Question 473General Subjects - Assistant Engineer

The correct answer is A. The explanation is as follows: 1) Answer A is correct because in a single zone HVAC system, the exhaust and outside air dampers are normally open to allow the flow of air, while the recirculation damper is normally closed to prevent recirculation of stale air. All three dampers are controlled by a single pilot air signal, which means they are operated together by the same control system. 2) This configuration is common in single zone HVAC systems to ensure proper air circulation and ventilation. The normally open exhaust and outside air dampers allow fresh air to enter the system, while the normally closed recirculation damper prevents the recirculation of stale air. 3) The other options are incorrect because they describe different damper configurations or control methods that are not typical for a single zone HVAC system.