Demand controlled ventilation (DCV) in school and office buildings: Lessons learnt from case studies

The results show that a DCV is interesting in rooms with a large and varying occupancy rate such as lecture rooms and landscaped offices. A good IAQ is measured in all cases studied even at reduced air flow rates. The effect of the reduced air flow on the ventilation efficiency is negligible. The VAV boxes react well to predefined set points for CO2 concentration. During the measurement period, the reduction for fan energy ranges from 25 to 55% and ventilation heat losses 25-32% compared to a constant air volume system (CAV) with a design airflow rate of 29 m3/(h.pers), i.e., IDA3 in EN 13779. However, commissioning of the DCV is necessary to obtain and maintain these performances.