The interesting part of the experiment was the characteristics of each light source. The incandescent had a CRI of 100, the maximum. The LED source only had a CRI of 40, way below the generally accepted range of good CRI for a light source. How is it possible that observers preferred the source with the lower CRI over a source with a CRI of 100?

To answer the question, first we must look at how we define color rendering. Color rendering is not just CRI. CRI is the color rendering index, and is not always reflective of a source’s ability to render color. Sources with the same CRI can have different spectral power distribution (SPD), and therefore render colors differently. For example, two sources, both with a CRI of 85, might have different short and long wavelengths, so that one source will render reds better, while the other source will render blues more vividly.

In order to define what makes up good color rendering, lighting designers must take into account the SPD of a source, the objects that are being illuminated, and the perception of the viewer.

Because CRI has limited ability to predict a person’s perception, another factor must be taken into account to determine a good luminous environment. That factor is called Gamut Area Index, or GAI. GAI is determined by plotting the chromaticity values of the eight color swatches used in CRI definition for a light source. The area of the polygon created by this plot is that source’s GAI, so the larger the area, the higher the GAI. High GAI is characteristic of a source with good color discrimination and saturation of colors, or vividness. Unlike CRI, GAI can be over 100, but this usually means colors appear oversaturated, and observer’s preference declines. In the experiment mentioned earlier, the preferred LED source had a GAI of 80, while the incandescent source had a GAI of only 40.

Examples of gamut area indices for various light sources. Each point of the polygon
represents the chromaticity of one of the eight color swatches used in traditional CRI
definition. The larger the area of the polygon, the higher the GAI of the source.

To ensure a good lighting design, designers should choose sources with high CRI and high GAI. The combination of naturalness provided by high CRI and vividness provided by high GAI ensure high viewer satisfaction for warm and cool sources, both at high and low levels of illumination, for either general illumination or accent lighting.

To achieve the best lighting design, one must also take the application into account. The question “what is being illuminated?” is critically important when choosing a light source. If the object being illuminated is red, you would want to specify a source that will render reds more vividly. But if the application is unknown, or will change over time, choosing a source with high CRI (85 or greater) and a high GAI (80-100) is generally the best approach.

Image credits: Alicia Miksic (1), Lighting Research Center (2)

Strike a balance between efficiency and functionality

The efficiency of a light fixture or system is not a replacement for functionality and aesthetics. On the other hand, the beautiful appearance of a chandelier does not mean it should be an energy hog either. Know where to pick your battles and try as hard as you can to design lighting that’s as efficient and beautiful as possible – together.

Having said that, do look for fixtures with 75% efficiency or better – certainly no lower than 50%. Not everything will conform, but if the bulk of your lighting exceeds this benchmark, you’re doing pretty well in getting the biggest bang for your electrical buck. As always, weigh efficiency against function – if it’s glary, those extra percentage points aren’t helping.

LEDs, coming soon…

LEDs have the awesome potential to the be next big thing in the lighting world. At the rate the technology is improving, they may be set to take over the fluorescent market in the next five years. But beware of false claims: make sure you’ve personally tinkered with any fixture you’re going to use on a project, and don’t forget to find out what it really costs – you may be shocked. Just as there was hesitation to adopt the early compact fluorescent bulbs because of their poor performance and color, we’re seeing the same with LEDs. Give them time and they will wow us, for real this time.

Do your homework. You don’t want a call from an owner in two years saying that they can’t replace a light source because it failed prematurely and they’re not available anymore; that whole fixture would have to be scrapped and replaced. Try to future-proof your designs.

Mind the costs.

Greener buildings are touted as being more expensive than traditional spec buildings, and that may well be true. But, good, efficient lighting doesn’t have to be part of that added cost. Mind your dollar-signs when selecting fixtures, and make your clients see that it’s the padding of the bill that jacks up the price, not the hardware. Of course, if you do pick a really expensive fixture, you’re on your own.

