Ventilation control strategy using the supply CO2 concentration setpoint

Ventilation control strategy using the supply CO2 concentration setpoint

Nassif, Nabil and Kajl, Stanislaw and Sabourin, Robert

HVAC and R Research 2005

Abstract : This paper proposes a new ventilation control strategy applied to multiple spaces subject to variable occupancy. The strategy specified for real-time, online ventilation control takes advantage of uninitiated air from some overventilated spaces to be used as fresh outdoor air in order to reduce system energy use while maintaining the indoor air quality (IAQ) in each space. This proposed strategy maintains a supply CO2 concentration setpoint low enough to dilute CO2 generated by full occupancy in critical zones. The supply CO2 concentration setpoint could be determined online using the monitored zone airflow rates. It is tested and evaluated by making comparisons with other known control strategies. An existing VAV system installed at the École de technologie supérieure is used to evaluate this new strategy. The outdoor air fraction and associated energy use of investigated ventilation control strategies are calculated using the VAV system component models that are developed and validated against the monitored data. © 2005 American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.