In the illustrated terminal reheat multiple zone system, what statement represents the functioning of the summer outside air duct thermostat? GS-RA-42 Illustration GS-RA-42: the U.S. Coast Guard has not released this illustration.

Correct Answer: Option A — During the cooling season, the summer thermostat senses the outside air temperature and closes the exhaust and outside air dampers when the outside air temperature is significantly higher than typical indoor air temperatures.

Summer operation requires minimizing the cooling load. The thermostat senses high ambient temperatures and closes outside air and exhaust dampers to prevent the intake of hot, humid air. This forces the system to recirculate conditioned indoor air, significantly reducing the latent and sensible heat load on the chilled water coils.