By the Time You Read This, Your Compact Fluorescent Lamps Will Have Come up to Full Brightness

October 26, 2010 / no comments

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Ever walk into a room, turn on the lights, and think, “This is really not as bright as I would like it to be,” then walk out and come back later to find the lighting is actually just fine? The reason for this lag in full brightness is the same whether for a commercial office project lighted with compact fluorescent (CFL) downlights, or at home where screw-in base retrofit CFL lamps have been used in formerly incandescent table lamps and pendants. That reason – amalgam technology.

I know you’re thinking that this is just not going to be something you need to know – unless you are trapped at a really boring party – but as fluorescent lamps become de rigueur in replacing inefficient incandescent lamps, it really is good to know a little bit about their inner workings.

All fluorescent lamps, whether linear tube or compact fluorescent lamps, contain MERCURY. The mercury, when heated by the incoming electrical current, is vaporized and converts electrical energy into ultraviolet radiation. The phosphor coating on the inside of the glass tube absorbs the ultraviolet radiation, and converts it into visible light.

In linear fluorescents, mercury is provided in a liquid or pellet form. But all of the twists and bends in a CFL cause liquid mercury to pool when the lamp is installed in different orientations. As a result, the mercury does not vaporize or distribute effectively. To resolve these issues, amalgam technology, in which mercury is imbedded in a metal alloy, was created to allow more stable light output, independent of burning position. Since the mercury is contained within the amalgam, the lag time to heat the amalgam and release mercury vapor creates the lag in light output; CFL lamps will take as long as 110 seconds to produce 80% of their total lumen output.

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Mercury is the dark side to the green story of fluorescent lighting; it’s essential, and it’s a poison. During the lifetime of a lamp, the mercury that is available to be energized is used up – bonded to the glass and phosphors. This reduced level of mercury will, for a time, allow the lamp to create light, but not enough to overcome the presence of the argon gas within the tube, resulting in a fatal, eerie bright pink glow.

The glass tube of the fluorescent lamp does create a sealed environment, so although the lamp no longer produces useful light, mercury is still present. Should a lamp break, whether linear or CFL, extreme care should be taken in disposing of not only the shards of broken glass, but also the powdery phosphors, which have now bonded with vaporized mercury.

Even though some lower-mercury lamps labeled as TCLP compliant are touted as having mercury levels lower than those regulated as hazardous waste, and could avoid additional disposal costs, recycling is still the best way to allow mercury to be reclaimed and stay out of the landfill environment. Recycling of screw-in base compact fluorescent lamps also allows the ballast components in the base of the lamp to be recycled.

And while amalgam technology allows for better recycling of mercury, it does mean that slightly more mercury is going into the lamp system. The LEED program is now allowing Innovation in Design credits to be awarded for the use of low-mercury lighting. This recognizes that while mercury is a fact of life in energy-efficient lighting, there are ways to minimize the total amount of mercury on a project (this includes high-intensity discharge lamps as well). Satisfying this credit entails meeting the target maximum for mercury content, and ensuring that 90% of the lamps purchased for a project comply with this target level – this puts amalgam technology CFLs at a disadvantage compared to linear fluorescents.

So, think incandescent lamps are a way to avoid this messy bit of mercury business? While incandescent lamps do not require mercury to operate, fluorescent lamp and sustainability advocates have computed the theoretical environmental mercury exposure created by the use of incandescent lamps powered by electricity from coal-burning power plants. This number is over three times the amount from compact fluorescent lamps.

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Photo Credits: Horia Varlin (1), Michael Hicks (2), Wikipemedia Commons image (3)

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Works Cited:

“Amalgam for Use in Fluorescent Lamps Comprising Lead, Tin, Mercury Together with Another of the Group Silver, Magnesium, Copper, Nickel, Gold and Platinum. – US Patent 5952780 Description.” PatentStorm: U.S. Patents. 14 Sept. 1999. Web. 15 Oct. 2010.

“Amalgam Technology.” Megaman Global: Green Room. Web. 15 Oct. 2010.

“Compact Fluorescent Lamp.” Wikipedia, the Free Encyclopedia. Web. 15 Oct. 2010.

“Fluorescent Lamp Containing a Mercury Zinc Amalgam and a Method of Manufacture – US Patent 5882237 Description.” PatentStorm: U.S. Patents. 16 Mar. 1999. Web. 15 Oct. 2010.

“Fluorescent Lamp.” Wikipedia, the Free Encyclopedia. Web. 15 Oct. 2010.

Harris, Tom. “HowStuffWorks “How Fluorescent Lamps Work””. Howstuffworks “Home and Garden” Web. 15 Oct. 2010.

The Rise of DALI – again?

June 22, 2009 / no comments

More often than not, if you ask a lighting designer or engineer what DALI is and if they specify it, you’ll get a puzzled look or a chuckle. Some designers are dipping their toes in the pond, but most are waiting to see what the other guys are doing, not wanting to be the first for fear of getting burned on an unproven technology. The truth is, however, that while the U.S. has been plodding along with good old switching relays, 0-10V, and line-voltage dimming, the European design community has already taken lighting control into the digital age and embraced DALI as the preeminent, universal lighting control language.

While those traditional technologies are tried and true, complacency does not constitute a reason to ignore a proven system which has the potential to save time, money, and energy, while increasing beneficial functionality. Here are a few points that examine why DALI has potential and why we aren’t using it enough.

First though, we need to know what exactly DALI is. DALI (not Salvador Dalí) stands for “Digital Addressable Lighting Interface”, and is basically the computer language that devices send and respond to, kind of like Morse code for lighting. The DALI control signals are transmitted over two low-voltage wires that connect to each DALI ballast or relay, each of which has a unique address. Control commands are sent out over the wires to tell individual devices or groups of devices to turn on and off, dim up and down, etc. The devices even have the ability to report back to the controller indicating a lamp failure or how much power they are using. This kind of send-and-receive communication is analogous to a teacher (controller) and classroom full of students (ballasts and relays). The teacher gives instructions to the students (which they obediently obey), and each can answer questions when called on.

What does DALI have that your current controls systems don’t have?

DALI systems can use up to 60% less branch wiring than traditional controls

That’s a strong assertion, but if you lay out the wiring for a traditional system and measure it, for any typical room you would see that by the time those switch legs go down and back up the wall and then out to each controlled zone you have quite a bit of wire. Don’t forget to consider the conduit – lots of metal! Now, if you lay out the same space with a DALI system, you simply don’t have all those switch legs to contend with. The branch circuit flies into the room from the adjacent space, hits each light fixture or addressable relay, and continues on to the next room. All switching and dimming is done in the ceiling at each fixture, not in a wallbox or remote cabinet. While there is some control wiring that connects all the controlled fixtures into a loop, that wiring can be Class 2, run without conduit, (or Class 1 that runs in the same conduit – still cost less than switch legs) and results in much less material, labor, and cost.

DALI wiring diagram

DALI is based on an open protocol

Using an open protocol means that anyone can develop their own DALI devices, ballasts, relays, sensors, etc. The programming language is freely available to anyone that wants it.

That also means that it has the potential to be a universal language for the lighting industry (as has happened already in the EU), so Brand X DALI light fixtures will work with Brand Y DALI control systems. You don’t need to worry about compatibility and which type of dimmer to use anymore.

DALI is easy to specify

Whether the lighting designer or engineer does it, someone has to figure out which traditional dimming ballast or transformer to use with which traditional dimmer. With DALI, it’s simply DALI – DALI ballasts with DALI controllers. Most of the major ballast and gear manufacturers have DALI ballasts already available, and their product offerings continue to expand. Even better, most ballasts, DALI or otherwise, are now universal voltage – you don’t even need to coordinate that!

The proliferation of DALI will also allow for three-name ballast specifications again, unlike the forced specification of a proprietary technology caused by no two systems being alike.

DALI is easy to install

A light fixture gets power (120 or 277 volts – it doesn’t matter as far as the control is concerned) and control wires – that’s it. The rest is in the programming. The control wires are polarity-free, so it’s virtually impossible to wire a fixture incorrectly, unless you forget to. Once contractors understand how easy the installation really is, and they get past the “new technology” hesitation, they should be jumping for such an easy system. Some already have.

Conduit

So why hasn’t the U.S. embraced this technology yet? Some of the reasons are more complex than others, but there are many possibilities:

Lack of specifier demand

This is simply a chicken-or-the-egg question. If specifiers don’t know about it or don’t understand it, how would they know to ask for it?

The perceived complexity of digital communication and control is something that might be hard for specifiers to wrap their heads around. It’s certainly a lot different from switching and dimming line voltage we’ve been using for the past 40 years. Since there are few manufacturers with front end systems, thus far, education has been lax.

Manufacturer hesitation

For the same reason that specifiers are hesitant to specify it before the competition weathers the “new technology” first, manufacturers are wary of investing in the development of a new system that is so different from what they already offer. They want someone else to do it first to see if it takes off or flops.

There are a few manufacturers that have come up with quasi-digitally-based systems but they’re mostly proprietary, operate in different ways (i.e. cannot be listed as equals), and usually end up converting a digital signal to analog. Unless these systems permeate throughout the industry, their fate will be to persist as a minority, or they will cease to exist.

Sometimes DALI is even discredited as “slow”, “old”, and “expensive”, rejected for specific business interests and investments in competing technologies. A lot of time and money has gone into developing all those other control systems, and to simply adopt DALI, the universal open protocol, would almost certainly cut into profit margins. This may be the single biggest hesitation factor in the U.S.

So what’s next for DALI? Will it ever fully take off in the U.S.? There certainly is vast potential for any manufacturer that wants to take up the technology. It makes sense from so many angles, and if we could just get everyone to agree to adopt it we’d really have something, but that’s a bit like herding cats – good luck!

Photos credit: Matt Latchford / Lam Partners Inc

Lite-Brite ™

June 14, 2009 / no comments

Remember when you would assemble those little translucent pegs in any configuration possible to create a luminous image of your wildest imagination? There were no limits to how the pieces could be arranged within the board boundary; each glowing pixel of plastic contributed to the overall illumination from an assembled light source.

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Some manufacturers are starting to realize this same freedom as they research and develop new lighting hardware utilizing LEDs. Taking a new technology or light source and inserting it into an existing fixture design doesn’t take advantage of the technology, though, and this is where many new LED products fall short. The fixture must exploit the benefits specific to the new light source and utilize them creatively to push the boundaries of what can be achieved with these assembled light sources.
There are still heat issues, light color, lamp efficacy, and lamp life issues that need to be dealt with and carefully understood. Not all claims are accurate, however, there’s no question that these factors are rapidly improving and the quality lighting manufacturers are developing new and exciting products.

Where LEDs, within architectural lighting applications, can really excel is in the optical design of the fixture. No longer do we need to bend sheet metal around a lamp to form a reflector that redirects the light in a particular direction. Clever LED configurations and mini-optical lenses can be and are being designed to precisely control light distribution. This Lite-Brite™ approach allows the fixture design, both optically and aesthetically, to develop without being constrained by traditional forms.

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Manufacturers of parking garage, roadway, and some exterior area light fixtures are beginning to thoughtfully explore possible LED configurations and tailor the luminous distribution in ways that begin to make LEDs a viable replacement for some lamp sources. Extremely wide and precise fixture distributions can be achieved, creating excellent uniformity ratios. While lamp efficacies (lumens per watt) of LEDs are not yet outperforming standard HID and linear fluorescent sources, it is possible to design LED fixtures with a higher overall system efficacy. Again, this is achieved by the mini-optic on each diode or the precise configuration of the LEDs themselves, rather than a bent metal reflector around a bare lamp.

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Don’t be fooled; I haven’t jumped on board the LED bandwagon entirely. One of the biggest downsides of many new LED fixtures is the increased glare and fixture brightness. Often, the wide distribution and increased uniformity is achieved at the cost of higher angle glare and less cut-off to the lamp source. With the lamp source right at the fixture aperture and the optics designed to maximize the lateral distribution, some LED fixtures are so bright that their negative impact on the nighttime visual environment is far greater than the potential benefits of the new technology.

