Sure, we had candles, gas lanterns, and finally electric incandescent sources, but it wasn’t until the confluence of air conditioning and the fluorescent tube that we stopped designing our architecture to receive air and light from the great outdoors. Technology has given us wonderful inventions that make our lives on earth easier, happier, more comfortable, and more productive – but for a price. The energy needed to power all of this technology is being depleted. We can heat, cool, and light our buildings in any climate, in any architectural style, but only as long as we have enough fuel.

Indigenous or vernacular architecture was born from solving programmatic needs, using whatever natural resources were immediately available. With the advent of air conditioning in early 1900 and the invention of the fluorescent tube in 1938, we could virtually turn our backs to the outside world and create environments inside our buildings to our liking. As a result, we saw our architecture dramatically change. Office blocks became very large and, consequently, the resulting interior spaces were further removed from the perimeters of buildings. Interior spaces were almost entirely illuminated by electric lighting. It was easier and more economical to use fluorescent lighting than to design a building with more perimeter space that got its light from the sun.

As the years rolled on, we started to realize that these environments were not as desirable as the ones created by nature. Studies started revealing that productivity was suffering, that students’ test scores were in decline, and that people’s health was being sacrificed – all based on a separation from the sun, which helped us to produce vitamin D, set our circadian rhythms, and provided balance to our physical and psychological well-being.

It’s not all a doom-and-gloom story however. Fluorescent lighting is still, by far, the most popular way of illuminating the interiors of our buildings, but with new technologies it is even more efficient than ever before. Furthermore, fluorescence plays well with daylighting. Instead of replacing it, fluorescent and daylight coexist in very efficient and comfortable ways through advanced control technologies and thoughtful design. Dimmable ballasts, photocells, vacancy sensors, individually addressable equipment, and proper design techniques all make it easy to save energy and create wonderful luminous interior environments.

In addition, technology gives us design tools and simulation programs that allow us to forecast energy savings and previsualize our designs in unprecedented ways.

But, in order to take full advantage of these available technologies, architects must reclaim daylighting in their design domain. Unfortunately, the history of architecture in the last century is tragically described as a continual delamination between art and science, because architects passed these technologies into the hands of specialist consultants.

Reyner Banham, in his book The Architecture of the Well-Tempered Environment writes: “… the idea that architecture belongs in one place and technology in another is comparatively new in history, and its effect on architecture, which should be the most complete of the arts of mankind, has been crippling… the art of architecture became increasingly divorced from the practice of making and operating buildings.”

Today the profession is filled with competent and useful consultants and specialists, but the architect must use them, just as technology itself, in a manner that supports the art, and the human being living within that art. We must learn from history, but also embrace technology in ways we’ve never done before, to create beautifully daylit architecture, completely integrated to produce a true balance between art and science.

Photo Credits: Prasad Kholkute (1), Lam Partners (2-4)

The following are some of our impressions of this year’s event:

Lightfair seems to be turning into more of an electronics show than a lighting show. But, I saw a lot of LED products this year that gave me hope about LED lighting in general. My favorite: retrofit LED lamps that are actually a good replacement for incandescent lamps! Sure, these things have been around for years now. They cost a fortune, last about a month, produce hardly any light, and the light they do produce is garish. But what I saw at Lightfair was lamps that dim, have good color, produce useful light, and are affordable! This is very encouraging. There are lots of wonderful products that can produce a low-power-density lighting design for a new project – but the majority of square footage in the world is not new, it’s existing. Affordable retrofit products that are actually starting to look good is a great step forward. We may even be able to reach the Architecture 2030 Challenge!

Other LED products I saw that give me hope are interchangeable light engines. They’re like LED light bulbs. There’s an industry-wide movement, called Zhaga, that is trying to standardize the specifications for the interfaces of these light engines. So instead of throwing the whole luminaire into a landfill, we can now recycle and replace just the LED module.

