283119 Examination of the Differences in Energy Efficiency Opportunities in Lighting Retrofits of Four Different Types of Campus Buildings
The University of Alabama at Birmingham (UAB) was determined to spend approximately 1 million dollars a week on energy costs. From June 2009 through November 2011, a series of walkthrough lighting surveys were conducted on the UAB campus in order to determine whether or not building lighting could be upgraded in order to save money and reduce environmental impacts including contribution to global warming. These lighting surveys involved the use of a ballast sensor, which flashed “green” when fluorescent ballasts were energy-conserving electronic, or “red” when they were less-efficient magnetic. Researchers proceeded through the rooms of each building recording data of sensor result, fixture size, and number and type of bulbs (chiefly T12 or T8). The buildings could be categorized into four different types based on usage as observed by researchers:
- Academic buildings (5): buildings in which classes are taught and professors have offices and laboratories.
- Community Service buildings (4): examples include health clinics and office buildings with little space devoted to laboratories.
- Medical Research buildings (6): most floors devoted to research laboratories and offices.
- Parking Decks (2): building's only use is parking of vehicles.
Raw data from the ballast sensors determined that 72% of academic buildings, 68% of community service buildings, 81% of research buildings, and 90% of parking decks were using magnetic ballasts. Various assumptions regarding wattage per fixture with respect to number and type of bulbs, as well as costs of equipment, were taken into account. Using these assumptions, it could be determined that while differences were small between wattage reduction potential when expressed as a percentage (47.5-54.5%), there were major differences those actual wattage reductions, as well as in payback periods (0.9-1.7 years) for the different building types. Despite a greater percentage of magnetic fixtures in parking decks than any other building type, the most beneficial type of building for these types of retrofits was determined to be academic buildings, as they had the highest potential wattage reduction (118.9 kW), as well as the lowest payback period (0.9 years). As a result of the actual retrofits that have been done on a sampling of all building types, UAB has saved approximately $5 million in the past year.