Interview with Hubbell’s Martin Werr on LED Trends

I recently had the pleasure of interviewing Martin Werr, Director of Product Innovation, Hubbell Lighting. The topic: trends in indoor luminaire design. I’m happy to share his responses with you here. The interview informed an article I wrote for the October 2016 issue of tED.

DiLouie: How would you characterize demand for LED luminaires in indoor commercial building applications in the new construction market? What is current market share in the new commercial building construction market for indoor LED luminaires? What are the hottest applications for sales?

Werr: LED lighting in the indoor new construction market has been a steep growth trajectory for the past four years, finally reaching the point where LED products now account for a larger share of the market than legacy technologies. There are effectively no remaining untapped areas where LED technology is not widely accepted and embraced.

DiLouie: How would you characterize demand for LED luminaires in indoor commercial building applications in the lighting retrofit market? In your estimation, what percentage of retrofit projects involves luminaire replacement with LED luminaires versus changing out the lamp to a new light source? What are the hottest applications for sales?

Werr: While most retrofit applications involve new luminaires, a significant percentage of customers accept half-measures through the use of LED replacement lamps in an effort to mitigate first costs. Typically, however, these result in less-than-ideal performance compromises. One exception can be luminaire retrofit kits that can provide state-of-the-art LEDs and drivers that perform as well as new lighting fixtures. Significant sales opportunities include warehouse and office relights, made even more attractive by utility rebates and closing the price gap between LED and legacy sources, particularly when dimming capability is factored in.

DiLouie: What are the most popular applications for LED luminaires in indoor applications?

Werr: The most attractive applications are, of course, those that deliver the greatest benefit per luminaire, pointing directly to warehouse high bay relight projects. Replacing HID—or even fluorescent—high bays with LED units can deliver extremely high wattage reduction per fixture. The second big opportunity is to replace the office lighting. Although the per unit wattage savings are lower than for high bays, the sheer quantity and ease of replacement makes for great ROI opportunities. Again, utility rebates can ease the labor cost impact, and the long lifespan of LEDs can reduce maintenance costs.

DiLouie: What are the top 3-5 trends in indoor LED luminaire design today?

Werr: The single biggest trend is the inclusion of dimming capability as an integral and expected function of nearly all LED luminaires—once a luxury upcharge for fluorescent and impossible for HID. Those in the market would be wise to choose a manufacturer that offers products with dimming capability at no additional cost. An additional benefit that comes along with standard dimming capability is the trend toward “smart sensing” in which each fixture may have integral occupancy/vacancy sensing, daylight harvesting or both, which maximizes energy conservation fixture by fixture. Those in the market can find fixtures that offers these options at a modest premium. Another trend is the ease through which lighting specifiers can select the lumen and wattage packages most appropriate for their projects. We offer our customers the ability to select light output levels in increments as fine as 50 lumens.

DiLouie: What impact are these trends having on the market in terms of moving the ball forward, satisfying users, and exceeding current conventional lighting offerings?

Werr: The trends emerging via LED technologies permit specifiers, owners and occupants to control their lit environments with unprecedented precision, comfort and energy savings.

DiLouie: Where do you see these trends going in terms of future direction?

Werr: The more the market embraces the unique features afforded by LED luminaires, the less expensive those features become, leading to increasing acceleration of adoption.

DiLouie: What do you see as future trends in indoor LED luminaire design that will become possible as the technology continues to develop?

Werr: One lightly tapped potential enabled through solid state technology is the ability to provide customized spectra tuned to the specific needs of non-human biology. For example, we offer an LED product that optimizes horticultural illumination by emitting light only in wavelengths needed by the process of photosynthesis.

DiLouie: Please comment on the evolution of optics for indoor LED luminaires, giving particular focus on how optics have changed to accommodate the LED light source.

Werr: Precise optical design for many applications becomes more effective the smaller the source gets. LEDs, being as near to pure point sources as our industry has ever seen, present optical engineers with unprecedented ability

DiLouie: Please comment on the evolution and demand for indoor LED luminaires that feature serviceable components such as light engines, drivers, heat sinks and optics.