The trade show itself was also encouraging. I was in New Orleans to attend the AIA convention the week prior, where the floor was dead compared to Lightfair. Is it because architecture is still hurting economically and there were just not as many people attending? Or is it that architects are chasing CEUs and attending more seminars rather than walking the trade show floor? Either way, Lightfair was wonderfully crowded and vibrant this year. People in almost every booth gave me hope that the industry is coming back. I ran into a lot of colleagues who said work was picking up, or that they were very busy. A sense of optimism seemed to be the brightest luminaire at Lightfair this year.

- Keith

I had two basic missions at Lightfair. The first was to check out innovations in current and upcoming lighting design software, and the second was to attend the IES Daylighting Metrics Committee meeting.

Tools to evaluate lighting are in a state of flux. Some lighting and daylighting metrics have progressed in sophistication, but the software has not yet been developed to employ all of them. Revit is becoming not only popular, but required on many projects, however, coordination of lighting into Revit models is still far from commonplace. This was clear in the short session I attended about BIM modeling, which showed many important capabilities of a variety of softwares, while also showing that in practice, transferring information between programs can be tedious and time-consuming (though one particularly bright spot revealed at Lightfair is a plug-in being developed for Revit which allows lighting analysis of Revit models without manually transferring the model into AGi32 and back).

On the other hand, there are good software tools available, but most designers have not yet learned how to use them. Researchers have developed robust and valuable new daylighting metrics that can only be used by a select few with advanced expertise of difficult, esoteric software. This is especially problematic when working with codes like IgCC and LEED. Better metrics can help foster better design, but it’s impractical to require compliance based on software that’s not widely known or easily available. Furthermore, as the Daylighting Metrics Committee discussed, there is a need to standardize metrics so that everyone is working from the same basic assumptions.

The rise of Revit and BIM provides new opportunities as well as challenges. In principle, it should facilitate coordination among architects, engineers, and consultants, but in its nascent stages, there are still a lot of hurdles to clear.

- Kera

After walking the many aisles of lighting booths at Lightfair, I was left with a feeling of brightness. Not with a sense of novelty or originality, but literally, glaring brightness. There was a vast display of LED site lighting pole fixtures looming above, packed with bright LEDs, and causing overpowering glare at almost every corner. As manufacturers touted the universal suitability of LEDs, the fixtures actually on display overwhelmingly revealed some of their biggest disadvantages, with high-angle glare and excessively cool color temperatures.

Even though it was slightly frustrating to walk around the exhibition hall, squinting my eyes to dodge bright LED fixtures, I found the experience to be, in a way, eye-opening, as the ever-present LEDs on display demonstrated the need for much continuing development and innovation before these products become practical.

On the other hand, it was interesting to see some of the manufacturers that are implementing LEDs into thin forms and planar fixtures, taking advantage of LEDs’ unique characteristics and compact quality.

The part of Lightfair I enjoyed the most, the part that left the biggest impression on me, was the keynote speaker luncheons. I enjoyed the camaraderie of sharing design experiences, and learning about the design process from visualization to concept to schematics, mock-ups, and final design. It’s great to simply get to know other designers, and to appreciate the projects from various points of view, with more than just a final photo of the result.

- Amber

My biggest impression at Lightfair was “who are these guys”? There were so many companies that I had never heard of. Seems like everyone sees this big market opportunity in LEDs, and if they can stick a chip into something and make it glow, they are a lighting company!

I was happy to see the development of small-aperture LED recessed fixtures with a choice of beam-spreads, as an alternative to MR halogen fixtures. They are still much more expensive, but the price should come down, and potential payback in energy savings can help. Of course, the lack of standardization in outputs and beam-spreads continues to be frustrating.

Speaking of lack of standards, let’s talk about controls. Unfortunately in this country there is no standard lighting control architecture or protocol. Add to this some really fascinating out-there control systems (low-voltage DC power, power-line carrier, wireless) and it gets really crazy. It will be interesting to see how this will settle out – but in the meantime, we’ve got to design control systems… sigh.

As usual I was disappointed by the lack of new, innovative fixture designs – sure, there were a few things, but none of my colleagues I bumped into were saying “you’ve got to go see this!”. And when it comes to LED (which is pretty much all anyone was showing), this means that I saw very few fixtures that took advantage of the unique form and electrical characteristics of LED. Sure, we need (cost-effective) LED downlights and troffers – but come on guys, use a little imagination!

