Select Page
LED Lifetime - L70 Rating and Lumen Depreciation

Navigating through the multitude of numbers, terms, and ratings on LED lighting fixtures and packaging can be overwhelming for many. From watts and lumens to amps and Kelvin temperatures, the abundance of data can be disorienting. Among these various specifications, one crucial rating to understand is the L70 rating, which pertains to the LED lifetime. In this discussion, we will simplify and clarify the significance of LED L70 in the realm of LED lighting.

Understanding the Gradual Degradation of Light Fixtures

The L70 rating for LED lighting marks the point at which the light output diminishes to 70 percent of its initial brightness, serving as a crucial indicator of an LED’s lifespan. After reaching L70, the light may need replacement or maintenance. According to the U.S. Department of Energy, useful life is often defined by the hours until the LED emits 70 percent of its initial light output, encapsulating the essence of the LED L70. This rating, measured in hours, aids consumers and professionals in assessing the long-term performance of LED fixtures for informed investment decisions.

Traditional light sources rely on heating filaments, reaching the end of life when emitting 70 percent of initial lumens. Despite not using filaments, LED principles still apply, and they exhibit slower degradation due to electroluminescence. LEDs often feature L70 lifetimes of 50,000 hours or more. For example, an LED bollard light with 2,100 lumens and an L70 rating of 50,000 hours gradually decreases in brightness, lasting longer than traditional lights. Although the LED may function beyond L70, it is commonly seen as the threshold for replacement consideration.

Click here or Click the Image on the Right to Download the L70 Lifetime Estimation Table in Years.

L70 Lifetime Estimation Table in Years

Evolution of Testing: Assessing Lifetimes of Traditional and LED Technologies

Before LEDs, traditional light bulbs, including fluorescents, high-intensity discharge (HID) lamps, and incandescents, were tested in groups of 100, expecting over 50 percent failure before 10,000 hours. This made predicting their lifespan consistent across manufacturers.

However, the introduction of LEDs altered this approach. Predicting the LED luminaire lifespan or the LED L70 is challenging since they do not have a clear failure point; instead, they gradually emit less light unless physically damaged. LEDs without filament burning last longer, are less prone to flickering, and generally prove more reliable than their predecessors, even though occasional failures may still occur.

The remarkable longevity of LEDs has led to a reevaluation of classifications for the average rated life of luminaires. Instead of testing over extended periods like 50,000, 60,000, or 100,000 hours, these luminaires undergo a 6,000-hour test at three distinct temperatures, as mandated by ENERGY STAR®. This approach, known as TM-21, involves mathematical calculations that replicate the entire lifespan. Typically, the data derived from TM-21 testing is more conservative compared to actual reported lifetimes.

Check Out an Example of the Lumen Maintenance Factor on the Right

Lumen Maintenance Factor

Challenges in Projecting Future LED Lifetimes and Strategies for Extending LED Lifespan

The constant advancements in LED technology pose a challenge in accurately forecasting the future rates of lumen depreciation in the marketplace. Each day, manufacturers and engineers are developing new LEDs with enhanced longevity, superior performance, and increased reliability compared to older designs. The testing processes may struggle to keep pace with these ongoing innovations.

Proactive strategies for extending the LED L70

  1. Implement proper heat dissipation mechanisms, such as quality heat sinks
  2. Choose LED fixtures with high-quality components, including LEDs, drivers, and power supplies
  3. Operate LEDs within their specified temperature and voltage ranges
  4. Use compatible dimming controls to reduce power consumption and heat generation
  5. Keep fixtures clean from dust and debris through regular maintenance
  6. Install surge protectors to shield LED fixtures from voltage spikes and power surges

Check Out Access Fixtures EXTREME-LIFE Fixture with an L70 Rating of 200,000 Hours for Sports Lighting on the right.

LED Lifetime – L70 Rating Life and Lumen Depreciation

Speak to an Access Fixtures Lighting Specialist or Start Shopping Now

Access Fixtures prides itself on using high-quality components to provide reliable LED lighting solutions. Whether you need LED sports lighting, LED high bays, LED bollard lights, or another kind of lighting altogether, Access Fixtures has the resources to get you the solution you’re looking for. Do you need to discuss a unique lighting project or an LED Lifetime? Talk with an Access Fixtures lighting specialist by phone at 800-468-9925 or by email at [email protected] today.