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How do you determine the Quality in LED Lighting?

by Steffan Semurath

In the Caribbean, LED(light emitting diode) lighting has only just begun to take off in both the commercial and residential markets. When the United States Congress passed the Energy Independence and Security Act in 2007, many lighting manufacturers were forced to develop alternatives to their less efficient bread-and-butter incandescent products. Traditional lighting, which include incandescent, fluorescent, HID, halogen, neon, and other filament and gas-based technologies, were produced mainly by a few major manufacturers.  The science behind the technology in addition to the manufacturing intensiveness, made it difficult for just anyone to break into the market.

However, LED lighting has changed all of that. LED lights are simple electronics, and there is really no complex science behind it. Light is produced when an electrical current passes through semiconductor material which illuminates a light source we call LEDs. The heat is absorbed into a heat sink (LEDs do produce heat). Now we’re in 2015 and there are now thousands of companies in every corner of the globe making and selling LED lighting. So how do you know if you’re getting a quality product?

Unfortunately the answer is not so simple, and because most LED lights cost many times what you’d pay for a traditional equivalent, it does matter. People frequently ask, should I look at the chip and driver being used? Should I look at through the LM-79 and LM-80 data? Should I just buy a big name brand? Having spent 3 years working with LED lighting products for a several major manufacturers, here is my advice.

Pay attention to Labelling

Labels like UL or ETL, Lighting Facts, Design Lights Consortium or Energy Star are things you ought to keep an eye out for. If the manufacturer has gone to the trouble of getting the safety certification for the US, then you know it is designed for this market’s mechanical and electrical requirements for safety, which in most cases surpasses that of the enforced standards of the Caribbean. While the safety mark does not guarantee reliability of a product, if they’ve also gone to the lengths of getting their products recognized by Energy Star or DLC, their products probably aren’t completely horrible.

Both DLC and Energy Star certify products as meeting or exceeding set standards of efficiency, performance and light quality, and products that carry these marks will qualify for any rebates offered from utility companies in some countries. (Note: a product will either have the DLC or the Energy Star mark, but not both. DLC covers lighting categories that Energy Star does not). Lighting Facts is an agency that verifies the specs listed on a product that has been tested to industry standards, and is a required step in getting DLC and Energy Star certification. These agencies require an extensive amount of data on the chip, the LED module (light source), LED driver, and the luminaire if it’s a fixture. They require a number of samples go through specific testing (LM-79 and in-situ temp testing among others) that look at how efficient the product is, what temperature the light source and power supply reaches when operating over time, if it is generating the amount of light and quality of light the manufacturer says, and where that light is going. In short, it verifies that the product actually does what the manufacturer’s specifications says it does.

Putting the products through this process is costly and time consuming for manufacturers, and it must be done each time an iteration is made to a product, so if they are doing it, chances are their products live up to their specs.

Warranty and Life Claims

Most manufacturers offer some kind of warranty on their products. The duration and coverage will depend on the product and maker, but generally LED luminaires carry a 5 to 7 year limited warranty, with few like Cree offering 10 year warranty. In terms of lamps, they typically carry a 3 to 5 year limited warranty. Warranties are different from life claims. You will often see the specs say something like 50,000 hour or 100,000 hour life, then the warranty will be something much less than that in years. Let’s look at these individually.

A warranty is a promise by the manufacturer to, at their discretion, compensate a buyer in the event that the product fails to operate within a certain time frame of purchase. The compensation can be with either a new or repaired product, or a refund. Typically this is limited to an all-out failure or some other structural or mechanical defect. So if your lamp starts to turn green or grows really dim, the warranty probably won’t cover it. And if it’s a commercial luminaire, the warranty also won’t cover labor costs to rip out the bad and put in the good.

Unlike all traditional light sources that suffer catastrophic failures when they reach the end of their life (e.g. the filament breaks), LEDs will continue to emit light almost to infinity so long as there is a current going to them. But that light will growing increasingly dimmer over time. When a manufacturer says that their product has a 50,000 hour life, that typically means that when the product reaches 50,000 hours of use, the amount of light loss will be such that the product will no longer be considered useful.

