My office recently upgraded the MDF room and installed a duct fan and a "Duct Stat TM" in-line thermostat to turn the fan on when the temperature gets too high:
As simple as it seems, I needed a little help getting it set up right, and found these Installation instructions and directions for Duct Stat Plug in Thermostat.
So, here's what I did:
Let me know if you've had better luck with a different strategy. Thanks!
Thru-wall fan: 29 watts low, 40 watts high