Posted By: cbatjesmond
Well if I don't report back on temperature differences between Kitchen and Sitting Room before the end of January 2009: Fear the worst! :-)
...
Mmmm not sure I'll remember to come back (or even still be around!) in December 2013. I will report back to this thread if anything crops up soon.

Well nothing's cropped up: I'm late but not fatally so: I'm starting to fit the bookcases that are the main furniture in the room. I hope that the SpaceTherm will support the weight of the books!

As to temperature, I'm disappointed with myself for not recording outside and room air temperature as well as floor temperature at all stages of the installation: bare boards, SpaceTherm+ply, SpaceTherm+ply+vinyl. All I can really do now is compare floor temperature in different rooms at the same time. It would have been nice to compare outside/floor/air temperatures across a range of conditions.

Anyway in unheated rooms, the floor with SpaceTherm is 1C warmer than than the kitchen (vinyl on ply on boards) and 1-2C warmer than the dining room (bare boards only). I would have liked a larger difference, but I hope it will make more difference when I get heating back on in the room. So it's not the one-step PassivHaus silver bullet I dream of :-/

I will be laying the rest of the ST I have in the dining room next and will *think* about using it if/when the hallway gets rebuilt.

Hope this helps.

Best wishes
-- CB

Posted By: spinkoxThe thing is - THEY say only 15% of heat loss from a room is through the floor so even if you had 10 layers of Spacetherm it would not make significant difference to the temperature . . .

But surely that's THEIR floor: MY floor's different! :-) Anyway, it is/was an experiment I was in a position to try.

Having just found the u-value calculator at http://www.vesma.com/tutorial/uvalue01/uvalue01.htm I estimate[*] that the u-value of the floor has changed from 2.69 (25mm floorboards) to 0.90 (vinyl, plywood, SpaceTherm, floorboards). Without the SpaceTherm it would have been about 1.94. So it's an improvement: more would be nice but within my constraints (max. 22mm rise in floor level, not pulling-up/climbing-under floorboards), I'm not sure I could have done better.

A rough calculation assuming 15C temperature difference between inside and outside, ignoring internal walls & ceiling:
oldfloor wall newfloor
area 25m^2 15m^2 25m^2
u-value 2.69 1.40 0.90
W 1009 315 337

So for MY floor in THAT room, I'm still losing more heat through the floor than the wall ... but only 1/3 of what I was.

* The calculator doesn't have SpaceTherm in its list, so I used isocyanurate (resistivity 0.020 W/mK) and multiplied the thickness by 33% to represent SpaceTherm's 0.014-0.013 W/mK.

The calculator doesn't have numbers on bookcases either: anyone know the thermal resistivity of bookcases? 11m^2 of bookcases against the walls has got to count for something :-)

Best wishes
-- CB

Using "typical house" percentages is hopeless. This may be "15% in a house with no loft insulation". As soon as you sort out the loft and drafts, the percentage loss through the floor will shoot up - while remaining exactly the same.

Posted By: mellie_manWhat humidity do you use!

I left RH at the defaults, but changed inside/outside temperatures to be more realistic worst-case for me: 18/0C

Since the calculator is done in JavaScript, you could try a different browser ... FireFox instead of IE ?