Literature review on CO2 based demand controlled ventilation.

Many ventilation requirements and recommendations are in the form of outdoor airflow rates per person. Ventilation systems are therefore designed to provide a minimum level of outdoor air based on the designed occupancy level multiplied by the per-person ventilation requirement. Because the indoor generation rate of carbon dioxide is dependent on the number of occupants, it has been proposed to use indoor carbon dioxide concentrations as a means of controlling outdoor air intake based on the actual number of occupants in the space as opposed to the design occupancy. Such demand-controlled ventilation offers the possibility of reducing the energy penalty of over ventilation during periods qf low occupancy while still ensuring adequate levels of outdoor air ventilation. This  paper reviews previous work on carbon-dioxide-based demand-controlled ventilation, including field demonstration projects, computer simulation studies, studies of sensor performance and location, and discussions of the application of the approach. The work is summarized and a number of research needs are identified