We've seen the light, and it lasts twice as long.
TM-21 calculations are in. RAB's conservative 50,000 hour estimates were a little too conservative. The L70 lifespan rating is now twice as long for all RAB LED products. Yes, you heard right. The 100,000 hour rating covers both new and previously released RAB LED fixtures. With an average daily use of 10 hours, all RAB LEDs are rated to last for 27 years.
L70 lifespan. What does it mean?
L70 is an industry standard to express the useful lifespan of an LED. It indicates the
number of hours before light output drops to 70% of initial output.
70% after 100,000 hours.
Studies have found that people can perceive a reduction in light output at 70% of
initial output levels. Assuming 10 hours of use per day, it will take 27 years for RAB LEDs to reach 70% of their initial output.
How does design affect LED lifespan?
LED life decreases if the LED is allowed to overheat. Only fixture designs with superb
thermal management allow long L70 lifespans. RAB uses state-of-the-art,
computational fluid dynamics simulations to design the ultimate in LED cooling and
ensure long L70 lifespan.
What is LM-80?
LM-80 measures light output reduction of LEDs over time. It was created by the IES
(Illuminating Engineering Society) to determine L70. LM-80 is run at three different
temperatures, so it applies to specific environments.
The TM-21 standard.
TM-21 is a new standard introduced in 2012, which enables manufacturers to use
LM-80 data to calculate lifetime projections for a specific LED fixture and environment.
L70 "claimed" vs L70 "calculated"
TM-21 allows manufacturers to calculate L70 based on LM-80 data for a specific
fixture and publish that number. In addition, TM-21 requires manufacturers to
make a "claimed" lifespan limited to 6 times the amount of LM-80 data collected. As more LM-80 data becomes available, the "claimed" lifespan increases towards