Reduce, reuse, recycle

First, don’t over-design – the more over-designed a space is, the more raw materials and energy it will consume. Building designs can’t accommodate every possible use. Designers need to pick the function of a space and stick with it, with exceptions for truly multi-purpose rooms.

Second, if designing for a large institution, especially renovating a space, ask if they have attic stock that you can use on your design. They’ll love you for not spending money, and you save manufacturing and shipping energy. That doesn’t mean you can use A-lamps instead of fluorescents, but if it fits the design, use it. That goes for controls, too. How can you augment an existing system to perform its new task even better?

Third, recycle: recycle old fixtures, recycle lamps, recycle control systems, recycle everything you throw out during a renovation, new construction, or simple maintenance task. Fluorescent and metal halide lamps, especially, need to be recycled as toxic waste. They both contain mercury, a neurotoxin, and we don’t need that in our water supply. Find your closest lamp recycler.

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)

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)

Recently a lighting company came into our office to show us their new LED fixture. I prepared myself for the usual spiel: tight quality binning, a high-performance heat sink, ELV dimming option. However, this particular fixture had been designed in a way that we haven’t seen from many other companies: the entire fixture, an LED cove/grazer product, was actually designed along sustainable manufacturing principles. Its connected load is more energy-efficient than that of its fluorescent counterparts (finally), but more impressively, the materials used to construct it had been thought through in a way few other products seem to manage.

The housing was not anodized aluminum, the standard seen in LED fixtures required for heat dissipation, but a zinc-based alloy that is less energy-intensive to make, and requires none of the toxic anodizing processes. The fixture is highly segmented for adaptability, and all components may easily be removed if failure occurs, allowing for easy replacement of parts. I was shocked.

Two years ago, before I left Lam Partners to pursue a Masters of Architecture at the University of Michigan Taubman College of Architecture, white LEDs were standard in steplights and other specialty fixtures, but only just catching on in mainstream lighting design, with a few linear fixtures, floods and downlights. Those fixtures were not terribly competitive at the time.

Since returning to the firm for the summer, at least once a week a manufacturer has come to promote their new LED products. As one lighting manufacturer’s representative correctly noted, I’ve stepped into the future. The once over-priced and under-performing LEDs now stand beside traditional sources, and in many cases outperform them; costs are dropping while efficiencies continue to rise.

The LED revolution is obviously the greatest thing since sliced bread, the introduction of fluorescence, or of incandescence before that. But just as growing pains occurred at those phase-changes, this revolution too has seen a dark side. In this new world, the slightly ignorant marketer walks into our conference room spouting how their fixture is ‘sustainable’ simply because it uses LEDs, or maybe includes some recycled decorative glass. It seems fair to say that many manufacturers misuse the term ‘sustainable’ as a marketing ploy, with mixed knowledge of what is needed to create truly sustainable products.

I was therefore pleasantly surprised when this particular company actually walked the walk. They’ve produced a product that begins to address some unspoken facts of the lighting industry: lighting fixtures require vast quantities of energy to produce, ship, and install, and poorly designed fixtures equal waste.

The discourse on life-cycle costing was made popular by William McDonough and Michael Braungart in their book “Cradle to Cradle,” and for some manufacturers of architectural materials, it transformed the way in which their product is conceived, produced, bought, and utilized. Moreover, the general adoption of LEED standards has greatly influenced the purchasing power of clients, who, through their architects, now regularly seek architectural products that account for embodied energy in some way, such as sustainably harvested wood or recycled or re-purposed metals.

However, LEED does not currently allow MEP equipment to count toward credits for material usage, with the understanding that the material quantities are considered negligible, they are not permanent to the architecture, and ultimately their ability to efficiently use energy trumps any material concerns. This seems like a missed opportunity, as the material in MEP equipment is hardly insignificant, and in many cases could comprise recycled or re-purposed materials.