- Glenn

Meh. Let me put my curmudgeon hat on:

Unfortunately, I feel this way more and more about each successive Lightfair I attend. Perhaps it’s because Lightfair happens too often (try a two-year rotation), but the last three I’ve seen have been dominated by the same theme: everyone trying to convert their standard products to LEDs. The problem is that LEDs are STILL only half-baked as replacements for standard sources and, until the industry agrees on some basic standards (like a replaceable LED module), it’s just the Wild West out there.

What’s more is that everyone is jumping on the bandwagon and copying everyone else. Where there were once two or three LED downlights, now there are 50, all making crazy claims of energy savings and unrealistic lifespans. The copy-catting was so bad this year that I had to walk up and down the aisles ignoring any company I hadn’t heard of before, because the probability is high that you won’t see them at the next Lightfair.

It’s not even a fad, it’s a frenzy. Most don’t even try to innovate – they just use the same old housings and stuff LEDs into them. Those that did their LED homework and are doing some ground-breaking stuff command some respect, and I was impressed to see their recent improvements. Still others, who have built their companies around standard light sources, are proceeding more cautiously, and I can respect them for that as well. But those that simply do it because everyone else is doing it – both specifiers and manufacturers – may end up getting burned in five years when everything needs to be replaced. There will be a glut of crap out there for several years to come. I’m not an LED hater. They have their time and place, but proceed with caution – now more than ever.

Curmudgeon hat off, optimist hat on:

I did see noted improvement in the more design-ey LED stuff. Some manufacturers have embraced the LED’s discreet nature and have developed fixtures around new forms. I saw some three-dimensional forms, curves, planes, stuff sandwiched between panes of glass, and other crazy shapes that really catch your eye (not like those that try to snare you into their booths by impairing your vision with LED headlights). That’s the kind of ingenuity we need to see.

As for controls, I saw a marked improvement in promotion of digital addressable systems, which are definitely game-changing technology. Just like for LEDs, there is currently no regulation or standardization out there, but those manufacturers that really get it are making significant headway. It’s a lot to sort out, but we’re finally seeing progress where for twenty years there had been none. Keep it coming.

- Matt

Image credit: LIGHTFAIR® International (photo by Lam Partners)

While LED technology has been the darling of fixture designers, linear fluorescent lamp and ballast manufacturers have been continuing to develop a diverse range of products that round out a comprehensive toolbox for sustainable design. In addition to providing smooth light output, high color rendering, a variety of color temperature options, and good value pricing, linear fluorescent lamp-life has slowly been increasing, bringing it in line with the rated life claims of LED systems.

Are LEDS really the best option for a light source with an extended rated life? Rated life of white light LED systems currently hovers around 50,000 hours. Of course, that exciting number needs to have IES standard LM-79-2008 and/or LM-80-2008 testing to give it credibility – and LED life is dependent on thermal management, meaning that long life can be compromised by excessive heat being trapped at the diodes.

Meanwhile, lamp manufacturers are introducing new T5 and T8 fluorescent lamps with similarly extended lifespans. Newer T8 lamps on instant-start ballasts can last as long as LEDs, or, with program-start ballasts, even 55,000 hours.

However, one thing the LED has done for fluorescent technology is reinforce the importance of the entire lighting system, in this case bringing the combination of lamp, ballast, and controls to the forefront. In linear fluorescent fixtures, it is the total package – lamp, ballast, and system efficiency – that counts. A common myth persists that T5 and T5HO lamps are more efficient than T8 because they’re a newer format, but in reality T8 lamps win the race, consistently offering better efficacy (light output, or lumens per watt).

Standard-output 28-watt T5 lamps produce around 2,900 lumens with a connected load of 34 watts (85 lumens per watt); high-output 54-watt T5HO lamps produce 5,000 lumens for 62 watts (81 lumens per watt). In contrast, a 32-watt T8 lamp with 3100 lumens on a high-efficiency ballast (0.88 ballast factor ballast) offers 28 watts – 97 lumens per watt.

