Under Floor Heating Layout

BarneyMc

I was sent a plan from my UFH installer and I've attached part of this showing one room. Although there are 3 circuits, would it be better to have the pipes laid in a spiral fashion rather than just over and back? Would the spiral layout distribute the heat better?

Calahonda52

What do u mean by spiral?

These chaps were in town recently looking for Irish agents. The English is a bit tough but message is clear enough
http://www.german-irish.ie/fileadmin/ahk_irland/New_Website_2011/Green_Tech/Passivhaus/14-Multibeton.pdf

They install the pipes fully pressurised with warm water so no after install testing required...but perhaps it means the manifold must be in place
The early slides have some interesting ideas about heat distribution with UFH

BarneyMc

This shows some basic layouts and it's explained here about half way down the page. As I say there are 2-3 circuits coming into most rooms so maybe it doesn't matter too much? My pipes are centred at 150mm throughout also. All feedback welcome!

murphaph

BarneyMc wrote: »

This shows some basic layouts and it's explained here about half way down the page. As I say there are 2-3 circuits coming into most rooms so maybe it doesn't matter too much? My pipes are centred at 150mm throughout also. All feedback welcome!

My UFH has multiple loops per room too but they are 100mm centres throughout and snail patterns everywhere. The snails make perfect sense as you always have flow, return, flow etc. alternating. With your layout there will be a less even heat distribution, but if that makes a practical difference I don't know.

BarneyMc

murphaph wrote: »

My UFH has multiple loops per room too but they are 100mm centres throughout and snail patterns everywhere. The snails make perfect sense as you always have flow, return, flow etc. alternating. With your layout there will be a less even heat distribution, but if that makes a practical difference I don't know.

Yes just reading about it here (three quarters way down page): http://www.u-u-h.com/technical/8-pipe/

hexosan

From memory the spiral pattern is normally used when pipes are spec'd at 100mm centres as the pipes can't be bent tight enough if ran up and down the room.

murphaph

hexosan wrote: »

From memory the spiral pattern is normally used when pipes are spec'd at 100mm centres as the pipes can't be bent tight enough if ran up and down the room.

Maybe but originally our kitchen had 2 loops @ 150 centres planned and they were also snails. I requested the change to 100 centres in 3 loops as I'm doing all I can to ensure the flow temp can be down around 30 degrees. I've agreed loop lengths between 70 and 100 metres to make balancing straightforward later. In places I've decided it's better to bin zonal control over say the guest WC and bundle it together with the hall to eliminate those otherwise very short loops, which are short circuits to the manifold really and mean you have to really throttle them to prevent too much pressure loss to these short loops. It's a bit of a trade off but as far as I'm concerned the WC should be slightly cooler than the hall, so it gets the return to the manifold while the hall gets the flow.