Werr: One unfortunate byproduct of the LED revolution has been the proliferation of “throwaway” luminaires that lack serviceable light engine components. Granted that certain specific applications make serviceability impractical, for most applications such as recessed troffers and high bays, specifiers and end users should insist on light engines, drivers and optics that can be replaced or upgraded from below. Despite the implication from some lower tier manufacturers, LEDs do not last forever, and even if they did, they are continuously improving in performance. Responsible manufacturers provide the ability to upgrade luminaires as more energy-efficient light engines become available.

DiLouie: Please comment on the evolution of form factors for indoor LED luminaires and viability of new form factors.

Werr: The most obvious impact on form factor for LED luminaires is the compact size of the light source. With small sources like LEDs, not only do they take up less physical space, but to achieve effective optical distribution, they reduce the distance needed between the source and light shaping elements such as refractors and reflectors. The small form factor of the LD, however, does not necessarily lead to smaller luminaires. Offsetting factors such as thermal mitigation, the ubiquitous 2’x2’ and 2’x4’ grid ceiling and the ongoing need to manage luminance to reduce glare imposes practical limits on the physical dimensions of luminaires.

DiLouie: What should distributors be doing right now to maximize the value they offer to their customers in lighting projects featuring LED products?

Werr: The first benefit distributors can offer in the LED revolution is in customer education. It is essential to become fluent not just in concepts like efficacy, CRI and CCT, but also in topics such as LM-79 and LM-80, TM-21 (reported vs. calculated) and MacAdam Ellipses to help dispel the widespread misunderstandings about the application of LED fixture.

DiLouie: If you could tell the entire electrical industry just one thing about trends in indoor LED luminaire design for commercial building applications, what would it be?

Werr: With steadily improving performance and falling cost of ownership, LED luminaires will all but displace incumbent technologies in a few years’ time, and a viable future usurper has yet to appear on the horizon.

Lighting Controls Association Adds New Course on Tunable-White Lighting

The Lighting Controls Association (LCA) has published a new course to enhance its popular Education Express program: EE303: Tunable-White Lighting. As acting education director of LCA, I was happy to have the opportunity to author this content.

LED lighting technology promises many benefits, one of which is practical color output tuning. Popular approaches include full-range, dim-to-warm and white light tuning. EE303 covers tunable-white lighting technology and application. Students learn color fundamentals and how to select and apply appropriate color-tuning approaches and tunable-white lighting technologies.

EE303 is registered with the American Institute of Architects (AIA) Continuing Education System (CES), which recognizes 2.0 Learning Units (LU)/Health, Safety, Welfare (HSW) credits; and the National Council on Quality in the Lighting Professions (NCQLP), which recognizes 2.0 LEUs towards maintenance of the Lighting Certified (LC) certification.

To register and take this course, click here and then click the Education Express button on the right.

Interview with Juno’s Scott Roos on Light and Health

I recently had the pleasure of interviewing Scott Roos, Vice President Product Design, Juno Lighting Group (Acuity Brands). The topic: lighting and health. I’m happy to share his responses with you here. The interview informed an article I wrote for the August 2016 issue of tED.

DiLouie: What do we currently know with a fair degree of certainty about the relationship between light and health?

Roos: We know with certainty that for normal populations exposure to blue rich light during the day supports optimal circadian health, and exposure to blue rich light at night disrupts our circadian rhythms with negative consequences for sleep and health.

DiLouie: What don’t we know yet? What research is being done to gain this knowledge, and how might it affect lighting practice?

Roos: Our knowledge of how specific wavelengths, doses and exposure times impact our various biological, physiological and behavioral systems and how these can be effected by personal factors such as age, caffeine consumption or specific health conditions, while increasing, is still limited. Numerous research studies continue to be conducted by both the public and private sector. As these research results along with early adopter applications come online with evidence- based results, our knowledge base and ability to provide more concrete recommendations for lighting practitioners will continue to increase. The most comprehensive listing of research in this field can be found on the Lighting Research Center website It is also important to understand that the study of light and health is a subset of a larger emerging field of study known as circadian medicine, of which light exposure is an important, but not the only component.

DiLouie: The relationship between light and health is now turning into a conversation about best practices related to lighting design and health. What can the lighting industry definitively claim at this time?

Roos: First, there is no substitute to being exposed to natural light. Taking time in the morning and during the day to go for a walk may sound simple, but it is probably the best way to optimize your circadian entrainment. Likewise, there are numerous studies going back many years that show how day lighted interiors with a view support health and well-being.

