The controller modulates the outside air damper based on the CO2 level through the ppm value selected between the range of 500 and 2000 ppm. The measured CO2 concentration value is compared with the set DCV setpoint. If the measured CO2 concentration value is below the DCV setpoint, keep the damper to the minimum position. Otherwise, enable DCV.

Once DCV is enabled, the DCV PID starts to run to control the indoor CO2 concentration value towards the DCV setpoint. The damper opens to the maximum position.

DCV is disabled if the controller receives no occupancy signal.