VAV Thermostat Proportional Heat or Cool Independent fan circuitry provides switching for up to three fan speeds Application Proportional Control of HVAC Heating and Cooling Valves Dampers and Fan Systems Control Range (F) 50 to 90 Input Voltage 24V AC Number of Relay Outputs 1 0 to 10V AC - 1 Proportional 3 Degrees F Analog Display Plastic