it has to do with Planck's law Carl, "heat transfer" is thermal radiation .... don't question it, just accept that it works to use the right black paint wink

Bill


Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics