Mechanical exhaust systems for enclosed parking garages shall provide a minimum ventilation rate of _____ cfm per square foot of floor area.

Mechanical exhaust systems for enclosed parking garages shall provide a minimum ventilation rate of _____ cfm per square foot of floor area.

• A. 1.5
• B. 1.75
• C. .75
• D. 1.0

Answer: (C)

For enclosed parking garages, the ventilation requirement is tied to floor area, not to a fixed room size. The essential point is that the exhaust system must move at least a certain amount of air per square foot of floor area to dilute vehicle emissions. The minimum rate is 0.75 cubic feet per minute per square foot (0.75 cfm/ft^2). That means you multiply the area of the floor being served by 0.75 to get the required total exhaust flow in CFM. For example, a 10,000 ft^2 level would need at least 7,500 CFM. If multiple levels are served by the same system, sum their floor areas and multiply by 0.75.

For enclosed parking garages, the ventilation requirement is tied to floor area, not to a fixed room size. The essential point is that the exhaust system must move at least a certain amount of air per square foot of floor area to dilute vehicle emissions. The minimum rate is 0.75 cubic feet per minute per square foot (0.75 cfm/ft^2). That means you multiply the area of the floor being served by 0.75 to get the required total exhaust flow in CFM. For example, a 10,000 ft^2 level would need at least 7,500 CFM. If multiple levels are served by the same system, sum their floor areas and multiply by 0.75.