Second, during the day when indoors, while we may not know everything about how the exact spectra and amount of artificial lighting effects our health and wellbeing, for normal populations you probably can’t have too much illumination or too cool of a color quality of light. Typical indoor artificial illumination is much warmer and at much lower levels than what we experience outdoors.

Third, at night minimize both the amount and the blue content of light.

And fourth, recognize that negative lifestyle habits, including using self-illuminated devices at night, can negate the impact of even the best thought- through interior circadian-sensitive lighting plan.

DiLouie: How do you feel about where the industry is currently going with this? Do you think we’re getting it right? Where are we getting it wrong? How close are we to an industry recommended practice?

Roos: The “typical” lighting scenario of working in a cool, brightly illuminated office during the day and a warmer, more dimly illuminated home environment during the evening is actually spot-on in terms of supporting good circadian health for normal populations. We are starting to characterize the circadian content of various light sources, which is different than the visual amount of light as measured in lumens or footcandles. Understanding this will help us do a better job selecting the most efficient light source in terms of either eliciting a circadian response during the day or preventing it at night. And optimizing the circadian content of a lightsource will allow us to stimulate a circadian response with lower levels of illumination, which will address the concern over having to using more energy for circadian lighting installations. As we continue the migration toward LED technology we will have more refined ways to optimize the quality and amount of light both during the day and at night.

For example, we can now spectrally tune LEDs both to insert or remove blue content and can specify warm dimming as an option on an increasing array of luminaire types. As far as IES recommended practices on Light and Health, while we can reasonably expect to start seeing references made to this subject in various publications, including the soon to be updated IES RP-29 Lighting for Healthcare Facilities, specific recommendations are still several years away. It is one thing for someone like myself who follows this topic to express opinions based on reviewing research, presentations and having discussions with leading experts. It is yet another for an industry organization such as the IES to publish recommendations that need to be based on exacting research and evidence-based results. By the time these are available I expect that the basic principles of healthy circadian lighting for normal populations will already be widely understood. The biggest impact that the recommended practices will likely have is on the nuanced use of lighting for non-normal populations such as shift workers, less mobile elderly in extended care facilities and people with specific health conditions.

DiLouie: In healthcare environments, what role can lighting play in facilitating well-being and enhancing the treatment and healing process?

Roos: The answer to this question contains both simple and complex components. The simple components involve providing as normal of an exposure to simulated day/night quality and cycles of illumination for the benefit of the patients. The medium complexity issues are how to best keep healthcare night shift workers alert, productive and less error prone while supporting their circadian health. And the most complex aspect of this, relating to enhancing the treatment and healing process, will be borne out of the growing body of research where scientists are studying the effect that different spectra, amounts of light, exposure times and time of day that exposures are administered have on various medical conditions and the efficacy of the plethora of pharmaceutical treatments.

The first issue can be addressed by the lighting practitioner with a modest bit of research and education. The second issue can be addressed by the lighting practitioner in cooperation with experts on 24/7 work environments and circadian health. This likely will entail both the specification/installation/commissioning of a given lighting system and ongoing monitoring of shift workers’ biological markers with real-time feedback to adjust the lighting system as needed. And the third issue will fall mostly outside the scope of a lighting practitioner and into the domain of a healthcare professional. The lighting practitioner may be directed to specify a given luminaire, likely listed with the FDA as a medical device, with a given set of capabilities and be responsible to place the fixture(s) such that their location and interaction with room surfaces optimizes the amount of light actually reaching the patient’s eyes. But a healthcare professional will be responsible to select the exact spectra, amount, timing and duration required for a given patient.

DiLouie: What are the benefits for owners of commercial lighting systems for giving design priority to lighting that is conducive to circadian health?

Roos: While still very early in the adoption cycle there is a small, but growing body of early-adopter applications that are demonstrating that the principles of optimized circadian lighting as proven in laboratories can indeed improve an occupant’s productivity, health, sleep and emotional well-being. This applies across a wide range of applications ranging from sports team locker rooms, classrooms, special education facilities, extended care facilities offices and 24/7 industrial operations. Each different application will yield its own set of benefits for which the building owner can decide if it is worth the extra effort and cost to achieve. For a school it might be higher student achievement/attendance. For an office it might be higher employee productivity & morale, reduced sick days/medical claims and lower turnover. For a healthcare facility it might be quicker patient healing times, improved health & attendance of night shift staff with a lower rate of errors. And in a 24/7 industrial it could be improved worker safety, performance and attendance.

