Make controlling your fans easy with our bathroom fan switches, huge savings ... These thermostats use snap action bimetal temperature control and. .... Air Vent Item #: 58030 - Automatic shut off feature.2 speed rocker. A typical greenhouse uses an exhaust fan to cool off high temperatures in the room. This type of fan is equipped with a thermostat that measures room ...Since it's thermostat controlled, it wouldn't run 24/7, only when needed. ... 4" extraction fan, the type normally used for bathroom ventilation. I would like to control it thermostatically, which is obviously easy enough using ... Installing a timer on the exhaust fan is a really good idea, too.