T5 and T5HO are still priced at two to three times the cost of T8 lamps. The real potential of T5 and T5HO lamps is that their smaller diameter allows better optical control, resulting in better reflector design, smaller fixture profiles using less material, and the opportunity for more efficient photometric performance.

To use T8 lamps successfully, there are lots of options to keep in mind. Four-foot T8 lamps come in many varieties: F32T8, F28T8, and F25T8 which allows for the design of tailored systems, with light levels and power densities to suit a project’s needs. But, should you need a controllable system that requires dimming, then the F32T8 in most cases is the only lamp that dimming ballasts want to work with (although ballast manufacturers are working on products to fill this gap).

Take charge and specify ballasts to write a better energy story. High-efficiency ballasts can result in higher system efficacy, using less power, but they need to be identified in fixture specifications in order to be provided. Otherwise you will end up with generic electronic ballasts (GEB) at the manufacturer’s discretion. High-efficiency, high-ballast-factor ballasts can over-drive T8 lamps to produce more light when needed, within allowable power-density criteria, without compromising rated lamp-life. This option is helpful in situations where one lamp is not quite enough light, but a project can’t allow the power density of adding a second lamp. When one lamp is too much, low-ballast-factor ballasts with high-efficacy lamps can provide a cost-effective continuous glowing cove, such as those used at the University of Chicago’s Gordon Center for Integrative Science, where a glow was desired to create a lantern-like effect.

High/low ballasts offer cost-effective switching options for meeting code requirements when the budget can’t afford a dimming system. However, care should be taken to determine if the 50% power level of this type of ballast delivers light levels appropriate for the space – otherwise the lights will always be switched to full output by the users.

Dimming ballasts save energy, and have been finding their way onto more mainstream projects (to support daylight-responsive dimming, or lower light levels during classroom projection), but the reality is that at full power, dimmable ballasts consume more energy than a standard high-efficiency ballast. There is a campaign for code criteria to recognize that power consumption over time is a more accurate way to document power and energy savings than connected load. Until that happens, dimmed fluorescent lamps use little energy, but in power-density calculations, they still exact a premium in terms of connected load.

Photo Credits: Arria Belli (tortoise), Polandeze (hare), Anton Grassl/Esto (project)

DALI is one of the latest buzz words in the lighting industry. Widely used in Europe, DALI is still in its infancy in the U.S., even though it was first introduced in the late ’90s. DALI stands for “digital addressable lighting interface”, a control protocol based on digital commands that are sent between ballasts and the control system. DALI has many benefits which make it a very attractive system for commercial lighting applications, however, there are a number of things to keep in mind when designing a DALI system.

How does DALI work? DALI is a standard digital communication protocol which allows DALI-compliant devices, regardless of manufacturer, to talk to one another. These devices include controllers, ballasts, switches and sensors. Since DALI is an open protocol rather than a proprietary system, there are a number of ballast manufacturers and control companies that offer DALI products.

A DALI system can include up to 64 individual DALI devices on a single loop, with each device having its own address. DALI ballasts can be individually configured, and that custom configuration resides in the electronics within the ballast itself. DALI ballasts are able to set light levels, fade time and fade rate, and individual address. These ballasts are able to be configured as part of multiple lighting scenes which can be selected by wallbox control devices or a central control system.

DALI ballasts feature two-way communication, which means that they receive digital signals from the control system telling them how to operate, while also allowing the ballast to provide feedback through the network, for instance, indicating if the ballast is on or off, how much energy it is using, and whether the lamp and ballast are functioning.

DALI systems have many attributes which make them worthy of consideration for commercial applications:

• With DALI, wiring is easier than in a traditional system and there is less of it. The electricians don’t have to care about how they circuit the fixtures. They just run power to fixtures the easiest way they can until they load up a circuit. Fixtures are controlled solely through the digital control wire, which can also be run arbitrarily to each device.
• The ballasts are individually addressable, allowing for control zones to be configured in the field – rather than on paper, prior to construction. Because control zones are not hard-wired, they can be easily reconfigured based on real usage. Programming zones and scenes is done through software, regardless of how the fixtures are circuited.
• DALI ballasts can be tied into Building Management Systems, which can monitor energy usage and identify lamp failures, making DALI an ideal system for clients interested in sustainability.
• DALI ballasts can dim to 1% for linear lamps and 3% for compact fluorescent lamps – this is of particular interest when considering daylight dimming along perimeter zones.

