Under-floor heating for proposed conservatory

If the conservatory is for occasional use and can be shut off from the rest of the house a wet underfloor fed from a hot water tank also under the floor and heated by a water filled solar system offers reasonable comfort for three seasons a year (except this July :-) and has zero running costs.

Its a great idea, but to do it properly you need a temp reducing valve, a separate pump and maybe a relay and thermostat.

The biggest drawback is that if its a full glass conservatory, its unlikely you will be able to heat it enough in winter just using underfloor.

About 115W/sq meter tops is what you can get out of a warm floor.

I'd still do it tho.

Would putting it at the low temp end of the CH loop not be ok?

This is ideal for solar though, and DIY solar collectors are not expensive.

Regards, NT

And whet happens if you have TRV's? water comes back as hot as it goes out...

I installed UFH in my new conservatory last year and used the following.

This bloke did it like this:

In article , Paper2002AD writes

I didn't think you were allowed to heat a conservatory unless you had planing permission

Definitely not on two counts.

Firstly, planning permission does not relate to the energy or construction specifications of the building.

The applicable legislation is in the Building Regulations which are the province of a different local authority department.

There are exemptions in both sets of legislation for conservatories of up to a certain size, in certain positions and with certain construction methods used. The effect is that the vast majority can easily be designed to be exempt.

One of the Building Regulations requirements for exemption is to make the conservatory outside the insulation environment of the house - therefore doors and windows leading into it have to be of exterior standard.

Another, relating to heating is that it is permitted to heat the conservatory, but there must be a means of independent thermostatic control. So you can add radiators or UFH, but there must be a means of controlling it separately to the rest of the house.

.andy

To email, substitute .nospam with .gl

True, but I think that can be worked around without much difficulty. Actually, not true, with TRVs the water will always go through at least one rad. Thus the water arrives at the ufh with always at least partial temp drop.

As Andy Hall explained, you msut have thermostatic control on your ufh. What I had in mind was to put a 2nd thermostat somewhere on the ufh pipes, and set it to switch off ufh circulation when a certain water temp is reached. So when the water supply is not too hot it will function as usual. And when the water becomes hot, as it will do at times, the circulation will be switched on and off in the ufh pipes instead of run continuously on. This will maintain the level of heat coming from the floor slab, and not cause overheating.

Thats the idea anyway, comments welcome.

Regards, NT

You can get UFH kits with a pump and a blending valve. These take water from the flow side of the boiler, blend it with cool water from the return of the UFH and pump it through the UFH circuit. Thus, you have an auxilliary pump circulating water in effect around the UFH circuit with a little hot introduced to raise the temperature. Some of the return water from the UFH circuit will go back towards the boiler.

.andy

To email, substitute .nospam with .gl

But they're a LOT cheaper if you buy the pump, blending valve and a few connectors separately.

If you decide to DIY it, I've got several (11 I think) red plastic sheets like these:-

and a few related bits I can let you have very cheaply

I'm near Bath

Nick Brooks

Might be worth considering how long you will spend in there at a time and whether it's south facing as UFH isn't that responsive AFIAK.

cheers, Pete.