LEDs are notable for being extremely long-lasting products, but they can’t last forever. The average lifespan of an LED is often rated up to 50,000 hours. This is about 50 times longer than a typical incandescent, 20-25 times longer than a typical halogen and 8-10 times longer than a typical CFL. If used 12 hours a day, an LED rated at 50,000 hours will last more than 11 years. Used 8 hours a day, it will last 17 years!
Why do LEDs fail?
LEDs are long-life light sources which generally do not suddenly fail, but gradually lose their brightness and performance over time. In other words, LEDs fade and don’t actually blow. The rate at which an LED loses brightness depends on the operating conditions and on external factors such as temperature, relative humidity and changes in the thermal load. In some poorly designed LED lights, bad heat sinking can result in overheating, which in turn could cause the LED to completely burn out or increase the rate of decline in brightness. The LED driver that provides the power supply can also be unreliable and cause premature failure, it is often the driver that fails and the LED remains operational.
How can LED lifetime be predicted?
In contrast to conventional light sources, an LED still emits light at the end of its life, just not enough. This figure is based on a LLMF (lamp lumen maintenance factor) of 70%. This is also referred to as L70. According to long-established industry standards, the lifetime of an LED is calculated as the exact period when its output arrives at 70% of the initial output.
Why 70%?
As researched by the Alliance for Solid-State Illumination Systems and Technologies, this is the point when the reduction becomes visibly different to the human eye. An amount higher than this becomes much more difficult to noticeably see the difference in brightness.
More questions?
If you’re unsure whether LEDs are the best option for your next project, contact us. Scott Lamp Company has spent years developing an understanding for what works, what looks good, and what is needed to engineer unique lighting solutions for any application.