SEARCH · Search NASA
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
A report using LED Lighting Facts data to examine the current state of the market for linear luminaires, troffer luminaires, and troffer retrofit kits.
This case study describes Target’s corporate-wide LED troffer lighting project at 107 sites, which saved an estimated 26 million kWh in annual energy use.
This case study describes CHRISTUS Health’s efforts to reduce lighting energy use 61% at St. Michael Hospital by replacing fluorescent lamps with LEDs. These measures were part of a larger lighting retrofit project across 5.5 million square feet that achieved a 58% reduction in energy use.
This report describes an exploration of troffer lighting as used in office and classroom spaces, which was conducted by the CALiPER program. Twenty-four pairs of 2×2 and 2×4 troffers were procured anonymously, documented, tested for photometric and electrical performance, and installed in a mockup office space in Portland, Oregon. Three of the pairs were T8 fluorescent benchmark products, 12 were dedicated LED troffers, five were fluorescent troffers modified for LED lamps (sometimes referred to as "tubes"), and another four troffers were modified with LED retrofit kits. The modifications were performed by a commercial electrical contractor, following the instructions provided by the retrofit lamp or kit manufacturer. Once installed in the mockup facility, the converted luminaires were examined by a NRTL (Nationally Recognized Testing Laboratory) safety expert, who provided feedback on safety issues. In September 2012, a group of lighting designers, engineers, and facility managers were brought in to observe the LED luminaires in comparison to fluorescent benchmarks. This report documents performance in measures that go beyond illuminance values or luminaire efficacy. Dedicated LED troffers are ready to compete with fluorescent troffers in terms of efficacy (lumens per watt), and in many lighting quality issues such as glare, light distribution, visual appearance, and color quality. That is not to say that each one is stellar, but each one tested in this CALiPER study bested the fluorescent benchmarks in terms of efficacy, and almost all were rated highly in several categories -- only one luminaire of twelve performed consistently poorly.
Although lensed troffers are numerous, there are many other types of optical systems as well. This report looked at the performance of three linear (T8) LED lamps chosen primarily based on their luminous intensity distributions (narrow, medium, and wide beam angles) as well as a benchmark fluorescent lamp in five different troffer types. Also included are the results of a subjective evaluation. Results show that linear (T8) LED lamps can improve luminaire efficiency in K12-lensed and parabolic-louvered troffers, effect little change in volumetric and high-performance diffuse-lensed type luminaires, but reduce efficiency in recessed indirect troffers. These changes can be accompanied by visual appearance and visual comfort consequences, especially when LED lamps with clear lenses and narrow distributions are installed. Linear (T8) LED lamps with diffuse apertures exhibited wider beam angles, performed more similarly to fluorescent lamps, and received better ratings from observers. Guidance is provided on which luminaires are the best candidates for retrofitting with linear (T8) LED lamps.
Although lensed troffers are numerous, there are many other types of optical systems as well. This report looks at the performance of three linear (T8) LED lamps—chosen primarily based on their luminous intensity distributions (narrow, medium, and wide beam angles)—as well as a benchmark fluorescent lamp in five different troffer types. Also included are the results of a subjective evaluation. Results show that linear (T8) LED lamps can improve luminaire efficiency in K12-lensed and parabolic-louvered troffers, effect little change in volumetric and high-performance diffuse-lensed type luminaires, but reduce efficiency in recessed indirect troffers. These changes can be accompanied by visual appearance and visual comfort consequences, especially when LED lamps with clear lenses and narrow distributions are installed. Linear (T8) LED lamps with diffuse apertures exhibited wider beam angles, performed more similarly to fluorescent lamps, and received better ratings from observers. Guidance is provided on which luminaires are the best candidates for retrofitting with linear (T8) LED lamps.
This CALiPER study examines the problems and benefits likely to be encountered with LED products intended to replace linear fluorescent lamps. LED dedicated troffers, replacement tubes, and non-tube retrofit kits were evaluated against fluorescent benchmark troffers in a simulated office space for photometric distribution, uniformity of light on the task surface, suitability of light output, flicker, dimming performance, color quality, power quality, safety and certification issues, ease of installation, energy efficiency, and life-cycle cost.
This report focuses on the performance of the same 31 linear LED lamps operated in a typical troffer with a K12 prismatic lens. In general, luminaire efficacy is strongly dictated by lamp efficacy, but the optical system of the luminaire substantially reduces the differences between the luminous intensity distributions of the lamps. While the distributions in the luminaire are similar, the differences remain large enough that workplane illuminance uniformity may be reduced if linear LED lamps with a narrow distribution are used. At the same time, linear LED lamps with a narrower distribution result in slightly higher luminaire efficiency.
Video about CALiPER Report Series 21 on LED Linear Lamps and Troffer Lighting, featuring interviews with Tracy Beeson and Naomi Miller of Pacific Northwest National Laboratory.
Solid-state lighting technology fact sheet providing guidance on the various factors to consider when deciding on an LED upgrade for a fluorescent troffer system.
This is a 2015 version of a lighting specification that provides a description of requirements that will result in energy savings for troffers, reliable performance, and energy cost savings.
This lighting specification provides a description of requirements that will result in energy savings for troffers, reliable performance, and energy cost savings. It also includes options for additional requirements such as emergency lighting, dimming, and controls.
This case study describes CKE Restaurant Holdings, Inc.’s use of excess capital to invest in troffer lighting retrofit projects that led to savings of 1.9 million kWh annually.
This case study describes a partnership between Sustainable Technologies and Clean Harbors Environmental to replace troffer lighting in Clean Harbors’ warehouse and offices, resulting in reduced annual energy use of 74%.
This case study describes U.S. Toy’s efforts to retrofit lighting troffers at its corporate headquarters in Grandview, MO. This work was part of an upgrade that significantly cut energy use.
This case study describes Cleveland Clinic’s efforts to retrofit 10,500 troffers with LEDs at its Lerner Research Center in Cleveland, OH, which saved the company 2.6 million kWh per year.
This fact sheet summarizes key components of the Better Buildings High-Efficiency Troffer Lighting Specification and how to apply it to save energy and money by upgrading to high- efficiency LED technology.
This document provides guidance for retrofitting existing fluorescent troffer fixtures with LEDs, as well as information about lighting controls. It outlines the pros and cons of three different retrofit options: Tubular LEDs, Retrofit Kits, and Luminaires.