Thanks for replies!
My apologies for poor terminology GDE; I'm referring to the exterior box that houses the heat exchanger. I don't want to tinker with the innards of the thing; am looking at a potential installation mod rather than trying to upgrade the furnace manufacturer's design. That said, a design that requires the box to shed heat to the surrounding air moving *over* it rather than the air moving *through* it (and then out to the distribution duct) is rather curious, especially since this now pre-heated air is what is drawn into the box.
Dutch, thanks for the vent idea. That would help with residual heat after the furnace turns off.
The reason I'm pursuing this in the first place is that the blower wasn't coming on when the thermostat told it to. It appears that there is a sealed relay on the Ignition Board CCA that routes power to the blower prior to furnace ignition. That relay appears to be sticking. It's working now, but that CCA and everything else in the enclosure gets really warm. Can't be good for electronics.
Failing the jacket on the furnace box idea, perhaps a cool air snorkel for the CCA.
Thanks again for the replies!