While operational energy accounts for the amount of energy consumed (power x time) by the product during use, embodied energy represents energy required to produce and transport the fixture, and how that energy becomes ‘trapped’ when the product enters the waste stream. A brick, for instance, has a relatively low embodied energy, requiring only the energy to collect the clay, fire it, and transport it, and then may be used multiple times before it crumbles and must be reformed (of course never once requiring connected load). The light fixture by comparison must be fabricated from an array of energy-intensive materials, like aluminum, steel, glass, plastics, and mined phosphorous (reserves of which, according to Wikipedia, we’re on track to deplete sometime in the next 100 to 300 years). These materials must then be assembled, requiring additional energy-consuming processes.

The current debate over LED lamps and fixtures exemplifies the necessity to think more constructively about lamp/fixture embodied energies and life-cycle costs. This is a two-part issue. First, LEDs are finding homes as retrofits: replacement lamps for old fixtures, and complete fixture replacements (as have also been seen with compact fluorescent or metal halide retrofits). If the fixture must be completely removed, the old product is often sent to the landfill, and in large-scale retrofits, this may be quite a sizable quantity of wasted metals.

Secondly, in the rush to get products out to market (for both retrofit and new construction), many manufacturers have created LED products with no option to replace failed components in the field, notably LED boards and drivers. Manufacturers tend to argue that, in order to achieve the desired output and long life, LED boards must be permanently attached to their heat-sinks, usually with some sort of thermal glue. This then gets extended to additional aspects of the fixture, including housings or reflectors. Apparently, to most manufacturers, in some glorious undetermined future utopia we won’t even have to worry about waste disposal… LEDs will last until our civilizations have long since perished, so it’s not even worth bothering with end-of-life issues. Unfortunately this leaves the end user with only one option when the fixture does, some time in the next 20 years (a brief blip in the realistic lifespan of a building), fail: completely remove the dead fixture and replace it with a new one. No governing body exists that demands that old MEP or lighting equipment be recycled or re-used in any way, so the manufacturer is off the hook.

One manufacturer suggested, as an option until they “figure out their policy on refurbishing dead fixtures”, that the specifier add the phone number of an ‘approved’ recycler into the notes column of the fixture specification, for the end user to contact at failure. This option certainly plays into the notion of American capitalism, but it is ultimately laziness on the part of the manufacturer. I would much rather put a note into the fixture schedule recommending that the end user contact the manufacturer or local representative to buy a replacement, at a discount in return for the dead fixture (assuming the fixture dies after the warranty period).

The manufacturer should be thrilled at this concept. They potentially regain a host of usable parts, which should be refurbishable, and moreover, they retain the business of the customer. This is already happening in the computer industry, as an alternative to shipping dead electronics to third-world countries where workers strip equipment under highly hazardous conditions.

For example, I currently have a three-year-old Macbook Pro. Still works, but running slow, and I’ll need to upgrade soon for school. Recently I went onto Apple’s website, and found that I could get a quote for my old laptop based on the model and working quality of specific parts (even if it was dead for some reason, I’d still get money back). By offering a trade-in for my old laptop that can be put toward the purchase of a new computer, Apple is not only able to recapture the energy they spent creating the old one (which can be refurbished and resold, or stripped for individual components), but they also retain my business for the new product.

Granted, Apple’s ubiquitous presence in local retail far exceeds that of any fixture manufacturer, so an alternative might involve local lighting representatives to build up quantities before shipping, which suggests that buying local MEP equipment also matters. Regardless, few if any lighting manufacturers have thus far marketed their products in this way.

The push to create highly energy-efficient, long-lasting LED replacements for inefficient technologies does allow for minimization of waste. But countless inefficient light fixtures are currently being pulled from ceilings in an effort to reduce energy consumption, arriving either in landfills (to be mined by future generations) or at recycling plants that must perform energy-intensive procedures to recapture materials. I would like to see future companies retrofitting old light fixtures with new light source technologies in the factory setting, and selling them alongside ‘new’ products. I look forward to the day when a high-visibility architectural project has only refurbished light fixtures installed. It may be my project.

