The rate at which CO2 is generated within an indoor space is proportional to the number of occupants in the space. If outdoor air ventilation is not provided at a rate of 15 cfm/person, an elevated CO2 concentration above 1,100 ppm can result.
It is important to note that carbon dioxide (CO2) is a gas that is generated by humans when they exhale. It is not to be confused with carbon monoxide (CO).