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There is a long way to go, and the designed balance between optical performance, lamp source technology, and fixture aesthetics is no easy goal to achieve. It is very clear that the endless creativity inspired by those assembled toys of luminosity point to an exciting time in fixture design and architectural lighting applications. The possibilities are limitless, so explore the design boundaries without introducing bright light!
Photo Credits: Crystl (1), HessAmerica (2), Beta Lighting (3), Jamie Perry / Lam Partners Inc (4)

LED HypeBusting

June 14, 2009 / no comments

Our clients often wonder why we haven’t switched to specifying LED lighting altogether for all our projects, especially when they see the steady stream of glowing LED hype being produced by the popular media. For both interior and exterior projects, we are taking a cautious approach to adopting LED products into our stable of recommended fixtures.

Unfortunately, there is a tremendous disconnect between the promise of general white LED lighting and the reality of the products that are out on the market today. Here are the three biggest problems with LED products today:

  1. Misleading claims about performance
  2. Difficulty in proving actual fixture lifetime claims
  3. Lighting fixtures designed as “disposable” products

The good news: industry standards are finally taking hold that, if adhered to by the manufacturers, prevent the shenanigans and level the playing field. General white LED lighting is beginning to mature to the point of useful, consistent products. The bad news: right now, the landscape is still littered with unproven fixtures and performance claims that run the gamut from realistic to ludicrous.

Let’s break down the problems:

Misleading claims about performance

Numerous manufacturers (out of questionable ethics or outright ignorance) have commonly used two ways to significantly cheat output claims:

Firstly, raw LED chips are rated at room temperature in perfect laboratory conditions. LED fixtures need to be rated at a stabilized, real world operating temperature. When LED chips are put into fixtures and run for a period of time, they generate a lot of heat, which means they run significantly less efficiently then their laboratory output ratings. You need to ensure that manufacturers are giving you real world performance numbers, not just the raw LED output.

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Second, cool-white LEDs have significantly higher efficiency then warm-white LEDs. Many manufacturers highlight the cool-white output ratings, but try to sell you the nice, incandescent-looking warm-white products. Be sure to know what the efficiency “hit” is with the warm-white output.

Added together, the impact of heat management and color temperature selection can easily mean you are getting half as much light as the specifications claim.

Difficulty in proving actual fixture lifetime claims

As mentioned above, heat is the enemy of LEDs. Good fixture design carefully mates LEDs to large, well-designed metal heatsinks to dissipate the waste heat created by the actual LED chips.

Lifetime predictions are gauged by the temperature at which the heatsink maintains the LEDs. Hopefully, all the other critical components around the LEDs are rated to last just as long as the LEDs themselves. Hopefully!

Here’s the problem: most of the lifetime claims are predicted lifetimes for just-released products with few, if any, real world installations. Manufacturers are trying to launch LED products so fast that they are essentially using their customers as lab rats to prove their products. Do you want to be the lab rat?

Lighting fixtures designed as “disposable” products

Traditional lighting fixtures are relatively easy to make: take a standardized lamp, a standardized socket, a standardized ballast, and throw them in some sheet metal. Presto, you have a product with highly predictable performance.

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LED fixtures, on the other hand, are “finicky fillies.” They require very careful engineering to ensure that the waste heat properly flows from the LED chip, through the circuit board, across the “air gap” to the heatsink, and that the heatsink is sized and shaped properly to radiate/convect the heat to the air around the fixture. Because they are so refined, with such tight operating tolerances, engineers are loath to design LED fixtures with modular, swappable components. Plus, it costs money to make a well-designed, repairable fixture; it is a lot cheaper to make a non-repairable product, and have a sales guy sidestep the whole maintenance problem by simply saying “don’t worry… it practically lasts forever!”

Not all doom and gloom…

In summary, the single biggest challenge with LEDs is heat. Contrary to misleading claims in the media, LEDs generate significant waste heat. It drastically reduces the operating efficiency and reduces the overall lifetime of LED chips. LED fixtures need to be carefully designed with generous, efficient heatsinks to dissipate the heat and maintain claimed output and lifetime ratings.

There are a lot of great, proven, reliable LED products out on the market; a quick look at a company’s showcase will give you a good sense of how long they have been out in the real world proving their products. Many are indeed ready for primetime. But be very wary when the sales rep comes calling with the latest, greatest, most amazing new LED product ever… you might get burned.

Photo Credit: Brad Koerner / Lam Partners Inc