On Jan 7, 10:21*am, Tim S wrote:
The Natural Philosopher coughed up some electrons that declared:

3 meters of wet soil is about the same as 50mm of polystyrene.

And wet (well quite damp) soil is what I have.

Bur the thermal 'mass' is vast.

takes days of heating to get it up to temp..

And it's going to arrive at a mean away from the walls at this time of year,
assuming room heated 50% of the day, of perhaps avg(5,27) = 16.

Repeating crappy calculation from earlier:

Area=19m2, deltaT=11C, U=1.63 - so total loss down is 340W

With 20mm Marmox and no UFH, lets say the mean earth mass is avg(5,20) = 12C
ish U=1.3, deltaT=8C so total loss down is 200W ish.

With that scenario, we could say the "luxury" of UFH costs us an extra 140W
for 19m2 room at 50% duty cycle heating. That's more like 2.50 quid/month
for the colder months.

Most of the other rooms downstairs are bedrooms, so should be on a lower
duty cycle, but as 2 are kids bedrooms, that may not always be true...

Hmm.

I'm off to have a look at doing better calculations...

Cheers

Tim

This is 'presumably?' electric cable underfloor heating?
An acquaintance has underfloor water heating cables, tied in with part
of an older installation of baseboard water radiators in the basement
area, from a conversion from oil furnace to electric hot water furnace
by a previous owner.