In the illustrated single zone HVAC system, what statement represents the relationship between the exhaust, outside air and recirculation dampers? GS-RS-09 Illustration GS-RS-09: the U.S. Coast Guard has not released this illustration.

Correct Answer: Option A — The more the exhaust and outside air dampers are open, the more the recirculation damper is closed, and vice versa.

HVAC damper modulation maintains building pressure and air quality. As exhaust and outside air dampers open to increase ventilation and purge stale air, the recirculation damper must close proportionally to maintain a constant total air volume and prevent over-pressurization of the space, ensuring efficient air exchange and thermal balance.