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.

Single zone HVAC damper sequencing utilizes a unified pneumatic control signal where exhaust and outside air dampers are normally closed while the recirculation damper remains normally open to maintain proper ventilation balance.