The Facts About LED and Light Degradation
As LED lighting awareness grows and adoption of the technology in grow facilities continues to increase, the knowledge base and standards of LED grow lights remain a mystery. This is due to the fact that there are currently no standards set for horticultural lighting. This is something that is being addressed and will most definitely play a part in helping customers choose the right product in the future. Hopefully, we can shed some light (pun intended) on the subject for you.
LED Design, Light Output, and Promises
When most people think of LED’s they think of super long lifespans, efficiency and a technology that has the potential to change the future of lighting as we know it today. Many LED grow light companies promise a 2, 3 even 5 and even 10-year warranty on parts such as fans or drivers. Depending on how the manufacturer built the light you may have other parts that need replacing which invariably will fail before your light does. But what about the intensity output of light and how it affects the plants. LED chips require well thought out design solutions to dissipate heat and good thermal conductivity. Overlooking these important facts can seriously affect the outcome of your grow and even worse lay to waste a large investment in the wrong grow light.
Current Testing Standards
When LED lights were first introduced they quickly became popular and as a result power companies offered federal grant monies to end users who reduced their carbon footprint and energy consumption by installing LEDs. Choosing an LED light can be confusing to the average customer and as the LED industry expanded, people quickly learned that not all products are made the same. This was due to the vast amount of “lower” end quality bulbs making it to the market while only a few products maintained high-quality standards. In order to keep federal tax payer money from being rewarded toward lower end LED products that don’t provide the true benefits of the technology, the department of energy set standards that if passed guarantee the true potential of LED technology. Those standards are called Lm79 and LM80.
LM79 & LM80 Data
LM or Lumen maintenance 79 is an approved method for taking electrical and photometric measurements of Solid-State Lighting products. It covers total flux (light output), electrical power, efficacy, chromaticity, and intensity distribution and includes parameters such as:
- Total lumens ( usable light )
- Lumens per watt ( efficiency )
- CCT color temp
- THD (total harmonic distortion)
- PF (power factor)
- Spread of light
LM-80 refers to a method for measuring the lumen depreciation and junction temperatures of solid-state lighting sources, such as LED packages, modules, and arrays. This is to establish a curve of the diminishing wear on the LED or an LED’s life time. LED chip manufacturers are required to delay product release to the market for a year. This is done to truly test the LED and make sure it does what the factories say it will. These tests must be done by third party labs that are certified by the Department of Energy.
How Is This Test Done?
A batch of LEDs (usually 50+) is tested at the junction point of the LED at three different temperatures, usually 55, 85 and 105 degrees Celsius. The lumen output is recorded every hour for 6,000 to 8,000 hours (almost a year) and a base line curve is made. With this data, a detailed performance chart can be produced showing actual LED lumens and usable light over time. You can now determine the degradation curve and know the lumens and lifespan of a specific lighting fixture. If this test data is available, one way to verify it is to compare the LM-80 data for an LED grow light fixture against the LED chip manufacturers data by matching the temperature of the LED inside the fixture to the manufacturer’s spec. This will tell you how much degradation your LED grow light has taken over time.
We are proud to say that Spectrum King LED grow lights are certified and tested by multiple third party laboratories and our light diminishing factor is about 1.4% per year of normal use. Grow operations using 12-12 time cycles can expect 6.5 years before losing even 10% of light ( 90% original light remaining ) and over 15 years to reach 70%. True quality.
SPECTRUM KING LED DATA SHEETS: