Underfloor heating with less of the "under floor"

[The Natural Philosopher]

To be honest, what used to happen is that there would be a two hour burn in the morning, which would make the passageway with the pipes a magnet for the cats, and then the temp would still be only up at about 15-16 in this sort of weather, and the timing comes on around 3pm, and it would not be fully warm by 8pm..so 5 hours of full boiler output more or less, mostly warming the slab, not the room.

Now I've gone 24x7, the most significant thing is that he return temps out of the floor are MUCH higher, showing the slab isn't icy, and the boiler is cycling as a result. i.e. its doing about a 50/50 cycle in the night, with about a couple of hours between demand for heat, but the boiler is only doing about a 50/50 cycles in that time..

My gut feeling is that its no worse, and may in fact be a bit BETTER.

Mainly due to the fact that there are no cold spots. The sta is mounted on a massive concrete brick faced double chimney stack..so that used to suck heat requiring a higher temp elsewhere. like the outside walls etc..now its all evened out, I suspect the air temps are better.

The other issue is that during fast heat up periods, the floor gets super warm - especially under the sofas. I suspect that in itself increases heat losses from the floor downwards as well.

I am tempted to leave it like that all year long, and simply let the stat take care of everything. In summer the nighttime temps in that room are seldom below 18 anyway.

Thats not too bad. Whats teh values for suspended block and beam :-(

[YAPH]

There's a 'standard' U value for solid floors of 0.36 from BS5449(1990)

[Tim S]

Tim S coughed up some electrons that declared:

Couple of factual followups, for anyone reading this later from google...

I've just handled a piece of 10mm (ish) "Warmup" under-tile insulation panel, down at Topps Tiles place. It appears identical to Marmox.

It is *very* robust. The surface is as hard as rock and the softer core foam (it's foam rather than squidged white stuff like jablite) feels very robust in the face of tearing or compression. I would have no qualms about using this to achieve basic insulation under tiles - though I'd go for at least

20mm if practical.

made by these people:

He says that he's checked and a couple of the big DIY sheds out there are carrying this product, so we conclude it probably has basic credibility at least. I'll follow up when i get my mitts on the sample I've been promised.

Cheers

Tim