Question 144Refrigeration & AC - 1st Asst/Chief

The correct answer is A) The duct thermostat determines the amount of water flow circulating through the cooling coil. In a class "D" air conditioning system, the duct thermostat monitors the temperature of the air flowing through the ductwork and controls the amount of water circulating through the cooling coil. This adjusts the cooling capacity of the system to maintain the desired temperature in the conditioned space. The other options are incorrect because: B) The cooling is achieved through the refrigerant circuit, not a direct type air conditioning unit. C) Increasing recirculated air would increase the heat load, not decrease it. D) The room thermostat controls the dry bulb temperature, not the wet bulb temperature, of the conditioned space.