Post-Script

As I implore manufacturers and lighting designers to consider life cycle as well as aesthetics and connected-load performance, the following are recommendations I would like to see incorporated into the ethos of the lighting industry:

To the Manufacturers:

In order to meet current LEED criteria pertaining to lighting, lighting must be incorporated into a design by an experienced design professional who is able to balance connected load energy usage and reduce light pollution across a complete layout of fixtures. In no way can an individual fixture really “help meet LEED” on its own terms. Blanket statements like these reveal the manufacturer as using jargon and marketing instead of truly attempting to make sustainable products.

Regardless of current LEED criteria, every material choice within a lighting product requires energy for production and disposal, beyond just connected load. These choices will begin to matter more to consumers in coming years. Prove that your fixtures were created sustainably, shipped sustainably, and can easily adapt to changes in technology or component failure for the lifetime of the architecture.

Components that may fail must be replaceable without requiring costly and wasteful entire fixture assemblies. When a fixture truly reaches the end of its useful life, provide robust programs that allow end users to return fixtures beyond warranty periods for rebates on replacements. Refurbishing the components of dead fixtures equal potential savings by keeping highly usable materials out of the landfill.

If in fact your products do go the distance, market these specifications! Is the fixture made of 100% recycled aluminum? Put that on the spec sheet! Can the plastics be disassembled and recycled? Clearly stamp those materials with the well-known ‘recyclable’ symbol with material type (in a location that will not affect light performance).

And finally, or course all manufacturers should commit to ‘greening’ operations and products – but do not roll out one product as your ‘sustainable fixture’ without also providing a plan to overhaul the rest of your product line and manufacturing operations. It’s hypocritical.

To the Designers:

Why not specify refurbished lighting products? Must the back-of-house troffers be made of pristine aluminum? Actively look for ways to minimize not only watts, but material-heavy fixtures, with preference given to the lighter, refurbished, or recycled products. Minimize the use of fixtures made from materials with energy-intensive or toxic manufacturing processes.

How can the architecture itself serve as a lighting system? Thoughful design can allow for replacement of the minimum quantity of material when technology changes, and allows renewable materials to do some of the lighting work, such as in valances or coves.

Finally, demand more from your product manufacturers. Lighting may be a relatively small piece of the puzzle, but it’s the piece over which you have control. Make the most of it. Specify high-performance sustainability.

Photo Credits: Dan Weissman / Lam Partners Inc

Many people would argue that the healthiest lighting at night is no lighting at all. Studies are revealing that biological rhythms are offset, sleep patterns are disrupted, even breast and prostate cancers are more likely with disrupted circadian rhythms, due in part to improper lighting at improper times of the day.

The human race evolved under both light and dark. The light-and-dark cycle sets our circadian rhythms and is responsible for our good physical and mental health. Relying on the sun, moon, and stars has for centuries provided us with high-quality, healthy lighting. That’s why there is such an interest in daylighting our buildings, not only to save energy, but to put us in touch with a natural light spectrum that changes throughout the day and provides us with healthy lighting. However, we sometime need to augment this cycle at times when tasks must be performed and there is no available “natural” light.

Exterior lighting provides useful illumination at night mostly through electric means, and there are a plethora of electric light sources available to light our cities, towns, and campuses at night. What’s the best choice? Unfortunately, that question is far too many times answered by “what’s the cheapest?” – cheapest to purchase, operate, and maintain. “What’s the most energy-efficient?” is another, more admirable, question.

Both metrics are easily quantifiable and, as a result, are used almost exclusively in decisions about what light source to use. But since we are primarily lighting for humans, we should be asking “what’s the healthiest lighting to provide at night?” This is a more difficult question to answer. We may find that the healthiest lighting at night is no lighting. But, if we determine that some sort of illumination should be provided for some given task, what kind of light is best?

