Exterior Lighting Upgrade at California State University Dominguez Hills
By engaging students in a lighting retrofit in three major campus buildings, energy managers and faculty at CSU Dominguez Hills used campus facilities as a living laboratory, enabling students to obtain hands-on experience in energy conservation projects. The project builds on past lighting upgrades that used student involvement to bring energy conservation into the school’s active-learning curriculum.
This lighting retrofit used custom fixture fabrication, advanced sensing and controls, and hands-on student involvement to create a cost-effective solution that enhances safety and saves energy.
The retrofit was completed in exterior circulation areas in three connected campus buildings all having exposed concrete waffle slabs: the Leo F. Cain Library, the Natural Science and Mathematics building, and LaCorte Hall. The project replaced obsolete 58-watt florescent fixtures that were recessed into the waffle slab structure in such a way that light output was constricted. Students in an Earth Sciences course assisted the project team by conducting an inventory of existing lights, and calculating the potential energy savings.
This night view of an exterior corridor shows ample and even illumination resulting from the retrofit.
The team came up with a creative solution — to install 44-watt LED troffer-style fixtures within custom mounting plates that would align flush with the bottom flanges of the waffle slab. Campus staff worked with a lighting manufacturer to have four prototypes fabricated and tested. The arrangement increased the light output dramatically, and also avoided any potential problems from birds nesting around the lighting. Because of the higher light output, the project team determined that only half as many new fixtures would be required. A total of 441 existing fixtures were replaced with 179 of the custom LED fixtures, with installation completed entirely by campus facilities staff.
Custom fabricated mounting plates align LED troffer fixtures flush with bottom of waffle slab to increase light output.
With the brighter illumination provided by the LED lights, it was possible to dim the lights well beyond their 44-watt rating, providing additional savings. Wireless controls from Enlighted were programed to dim lights from a maximum of 50 percent down to 10 percent, consuming only 25 to 9 watts. The controls dim or turn lights off when spaces are not occupied, and during demand-response events they limit the maximum lighting levels. Lights brighten as they are approached, giving people the sense that the system is working to provide safe lighting and also to save energy. Students assisted during installation by verifying that light levels were appropriate and comfortable.
The results have been received favorably by campus, as the higher lighting levels contribute to making spaces feel safe, and energy savings have been consistent in all retrofit areas. Project manager Kenneth Seeton notes that people have said that even spaces that previously seemed dim now appear brightly lit, and generally people feel safer with the new lighting. He also points out that LED lighting, which was prohibitively expensive only a few years ago, is now an obvious choice for all campus lighting upgrades, and the results of this project have led the campus staff to consider additional LED updates.