UFH Installed from Below ?

[Feltwell]

Routing pipes down to radiators from first floor level unobtrusively can be problematic. If there's no obvious way in the room concerned, is there a way in an adjoining room, perhaps having radiators back to back either side of a wall? I've got that in my downstairs rooms, plus running some pipes - insulated - down through a kitchen larder cupboard and into the sub-floor space.

Another tip is if you have unpainted skirting or panelling then raw copper dulls down and blends in nicely over time with old timber.

Agree with all the above about UFH under wood being a bad idea.

 

[CliffordPope]

If you have a source of heat under a floor, and insulate very efficiently underneath the heat source so that none can escape, where can the heat go except up through the floor?

 

[Flyfisher]

My dad DIYed an UFH system under marble tiles back in 1981, and that was efficient.

I've no doubt it was, and I don't think anyone here is dismissing UFH in principle, only in your proposed configuration. A marble-tiled floor, on the other hand, sounds ideal for UFH.

Basically a really efficient system requires 'perfect' insulation UNDER the heating coils and 'perfect' conduction ABOVE the heating coils so that all the heat escapes into the room and not into the earth. Of course, things are less than 'perfect' in practice but starting off with a layer of poorly conducting wood on top of the heating elements is a recipe for disappointment.

We have rooms with UFH and rooms with suspended wooden floors, but not both!, and like the above suggestions chose cast iron radiators for the rooms with wooden floors. As for hiding the pipework, I guess we're less fussy (within reason) and have found that when painted the same colour as the background wall or skirting then they very quickly 'disappear' - from our eyes at least.

 

[Flyfisher]

If you have a source of heat under a floor, and insulate very efficiently underneath the heat source so that none can escape, where can the heat go except up through the floor?

True, the heat will escape through a wooden floor to an extent, but the real issue is how much? In a 'wet' UFH system most of the heat may simply be returned to the hot water tank and in a 'dry' (electric) system the thermostat will cut out to protect the heating elements from overheating if they can't lose heat fast enough through the floor. Thus it could be that not enough heat escapes into the room compared to losses from the room through draughty doors or windows, leading to the room not really heating up very much or, in extremis, at all.