Exhaust ducts for domestic clothes dryers must be supported at intervals not greater than?

• A. 2 ft
• B. 4 ft
• C. 6 ft
• D. 8 ft

Answer: (B)

Exhaust ducts for domestic clothes dryers must be supported at intervals not greater than four feet to ensure they are securely positioned and to prevent any sagging. Proper support is critical for maintaining the efficiency of the exhaust system and for ensuring that it does not become obstructed or damaged due to weight or movement. A distance of more than four feet between supports could lead to an increased risk of disconnection or kinks in the duct, which could impact the system's performance and create a fire hazard. Thus, the four-foot interval strikes the right balance between structural integrity and functionality, ensuring ventilation remains clear and properly routed.