CO2-Based Demand-Controlled Ventilation and Its Implications for Interior Design

CO2-based demand-controlled ventilation (DCV) is a ventilation method that resets outdoor air supply rates using CO2 as an operating parameter (ASHRAE, 2007a). Even though CO2 itself is not harmful, high levels of CO2 concentration in indoor environments displace oxygen in the air and can cause a deficiency of oxygen for breathing. The most important aspect of CO2 in DCV is that it is a good indicator of occupancy in indoor spaces. Therefore, CO2 is an effective parameter for controlling ventilation based on occupancy level. CO2-based DCV has been increasingly used in recent years to optimize the energy consumption in ventilation systems as technological advances make its implementation more feasible and interest in environmentally responsible building design grows. This study aims to provide information about CO2-based DCV and suggest implications for interior design practitioners and educators. To achieve this purpose, this study reviewed previous studies and examined the current practices in CO2-based DCV in order to suggest guidelines for CO2-based DCV implementation for interior designers. The guidelines focused on proper CO2 sensor location design, taking into consideration the activities and other equipment in the room. In addition, a study of CO2-based DCV in the lecture halls of a university campus was conducted. Physical measurements were done in the lecture halls, and trends data were collected from the university's facility management department to compare the measurements. A perceived indoor environmental quality survey was also done to explore the occupants' responses about CO2-based DCV.