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

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

Single zone HVAC systems typically utilize pneumatic control signals to operate dampers. Exhaust and outside air dampers are normally open to ensure ventilation upon system startup or power loss, while the recirculation damper is normally closed. A single pilot air signal ensures synchronized movement of all dampers for balanced airflow.