We built a simple sunroom on our house. It has 9' high 8mm double wall polycarbonate walls and an insulated ceiling. It isn't sealed up tight yet but when the sun comes out, it easily gets 30-50 degrees temp rise. The other day it was 21 outside and 86 in the sunroom. We open a window into the kitchen and let the heat come in. What I'd like to do is mount a squirrel cage fan up near the ceiling and have it blow into the window whenever the sunroom gets hotter than the house. We usually keep the house around 68. Would an air conditioner thermostat be what we need? I want the room to warm up then blow in the hot air until the room cools, but I don't want it cycling on and off every minute or two. I plan to have a simple flap seal the vent up when the fan is not running.