CO2 demand control ventilation

Variable air volume (VAV) ventilation systems reduce fan power consumption compared to constant air volume (CAV) systems because they supply air according to the airflow demand. However VAV ventilation systems do not take fully into account the potential energy savings as the control strategy operates the terminal boxes and the air handling unit (AHU) independently without pressure integration. The pressure in the main duct is maintained at a constant static pressure (CSP) which corresponds to the pressure required under the design full load condition.