Underfloor heating

[Steve Firth]

We're getting towards having to buy the kit to install underfloor heating. We have 120 m^2 of floor to heat and as previously mentioned it's out intention to use a thermal store with inputs from solar, wood burner and an LPG boiler.

I think we have this more or less worked out and we were planning to use pipework at 200mm centres for the underfloor heating[1] with an 8 port manifold. I think we'll also simplify the job by getting some of that template material to lay the pipe into before screeding.

Can anyone think of anything that I particularly need to look out for when ordering the pipe, manifolds, valves etc? We're intending to get a thermal store fitted with a mixer valve for the UFH so presumably no need to have a an over temperature shut off valve on the flow to the manifold?

[1] The house is in Italy remember so I think 200mm would be OK, unless someone can think of a reason to reduce the spacing.

[Lightman]

Hi Steve

I've used the red template trays and they work very well!

My underfloor heating is half installed and I was thinking of adding a thermal store with various inputs.

I'm very interested to know what make and model of thermal store you went for?

Regards - Lightman

[Steve Firth]

We're still dithering between a 250 litre thermalstore from Newark Cylinders and a solar heatbank from DPS.

[The Natural Philosopher]

That should give you about 50W/sq meter OK..I have full compliant insulation and that spacing its just enough left on 24 hours with -5C and a wind all day..Use as much underfloor insulation as you can fit. ESPECIALLY with a suspended concrete floor.

I have to say I used reinforcing mesh under the screed anyway - needed it for strength, and used cable ties to lace it too that.

It took no time at all.

I followed Polyplumb directions.

- no joints in the pipes at all.

- No circuit more than 100meters most less than 50 meters

- pressurisised the whole thing to 4 bar before AND DURING screeding.

Apart from a motorised valave that stick on, and causes a turkish bath one day, its been faultless.

[Christian McArdle]

Just remember that 200mm will be relatively uneven in heat distribution compared to closer spacings. This may or may not be a problem.

Christian.

[The Natural Philosopher]

In a screed, it was noticeable when I laid some self levelling..you could see exactly where the pipes ran as it dried out ;-)...but in use, with tiles over, or laminate, its pretty hard to tell with the bare tootsies where the pipes are..