Positioning of manifold for UFH?

[windsortg]

I am having an orangery built and it has been suggested to have a Prowarm high output water underfloor heating system installed. The boiler is in the garage and is a distance away from the orangery. I have an airing cupboard in the landing where the megaflo, heating pump, and zone valves are located.

I have a bedroom nearby the airing cupboard on the first floor which is 6-7 metres away from the airing cupboard. This bedroom contains a small cupboard. It has been suggested by a few plumbers to run 22mn pipes from the return & flow in the airing cupboard to this small cupboard where the manifold for the UFH can be positioned. From this manifold, a hole can be punched out of the wall in this small cupboard and the UFH pipes run down the wall down into the new orangery.

This drop is about 2.5 metres. However, I have had a UFH installer who does not recommend having the manifold on the first floor with the UFH pipes running down the wall. He thinks there will be problems later on with the flow and discourages from having 90 degrees bends which he says is likely when the manifold is on the first floor.

Does anyone see any issues with having the manifold on the first floor and the UFH pipes running down the wall into the orangery?

 

[Milleniumaire]

Hi windsortg, just wondered how you got around this issue i.e. where did you install your manifold in the end?

I have a similar "issue", but in reverse. I have an existing manifold in the garage with a spare port, which I want to use for a new UFH system in an en-suite bathroom, which is directly above the garage, so easy enough to run the UFH pipes, but they would also need to turn at 90 degrees.

I'm also concerned that if air gets in the UFH pipes, it will not be possible for it to escape as the manifold (with auto air vent) is lower down and obviously, air rises.

 

[windsortg]

hi @Milleniumaire, at the end, the UFH manifold was installed on the ground floor next to the orangery that got built. The pipework from the manifold runs up along a wall in a room on the groundfloor (pipes are boxed in so looks fine), under the floorboards in the bedroom & hallway above, and pops up into the airing cupboard where they are connected to the UFH zone valve and heating system.

From what I can tell, I don't think I have experienced any air getting into the UFH pipes. Hope this helps

 

[Milleniumaire]

Okay, thanks for letting me know. Air in the UFH pipes usually happens when filling the system and over time you would expect the air to be purged through an auto air vent, usually on the manifold.

 

[Madrab]

I'm also concerned that if air gets in the UFH pipes, it will not be possible for it to escape as the manifold (with auto air vent) is lower down and obviously, air rises.

Doesn't work like that in UFH. As it is a closed loop of pipe, the system pressure will push the system water through it and the air along with it. As long as it is commissioned properly and the loop filled and bled correctly then there shouldn't be a problem. Any air that may find it way in once running will be naturally pushed around the loop until it reaches the AAV on the manifold.

 

[Milleniumaire]

Doesn't work like that in UFH. As it is a closed loop of pipe, the system pressure will push the system water through it and the air along with it. As long as it is commissioned properly and the loop filled and bled correctly then there shouldn't be a problem. Any air that may find it way in once running will be naturally pushed around the loop until it reaches the AAV on the manifold.

That's useful to know as it was my heating engineer that suggested I might need to install an air vent as part of the UFH pipe run due to it being higher than the manifold when I explained that I might be able to use the spare port on the existing downstairs kitchen manifold for the new en-suite UFH loop. It wasn't something I had thought about prior to my heating engineer mentioning it.