A sensor saves energy only when its settings fit the way the room is used. Before choosing hardware, record occupied hours, daylight availability, and the level of control people need.
Define what the room needs
Check the building rules and project specification for automatic shutoff, daylight control, zoning, and manual overrides. Requirements vary with the location, building type, work scope, and adopted code edition.
Choose the detection method for the task
PIR detects movement across its field of view. Other technologies can respond differently to partitions, small movements, and activity outside the intended zone. Compare the coverage diagram at the actual mounting height and trial the sensor in place.
Set daylight control at the working area
Group fixtures so daylight near a window does not dim the back of the room unnecessarily. Position and calibrate the sensor, agree on the target level, and test it at different times of day.
Calculate savings from the schedule
Estimate hours at each operating level and use the fixture’s measured watts at those levels. Compare that energy with the existing schedule. Avoid adding a generic sensor-saving percentage to a separate dimming percentage; the same hours may be counted twice.
Check controls and drivers together
Specify the control interface, minimum dim level, off-state behavior, standby demand, and response after a power failure. Confirm sensor mounting height, detection range, time delay, and access for adjustment.
Budget for commissioning
Include setup, occupant feedback, and a follow-up adjustment in the contract. Keep a record of zones, time delays, setpoints, and overrides. A system that repeatedly switches off on seated workers is likely to be bypassed.
Frequently Asked Questions
Are occupancy sensors suitable for every room?
Coverage and operating mode must suit the task. Small movements, partitions, safety requirements, and continuous-use areas need specific review.
How much energy will controls save?
Use the actual occupancy and daylight schedule with measured input watts. There is no single percentage that applies to every building.