Referring to the illustrated single zone HVAC system diagram, what statement is true concerning the damper controls? Illustration GS-RA-09 Illustration GS-RA-09: the U.S. Coast Guard has not released this illustration.

Correct Answer: Option B — The exhaust and outside air dampers are normally closed and the recirculation damper is normally open and all three dampers are controlled by a single pilot air signal.

In standard HVAC pneumatic control logic, exhaust and outside air dampers are normally closed to prevent uncontrolled ventilation during system shutdown. The recirculation damper is normally open to maintain air circulation. A single pilot air signal ensures synchronized operation, allowing the system to transition to a balanced state upon activation.