In rooms that are unoccupied for extensive periods of time or where lights are repeatedly left on, an occupancy sensor can reduce lighting costs by up to 50%. According to the U.S. Department of Energy’s Federal Energy Management Program (FEMP), an occupancy sensor in a small home office can lower energy use by nearly 30%*. Occupancy sensors range in price and are designed to work with a variety of lighting technology, so be sure to do your research when determining which system is best for you.
Dual-technology sensors, as the name indicates, combine both infrared and ultrasonic methodology. While more expensive than single-method sensors, they offer increased accuracy and versatility.
Triggered on or off by a room’s temperature change, infrared sensors work best in rooms where the sensor’s line of view can be unobstructed. Their typical range is about 15 feet, which means they’re best suited for smaller areas.
Ultrasonic sensors transmit a high-frequency sound that’s undetectable by human hearing. The sensors monitor the reflection pattern of this sound which can travel around obstructions such as furniture, cabinets and shelving–and, if the pattern changes, activate the lights. Once the pattern returns to normal, the sensors turn the lights off. Ultrasonic sensors are best suited for larger areas where many obstructions are present or where 360-degree coverage is desired.