Showing the key features of the ACInfinity Shutter Exhaust Fan System, with a very nice temperature and humidity control system. The controller can activate & power up to two exhaust fans or ACInfinity exhange boosters. There are set points for hot temperature activation, cool temp activation (maybe you only want your fan to come on when the temperature goes BELOW a certain point), high and low humidity activation points, plus alarms at high and low settings you control, or deactivate.
The fan itself is controlled over 10 adjustable speed steps. This video lets you hear and see what the different speeds are. I have installed this in a sliding window inside our sunroom as an experiment - my installation is a quick-fix without routing the wires and sealing up the air gaps.
Available at Home Depot.