Student Center Lighting Upgrade at the University of California, Irvine
The Student Center at UCI is a hub of the campus community, housing the campus bookstore, dining facilities, meeting rooms and offices. As the center is open daily from early morning until midnight, its intensive energy use provided opportunities for meeting campus goals of reducing energy use and greenhouse gas emissions. A project team from both Facilities Management and Student Affairs implemented a lighting retrofit that reduced total energy use by 21 to 60 percent per fixture. These changes improved lighting aesthetics and illumination levels, and drove savings of over $126,000 annually with an impressive payback period of less than three years.
This lighting retrofit used plug-and-play LED products to improve color rendition, reduce annual and peak electricity use, and yield a simple payback on investment of less than three years.
Before the retrofit, the building had a combination of older compact fluorescent lamps (CFLs), T8 fixtures and many older and less efficient T12 fixtures. Some lighting had been upgraded as magnetic ballasts failed, however lamps were replaced inconsistently, resulting in spaces having visibly uneven lighting colors. Because Student Affairs must fund energy projects directly, without bond financing, the project goal was a simple payback of less than five years. After a series of retrofit alternatives were considered, the payback was determined to be less than three years, meeting Student Affairs' return on investment criteria.
Existing CFLs were replaced with highly energy efficient 13-watt LED fixtures.
A total of 3,200 fixtures and lamps were replaced with LED fixtures and lamps. Existing 100-watt 2’x4’ recessed fixtures having obsolete T8 and T12 lamps were replaced by 44-watt Cree ZR Series LED troffers. The new fixtures have full dimming capacity to provide additional energy savings when dimming controls are added in the future (not included in this phase due to budget and time constraints.) Existing 26 or 32-watt CFLs were replaced with 13-watt LED fixtures from Lunera that fit into existing 4-pin CFL fixtures, providing cost-effective energy savings of 50 or 60 percent. In storage areas and under cabinet locations, Cree UR Lightbars replaced T8 and T12 utility fixtures. In offices and storage areas, new occupancy sensors further reduce energy use, and the project overall provides total on-peak reduction of approximately 94kW.
Retail display lighting in the student center bookstore.
In addition to the energy reductions, the LED lamps have a high color rendition index (CRI) of over 90, and provide a consistent and neutral color temperature of 4000K. Spot measurements in the bookstore show that the average illumination is about 10 foot-candles higher than before the retrofit, which is more appropriate for a retail space. The bookstore managers have praised the updated appearance, and hope that improved customer experiences may increase sales. Additional benefits include reduced labor maintenance costs from lamp replacements, and the elimination of mercury found in fluorescent lamps.
While much feedback from the building users has been positive, some people complained about the higher lighting levels that resulted from one-to-one light replacement. However some office occupants are using the “A/B” switching to reduce lighting by half, reducing the brightness and also energy use. The feedback about brightness may provide additional incentives to expand dimming controls throughout the building in the future.