There are a couple of caveats to keep in mind when examining a life claim. One is the LED driver. While the LED may operate to infinity and beyond, the power supply that drives it certainly will not. The driver is the weakness in all LED lighting (and this is where the warranty comes into play). Most power supplies will have a max life span of 5 to 7 years when operated in ideal conditions, so any life claims that are in the 100’s of thousands of hours aren’t being up front that the power supply will likely need replacing (if it even can be replaced) during that time.

The second caveat is understanding how LED life is calculated and reported. Chip makers will test their LEDs at various temperatures over the course of 10,000 hours and measure the light loss (also known as lumen depreciation). Because 10,000 hours is only about 9 months’ worth of testing, multipliers are added to this number to come up with an overall life claim on the chip. DLC and Energy Star require a method known as TM-21, which restricts the multiplier to 6x of the testing. So if you see life claims of 200,000 hours, chances are this is based on a calculated number by the chip maker and not TM-21 standards.

In short, if the numbers seem too good to be true, they probably are. If a manufacturer provides a warranty longer than they’ve been in business, I’d think twice. There are a lot of wild claims being made, but the reality is it’s just too soon to know how many LED products will perform over the long haul.

 Beware of Misleading Advertising

Having seen many new players enter into the LED market whether at a manufacturer level or distribution level, you need to beware of marketing material that may be misleading. If a manufacturer or a distributor needs to lie to you about the performance of their product or the comparison of their product to various traditional lighting sources, then you need to reconsider purchasing their items. See the example below

 In the above picture is from an actual data sheet being distributed as marketing material. To point out a few of the flaws in this piece, firstly, the average fluorescent tube’s lifespan is 30,000 hours, we some newer ones going much longer. In terms of the warranty and the voltage surges, this all depends on the ballast being used. For anyone who knows a little about fluorescent lighting, knows that the majority of cooler to daylight color temperatures are used for these in lighting, especially in the Caribbean. This would lead us to our next point.

 Educate yourself

While it may seem silly to research buying a light, consider that today’s LED lights are electronic devices like your phone. Further, the language for lighting has changed. Light emitted from and an LED source is described in lumens per watts(LPW’s), so understanding the amount of light an equivalent LED bulb will deliver over your familiar incandescent is important. Because the properties of LEDs are different from incandescent, manufacturers will play up features such as “CCT dimming” (which just means the light color turns a warm red/orange color when dimmed like an incandescent bulb). Specifications such as correlated color temperature (CCT) and color rendering index (CRI) will also be featured on packaging. Understanding what is most comparable to your existing light source will help you select the LED product that best emulates what you’re accustomed to.

If you’re considering buying a relatively cheap LED bulb, spending a significant amount of time researching and comparing may not be worth it, however if you’re replacing all the lights in your home, or spec’ing lighting for a large installation, or thinking about entering into a relationship with an LED component or fixture supplier, these things will be of the utmost importance. A quick visit to the manufacturer’s website will tell you if their focus is on the US or European or Asian markets. If there isn’t a website or clearly stated information, maybe you need to think twice about that product. Check to see if their product specs are clearly and completely listed, including photometric files. Any reputable manufacturer will be able to provide you with 3rd party testing data such as LM-79 and LM-80, and if they can’t, find someone who can. If they claim their products are UL or ETL approved, have them send you a copy of the certificate of conformity.

The LED lighting industry is growing and evolving at phenomenal speed. Much like your phone or tablet, if you bought an LED light today it’s already on the path to obsolescence. Chip makers are producing ever more efficient LEDs, and material substrates are constantly improving. You can bet with certainty any LED light you install today will have a more efficient successor within months. But it’s never too soon to make the switch to more efficient lighting. Falling prices can get you your Return on Investment a lot sooner.