DiLouie: What should electrical distributors be doing at this time to properly promote and sell lighting solutions that are conducive to health?

Roos: The biggest thing that an electrical distributor can do at this point in the adoption cycle is to educate themselves such that they can at least bring up the opportunity and benefits that optimized circadian lighting can have, on top of basic energy savings, to their clients, and then position themselves to partner with independent consultants and knowledgeable manufacturers to help them recommend and implement the best solutions. Also, it is important to be able to recognize and point out situations that can be especially detrimental if circadian lighting principles are not adhered to. For example, if you are working on project to light classrooms or lecture halls that will be used both during the daytime and evening, you owe it to your customer to make them aware that providing blue rich light in a classroom at night can negatively impact student performance and well-being. Or, if you are lighting an extended care facility consider recommending that your customer work with an expert to optimize the lighting such that it will significantly improve the physical and emotional health and social integration of residents, help improve the working conditions for staff and likely lower the cost of care.

DiLouie: If you could tell the entire electrical industry just one thing about lighting and health, what would it be?

Roos: The whole field of circadian medicine, which includes circadian lighting, is an emerging field that is poised to have a monumental impact on human health, well-being and productivity. It will increasingly effect preventive health, medical treatment protocols and guide how we light our daytime and nighttime environments. Like any new field it likely will take a decade or more to become mainstream, but that creates a great opportunity for you to lead your organization into this emerging field and create your network of experts that allows you to step into a non-commoditized “blue-ocean” field and differentiate yourself in your served markets. Don’t take my word on it…do your own research, starting with the information posted on the Lighting Research Institute and Human Centric Lighting web sites, and form you own conclusions.

AIA Survey Finds Healthy Buildings Becoming Key Design Priority

Nearly three quarters of U.S. architects say the health impacts of buildings are influencing their design decisions. That finding parallels a strong market demand by building owners, with a solid two-thirds surveyed also reporting that health considerations affect how they design and construct buildings.

These findings and others were recently released in a new report, The Drive Toward Healthier Buildings 2016 by Dodge Data & Analytics, in partnership with Delos and the Canada Green Building Council, and with the participation of the American Institute of Architects as a critical research advisor and partner.

According to the report, the top five healthier building features implemented by architects include:

· Better lighting/daylighting exposure

· Products that enhance thermal comfort

· Spaces that enhance social interaction

· Enhanced air quality

· Products that enhance acoustical comfort

Use of nearly all of these is expected to grow considerably, the report found.

The findings suggest electric lighting and daylighting will play a leading role in this trend.

Check out the report here.

Product Monday: LumeLEX Pendant Downlight by Lighting Services Inc

Lighting Services Inc’s LumeLEX 2048 Series is an elegant fixed pendant downlight designed with Dim to Warm and Xicato XTM LED technology up to 23W.

Developed specifically for hospitality and transitional space lighting, the LumeLEX 2048 with Dim to Warm differentiates itself by providing up to 1,300 delivered lumens with a system efficiency of 59 lumens/W, a proprietary mixing optic for smooth even light (20°- 50°), halogen mimicking color CCT from 2800K down to 2000K, and a full range of internal accessories.

The LumeLEX 2048 with Xicato XTM offers up to 2000 delivered lumens, choice of color temp (2700K or 3000K), optic choice (10°- 60°) and a full range of internal accessories.

Click here to learn more.

Five Major Trends in Indoor LED Luminaires

Below is my lighting column published in the October issue of tED Magazine. Reprinted with permission.

Strategies Unlimited has forecasted that by 2022, LED luminaires will achieve a 60 percent share of global luminaire shipments.

In the U.S., three major manufacturers of indoor LED luminaires say LED already constitutes a majority of their indoor luminaire sales.

“The rate of change in the lighting market is unprecedented,” says Jerry Mix, CEO, Finelite, Inc. “Five years ago, LED was suspect, incandescent was standard for residential applications, and fluorescent dominated commercial lighting. Today, incandescent is out, and fluorescent is being overtaken by LED.”

“We see legacy sources being almost completely eliminated from our business within the next few years, speaking strongly to the level of market share and adoption,” says Imran Ahmad, General Manager, Architectural Lighting, Eaton’s Lighting Division.

