Question 219General Subjects - 1st Asst/Chief

The correct answer is A) The supply air duct thermostat controlling the steam flow is set several degrees lower than the design off-coil temperature associated with the cooling coil. This is the correct answer because the supply air duct thermostat controlling the steam flow is set to a lower temperature than the design off-coil temperature of the cooling coil. This prevents the simultaneous flow of steam through the preheat coil and chilled water through the cooling coil, as the system is designed to only use one source of heating or cooling at a time to maintain the desired temperature in the space. The other options are incorrect because B) setting the thermostat equal to the cooling coil's design temperature would allow simultaneous heating and cooling, C) simultaneous heating and cooling is not typically permitted for humidity control, and D) setting the thermostat higher than the cooling coil's design temperature would result in continuous heating, not the desired sequential heating and cooling.