Would any happen to know how I could rig a thermostat to my fans (2'x2' box fans with ordinary outlet plugs) so they would come on when it got too warm in the room?
no sorry, what are the fan timings now? if the box is getting too hot, then increase the amount of time you have the fan on. cheaper and simpler alternative to thermostats. good luck
You could buy a thermostat that can handle the power rating of your fan. If the fan is about 12" I would guess 100 watts would do it. just get a t stat that can handle line power should costs about $20 and hook splice one of the wires to the fan through the t-stat. I am assuming you are in USA and using 120 Volt AC power. But no amtterwhere you are you can get a line rated t-stat. I'll tell you where to mail the doobie. LOL