A novel and dynamic demand-controlled ventilation strategy for CO2 control and energy saving in buildings

Although conventional CO2-based demand-controlled ventilation strategies, such as proportional and exponential controls, can ensure buildings/spaces meeting the minimum requirements of outdoor air by industry standards, they are operated under the assumption of equilibrium condition which can hardly be reached in practice and therefore there is still much space to improve on conventional strategies in terms of energy saving. In this paper, a novel and dynamic control strategy was developed for hourly scheduled buildings. The strategy utilized schedules by setting a base ventilation rate for unoccupied periods and calculating ventilation rate dynamically at each occupied period by solving the CO2 mass balance equation to keep indoor CO2 near the set point during the occupied period. Experimental simulations were made over a sports training center using both simulated and experimental CO2 generation rates. Results show that the new strategy can save +34% of energy related to ventilation air compared to proportional control. The new strategy was also extended to common buildings which are occupied for almost all opening hours. In the case of common buildings, the new strategy can save about +26% of energy related to ventilation air compared to proportional control. The new strategy is simple, dynamic, flexible and efficient.

► We developed a novel and dynamic CO2-based DCV strategy for sports training arenas.
► Indoor CO2 concentration can be controlled near the set point at each training session.
► About +34% of energy related to ventilation air can be saved compared to proportional control.
► The new strategy can also be applied to common buildings which are occupied for almost all opening hours.