Question 143Refrigeration & AC - 1st Asst/Chief

The correct answer is C: The dry bulb room temperature is controlled by a steam heated reheater and its associated pneumatic control valve. This is correct because in a Class "A" air conditioning system used to condition large public spaces, the dry bulb temperature of the space is controlled by a steam heated reheater. The reheater, and its associated control valve, are used to reheat the air after it has passed through the cooling coil, allowing precise temperature control of the space. The other options are incorrect - A is incorrect because the preheater steam flow is typically controlled by a separate thermostat, not the space thermostat. B is incorrect because the cooling coil and reheater can be used simultaneously to provide precise temperature control. D is incorrect because the reheater is used even when in the cooling mode, to provide the final temperature adjustment.