Electric lights that are turned on and off by motion sensors will save Kansas University almost $14,000 a year in utility bills, university officials say.
As part of KU's energy conservation project, motion sensors are being installed in four campus buildings -- the Art and Design Building, Learned Hall, Murphy Hall and Blake Hall. Sensors will be placed in classrooms, restrooms and some offices.
The sensors will cost $52,000 to buy and install and will save about $13,967 in electricity a year. "The energy saving pays off the cost in about four years," said Myron C. Reed, KU engineering manager for capital programs. "The sensors should last at least 10 years, and most likely, 20 years."
In classrooms and offices, the motion detectors are passive infrared units that detect motion when light beams are disturbed. In restrooms, the sensors use ultrasonic waves because of the metal stall partitions.
"Ultrasound will 'bend' around corners," said Reed, "and it's more efficient in areas like the restrooms."
At KU, sensors are set for lights to go on immediately if motion is detected and turn off about five minutes after motion has ceased. Sensors can be adjusted to turn lights off from 30 seconds to 10 minutes after the room is vacant.
Sensors can help to make campus rooms a little safer. "If someone is trying to hide in an office or a room, chances are they are going to move. It would be really hard for someone to not be detected," Reed said.
Other energy saving measures being carried out on campus include installing variable air-volume units for heating and cooling and replacing fluorescent light ballasts as they wear out with newer and more efficient units.