Most of America’s highways, streets, and pathways are illuminated with high-pressure sodium lamps, a yellow, monochromatic source. Many lighting designers, though, prefer metal halide over sodium vapor due to its “whiter” color and superior color-rendering properties. However, designers have had a tough time justifying this qualitative aspect when compared to the efficiency and long life of sodium.

Then, a number of years ago, studies started to show that cool or bluish light (white light with relatively high color temperatures, 5000K to 6000K) improved visual acuity in off-axis seeing tasks. There was even discussion about measuring this benefit for exterior lighting applications, since off-axis tasks were very important for good nighttime vision, (scotopic) driving, and walking. Finally, designers had a scientific reason for recommending metal halide over sodium for ‘people-centric’ tasks.

On the other side of the coin is the research saying that blue light at night is bad. Studies are starting to reveal that exposure to light with higher concentrations in the blue spectrum at night may actually be bad for our health. Apparently, it is especially harmful to people prone to macular degeneration. Cool blue light in the morning and during the day, at high levels of illumination, is crucial in setting our circadian rhythms by producing serotonin in the body.

Conversely, warm-colored light at night does not suppress melatonin, which is needed for proper sleep cycles. This is why some claim that night lights should be amber or red so as not to disturb sleep patterns through the night, or that people should stop working on their computers or watching TV at least an hour before going to bed, because of blue-rich light emanating from the visual displays.

And then there is the psychological side. Most people prefer a warm tone for low levels of illumination. It feels more natural. The sun gets warmer closer to sunset. Firelight has a nice warm glow. Dimming an incandescent lamp warms its color temperature. Kruithof’s amenity curve reinforces the notion of relating color temperature to the illuminance level.

Just to complicate matters, many exterior applications are beginning to embrace the burgeoning technology of the LED. It seems to make sense from a maintenance standpoint, since LEDs have a very long lamp life. However in order for these diodes to be very efficacious, they must be in the very cool or blue end of the spectrum, about 6000K. When this color temperature is used for outdoor applications of 10lux or less, the resultant lighting system looks very unnatural, not to mention what it does to skin tones.

On the Boston Common, like in many communities across the nation, there is a mock-up of several different styles and manufacturers of LED pedestrian lanterns. One evening, as we were observing the differences between the luminaires, we received an unsolicited opinion from a passer-by who commented on how the warm-white LED lantern looked the best. I tend to agree. The blue light at night simply looks unnatural. I often wonder why induction lighting is not more common for exterior lighting applications – the color temperature and rendering properties are superb, and it is rated at twice the life of most LED systems.

Ultimately it comes down to good lighting design:

1. Identify what needs to be illuminated and what can remain dark, in order to create useful contrast and manage energy usage wisely.

2. Highlight features to reinforce a hierarchy of events and provide orientation for the user.

3. Arrange light sources in clear, understandable patterns to create optical guidance for wayfinding.

A comprehensive nighttime visual environment must provide safety, foster a sense of security, be convenient for performing tasks, and appear aesthetically pleasing. When it comes to choosing the source, it should have a high color-rendering index and a nice warm color somewhere in the 2700K range. And, remember the rule of “everything in moderation”! Providing low levels of well-considered lighting will reveal the environment to the user much more effectively than flooding an area with high levels of potentially glary light, and chances are we’ll all be healthier for it. We won’t be breathing air that is polluted by power plants used to produce electricity to power exterior lighting, and we won’t be subjected to luminous energy that disrupts our biological rhythms. A win-win situation for everyone!

Photo Credits: longhorndave (1), *melody* (2), kevindooley (3), Lam Partners Inc (4)

Lighting design hasn’t changed much since someone first decided to call himself a lighting designer. Twenty years ago, the most earth-shattering developments were in fluorescent lamps; ten years ago saw advances in ceramic metal halide; today we’re cautiously welcoming LEDs into regular practice. LEDs really do have the potential to displace a lot of the existing technology, once we’ve smoothed out all the bumps, but even technological jumps of this sort won’t completely address the energy crisis we are facing. Yes, LEDs will give us more light per watt, but they still produce heat and we’ll have to get rid of it somehow. We’re still using energy. So what else is there?