Martin Werr, Director of Product Innovation, Hubbell Lighting, believes a majority of LED retrofits now involve new luminaires. “A significant percentage of customers, however, accept half-measures through the use of LED replacement lamps in an effort to mitigate first costs,” he adds. “Typically, however, these result in less-than-ideal performance compromises.” An exception, he points out, being luminaire retrofit kits.

Mix, Ahmad and Werr identified five key trends in indoor luminaires that reflect innovation and are driving category growth.

LED luminaires are getting sleeker. LED sources are highly compact and reduce the distance required between the source and optics. As these sources become more efficacious—producing more lumens per watt—fewer sources are needed, which reduces the size of the heat sinking and housing. As a result, the early clunky LED luminaires are giving way to the current generation of sleek products. While sleeker, luminaires are not necessarily smaller, as they are often designed to replace existing luminaires. However, the smaller light source enables new form factors now being explored.

Mix calls this “tailored lighting”—luminaires that follow architectural forms, available in quick-shipped custom configurations. “Demand for the design freedom of tailored lengths and configurations is growing exponentially,” he says. “Tailored lighting—lines of light defined by architecture—has seized the imagination of architects and lighting designers and changed the expectations of owners and tenants.” Mix sees lighting as becoming defined by architecture and a more permanent part of the built environment, similar to windows, doors and walls.

While most luminaires are highly integrated appliances, a growing number of manufacturers are offering serviceable luminaires, though these features may impose a cost premium in exchange for the added value. “For most applications such as recessed troffers and high bays, specifiers and end-users should insist on light engines, drivers and optics that can be replaced or upgraded from below,” says Werr. “Despite the implication from some lower-tier manufacturers, LEDs do not last forever, and even if they did, they are continuously improving. Responsible manufacturers provide the ability to upgrade luminaires as more energy-efficient light engines become available.”

LED lighting is available in custom configurations and lengths, allowing lines of light to be integrated into the built environment. Image courtesy of Finelite.

LED lighting is available in custom configurations and lengths, allowing lines of light to be integrated into the built environment. Image courtesy of Finelite.

LED sources and optics have become integrated. As highly compact, directional point sources that produce very little radiated heat, LEDs offer the ability to attach optics directly to the source. This promotes very high optical efficiency (90-95 percent) while enabling light to be placed in precise patterns, improving application efficiency.

“Given that LEDs deliver flux within a narrower zone than traditional sources, LED optical systems are much more efficient since much less light is wasted,” says Ahmad. “Over time, we have seen optical systems evolve by getting smaller, more efficient and more precise.”

New optical approaches include total internal reflection (TIR) lenses, prismatic films and light guides. For tunable-white lighting, a diffusion film of frosted internal optical elements may be used. For architectural visual-comfort applications, edge-lit panels are trending.

Lighting is increasingly customizable. Traditional lighting is typically specified in standardized lumen packages and form factors, designed in more-or-less standardized layouts, and not very controlled. In contrast, LED lighting can be specified with drivers programmed across a wide range of lumen and wattage packages, which allows light levels and power to be tuned to individual project needs.

Good controllability is broadening application of lighting controls. LED lighting features instant-ON (with negligible depreciation in source life), inherent compatibility with intelligent controls, and dimming as a standard or standard option for the large majority of luminaires. Coupled with the miniaturization of sensors and advances in radio-frequency wireless communication, many luminaires are now being packaged with onboard sensors and wireless networked lighting control. This facilities greater energy savings, flexibility and potentially collection of data.

“The single biggest trend is the inclusion of dimming capability—once a luxury upcharge for fluorescent and impossible for HID,” says Werr. “Those in the market would be wise to choose a manufacturer that offers products with dimming capability at no additional cost. An additional benefit is the trend toward smart sensing in which each fixture may have integral occupancy/vacancy sensing, daylight harvesting or both.”

This luminaire combines OLED and LED light sources in the same luminaire, producing comfortable direct lighting via the OLED and precisely controlled uplight (the primary source of illumination) via LEDs. Image courtesy of Peerless Lighting (Acuity Brands).

This luminaire combines OLED and LED light sources in the same luminaire, producing comfortable direct lighting via the OLED and precisely controlled uplight (the primary source of illumination) via LEDs. Image courtesy of Peerless Lighting (Acuity Brands).

