While the CT-DH-3 has many applications, it was primarily developed to be used with CO2 equipment and exhaust type fans. Internal sensors will allow a 7 ° temperature comfort zone and a 7% humidity (differential) between the time the fans go ”œOff”œ and come back ”œOn” again. Temperature or humidity rise will activate the right hand (Exhaust Outlets) outlets and deactivate the left hand outlets (CO2 Outlets). Plug the controller into a power surge protector to protect your valuable equipment, and then plug the surge protector into a 110 wall outlet. Set the temperature and humidity to the desired settings.