Development of a dual-mode demand control ventilation strategy for indoor air quality control and energy saving

A dual-mode demand control ventilation strategy was established targeting at use in buildings where the number of occupants varies frequently. The first contaminant chosen for sensor control is CO2 and the second is a non-occupant-related indoor pollutant which indicates the demand of fresh air to dilute the non-occupant-related indoor contaminants. Experiments were conducted to verify the performance of this control strategy. The experimental results showed that an acceptable indoor air quality could be obtained. More than 90% of the occupants thought that the indoor air quality was acceptable. Comparing with the original fixed-rate ventilation control strategy, about 8.3–28.3% of the daily electrical energy could be saved.