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Occupancy Sensor

Occupancy sensors are widely applied for lighting control in commercial buildings for spaces with frequent on/off uses such as conference rooms, classrooms, and restrooms. There are two types of occupancy sensors: ultrasonic and infrared. Ultrasonic sensors detect sound, while infrared sensors detect heat and motion. Each technology alone is not totally reliable, which can cause inconvenience when using the sensors to control lights. Combining sound, heat, and motion detection can potentially generate decent savings without causing complaints.

In houses, turning lights off alone may not generate enough energy savings to justify the use of an occupancy sensor. Increased homeowner awareness with good habits of turning off lights upon exiting the room can have similar savings. However, when coupled with gadgets to kill the standby power from miscellaneous electric equipment such as home theatre and home office equipment, occupancy sensors can potentially generate big energy savings. More sophisticated home energy management systems use occupancy sensors to turn off appliances and electronics, so occupancy sensors may become more common in homes.

The Commercial group at NREL has developed a new type of occupancy sensor technology.