In commercial buildings, how should thermostatic setback controls function for maintaining zone temperatures?

Thermostatic setback controls in commercial buildings are designed to enhance energy efficiency while maintaining comfort within different zones. These controls should have the capability to temporarily operate the heating or cooling systems in addition to setting back the temperature during unoccupied hours or periods of reduced activity.

By using setback strategies, the systems can reduce energy consumption when spaces are not in use, yet still have the capacity to temporarily operate to bring the zone to comfortable temperatures in a timely manner when it's occupied again. This allows for a balance between energy savings and tenant comfort, as the system can respond dynamically to varying occupancy levels and associated temperature needs.

The option that states a fixed temperature would lack flexibility and might not adequately respond to varying occupancy and comfort preferences. Focusing on controlling humidity only would ignore the critical aspect of temperature management, which is essential for overall comfort. Lastly, a mere setback would not suffice in ensuring that spaces reach a desired temperature quickly when occupied, highlighting the necessity for the dual function of setback and temporary operation.