LED in Low Temperature Reach in Refigerated Display Case

This lab evaluation project evaluates the energy and demand savings of light-emitting diode (LED) lighting systems and traffic-sensitive lighting controllers in low-temperature reach-in refrigerated display cases. Additionally, LEDs may have longer life and lower maintenance costs. The LED systems for refrigerated display case applications are commercially available by several manufacturers. This data will be used to develop workpapers.

This project evaluates the energy and demand savings of light-emitting diode (LED) lighting systems and traffic sensitive lighting controllers in low-temperature reach-in refrigerated display cases. The lighting systems were installed in a 35,000 square foot supermarket in West Covina, California. The case lighting in this store was on a timer that turned the lighting off between the hours of 11:00 PM and 6:30 AM. Data was collected for several weeks fore each of three project phases. The first phase monitored the existing T8 fluorescent system with electronic ballasts. The second phase monitored the new LED system operating at full power. The third phase monitored the LED system with a trafficsensitive controller installed. Results showed that a 67% reduction in lighting power and energy was achieved by switching from T8 to LED systems. An additional 5% energy savings was achieved with the addition of the traffic sensitive controllers. The controller did not provide significant savings during the middle of the day. Rather, savings were most prevalent during the shoulder periods of 6:30 to 11:00 AM and 8:00 PM to 11:00 PM (Figure 1).