Most buyers of digital signage will be familiar with the claim that an LED display has a life span of 100,000 hours. If you have done the maths you will have worked out that this means a sign that runs 24 hours a day / 7 days a week will have a lifespan of 4,166 days or 11.4 years.
But what does this claim about signage really mean?
Importantly, this is not an estimate of when an LED sign will stop working altogether rather, it is the time it takes for an LED chip to reduce in brightness by 50% when operated at a temperature of 250C or less. In other words, this is the theoretical life span under ideal operating conditions.
While there is no doubt that signage does have long life spans, for a chip to last 100,000 hours everything from the quality of the componentry, the drive current, assembly, ambient temperature and junction temperature needs to be faultless.
In reality the greatest impact on the life span of an LED display is its operating environment. For example, it is highly unlikely that an outdoor sign without air-conditioning will be able to consistently run at 250C. This means that a lifetime of 100,000 hours at ideal brightness will be difficult to achieve.
Brightness is lost over time due to the degradation of individual diodes. Depending on conditions, design and chip quality an LED sign can lose 10% of its brightness after only 13,000 hours if temperatures are not properly controlled.
Under the same conditions a premium LED can take 4,000-5,000 hours longer to lose the same amount of brightness. But the combination of a premium LED and intelligent design can result in 30,000 hours operation before brightness is reduced by 10%.
It should be noted that an LED sign is generally considered not to be an effective outdoor display once its brightness has reduced to 60%.
As can be seen from the charts below only a premium LED chip operating under ideal conditions will run for 100,000 hours as an effective LED display. This compares to 65,000 hours at 350C.
Regular servicing, appropriate cooling and a fit for purpose LED chip choice will all help to prolong the life of an LED display.