The 2298 Series Unit Ventilator Thermostat has been designed for the proportional control of pneumatic devices and actuators in environmental control systems. These devices are designed primarily as return air controllers in induction units, fan coil units, and unit ventilators. The 2298 Series will also replace the obsolete 2264 Series Unit Ventilator Temperature Controllers. These two-pipe controllers incorporate a receiver controller which when coupled with the highly-sensitive remote bimetal sensor system, provides accuracy and stability over the entire operating range. Models are available in direct or reverse acting only, or dual pressure summer/winter models for heating and cooling applications. (See Ordering Data.) Set point adjustment is accomplished by means of a serrated "thumb wheel". A "cooler/warmer" cover with graduated marks representing 5?F increments from 65 to 85?F is provided with each controller