WASHINGTON (Army News Service, Sept. 30, 2010) -- The Army is using new, high-tech energy-saving lighting technologies in at least seven buildings at Fort Irwin, Calif., as part of an effort is already saving 35 to 40 percent of the light energy expended there.
The equipment can control lighting based on who is in the room and existing ambient light.
"This is advanced control lighting and other Army facilities are looking at these systems as well," said Hossam Kassab, the resource efficiency manager with the Fort Irwin directorate of public works.
Instead of using purely manual switches and electrically-wired fixtures, the new lighting technology uses wireless technology, occupancy sensors and vacancy sensors to adjust and use light energy to the extent that it is needed in a given area.
"Occupancy sensors mean the light will not come on until someone comes in," Kassab said. "The same sensor will work as a vacancy sensor and will turn itself off if somebody leaves the room."
The occupancy sensors used by the Army draw from both infrared and ultrasonic technologies.
"An infrared occupancy sensor senses your body heat so when it sees that something of a different temperature is moving around, it will send a signal to leave the lights on," said Shaun Taylor with Lutron Electronics, a manufacturer of lighting controls. "Also, you can predetermine the amount of time that the sensor will work."
Taylor said some equipment also uses ultrasonic sensors, which use sound waves to detect motion in a room.
"If something stands in front of it -- something that has a different echo -- it will detect that there is something moving around," he said. "There is also dual technology that incorporates both ultrasonic and infrared."
The lighting technology also uses wireless daylight sensors to adjust electric lights based on the amount of natural light already available.
"It measures the amount of light in a space, and once it senses there is enough light it will say 'okay, I don't need the overhead lights,'" Taylor said. "It will send a wireless signal over to your switch and either turn off the lamp or dim it."
Kassab said the daylight sensors can adjust to temporary changes in light due to surrounding weather.
"We have a dimming system in the lighting fixture which means if there is a cloud that passes outside, the lighting sensors will immediately respond and adjust the light in the room for a temporary period of time," he said.