversible a/c unit is an extra capital cost and even if you just used the very cheap ones then they are still far more expensive than a radiator ( or my preference a fanned radiator ).

I would also point out that it seems very odd to me to want to sit INSIDE your conservatory on a hot day burning electricity to keep cooler when its cooler to just go outside in the garden!

If you must have the luxury of a/c then I would have that inside the core of my house.

Are there any cheaper small a/c units which can give up their heat for water heating?

Tony
 
They are my Corgi trousers with the legs unzipped because it was a hot day!

In the evening and if going anywhere special all I have to do is to zip them back on again.

Bought them in the Last of the Corgi sale! Very useful, they have been to England, Wales, Holland, South Africa and Zimbabwe so far and I hope they will go a lot further too!

Tony
 

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