The new Primair twin speed controller with thermostat and probe is the ultimate in simple climate control. It consists of two separate intake and exhaust speed dials that are thermostatically controlled.

Simply set fans at the appropriate idle speeds to control room temp and set the thermostat at what you want your max temp to be (ie. 28 degrees). If the room hits your max temp setting the fans automatically switch to full output until the environment drops back under your max temp setting and your fans will then again automatically return to idle speed as set on the speed dials. Temp range 14-36 degrees.