The Standards for the ASHRAE CO2

What a CO2 Level Means

• According to The Engineering Toolbox, the amount of CO2 present in an interior space is an indication of how much fresh air is present in that space. Because humans inhale the fresh air and exhale CO2, the higher the carbon dioxide level, the less fresh air is available. This lack of fresh air can have effects such as occupancy limits on a space since, as The Engineering Toolbox explains, "CO2 is exhaled by people at predictable levels;" the number of people and therefore the amount of CO2 acceptable for a room can be determined and limited ahead of time.

ASHRAE Standards

• To prevent discomfort and other complications from high CO2 levels in public spaces, ASHRAE has created standards for the amount of fresh air and carbon dioxide acceptable measured in cubic feet per minute (cfm), which is a standard unit of measure for air. According to the Engineering Toolbox, the ASHRAE standards are "classrooms and conference rooms 15 cfm per occupant," "office space and restaurants 20 cfm per occupant," "hospitals 25 cfm per occupant."

Remedies

• If a space is found in noncompliance with ASHRAE standards, the space and situation must be corrected. Additional ventilation must be added. That is, more fresh air must be brought into the space and more CO2 allowed to escape. Serious health complications for the occupants of a noncompliant space can be one of the consequences.