Posted by Rod Nissen on December 01, 2001 at 09:00:07:
In Reply to: Air cooled walls posted by Allan Greene on November 13, 2001 at 16:02:13:
I've seen it on a coil type steam generator or hot oil (thermal fluid) heater. The air is actually being preheated for use in the burner, and has the other advantage of the unit not needing so much insulation on the outside, as the air space and flow provides for it.