Basic Sustainable Lighting Concepts: On Lighting Controls

September 26, 2011 / no comments

Part 4 of an ongoing series outlining design principles for sustainable lighting design: here are a few ideas regarding daylighting, to help navigate the greenwash.

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Controls: use them!

It’s really not acceptable to use simple switches and whole-floor relays anymore. Some energy codes may still allow it, but that doesn’t mean it’s good practice. Have you ever walked around a city at night and looked up at the skyscrapers to see entire floors, or even whole buildings, with all the lights on late at night? Chances are there are only a handful of people there, or none at all. Sensor technology has improved a lot over the years and should be applied liberally to take care of all those lights that no one is there to use. It not only saves electricity, but the time, effort, and additional energy it takes to replace lamps that burned out too soon from overuse.

Make sure you use sensors correctly, too. If a sensor is placed behind a bookshelf, it’s doing no good back there. If you put one right in front of a door and the light stays on all the time, how it that helping? There are a few simple tricks that the manufacturers can educate you about to create good sensor design.

And, consolidate your sensors. Most sensors can be used for both lighting control and HVAC control. Instead of two sensors in a space, use one.

K.I.S.S. – keep it simple, stupid!

Lighting controls can be daunting. Even the simplest systems have gadgets, widgets, and enough wiring diagrams to make the savviest engineer’s eyes go crossed. When selecting the system you want to use, make sure that price isn’t your only deciding factor – consider how easy it is to design, install, and program. Making people’s lives easier will result in a higher probability of your controls design being implemented the way you designed it.

Minimize the amount of wiring you need to make your system work correctly. Wiring in any given building can add up to hundreds or even thousands of miles, if you tied it together and stretched it out. Any way to reduce that raw material used (and the energy used to make it) helps. If one system uses 40% less branch wiring than another, consider it.

Basic Sustainable Lighting Concepts: On Electric Lighting

August 22, 2011 / no comments

Part 3 of an ongoing series outlining design principles for sustainable lighting design: here are a few ideas regarding electric lighting to help navigate the greenwash.

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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.

 

Basic Sustainable Lighting Concepts: On Daylighting

June 27, 2011 / no comments

Part 2 of an ongoing series outlining design principles for sustainable lighting design: here are a few ideas regarding daylighting, to help navigate the greenwash.

Only a little direct sun, please

Too much direct sunlight increases the indoor temperature, creating higher cooling loads. It also increases the potential for glare. If there’s too much glare, people are likely to pull the shades and leave them that way, which equals no more daylighting! Most interior shades do little to reject the heat load. Consider using exterior overhangs to keep excessive sun outside, and light-shelves to distribute the daylight indoors so it’s more useful.

Don’t add complexity and cost by creating one problem and mitigating it with another technology. The New York Times Building has been criticized for this. Its floor-to-ceiling glass has the potential to let too much light and heat inside, so the ceramic tubes outside the glass were introduced to help block some of it. If you have less glass to begin with, you can use less exterior shading… If you can afford it and don’t care, then have at it, as long as you keep your energy use down. Otherwise, try not to pile on unnecessary complexity chasing an aesthetic.

Installing shades is not daylighting

Simply installing internal glare-control shades or blinds is NOT a form of daylighting. Neither is using a lot of glass just to get more light inside. The façade of a building must engage the sunlight to utilize it in a meaningful way, coaxing the useful light in while controlling excessive light and rejecting heat. This means articulated façades, not flush glass.

If you do use shades, make them automated if you can afford it. Automated shades can adjust for different lighting conditions throughout the day, and they don’t rely on a forgetful occupant to pull them back up. If you can’t afford automated shades, try to design your envelope with external shades or a light-shelf such that you can keep the upper part of the window open all the time and still allow manual shading below it.

Dimming the lights

Daylight switching is no replacement for daylight dimming. Switching has a tendency to irritate occupants, because it flips the lights on and off throughout the day when the ambient light is near the threshold light level. More often than not, if it doesn’t work correctly, it will simply be disabled instead of fixed. You definitely can’t rely on people to make the best choices on an hourly basis either – the lights go on and stay on all day. Flipping a switch is what we’ve been trained to do all our lives.

Rely instead on dimming your perimeter spaces. There are variable levels of savings to be had here, from actual energy savings, to rebates just for putting daylight dimming systems in. Every little bit helps in terms of energy – initial cost is a different matter. There may be legislation or changes to the building codes in the near future that would require you to use daylight dimming anyway.

Digital is in!

All the ballast manufacturers, and a few lighting controls manufacturers, are finally, albeit slowly, switching over from older analog technologies, to digital or hybrid analog/digital systems that operate with greater precision and functionality. If you use one of these emerging technologies, your system is more likely to still be in style in the next decade or so (but don’t jump the gun on a brand-spanking-new product, lest it be discontinued). DALI is one of those technologies; it’s been around for about ten years now, and is slowly catching on in the US.

Don’t go crazy

Just because dimming is warranted in daylit zones and conference rooms, doesn’t mean you should use it everywhere. Some advocates claim additional energy savings by being able to dim the lights everywhere, but that would only be if you’ve over-illuminated your interior spaces to begin with. Design them correctly and you can save a lot of materials and costs. Dimming everything is another example of mitigating a problem that you may have created yourself.

A DALI Checklist: Things to Keep in Mind

January 5, 2011 / no comments


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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

Specification Grade Sustainability

September 13, 2010 / no comments

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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.

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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.

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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).

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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.

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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