Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LED's
Abstract
Synopsis: Light loss factors are used to help lighting systems meet quantitative design criteria throughout the life of the installation, but they also influence energy use. As the light sources currently being specified continue to evolve, it is necessary to reevaluate the methods used in calculating light loss factors, as well as carefully consider the consequences of different product performance attributes. Because of the unique operating characteristics of LEDs and lack of a comprehensive lifetime rating—as well as the problematic relationship between lifetime and lumen maintenance—determining an appropriate lamp lumen depreciation (LLD) factor for LED products is difficult. As a result, a unique solution has been advocated: when quantity of light is an important design consideration, the IES recommends using an LLD of not greater than 0.70. This method deviates from the typical practice for conventional sources of using the ratio of mean to initial lumen output, and can misrepresent actual performance, increase energy use, and inhibit comparisons between products. This paper discusses the complications related to LLD and LEDs, compares the performance of conventional and LED products, and examines alternatives to a maximum LLD of 0.70 for LEDs.
- Authors:
- Publication Date:
- Research Org.:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1095452
- Report Number(s):
- PNNL-22727
BT0301000
- DOE Contract Number:
- AC05-76RL01830
- Resource Type:
- Technical Report
- Country of Publication:
- United States
- Language:
- English
- Subject:
- Energy Efficiency; Solid-State Lighting; LED; Light loss factors; Lamp lumen depreciation factor; Lighting design; Product specification
Citation Formats
Royer, Michael P. Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LED's. United States: N. p., 2013.
Web. doi:10.2172/1095452.
Royer, Michael P. Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LED's. United States. https://doi.org/10.2172/1095452
Royer, Michael P. 2013.
"Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LED's". United States. https://doi.org/10.2172/1095452. https://www.osti.gov/servlets/purl/1095452.
@article{osti_1095452,
title = {Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LED's},
author = {Royer, Michael P.},
abstractNote = {Synopsis: Light loss factors are used to help lighting systems meet quantitative design criteria throughout the life of the installation, but they also influence energy use. As the light sources currently being specified continue to evolve, it is necessary to reevaluate the methods used in calculating light loss factors, as well as carefully consider the consequences of different product performance attributes. Because of the unique operating characteristics of LEDs and lack of a comprehensive lifetime rating—as well as the problematic relationship between lifetime and lumen maintenance—determining an appropriate lamp lumen depreciation (LLD) factor for LED products is difficult. As a result, a unique solution has been advocated: when quantity of light is an important design consideration, the IES recommends using an LLD of not greater than 0.70. This method deviates from the typical practice for conventional sources of using the ratio of mean to initial lumen output, and can misrepresent actual performance, increase energy use, and inhibit comparisons between products. This paper discusses the complications related to LLD and LEDs, compares the performance of conventional and LED products, and examines alternatives to a maximum LLD of 0.70 for LEDs.},
doi = {10.2172/1095452},
url = {https://www.osti.gov/biblio/1095452},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Sep 17 00:00:00 EDT 2013},
month = {Tue Sep 17 00:00:00 EDT 2013}
}