LED Lifetime and Reliablity

Manufacturers describe the life of white LEDs by the number of operating hours until it emits 70 percent of its original light output.  Good-quality LEDs generally last 50,000 hours or longer.  This compares to a typical incandescent bulb which lasts about 1,000 hours; a CFL, 8,000 hours; and linear fluorescent lamps, 10,000 hours or more.   But how LEDs are designed into a light engine, and the light engine into a light fixture, dramatically impacts the useful life of the product to an end-user.

A primary cause of reduced LED life is heat generated at the LED junction. Unlike other light sources, LEDs don’t emit infrared radiation (e.g. heat), so it must be removed by conduction or convection.  Thermal management is arguably the most important aspect of a successful LED fixture design.  

To see the related article by the US Department of Energy, click here.