SIMPLE ORDERING

HOME PAGE

Multi Function TAIL LIGHTS

FEDERAL  #108 SUMMARY

3rd BRAKE CHMSLs Etc

TESTIMONIALS

ABOUT  US

CLEARANCE, SIDE  MARKER  and  I.D.s

COMPARING COMPETITORS

LEGAL CLARIFICATIONS

TLC #311-1 Defining LED Useful Life "of LEDs"  (U.S. Department of Energy)

U.S. Department of Energy - Energy Efficiency and Renewable Energy Solid-State Lighting                                                         311-1

Defining LED Useful Life
To provide an appropriate measure of useful life of an LED, a level of acceptable lumen depreciation must be chosen. At what point is the light level no longer meeting the needs of the application? The answer may differ depending on the application of the product. For a common application such as general lighting in an office environment, research has shown that the majority of occupants in a space will accept light level reductions of up to 30% with little notice, particularly if the reduction is gradual.

Therefore a level of 70% of initial light level could be considered an appropriate threshold of useful life for general lighting. Based on this research, the Alliance for Solid State Illumination Systems and Technologies (ASSIST), a group led by the Lighting Research Center (LRC), recommends  defining useful life as the point at which light output has declined to 70% of initial lumens (abbreviated as L70) for general lighting and 50% (L50) for LEDs used for decorative purposes. For some applications, a level higher than 70% may be required.        

    Back to Index