While there are quite a few positive features to a DALI system, there are a number of things to keep in mind when designing such a system:

• At the moment, there are a limited number of ballast types available. While the choices are vast in Europe, as of this writing, U.S. manufacturers only offer DALI ballasts for four-foot linear fluorescent lamps (T8, T5, and T5H0), two-foot T5 lamps, 18/26/32-watt quad- and triple-tube compact fluorescent lamps, and 40-watt biax lamps. There are no manufacturers in the U.S. currently offering a three-foot linear fluorescent DALI ballast. This proves problematic if designing continuous coves or slots, which can require three-foot units to make up a continuous lighted run.
• Something else to consider is the inability to locate a DALI-compliant ballast remotely. Lighting fixtures are becoming smaller and smaller due to the demands of both designers and architects, and in some cases the ballasts just don’t fit inside the fixture housings. For a DALI system, designers can select only fixtures with integral ballasts, because as of this writing, DALI ballasts cannot be located outside the fixture.
• Another factor is that many people are hesitant about implementing a DALI system because they just don’t know enough about how it works. There is the notion that a DALI system will cost more than a traditional system, however, one must consider the lower cost of installation and simplified wiring configurations.

While DALI might not be right for every application, and it does indeed have some drawbacks, the time might be right for more DALI installations in the U.S., and perhaps the U.S. ballast manufacturers will soon start developing and offering more options for DALI ballast/lamp combinations – especially when it comes to three-foot lamps!

Photo Credit: © Carlene Geraci/Lam Partners

One of the things that has bothered me most about LED fixtures is their visual color temperature. The products that I have seen and tested give off a light that is too cool for my preference. But, the world is changing and perhaps my perspective is starting to change a bit too. The following is A Tale of Two Task Lights: a Recently Acquired Fixture and the Lessons Learned.

Good tales often begin with a historic perspective, and so shall this one. Throughout the ages, people have associated low-level lighting with the warmth of firelight or of a candle. I confess that I love the warmer color temperature of a halogen task light. My desk lamps and even the under-cabinet lighting in my kitchen have always been halogen.

The indirect fluorescent lighting that I also have in the kitchen provides a very energy-efficient and comfortable ambient light level in the evenings, but the color does not deliver the same warm glow as the halogen. When the under-cabinet halogen lights are dimmed, they get even warmer and more ‘buttery’. I have yet to achieve that same warm, low light level with LED, compact fluorescent, or linear fluorescent products.

From among the outpouring of new LED products, I purchased my first LED task light this year. I did this to begin to wean myself off of my halogen diet, or at least to try in good faith to live with this new technology. Perhaps it also relates to the overall picture of striving to live healthier and in a more sustainable way. I suppose a parallel could be made with eating healthier – using less butter and more olive oil, for example. Yes, I started to compost as well.

I put my 50-watt, 2850K halogen task light into storage, and began to use my sleek new 9-watt LED desk fixture. The color temperature is specified at 3000K. For the first month or two I had a knee-jerk negative reaction whenever I turned it on. Too cool – as in temperature, not hip factor. I missed that warm buttery glow. However, over the course of a few months, I am beginning to grow accustomed to its cooler cast. The fixture has excellent glare control and the output is comfortable. If the fixture produced glare, or was either too dim or too bright, those factors would have certainly biased me against the LED task light. But I couldn’t find fault with it in those areas.

It has been about six months and I am now acclimated to the light quality of my new task light. I enjoy using it and the color temperature has sort of grown on me. Does making healthy choices involve accommodation and adjusting our standards, or is it the retooling our thinking and attitudes, which open us up to new options?

I believe that, as LEDs become more widespread in offices and homes, retail, street lighting, parking garages, etc. in the next few years, their shortcomings – particularly in the area of color temperature and glare control – will cause a backlash among users. The marvels and mysteries of LEDs as the great hope for our future will be tarnished by products that don’t live up to their promises and our expectations. While I do believe that the industry will have to deal with these shortcomings, what I have learned is that people are surprisingly adaptable to new technologies.