Luminaires now offer ability to tune shade of white light.
LED luminaires are available that allow color output to be adjusted automatically or manually. The major options include dim-to-warm, full-color-tuning and tunable-white products. This has allowed greater LED penetration while opening new applications and joining the growing conversation about lighting that supports circadian health. LEDs can also be designed with customized spectra for specialized applications such as horticultural lighting.

“There’s no doubt that demand for tunable white light, circadian design and individualized control over color and intensity is rising,” Mix says. “As we gain a better understanding of the impact of the color of light on health and wellness, demand for this technology will accelerate.”

These trends will strengthen in the future. With performance and reliability increasing while costs decline, the future will see these trends accelerate toward an LED future. Meanwhile, new software and infrastructure will promote luminaires equipped with additional sensors that enable the collection of data that can improve business operations.

“In the future, luminaires will be more intelligent and will be a primary vehicle for receiving and delivering meaningful data to the owner and/or occupant of the space,” Ahmad says. “Intelligent features will range from wireless communication, occupancy sensing, heat sensing, daylight sensing and color changing, and will be built in for a relatively low cost compared to today. The next frontier of lighting will be the development of software tools and applications that help clients run their businesses better.”

Jim Brodrick on Optimizing Human, Animal and Plant Responses to Light

Republication of Postings from the U.S. Department of Energy (DOE) Solid-State Lighting Program by Jim Brodrick, SSL Program Manager, U.S. Department of Energy

Among the many possibilities enabled by the advent of SSL is the use of light to trigger or suppress certain physiological responses of living things — from humans, to animals, to plants. SSL makes this possible because of its controllability in terms of on/off/dim, spectrum, and light distribution. But a much better understanding of the responses to light by humans, animals, and plants is needed in order to take full advantage of this intriguing potential.

That’s why DOE recently facilitated two roundtable meetings — one in April on animal responses to light, and one in July on human physiological responses to light. The roundtables featured experts in the respective fields (human or animal response to light), along with members of DOE’s SSL team and experts in LED lighting. The discussions highlighted what we know and what we don’t know, focusing on common research themes, research challenges, and paths forward toward a better understanding of human and animal responses to light.

The April roundtable, hosted by the Midwest Energy Efficiency Alliance in Chicago, focused on three fields of animal research: livestock productivity and wellbeing, wildlife and landscape ecology, and animal testing for human medical research. While each faces unique challenges, the attendees indicated that research should focus on determining what lighting spectrum, control protocol, distribution, and intensity are necessary for the desired benefit. This understanding would enable development of SSL products that increase animal wellbeing and the productivity of livestock operations, minimize wildlife and ecological impacts, and improve the effectiveness of human medical research.

The July roundtable meeting focused on human physiological responses to light. Participants identified four research themes: photoreceptive inputs and their responses, methods of circadian and neurophysiological regulation, human physiological responses to light, and product application hurdles. It was agreed that the researched effects of light on humans are critical for understanding what inputs could produce different nonvisual effects, and that much more research is necessary. Additionally, with the proper understanding of the specific effects of light on alertness and sleepiness, light could potentially act as a non-pharmaceutical tool to support a healthy circadian rhythm. And while existing research assures us that short periods of direct LED light exposure from almost all commercial products will not cause optical damage, additional work is needed to confirm that, for any kind of light source, there are no spectral power densities that can cause problems with prolonged exposure. The experts concluded that findings from controlled laboratory-scale studies need to be further evaluated under real-world conditions. Studies coordinated between physiologists and LED lighting experts would help clarify what happens when photoreceptors receive different inputs, and how light could best be applied to help control circadian and neurophysiological regulation and reduce the occurrence of light-influenced disorders. Ultimately, this will enable better metrics for describing physiological impacts of light and creating products that address these responses.

In addition, in May DOE participated in the 8th International Symposium on Light in Horticulture (LightSym 2016) at Michigan State University, in order to learn and to take part in the discussions. The use of LED lighting in horticulture is attracting considerable attention, since spectral, distribution, and instantaneous on/off/dim capabilities of LED lighting can be used to affect the size, color, nutritional content, and growth rate of vegetables, fruits, and flowers in greenhouses and vertical farms. The underlying efficiency improvements and cost reductions that have allowed LED lighting to gain adoption in general illumination are also expected to drive adoption in horticultural applications.

