Which component shall not be used?

Which component shall not be used?

• A. Welded connections
• B. Exhaust fans
• C. Access doors
• D. Flexible connectors

Answer: (C)

Access doors are service openings, not primary duct components. They’re placed to provide access for inspection, cleaning, or servicing internal parts like dampers, filters, or sections of the system. Because they are not built to carry the airflow as a joint or to meet the same airtightness and fire-resistance requirements as actual duct joints, using an access door as a main duct connection would create leaks and compromise system performance and safety. Welding creates rigid, airtight joints; exhaust fans are part of the air-moving equipment; flexible connectors accommodate movement while remaining part of the duct system. So, access doors aren’t suitable as the duct component that carries and seals the airflow.

Access doors are service openings, not primary duct components. They’re placed to provide access for inspection, cleaning, or servicing internal parts like dampers, filters, or sections of the system. Because they are not built to carry the airflow as a joint or to meet the same airtightness and fire-resistance requirements as actual duct joints, using an access door as a main duct connection would create leaks and compromise system performance and safety. Welding creates rigid, airtight joints; exhaust fans are part of the air-moving equipment; flexible connectors accommodate movement while remaining part of the duct system. So, access doors aren’t suitable as the duct component that carries and seals the airflow.