[masraum]

Originally Posted by T77911S

the Tstat should have a switch just for the fan, then when the temp gets too hot, the compressor will kick in, this will run the fan 24/7 though

i dont think you need diodes. the Tstat is just a switch, unless you have a digital one. even then, as long as the 24vac is from the same source it sould not matter. plus, the controls are AC not DC.

the foam is pricey. i paid around $600 to insulate a 400 sq foot room. but if you are going to keep the house, it may be worth it.

Right, I'd like to not have the fan running 24/7. Right now that's what I do, or I turn it on when I leave for the day and then turn it off in the evenings. It'd be nice to have something that could automatically do the trick. Moving the thermo upstairs, I think would be an improvement, but even then, I couldn't set the fan to come on based on the thermostat, it'd be the AC.

I was thinking diodes would be necessary if I had 2 sets of switches/thermostats in case one was on and then the other came on, but maybe not.

Sounds like the foam would be pricey to do our roof. I'd love to vacuum all of the old crap out of the attic and put some new insulation in. Hell, I'd think that even some foam panels between the rafters would have to help.