______ shall not be used.

______ shall not be used.

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

Answer: (A)

Flexible connectors should not be used for primary ductwork because they are prone to air leakage, sagging, tearing, and moisture retention, which compromises airflow, energy efficiency, and the duct system’s cleanability and sealing. Rigid, welded (or properly sealed) joints provide a continuous, predictable air path that meets typical code requirements for leakage, fire/smoke containment, and maintenance. Exhaust fans and access doors are distinct components—an exhaust fan moves air, and access doors provide service access—not joint methods for linking duct sections. So the statement targets the practice of avoiding flexible connectors in main ductwork.

Flexible connectors should not be used for primary ductwork because they are prone to air leakage, sagging, tearing, and moisture retention, which compromises airflow, energy efficiency, and the duct system’s cleanability and sealing. Rigid, welded (or properly sealed) joints provide a continuous, predictable air path that meets typical code requirements for leakage, fire/smoke containment, and maintenance. Exhaust fans and access doors are distinct components—an exhaust fan moves air, and access doors provide service access—not joint methods for linking duct sections. So the statement targets the practice of avoiding flexible connectors in main ductwork.