Andrew Gabriel coughed up some electrons that declared:

It won't make any difference. When bottom fed, the hot rises to
the top in the first couple of channels, and then it's like a top
fed radiator. It's important the return is from the bottom, but
the flow can be either.


I wonder - how much difference would it actually make if the flow was at the
bottom and the return from the diagonally opposite top?[1] If you have
drops from ceiling to all your rads, as I will have, it would help clear
the air from the system.

I suppose it partly comes down to how fast is the water flow through the
rad - if it's fast enough to beat convection, perhaps it won't make much
difference...

Stupid thought for the day ;-

Cheers

Tim