In order to increase the emitter area of our UFH* could we continue it up an internal blockwork wall? Is there anything to consider when doing this? Can it be done? Will it effect pump size? Could we simply staple it to the wall and plaster over with clay plaster?

* in order to increase the amount of radiant heating the body receives and lower air temperature.

probably it will crack the plaster and get drilled through eventually.

shouldnt be needed.

I would hope not as most people don't nor do they have particularly good insulation standards, hopefully you do.

Running the heating up the wall as well will definitely increase the area and thereby lower the temperature needed. Running the pipes in the ceiling is also another possibility. There are special products - kind of like flexible plastic radiator skeletons - made to be put in walls or ceilings. The question is how much is needed?

I think floors are usually used in preference to walls because they're easier and it's easier to pre-plan where nails need to go. One reason UFH is touted over radiators is the freedom to use the wall space as you wish. If the walls are full of pipes then that advantage goes away.

Same way as ordinary radiator sizing surely.

How would you deal with any trapped air?

Heating the walls could, at least in principle, encourage stratification and convection. So you might actually lose some of the comfort benefits of UFH.

Though of course it would never get as bad as with 'radiators', which can create a useless blanket of warm air under the ceiling, while stirring up frosty draughts around your ankles.

Posted By: gyrogear: “AS I understood it, heating from a radiant floor or wall is essentially by convection anyhow ?”

I think it's about 50:50 between convection/conduction vs radiation for UFH:

http://edavies.me.uk/2014/08/radiators/

Well, I'd be using the proprietary products designed for the purpose, so I wouldn't be snaking any pipes.

Rhamdu, I agree and I don't think I''ve said anything to the contrary. It's Gyrogear who seems to think otherwise.

I think Ed and rhamdu are using radiant in its scientific sense, not as slang.

Posted By: gyrogearWith respect, gents, I don't think otherwise at all !

We're discussing if it mostly works by convection/conduction or whether radiation is a significant part. I think we're all agreed that (in appropriate circumstances) it's a good thing.

Don't know for sure but radiation seems to only account for about 5 W/(m²·K) of the generally accepted 10 W/(m²·K) output from the floor surface. Convection and conduction, including conduction up walls, table legs, etc, in addition to through the air presumably needs to account for the difference. It doesn't need to be “formal” convection - just bulk movement of air because of ventilation, people moving around and so on.

On my web page referenced above I estimate that the convective/conductive transfer from a radiator is about 5/6ths of the output but from a UFH floor about half so that's a pretty sharp fall (and, proportionally, a bigger increase in radiation) but it doesn't follow that convection/conduction is negligible for the floor, either.

Walls and floors.
I think its possible. Companies will try to sell anything : http://www.variotherm.at/en/home/products.html
Only issue i guess is possible temperature differences in the flow in.

As for wall heating, works. Just works. I stand a few metres away and i know which bits are on. Feel it on my face, maybe i have the skill to feel heat. Sadly it only comes on every other day or so to keep the place warm. So i have to turn it on. As for holes in walls. We have picked out places unlikely to be drilled. Put in hanging lines from ceiling. Put in places that can be drilled into. Lots of photos were taken while we drilled in the holes to hold the pipework.

Only comments from to add. make sure the pipes are laid with the return flow next to the out flow. Unless your going for a really warm piece of wall (great to lean against seat near by to). Then use short runs or just a mid length run without the return flow next to it.
Airtight houses just do not need the heating time periods to get whole walls warm evenly. We have some of the variotherm panels. I thought, I'd use less than then recommend per run of pipe . Even then the last wall panels are not very warm by the time the heating goes out.
Between the panels/walls if running in voids we wrapped everything in insulated pipe. Some companies supply the pipe in that form (henco). We have used 3 varying types of pipe.
So far no plaster or clay has cracked. left it to dry all summer, and slowly built up temp of system first, as per installer instructions ( and fears).
I could ramble on further.

Yes, more rambling please. Photos would be great too. Thanks for the Variotherm link.