I mounted my Sanyo XP21N projector on the ceiling in an enclosure that has a duct from the exhaust fan up into my attic. The manual says not to have any "obstruction" within 3 feet of the exhaust port but I built a duct (not an obstruction), right? Anyway the exhaust temperature is the same as when it was un-"obstructed" at 130 degrees F. Just to make extra sure the unit is as cool as possible (with Summer coming), I'd like to put a supplemental fan in the attic duct that would come on automatically. It could either be triggered thermally when the temp exceeds X degrees or by when the projector fan is running (the projector has "power" always). Can anyone suggest a device I can use to accurately sense either current or temperature to trigger the fan? I can wire up something if given a bit of direction. If these ideas are too lame, what other options do I have?