Question 217General Subjects - 1st Asst/Chief

70% to pass

Referring to the illustrated single zone HVAC system diagram, what statement is true concerning the damper controls? Illustration GS-RA-09

AThe 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.

BThe 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.

CThe exhaust and outside air dampers are normally closed and the recirculation damper is normally open and each damper is controlled by its own pilot air signal.

DThe exhaust and outside air dampers are normally open and the recirculation damper is normally closed and each damper is controlled by its own pilot air signal.

AI Explanation

The correct answer is B. The exhaust and outside air dampers are normally closed, and the recirculation damper is normally open. This allows the system to primarily recirculate air within the building, minimizing the need for outside air. All three dampers are controlled by a single pilot air signal, which means they move in unison based on the control system's needs. The other options are incorrect because they do not accurately describe the normal positions of the dampers or the control method. Option A has the dampers in the wrong normal positions, and option C and D have each damper controlled by its own pilot air signal, which is not the case in this single zone HVAC system diagram.