Which duct carries exhaust air from two or more branch ducts?

Which duct carries exhaust air from two or more branch ducts?

• A. Common Duct
• B. Branch Duct
• C. Return Duct
• D. Supply Duct

Answer: (A)

Exhaust air from several branches is collected into a single duct called the common duct. When multiple branch ducts converge, their airflow is joined in the common duct so it can be carried to the exhaust fan or out to the outdoors. This setup is different from a branch duct, which serves a single area; from a return duct, which brings air back to the air handling unit for recirculation; and from a supply duct, which delivers conditioned air to spaces. So the duct that carries exhaust from two or more branches is the common duct.

Exhaust air from several branches is collected into a single duct called the common duct. When multiple branch ducts converge, their airflow is joined in the common duct so it can be carried to the exhaust fan or out to the outdoors. This setup is different from a branch duct, which serves a single area; from a return duct, which brings air back to the air handling unit for recirculation; and from a supply duct, which delivers conditioned air to spaces. So the duct that carries exhaust from two or more branches is the common duct.