Hi Erik,
Yes, I should have mentioned that I tried that too. That is typically
what I do, but I thought perhaps defining a heat source with a small
amount of capacity would be a reasonable way to alleviate the "free"
heat energy I appear to be getting...

Attached is a quick and dirty wizard model that illustrates the issue
(you will need to download .bin file or change to something
comparable). This is representative of the configuration I was going
for except air-cooled DX.
David