The Single Speed Injection Fan adds a binary output to control a single speed fresh air fan. This fan operates under occupied conditions. If the optional Two Position Damper is selected, an additional binary output is added to control the damper, open during occupied, closed during unoccupied.
The Variable Speed Injection Fan adds a binary output and an analog output to control a variable speed fresh air fan. This fan operates under occupied conditions varying the speed as necessary to maintain the minimum outdoor airflow at setpoint. There are two options for measuring the airflow, Velocity Pressure (Pitot Tube) or Flow Measurement (Scaled). Velocity Pressure adds an input for the velocity pressure and performs the calculation provided you enter the K factor and duct area for your system. Flow Measurement supports direct flow reading flow measurement devices. Either input must be scaled to match your sensing device. Additionally, you must select how the fan reacts to an unreliable flow sensor input. Close Damper - Turn Off Fan or Open Damper - Fan Maximum Speed are the two choices. If the optional Two Position Damper is selected, an additional binary output is added to control the damper, open during occupied, closed during unoccupied.