Field analysis of occupancy sensor operation: Parameters affecting lighting energy savings

A field study of the actual lighting savings achievable from occupancy sensor use was performed by Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE) on the Hanford Site near Richland, Washington. The study involved two seperate field assessments. The objective of the first test was to assess and effectively quantify the potential ``wasted-light`` hours associated with different occupant and space types associated with occupancy sensor control installations. These quantities are the primary factor in determining actual lighting energy savings associated with occupancy lighting control. The second test was conducted to explore the potential additional savings from more sensitive sensor equipment or better equipment adjustment that might reduce the need for delay timers. This information provides quantitative insight into the energy savings lost because of the limitations of current sensing equipment.