Which option describes the best practice for managing energy usage during periods of low occupancy?

Implementing setback strategies for heating during periods of low occupancy is considered best practice for managing energy usage effectively. This approach involves lowering the temperature when the building is not in use or when occupancy is minimal. By allowing the temperature to drop, significant energy savings can be achieved, as the heating system does not need to work as hard to maintain a comfortable environment when it is unoccupied.

This practice takes advantage of the ability to control heating systems intelligently, ensuring that energy is not wasted maintaining a higher temperature than necessary when few or no occupants are present. Setback strategies can lead to lower energy costs while still ensuring that the building remains comfortable upon re-occupancy.

Other options do not provide the same level of efficiency or cost savings. For instance, maintaining a consistent temperature may lead to higher energy usage during unoccupied periods since the system is continuously working. Regular maintenance is essential for system efficiency but does not directly reduce energy consumption during low occupancy times. Relying solely on electric heating systems does not necessarily equate to energy conservation, as the efficiency of heating methods can vary widely based on system design and energy sources.