The physiological responses of plants, animals, and humans to light represent a complex interaction that requires dedicated research efforts. At the same time, the advent of SSL has enabled new levels of control over lighting that can be guided by better understanding of its nonvisual benefits. These new levels of control enhance the value of SSL in many applications that go beyond the static provision of light. This new added value can be applied to lighting that interacts with living things. However, a better understanding of the underlying responses to light is critical, as well as new metrics and criteria that can be used to drive product development and communicate the new values presented by LED technology.

The roundtable reports are available online.

Interview with Hubbell’s Chris Bailey on LED Optics

I recently had the pleasure of interviewing Chris Bailey LC, LEED AP BD+C, DDI, MIES, Director, Business Development and Product Innovation, Hubbell Lighting, Inc. The topic: trends in LED optics. I’m happy to share his responses with you here. The interview informed an article I wrote for the June 2016 issue of tED.

DiLouie: What is the purpose of an optical system, as applied to a light source in any luminaire or directional lamp?

Bailey: The purpose of an optical system is to redirect the light emitted from the source or sources as a means to achieve a desired photometric effect. This may vary from the overtly creative to the highly technical. Whether the goal is to enhance productivity, reduce errors, prevent crime, increase occupant safety, satisfaction and comfort or to simply create drama, light is capable of doing so much, given the appropriate optical system.

DiLouie: What optical approaches are common for traditional fluorescent, HID and incandescent/halogen luminaires and directional lamps?

Bailey: Light emitted from most any lamp is controlled in a similar way, through reflection and refraction. Lamp characteristics such as surface temperature, lamp profile/shape, lamp source distribution pattern, lamp envelope (size), surface brightness, etc. play a role in how optics are physically carried out. To the extent that these characteristics are somewhat similar, the optical systems deployed are similar as well.

DiLouie: What optical approaches are common for LED luminaires and lamps? Why were these approaches developed?

Bailey: Just as the use and application of LED technology broadly covers general ambient and specialized categories, the optical systems in use today for LED luminaires and lamps ranges from the simple, like frosted diffusers, to the complex and elaborate, for example nested TIR (total internal reflection).

In residential applications, as well as some recessed linear commercial applications, it is relatively common to use an interior reflective white surface or frosted (at times prismatic) diffuser, prismatic film, or a combination thereof, to collect, shape, diffuse, control and transmit the light emitted from a luminaire. Typical materials for both recessed and suspended linear products include matte and mirrored linear reflectors, molded prismatic lenses (for control and diffusion), louvers and light guides.

Recessed downlights intended for architectural and commercial applications more frequently utilize specular reflectors in an effort to maximize efficacy, enhance photometric precision, manage striations, minimize the apparent brightness of the reflector surface and generally blend into a commercial or architectural ceiling. Typical materials and approaches include Alzak reflectors, molded baffles, Fresnel lenses and regressed optics. More recently, the use of TIR optics and/or prismatic films have been deployed in this category of products. As such, the role of the specular reflector, in some cases, is has become simply aesthetic or used for lamp source shielding. The use of diffusion film of “frosted” internal optical elements are also used today where different (color or color temperature) LEDs are being utilized (ex: multi-die LED array) within a single luminaire; as would be in the case in a “color tunable” and some “dim-to-warm” products.

Perhaps the most common optical system in use today for industrial, outdoor and some indoor products is the TIR optic, which are available in a range of materials such as acrylic, polycarbonate, silicone and glass. While some reflector-based LED optical systems are in used today, this approach has proven to be one of the most efficient means of maximizing both optical coupling (light extraction) and optical efficiency (light transmission). These lenses can be designed as single elements or molded in an array to control the light from multiple LEDs and encompass some of the necessary mechanical provisions.

DiLouie: What are the benefits of these optical approaches compared to optics for traditional products?

Bailey: While some of these optical approaches should seem quite familiar, some are distinctly new (ex: light guides and TIR optics). Given the relatively small format of LED sources and inherent directionality of light emission, these approaches uniquely enable LED luminaire designers to imagine new luminaire physical profiles and maximize luminaire efficacy.

DiLouie: What are the top three trends in LED optical design? Light guides, TIR and diffusion

Bailey: Light guides, TIR and combination optics (reflector + TIR overlay).