Buildings, as we build them now, are barely more efficient than they were 50 years ago, even the LEED ones. What are we doing wrong? We are pushing the limits of our technology but we continue to increase our per capita energy consumption. To borrow an oft-used quote, Einstein defined insanity as “doing the same thing over and over again and expecting different results.” Perhaps our efforts to design better simply haven’t been enough, to the point that we’re essentially doing the same thing over and over again. Sure, using fluorescent lamps and super-efficient fixtures en masse throughout a building can make an impact, but is it enough to make the fundamental leap to save us from ourselves?

So, are we too cheap? When it comes time to pay the bill, do we argue about what’s on it, or look around and ask others to chip in? Ask yourself, as a designer, how many times have good, common-sense design elements been deemed expendable when the budget hits the fan? And when those tough decisions are made, what takes precedence over sustainable functionality? Immediate satisfaction! More square feet per dollar – that’s the sad bottom line. Next time you consider skimping on controls or settling for that less-efficient pendant, consider the big picture: eventually all those 1% savings here and there can add up. Budgets need to support projects in their entirety and keep what really matters. If it means sacrificing marble floors for more daylighting, do it! We’ve gotten off too easily for too long on the cost of responsible building.

Or, perhaps we’re all lazy. Take an example: as an undergrad I spent a summer in the wonderful city of Portland, Oregon, and was awed by what I saw there. Buildings without any air conditioning! Now, I’m not so sheltered that I’ve never seen a building without AC – I grew up without it – but I was astonished to see large commercial buildings without it. The climate obviously had a lot to do with it, but, when you looked around at the older architecture of the city, the pre-AC stuff, you saw that they simply designed the buildings to function without it. Big windows, high ceilings, narrow floor plates, atria, architecturally integrated daylighting, and on and on. Those designers relied almost exclusively on passive systems and when the sun went down, people went home.

The point is that all of our wonderful innovations, however efficient, have made life so convenient and comfortable that we’ve detached ourselves from the natural environment, from house to car to office. Life is actually too easy for the majority of people. Look at the nation’s waistline as an indicator. We work late because we can (the lights and AC stay on) and, consequently, we exercise less. We use more electricity by working on the fringes of the day (fewer people in the office, but all the lights are on) and even though the lights are more efficient than before, we leave them on longer. Net result: same energy use and fatter people. Just recently, the BBC published a story citing: “People who regularly put in overtime and work ten or eleven-hour days increase their heart disease risk by nearly two-thirds, research suggests. The findings come from a study of 6,000 British civil servants, published online in the European Heart Journal.”

One more guess then: is it vanity? Just because we can build all-glass buildings doesn’t mean we should – all that heat-gain and glare. Just because we can make floorplates 200 feet thick doesn’t mean we should – they only exist on life support (i.e. electricity). Just because they make light fixtures that are two inches wide doesn’t mean we should use them – those two-inch-wide fixtures are super inefficient, by the way.

Exceptional design and creativity can promote advances in technology, and those advances fuel, in turn, exceptional designs. But if an aesthetic that technology can’t efficiently support takes priority over the energy use, the cost of pretty goes way up. Is there another pretty, or could you do it another way entirely? Can practicality and originality coexist?

If it’s all or none of the above, one thing is sure: we need to make a sacrifice and adjust our values. To quote Thomas Friedman in a recent New York Times editorial:

Our parents were ‘The Greatest Generation,’ and they earned that title by making enormous sacrifices and investments to build us a world of abundance. My generation, ‘The Baby Boomers,’ turned out to be what the writer Kurt Andersen called ‘The Grasshopper Generation.’ We’ve eaten through all that abundance like hungry locusts.

