"Roger" wrote in message
k...
The message
from Andy Wade contains these words:

I'm not convinced that the marginally greater radiation from warmer
walls would have any significant effect (see final para for the
reverse
effect) but to the extent that it does it makes diMMs conjecture even
less tenable.

I'm having difficulty following your argument. I agree that the
difference in surface temperature, at least in the steady state, is
pretty small. If you compare two walls, one with a U-value of 0.4
W/(m^2.K) and the other with U = 2.2, assuming 21 deg. inside temp and
-3 outside, and using the usual value of 0.06 m^2.K/W for the resistance
of the internal boundary layer, the difference in the inside surface
temperature works out at only 2.6 K, according to my back-of-envelope
calculation. However that 2.6 K difference is about 15% of the
temperature difference between the couch-potato-body and the wall, so it
will have a fairly significant effect on the heat flux. With
intermittent heating in the poorly insulated place the difference will
tend to be larger, due to the lag introduced by the thermal mass of (for
example) solid brick walls.

I may be venturing into the unknown

NO. you are totally in the dark

snip stuff not worth reading