Wet UFH design advice

[naylorpd]

Hi, I have a seaside apartment in Azerbaijan, currently a bare core & shell, not even internal walls yet, and am intending to put in wet UFH with ceramic tiles on top. Although we will get someone to do this for us, in my experience here it's always best to have a pretty good idea of what needs to be done first, to avoid any misunderstandings.

Apartment size is approx 80sqm and I've been told so far that:

• there are 6m of pipe per sqm so 6x80 = 480m of pipe
• max 50m of pipe on each manifold, so approx 10 manifolds

...thus making about 1 manifold for each 8 sqm - which I guess will be a useful number when creating zones for the rooms.

I'd really like to validate those numbers to start with.

Thanks

 

[Basher]

Responding as a non-professional from the UK, I believe our figures would typically be 5 m of pipe per sqm with 200mm spacing, or for higher heat loss areas, 6.6m of pipe per sqm with 150mm spacing, for 15, 16 or 20mm pipe.
But up to a max of 100m of pipe per loop rather than your max of 50m. And we typically put multiple loops (eg up to 8) on a single manifold. Maybe the distinction between an individual loop of pipe and a manifold feeding multiple loops from a pump, mixing valve and actuator for each loop is a matter of custom or terminology.
Just to say my wet UFH has small rooms with 1 loop, and bigger rooms with two or three loops (each loop on an actuator but with two or three actuators connected in parallel controlled by the one thermostat in that room.

 

[Ben-gee]

I have ufh in kitchen, it is 46 sq m and comprises of two loops back to a single manifold. I laid it in two reversing snail patterns and it works brilliantly- I wish I had cupped my balls and dug up all the existing floors at the same time, but two small kids and we were living there so didn’t do it.
(As its kitchen, there is no ufh under units or appliances- hence it could be done in just two loops)

In answer to your question, taking into account you don’t go right to perimeter and best not to go under food storage cupboards etc etc the area you are looking at could be covered by 4 loops.

However

You most likely want separate rooms on separate loops for control purposes- so in reality the number of rooms will determine how many loops you need.
The whole thing can be run from a single manifold/pump/blending valve setup.

Best thing is to hand over plans to our sponsor Jake at Uheat and get them to design it for you and supply the goods for a successful project.

 

[naylorpd]

I guess I mean 10 loops rather than 10 manifolds (!) but as noted it should be less if I don't put heating under kitchen cupboards or where wardrobes will be etc. From the layout I think that 2 manifolds would work, one at either end of the flat.

For plumbing in Azerbaijan we use plastic pipes which are heat-welded so it's really easy to run a pipe from one end to the other under the floor. But I guess we'd need to be careful that didn't introduce favouritism for water flow into one of the manifolds due to lower water resistance. Not sure how to deal with that, maybe just a valve to balance flow between the two?

For UFH materials I think it will be best for our plumbers to use materials bought locally so they are familiar with everything.

 

[Ben-gee]

The individual circuits have control at the manifold to allow you to balance as required.
It sounds like you ought to get it specced up by a manufacturer if you are unsure how it works.