Now we and our kids together need to become ‘The Regeneration’ – one that raises incomes anew but in a way that is financially and ecologically sustainable. It will take a big adjustment.

Not only do we need to radically change our building designs but we need to use them way more efficiently. We need to change our habits – turn out the lights, or not use them at all.

Photo Credits: ume-y (1), code_martial (2), BLW Photography (3)

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 is more: classical architecture in an age with limited technical and material capability.

Less is more: modern architecture responding to the abundance of the industrial age.

Less is a bore: post-modern architecture seeking to reconcile minimalism with a consumerist society.

Less or else: the struggle to develop “sustainable” strategies using pre-existing paradigms and technologies.

Let’s propose a new strategy:

More for less: finding a guilt-free, sustainable lifestyle as culturally rich and pleasurable as any previous trend.

It is quite apparent that the lighting design community is tiring of stuffing decades-old technologies and lighting paradigms into the limited metric of ever-decreasing watts per square foot. Lighting designers are hungry for new technologies, new fixture applications and new opportunities to work with architects to develop creative new design approaches.

If we want to find the pleasure inherently possible in living sustainably, then we need to change broader attitudes in the design profession. This requires an approach far more complex then simply forcing down allowed watts per square foot.

Accepting Random Variability and Darkness as Wonderful Things

Encouraged by various sustainable design initiatives, architectural technology is moving from the tectonics-based “isolated shelter: humans versus nature” approach, toward an approach that considers buildings as living, dynamic organisms, constantly exchanging energy and resources with their surrounding ecosystems.

Therefore, designers of buildings need to move beyond their constant drive to create interior environmental stasis and pervasive homogeneity of light and air; they need to explore and exploit natural patterns of variability. In lighting, this means ignoring decades-old “best practices” routed in fixed equipment that was either on or off, with fixed outputs, without any functionality for accommodating change, and instead exploring more naturally derived patterns of light and shadow, variable color palettes, visual patterns, and other forms of dynamic change.

Darkness is wonderful: it helps people see the light. Designers must learn to not be so scared of it. And variability keeps a space alive, long after the design and construction process has ended.

Ateliers Jean Nouvel, Louvre Abu Dhabi

Jean Nouvel has designed a perforated dome structure to provide shade from the piercing sun of the Persian Gulf. The organic pattern of the perforations softens the light and casts visually rich patterns across the structures below.

The Banality of Average Footcandles

Why must every corner of a building be lit to predetermined, fixed levels? Why have architects come to imagine their designs as compositions set in perfectly uniform environmental conditions with predetermined levels of light? Why have codes reinforced this simplistic thinking?

For example, modern office spaces have become terrible places to work because nothing ever changes. The lighting, the air flow, the ergonomics of the furniture, the sound, and, via constant computer usage, even the focal point of a worker’s gaze has become so fixed that the worker is completely deprived of any natural stimulus. Many commercial and institutional projects have suffered similar fates.

It is ironic that “stimulus deprivation” such as described above is recognized as one of the most effective forms of interrogation. We’re literally torturing the inhabitants of our buildings.

Down with Downlights!

Modernist architects of the 1960s, along with pioneering lighting designers and fixture manufacturers, developed concealed light sources to keep the visual focus on their bold geometric forms and rich materials. They artfully used their exquisite architecture to create pleasurable contrast, sparkle, and perceived brightness.

Four Seasons Restaurant, New York

With lighting design by Richard Kelly and fixtures from Edison Price, this fine example of 1960s International Style uses concealed fixtures to highlight exquisite materials and bold geometric compositions.

That’s fine if you’re Philip Johnson and Mies van der Rohe designing the famous Four Seasons Restaurant in the classic Seagram Building. The problem is that for the rest of us working on budget-driven commercial and institutional projects, the only materials we often have at our disposal is plain sheetrock and acoustic ceiling tiles. This combination of lost materiality and the lingering desire of many architects for “invisible” light sources (such as recessed downlights) has virtually wiped out tools such as contrast, sparkle, and perceived brightness from many designers’ kit of techniques.