The visual issues that manufacturer’s have been dealing with – glare, multiple shadowing, effective dimming, cooler color temperature, and that strong desire for warmer color temperatures when dimmed – will get worked out over time as we grow accustomed to a new light.

Photo Credits: Schani (1), Lam Partners (2, 3)

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.

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.

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.

I love LEDs. Really, I do! They offer so many possibilities for new ways to light our world with less negative environmental impact. And besides, they’re cool! What I can’t stomach is the continuing hype. Frustration with LED hype is old news for lighting designers and for readers of this blog, but I thought by now it would have simmered down. It hasn’t. That LED Kool-Aid is still being poured and plenty of people are still chugging it down.

There are two flavors of this Kool-Aid that are really bugging me these days. Here they are:

Flavor #1: “Berry, Berry, Efficient”

Why are we still hearing unqualified claims about how LEDs are super-efficient? Claims like “use 80% less energy”, “seven times more efficient”, or the headline on a recent New York Times article, “LED Bulbs Save Substantial Energy, a Study Finds”. The question always should be, COMPARED TO WHAT?

So, based on manufacturers’ data, here is my grossly oversimplified analysis of how efficacious LEDs really are.

LED fixture efficacy compared to:

• Incandescent/halogen fixtures: 0 to 5 times better
• Compact fluorescent fixtures: about the same
• Linear fluorescent fixtures: 25% better to 50% worse
• Metal halide fixtures: about the same to 50% worse
• High-pressure sodium fixtures: about the same

So if I’m right, where are these claims coming from? They may start with misleading statements by manufacturers, but I think it is the popular media that is mainly to blame, for not doing the research and then promulgating bad information. This is picked up by the consumer and by public policy people, and then the more it is repeated, the more it must be true!

Here’s an example. The City of Boston is currently testing six different pedestrian-scale post-top fixtures on the Boston Common and asking for public reaction. Right on the project web site it says things like “Light Emitting Diodes (LEDs) use far less energy in producing more and better quality light than traditional lighting,” and “The large number of city street lights (67,000+) has the potential to significantly cut energy use and carbon emissions (currently 24,000 tons/yr) by switching to LED lighting,” and “High efficiency with the potential to offer 50 to 80 percent energy savings”.

Where do they get this stuff? Maybe it is the New York Times, but it could also be the manufacturers themselves. Right on the Cree web page talking about the Boston program it says “LED streetlights consume 50 percent or less energy compared to traditional streetlights”. I’m guessing that “traditional” is a significant qualifier in this statement, but I don’t know what they mean, and is the average person going to understand the distinction?

Flavor #2: “Numbers Crunch”

“Numbers Crunch” is the favorite flavor of LED product development engineers and marketers, especially those designing and selling LED lighting for streets and parking garages. They love to tell you about the amazing engineering that went into their fixture and how it delivers incredible numbers. The only thing they want to talk about is how the fixture delivers light to the ground, how awesome the uniformity can be, and how far apart you can space the poles. But what do these fixtures look like at night? Can I see well with them?

The true purpose of outdoor lighting is to make it easier to see at night, not to just deliver light efficiently to the ground. What we have seen with many LED outdoor fixtures is that they are very glary. Glare makes it hard to see. Sure, lighting the ground is important, but if the glare makes it harder to see, then it doesn’t matter how efficient the fixture is or how great the uniformity is. Sometimes I wonder if the engineers who designed these fixtures ever left their computer and stuck the fixture out on a pole at night and just looked at the thing!

So back to the Boston Common. I’ve looked at those six fixtures at night, and they perfectly illustrate what I’m talking about here. They all do about the same job of delivering light to the ground. But four of the six are terrible “glare bombs”. I don’t care what the numbers are, if the glare makes it hard to see and they’re unpleasant to look at.

OK, I’m done. Time to get a glass of cool clear water (or maybe a stiff drink!). What do you think?

Photos credit: Glenn Heinmiller / Lam Partners Inc

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 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.

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

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.

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.

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.

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)

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.

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.

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