The University of Minnesota (U of M) installed Lithonia Lighting® W Series LED Luminaires from Acuity Brands, Inc. after determining new LED lighting with embedded controls could lead to significant energy savings. The University initiated tests to investigate stairwell usage across campus, which revealed low foot traffic even during peak daytime operating hours. Many indoor and outdoor stairwells, back hallways and corridors were used only for brief time periods during the day, but remained illuminated 24-hours a day with standard fluorescent and HID fixtures.
The W Series LED luminaires feature integral occupancy sensors to manage lighting usage in low-traffic or low-occupancy areas such as stairwells, as well as corridors and restrooms. The LED luminaires automatically increase to 100 percent illumination as occupants enter the stairwells, walk corridors or enter a seldom-used space, then dim to 10 percent when areas are unoccupied. The dimming capability significantly reduces energy consumption by not fully lighting spaces, such as dormitory stairwells, when they are not in use.
"The LED luminaires were chosen after careful consideration and evaluation that determined the price made sense and the payback was worthwhile," said Blaine O'Brien, Senior Energy Auditor for Energy Management, a division of Facilities Management at U of M. "Our testing demonstrated this concept was a good solution for our needs."
Currently, the University has retrofitted 961 W Series LED luminaires in stairwells on the West Bank of the Twin Cities campus, providing an estimated annual energy savings of 379,392 kilowatt hours resulting in an estimated $30,000 in annual savings. Based on the success of the initial installation, U of M plans to install an additional 6,000 W Series LED luminaires in 120 buildings across campus.