Bi-level Hybrid Fluorescent LED Lighting for Stairwell/Covered Parking Lab

This project is aimed at evaluating Bi-level Hybrid Fluorescent LED Lighting for Stairwells and Covered Parking as an energy efficiency measure. The project will field test fixtures to determine the potential for energy savings.

A paper study using the earlier Downey Covered Lot (SCE ET 07.08.1)project’s old and new lighting systems as anchors to establish, then compare and contrast (via AGI-32 computer modeling) an expanded array of lighting systems. Additional light-emitting diode (LED) information was gathered from the Downey Covered Lot Re-measure Project (same site). LED light levels were measured at Time zero and Time = plus 15K-hours, all of which was a 24/7/365 operation. Results and data gained from this paper study provide insight for customers planning, designing, funding, and installing covered lot lighting as to those technologies and products that will provide maximum energy savings and potential cost savings. The AGI-32 models demonstrated that design of the luminaire is as critical as the light source selected for maximum performance. Optics of the luminaire, as well as other luminaire characteristics, can greatly influence overall performance including energy savings. Modeling the various light sources indicated that with proper design and luminaire selection all current sources used in the modeling can provide the required illumination at lighting power densities (LPD’s) well within current code requirements. (California Title-24-08 as an example.) As a rule luminaires with high intensity discharge (HID) and/or LED sources offer a wider array of optics with better optical control than typical fluorescent and/or induction luminaires. Where design criteria requires superior luminaire optics suited to parking structure needs, HID, or light-emitting diode (LED) are preferred options. Optics for fluorescent and induction sources are often less effective at properly and effectively directing the light distribution in critical applications. While High Pressure Sodium (HPS) performed well, meeting IESNA lighting requirements with excellent energy efficiency, its use as a source for parking lot illumination is not recommended. Color rendition as indicated by a color rendering index (CRI) of 100 = perfect of 21 is very poor. The need for visual acuity, including color perception is important within parking structures. It is our recommendation that only light sources with a CRI of 65 or better be used for parking lot lighting.