Homeowners across the country are switching to LED bulbs, and for good reason. LEDs have a number of advantages over conventional incandescent bulbs:
- Higher energy efficiency
- Improved light quality
- Average rated life of up to 25,000 hours or more
That all sounds great, but what exactly does "average rated life" mean? How's that different than "actual" life? After all, you want to know how long a bulb really lasts, not how long it's rated to last. We'll explain average rated life, how bulb manufacturers test for it and what it means to you.
The facts of LED life
Average rated life is the life expectancy in hours based on laboratory tests of a sample set of bulbs. The "average" rated life is the point at which half the sample bulbs failed. For example, if 100 bulbs are tested and 50 of them fail at 25,000 hours, then their average rated life would be 25,000 hours.
The useful life of LEDs is defined differently than it is for other lighting technologies. Incandescent bulbs fail when the filament burns out. LEDs typically don't burn out. They experience "lumen depreciation," where their brightness slowly fades over time.
Research has shown that people generally do not notice light reductions of up to 30%. The average rated life of LEDs is therefore determined by projecting when their light output will decrease by 30%. Some lights have a built-in depreciation compensation feature, which helps slow down their degradation over time.
Multiple factors can impact a bulb's actual lifespan — operating voltage, frequent switching on and off, exposure to moisture or extreme temperatures and more. LEDs, however, are very durable and typically last much longer than conventional lights.
