UFH Experiences and recommends please

[mrgobby]

Which pipe, PEX AL PEX, Pert al pert, Pex al HDPE all the different suppliers offering different pipes, choices of manifolds and controls. Trying to decipher the best option or supplier for my install. Does anyone have any knowledge, experience or recommendations? I will later extend ufh further into other area (another story) but will probably site another manifold for that rather than try to fit a larger than needed manifold. I'll have to run a fair length of flow and return pipe to it too which will go in the screed.

It's 30m2 single room with vaulted ceiling, new build single storey extension. Slab is down, will be fixing to 100mm celotex type insulation then screeded over. Possibly flow screed or traditional, not sure yet what I will use, depth available will determine. Between 70-60mm depth I think but will need to lazer all over to get better idea. I guess I can vary the celotex thickness 10-20mm and still comply with regulations but prefer more insulation than less!

Thanks

 

[MeldrewsMate]

PEX seems to be the standard for UFH in screed, the others having more specialised applications, with prices to match.
I would advise to try to accommodate the extra heating zones into the single manifold; it saves on running larger (assuming 22mm) pipework in your screed, it saves on the cost and space you will have to provide for an additional manifold, and it saves on the energy used to run an extra pump.
I assume your 30m2 room will only have two heating loops, and therefore a four zone manifold will do the trick. If you can run flexible conduit or 21.5mm overflow pipe in the screed (in as straight a route as possible) with a draw wire in each then PEX pipe can be pushed and pulled through as and when you build the extra room - while you're at it, a third conduit for the thermostat electrics may save you bother later.

More insulation is good, more still is better. I think we will look back in twenty years and wonder how we ever got the rooms warm with only 100mm of Celotex under the floor.

 

[mrgobby]

Probably right on the floor insulation of the future, hopefully a more economically priced solution for it too! Nice idea on conduit , hadn't thought of that one. I'd have to run 2 - 3 pairs as intend to join into a detached garage / workshop with 2/3 zones. 'why I'd considered a second manifold as just run a flow and return through but I'll look at the angles I'll have for conduit, thanks.

 

[gassymark]

Have you had heat loss calcs as it’s impossible to add more pipe in the floor once it down make sure you have enough ,with a vaulted ceiling you might have to be 100mm centres I’ve always used all pex but not sure if better or worse.

 

[mrgobby]

Hi, no calcs as yet, going to have a chat with them after Christmas holiday and send them drawings to design it. I say vaulted but it's not like a cathedral roof, just low pitched and 5.25m x 5.7m space, maybe 3m at highest.

 

[cross thread]

just done my own extension very similar to your SQ meters and vaulted ceiling laid 100mm ballytherm with 70mm fiber screed,150mm centers giving 2.9kw it is excellent,used continental underfloor

 

[mrgobby]

I'll look at the UFH supplier you used

 

[snb]

polythene sheet over celotex. then clip pipe to it. use MLCP on 150 to 200mm centers. mlcp is vastly superior product with better heat conductivity

 

[Ryler]

MLCP is also easier laid.

 

[mrgobby]

Was thinking to ask these https://www.underfloorheating.co.uk/