In article ,
Malcolm Hoar wrote:
In article , wrote:
Eric in North TX wrote:

Warm air rises, cold air sinks...

But air conducts

..less than almost anything other than a vacuum. Check
the thermal conductivity of air in a suitable reference
work.

and heat radiates downwards.

And a floor, which is generally not very warm to start
with, isn't going to radiate very much (in any direction).

Indeed!

I recall from eons ago class that the radiation amount
varies as the (absolute!) temperature TO THE FOURTH POWER.

David