The Natural Philosopher wrote:
Tim: the heatloss down to heat loss up ratio is entirely dependent on
the ratio of insulation underneath to isnualation above `(flooring,
carpets dogs/cats sofas etc)

Seems improbable.

If the floor's at 25, and the room at 20, but the ground underneath at 5
I'd expect a *lot* more loss downwards that if the ground underneath
was at 15.

And I suspect the "U" value of several metres of dry soil could be quite
high - whereas wet soil, with water trickling through it, could steal
enormous amounts of heat.

Andy