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LED brightness decay over time?

Posted by janesylvia (My Page) on
Thu, Feb 21, 13 at 3:43

A friend of mine told me that LED light's brightness would decay over time, Is it true? If it is true, I might consider installing 9 LED recess lights instead of 6 in living room.

Thank you very much.

This post was edited by janesylvia on Thu, Feb 21, 13 at 3:45

Follow-Up Postings:

RE: LED brightness decay over time?

Yes it will. However, the rated lifespan quoted for LEDs is the time taken to decay to 70% - more than 10 years.
Other lights also decay. For instance CFLs gradually lose output over a shorter period of time (in some cases < 1year).
Putting in extra lights is not the solution.

RE: LED brightness decay over time?

Thank you very much, David.

RE: LED brightness decay over time?

I agree putting in extra lights is not the solution. Most LEDs are rated from 25,000-100,000 hours at L70. L70 is a 30% decrease in light output. The human eye can start to tell the difference when the light has dimmed 30%. This is reason why L70 (lumen depreciation to 70%) is important.

John Cambruzzi
Certified Landscape Lighting Specialist

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