Post-modernism only worsened the problem, treating visible light fixtures as kitschy historical references while using “invisible” sources to do the “real lighting”. Hence we are left with a legacy of recessed, concealed fixtures that waste nearly half of the light from the lamp in a desperate attempt to look “invisible”, along with decorative pendants and sconces, a duo ultimately derived from gaslight fixtures circa 1900.

The most positive benefit of LED lighting is the plethora of new formats LEDs are spawning, such as grids of tiny direct-view point sources, super-compact linear fixtures, or glowing panel systems. LEDs are encouraging designers to treat light as a material, which helps them to explore new forms of self-illuminated architectural elements.

Jason Bruges Studio, Hotel Puerta America, Madrid

This excellent example of a light source integrated into an architectural wall system also demonstrates cutting-edge control: cameras integrated into the wall track a person’s movement and create animated “digital shadow” effects.

Experience Designers (Formerly Known as Lighting Designers)

Digitally controlled, intelligent lighting systems are becoming inexpensive and widespread. Savvy, creative use of daylight is being included far more extensively in architectural design. Hence, designers must reincorporate the dynamic and experiential element of time into their thinking.

Once an architectural composition is considered as a dynamic scene, a range of questions spring up: When can an area be dark? When must it be bright? Should the lighting respond to the external environment? Will a fade between two colors achieve the same visual effect with lower wattage? Will an animated surface make a space feel more natural?

Because of the wide crossover between the theatrical lighting and architectural lighting professions, most lighting designers are already well equipped to handle such dynamic design strategies. The challenge is to incorporate novel ideas for energy conservation into the client’s preconceived notions and within the restrictions of outmoded code requirements. Another challenge is far more pragmatic: How do you document the element of time in an architectural drawing set?

The core question becomes: How can we, as lighting designers, enrich an occupant’s temporal experience of a place while using fewer resources?

With Love, Bill Gates: Lighting Design Becomes Interface Design

Architecture, by its very nature, interfaces with the natural environment. But there is another highly variable environment that architecture must also address: the digital realm.

Buildings must now be considered not only as shelters but as portals to digital content. How will new lighting technologies and media displays enable richer, more variable portals between the human world and the digital world? How will buildings exchange data with their inhabitants?

Interactive wall and table concept, Microsoft Office Labs

Microsoft’s stunning view of the future shows non-luminous, multi-touch interactive wall and table displays set in natural daylight.

Lighting designers will soon have to adopt a wide range of new technologies – including thin-film light sources, low- and high-resolution video displays, digital content servers, and interactive proximity-based control systems – into their range of commonly used tools. Lighting designers are also well positioned to help clients integrate photovoltaic solar cells into a building’s façade systems.

With the lack of high-level innovation in the lighting industry, lighting designers increasingly have to depend on technology coming from outside of the industry in order to stay relevant to their client’s needs. All of this technology, however, will have to be integrated into architecture with the highest levels of sustainable design. What will digital media systems, integrated into architectural building systems and developed in a true, cradle-to-cradle sustainable fashion, ultimately look like?

Simone Giostra & Partners Architects, GreenPix Zero Energy Media Wall, Beijing

The GreenPix project includes photovoltaic solar cells artfully integrated into a glass rain screen system, with each panel backlit with an LED pixel. During the day, it collects all the energy it needs; at night, it dazzles with textural “low-resolution” video effects.

Conclusion

The intersection of digital media design and green building systems poses an area of development rich with innovative opportunities for designers and manufacturers alike. The next generation of buildings will be living, breathing organisms, respirating and conserving energy and light through naturally derived exchanges, full of dynamic variability, and rich with digital content. The future for lighting systems has never been brighter.

Photo Credits: Ateliers Jean Nouvel (1), Four Seasons Restaurant (2), Jason Bruges Studio (3), Microsoft Corporation (4), Simone Giostra & Partners Architects (5-6)