Demand-controlled ventilation: do different user groups require different CO2-setpoints?

Abstract

The aim of this study is to investigate whether children's bioeffluent generation rate is proportional to their carbon dioxide (CO2) generation rate. Consequently, to assess if there is a need to differentiate the CO2- setpoint for different user groups, focusing on children. Perceived air quality (PAQ) and odour intensity (OI) were assessed in three classrooms in Oslo, Norway. Two second-grade classes (7-8 years old) were compared with one eighth-grade class (13-14 years old). An untrained test panel consisting of 16 people visited each classroom twice and were asked to evaluate PAQ and OI upon entering the classrooms. The CO2 levels in the classrooms were kept constant at either 600 ppm or 1100 ppm during each visitation. The results showed that average PAQ-score was significantly worse in the second-grade classrooms compared to the eighth-grade classroom. For perceived odour intensity, the average score indicated that the odour was stronger in the second-grade classrooms compared to the eighth-grade classroom, however, this difference in score was not significant. Our results indicate a need for differentiation of setpoints for CO2-DCV based on user groups, especially for children.