DiLouie: Some manufacturers are offering 3D printed optical systems allowing optics to be made to individual specification. What are the pros and cons and target markets for this offering?

Bailey: 3D printing holds much promise for the solid-state lighting industry. Given the relatively high cost of injection molding reflectors or TIR optics, 3D printing enables optical designers and manufacturers to either quickly evaluate several optical approaches or confirm design assumptions prior to committing to the cost and lead-time for optical tooling and first article parts. While the precision of some 3D printers might be high enough for production optics, these printers are still rare, and the piece part pricing is still much higher than traditional injection molding. Also, the UV stability, transmission (clarity) and surface finish available from the resins and 3D printers in use today may limit the applications to those indoors, at least for the time being. However, the recent developments with 3D printing technology certainly holds promise for cost-optimized and production-grade 3D printed optics in the future.

DiLouie: Some manufacturers are now offering TIR lenses for chip-on-board arrays. What are the pros and cons and target markets for this offering?

Bailey: Generally speaking, the sheer size of chip-on-board LED array require larger discrete optics. This can be somewhat limiting when molding precision plastic parts. Also, efficiently coupling to a plurality of LEDs within a single LED package can be challenging as well. If a generally symmetrical optical pattern is desired, then a COB with a TIR or combination (reflector + TIR) optic may hold promise. However, it may not be ideal for COBs – at least today – in asymmetric outdoor distributions or those applications requiring high center beam candlepower (CBCP). Companies, such as Fraen, have developed nested two-piece TIR optics for COBs which utilize a transition layer to aid in the collimation of light emitted by larger COB arrays. Most recently, many manufactures have resorted to “oversizing” the COB and lowering the current density to the internal LED array which helps overcome lower optical efficiencies by increasing source efficacy. While this may lead to relatively high delivered system efficacies, this approach does not necessarily improve lumen utilization or light on target.

DiLouie: What is the overall trend in LED optical design? What will LED optics look like in 3-5 years?

Bailey: As luminaires are purposely designed around LED sources, versus the common practice of “LEDifying” luminaires designed for legacy technologies, optical systems will continue to grow in significance. It is the “business end” of the luminaire. It represents a significant opportunity for specifiable differentiation and will remain such for years to come. As the overall physical footprint of LED luminaires scales, presumably down, to LED sources, optical systems may also play an increasing role in the overall fixture design and aesthetics.

DiLouie: What is the minimum electrical distributors should understand about optics when selling LED products to their customers?

Bailey: It’s not about lumens and efficacy. Some of the better performing luminaires may require less light (and corresponding fixture power) to meet the required light levels. Also, some products may sacrifice system efficiency to provide significant improvements in uniformity, reductions in glare and increased target efficacy. Suppliers should demonstrate a solid understanding of how to make LEDs work for you and provide compelling application performance for your customer though advanced optical design and technology.

LED A-Line Lamp Shipments Decrease in Second Quarter of 2016 While Still Maintaining Year-Over-Year Growth

LED A-line lamp shipments posted a 21.2% quarter-over-quarter decrease in the second quarter of 2016 compared to last quarter, but enjoyed year-over-year growth of 40.6%.

Meanwhile, halogen A-line lamps shipments show virtually no year-over-year growth at 0.2%, but after a decrease in the first quarter, saw a 14.5% increase in Q216.

Compact fluorescents lamp (CFL) shipments dropped a whopping 55.3% compared to last year and 16.3% compared to the first quarter of 2016.

In Q216, LED A-line lamps comprised 20.7% of the consumer lamp market, halogen A-line lamps 50.7%, CFLs 15.9%, and incandescent A-lamps 12.7% Incandescent A-lamps largely consist of 15W and 25W incandescent lamps.



Product Monday: New LED Lamps by Cree

Cree’s new portfolio of LED lamps includes 25 new products, designed to offer better light quality, dimming, life (most up to 22+ years), warranty and pricing. Color rendition is improved, with smoother, quieter dimming to levels as low as 1 percent. The new lamps meet or surpass the requirements for ENERGY STAR product certification and are covered by a 10-year warranty. The new bulb portfolio includes new A-lamps, BR lamps, PAR lamps and Candelabra lamps, as well as a new series of recessed downlight retrofit products.

Cree’s new lamps are available online and in-store at The Home Depot. Click here to learn more.