November 19, 2015
Not LM certified? Of course not.
There is no doubt the last several years has brought about a number of organizations developing a plethora of standards and methods around LEDs. UL? Check. IES? Check. ANSI? Check. DOE? Check. DLC? Check. CEC? Check. All to make it less confusing to specify quality LED products. Thanks. The truth is, all of these organizations have worked hard to ensure the successful adoption of a radically new light source. And although confusing, it is working. Especially for those who take the time to understand which acronyms and random numbered standard applies to their application.
Let’s start with the IES. The Illuminating Engineering Society has been at the forefront of improving the lighted environment for over 100 years. They publish recommended best practices, methods and test procedures. They do not enforce standards or compliance.
Regarding light sources, they do not judge. They just want you to have the proper information in a consistent format. So you can judge. “Is it LM-(63, 79, 80….) certified?” No such thing. “Passed?” Nope. “Approved?” Not possible. “Is data available in LM-** format so I can use my lighting knowledge to evaluate it in a format that is consistent across the lighting industry?” Absolutely!
LM-79 – The recommended method for photometric testing of an LED product. Used by lighting measurement laboratories. If you obtain a photometric report, or “IES” file, for an LED fixture from a reputable lab, it has been tested according to this process.
LM-80 – The method for measuring LED light output (flux) and color change over time. Used by lighting measurement laboratories. Mainly for the diode package manufacturers. Produces a very large report that includes many tables of raw data (see TM-21).
TM-21 – The LED lifetime calculation method. Used by fixture manufacturers. Remember that statistics class? Good, you don’t have to. All that LM-80 data along with in situ temperature and electrical data (from the actual product used in its intended application) are plugged into the TM-21 formulas. The output is a standardized prediction of lifetime to a specific degraded flux level (e.g. L70, or 30% less than the initial light output).
TM-30 – A (new) method for evaluating light source color rendition. This is a very different from the CRI method most lighting geeks are familiar with. It includes values for color fidelity, color gamut and a vector graphic that is used to visualize shifts in hue and chroma. Its adoption as a specified metric will be interesting to follow. Light color will always be difficult to define as an exact value. How much detail is required may vary by application. For now, I’ll stick with my closet full of Garanimals.
Underwriters Laboratory (UL) is the familiar safety assurance company which operates as a standards writer, a compliance provider and a testing facility. They have adapted their existing light fixture standards (e.g. UL1598, UL2108) to include LEDs. They have also developed a new standard (UL8750) for LED components. It is important to note that the focus of UL standards is based on safety (shock and fire hazard) and not performance. Make sure the LED products you use are listed to UL standards!
“I’m from the government and I’m here to help.” The Department of Energy (DOE) is the US government agency formed “to ensure America’s security and prosperity” through thoughtful energy solutions.
Two programs related to LEDs are:
Energy Star – Geared toward consumer and residential products. Fixtures certified as “Energy Star” have passed minimum performance and longevity metrics. These varying metrics are based on the intended use category, such as “under-cabinet” and “Outdoor wall-mounted porch lights”. Unfortunately, there is not yet a category for strobe lights or black lights.
LED Lighting Facts – Geared toward products sold at retail, this program verifies the performance of any LED lighting product. It also provides a standard means of displaying efficacy and color information to make comparison easier. It does not certify or approve, it just confirms and states the facts and just the facts, ma’am.
The DesignLights Consortium (DLC) maintains their Qualified Products List of LED luminaires that meet certain efficacy and lifetime requirements. This as a way to help utilities, state and regional energy efficiency programs make choices at the fixture level. This is geared toward commercial applications, retrofit and rebate opportunities.
The California Energy Commission (CEC) is that states energy policy and planning agency. However, given their progressive requirements (Title 20 & 24) that typically exceed those of any other certification body, they are looked to as the future of requirements around the country. They certify luminaires, ballasts, controls and systems as meeting minimum efficacy, quality and warranty requirements. Not all products in an application need to be certified. The requirements vary by space type/use and if dimmers and/or vacancy sensors are in use.
Navigating all of the standards, recommendations and certifications can seem daunting. Start with the building codes that apply to your project. Then move on to the desired goals of quality, efficiency and product support. Don’t forget about the budget! Work with suppliers that are reputable and ask for supporting documentation (preferably from independent testing labs) if you have any doubt.