What is the purpose of occupancy sensors in lighting design?

• A. To adjust color temperature based on occupancy.
• B. To measure room temperature.
• C. To detect smoke.
• D. To automatically turn lights on/off based on occupancy, saving energy.

Answer: (D)

Occupancy sensors in lighting design are used to control lights automatically based on whether people are present. They sense when a space is occupied and switch lights on, then turn them off after the space is empty, usually with a short delay. This automatic on/off capability reduces wasted lighting and saves energy, especially in areas that aren’t in constant use like restrooms, corridors, or meeting rooms. Some systems also coordinate with daylight sensors to avoid turning lights on when there’s enough natural light, further boosting efficiency. Color temperature adjustment, room temperature measurement, and smoke detection are handled by other devices, so the primary role of occupancy sensors is to automate lighting based on presence to cut energy use.