Can anyone expect to keep up?
The deeper you venture into the lighting industry these days, the more you find yourself bombarded with information. Mastering the nuances of theatrical lighting, architectural, commercial, residential, lamps, ballasts, software, manufacturing, optics, codes and the rest of the continually expanding universe of lighting exceeds the capacity of any one human being. No one can absorb it all.
And just when we think we’ve acquired at least a reasonable foundation of knowledge about our industry, some new issue arises, and we are compelled to venture into yet another minefield of complexity. Consider just a few of the more recent issues to affect lighting:
Photobiology, the science of how living organisms interact with light;
New light sources such as optoelectronics and quantum technology;
New scientific methods for evaluating perception of light, which will force us to radically reevaluate recommended practices;
Sweeping energy and environmental legislation that is changing luminaire design and restricting lamp sources;
The expansion of the global marketplace.
Is the time drawing near when we’ll all need advanced degrees in physiology, psychology and international economic theory just to survive? Probably not, but follow these cursory descriptions of the issues listed above and it quickly becomes clear that there’s no room for dummies in this business.
Once visibility was simply accepted as the essence of lighting. But at the CIE Conference in June, Peter Boyce presented a paper asserting, “The future of lighting research in interiors lies in a move beyond visibility and visual discomfort to areas where lighting operates on mood and behavior through the ‘message’ it sends, and on health and task performance through the circadian system.”
At the same conference, George Brainard and Gena Glickman presented a paper titled “The Biological Potency of Light in Humans: Significance to Health and Behavior.”
And last January, at the 50th Annual Lighting Conference in Israel, Dr. Gerrit van den Beld observed in his talk, titled “What Is Healthy Light in the Workplace?” that “we are just beginning to understand the limits of light.”
While 24-hour artificial light cycles began influencing social behavior in the early 1900s, Dr. van den Beld pointed out, the human biological clock was not discovered until 1986, and the existence of photoreceptors other than for vision were not discovered until 2002. In other words, we are just beginning to learn about the total effect of light and darkness on all life forms, but especially on human health. Consider just a few critical recent findings:
Non-visual information is transmitted by a neural pathway into the part of the hypothalamus that is the primary circadian regulator of the sleep/wake cycle, body temperature rhythms and 24-hour secretion patterns of hormones.
Levels of melatonin, a hormone that affects our immune system, are suppressed by light. Thus, they are secreted at night and drop during the day. Even a very low level of “white” light results in dramatically decreased melatonin levels, a condition associated with increases in breast and prostate cancers. But the discovery of light-induced mela-tonin suppression also led to treatments for winter depression and circadian rhythm shifts.
Variations in light exposure can produce swings of up to 35% above or below normal morning levels of cortisol, a
steroidal hormone essential to regulating metabolism and the body’s reaction to stress.
Light has been shown to improve weight gain in premature infants.
Artificial light at night discourages zooplankton from surfacing in urban lakes, thus reducing the surface algae consumed by microscopic organisms and possibly leading to algal blooms and poor water quality.
Millions of birds die annually when they fly into lighted buildings at night. Moths and other insects waste energy flying around exterior lights and do not eat or reproduce, causing reduced populations in the Northeastern U.S. Exterior lighting has also contributed to problems with hunting, reproduction and foraging by nocturnal animals such as endangered ocelots and jaguars. Lights from developments of condominiums, houses and hotels along U.S. coastlines discourage sea turtles from nesting and cause hatchlings to become disoriented and wander inland, where they often die of dehydration or predation.
The light reflected off colored mulches now being used by strawberry and turnip growers affects leaf size, root size, flavor and aroma, as well as sugar and vitamin C content.
These kinds of research have already begun to change how we design luminaires and applications. In the future, it will not be sufficient to ask if we have enough light; henceforth, we will need to ask if we have too much light in the wrong places and if the spectral distribution is correct for the task.
Energy and Environmental Legislation
As of July 15, the ASHRAE/IESNA 90.1-1999 standard established minimum federal energy requirements for buildings in the U.S. Generally regarded as the definitive standard for achieving energy efficiency, it is being adopted as part of many other codes and standards, including the latest version of the International Energy Conservation Code or IECC. Widespread enforcement will shift demand from price sensitivity to a greater focus on efficiency.
The Leadership in Energy and Environmental Design (LEED) Green Building Rating System is a voluntary, consensus-based national standard for developing high-performance, sustainable buildings. LEED standards are flexible, enabling buildings to be certified according to their level of commitment to green design, which is reflected in a points-and-labeling system.
The International Dark-Sky Association, a tax-exempt nonprofit advocacy group, has influenced legislation in hundreds of municipalities in 31 states and 70 countries. The association works to stem the adverse environmental impact of light pollution and advocates solutions to improve the quality of nighttime lighting.
The Model Lighting Ordinance (MLO) from the IDA addresses exterior lighting concerns for communities and offers a lighting zone template for light levels, shielding, maximum lamp wattages and curfew times. The shielding stipulations and the wattage limitations will cause manufacturers to reevaluate their exterior luminaires. Some existing products, especially 1000-watt HID and unshielded types, will have little or no application opportunities.
The Global Market
As fixture and lamp manufacturers find themselves competing worldwide, international standards must be established and adhered to. U.S.-based luminaire manufacturers are embracing IP ratings, metric measurements, and an international paint-matching system. Electrical safety and hazard standards still vary by country, but efforts are underway to qualify and compare existing testing procedures for broader acceptance. Global testing standards will initiate a competitive world marketplace of lighting fixtures.
ETAL and Perception of Light
Evaluation Task Adaptation Luminance (ETAL) provides a scientific, rather than consensus-based, method for determining appropriate light levels. The challenge, paradoxically, lies in achieving a consensus on what the science means. “Spatial frequencies” are analyzed, with low spatial frequency defined as a large task, and high spatial frequency defined as a small task or a task with sharp defining lines. Digital images are used to calculate spatial frequency and to determine contrast ratios. Once our eyes have adapted to low light levels, it takes less light to illuminate a task, so task levels must be established for different levels of adaptation correlating to the lighting zone system. Once levels are clarified, energy consumption restrictions can be applied.
But how all that translates into practical applications is anything but clear. Type “scotopically enhanced” into any Web search engine and stand back. Debate on how to quantify the relationship of spectral distribution to our perception of brightness continues, but what is emerging is a trend toward cooler sources to maximize the appearance of brightness while reducing energy consumption. U.S. retail chains are considering 5,000K lamps indoors, and legislation requires metal halide sources in some municipalities. Industry recognition of this “blue lumen” effect is now widespread. Although the information conflicts, the color shift is visible.
Conventional lamp sources continue to yield market share to optoelectronic products, including light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs). Brighter “white”and “warm white” LED products (and the training of bi-lingual professionals who can bridge the language barriers separating the two industries) are propelling LEDs into new applications. In 2003, LED modular closet, undercabinet, IP68 rated, exterior pole mount, dock and medical chart lights were already offering alternatives to conventional sources. Unlike the point-source characteristic of an LED, OLEDs tease us with the promise of a general light source having long life, programmable color and numerous other advantages. Neither of these optoelectronic options has reached maturity yet, and we can count on continued growth into specialty and niche applications.
Many new methods of generating light will shape fixture and application design. For example, Tungsten Photonic Lattice shows opportunity for improved efficiency in incandescent filaments, while Multiple Quantum Dots placed near UV-emitting LEDs efficiently convert ultraviolet to visible wavelengths, with the shape and composition of the dots determining spectral characteristics. Vertical Cavity Surface Emitting Lasers (VCSEL) take advantage of short wavelength “blue” lasers to stimulate phosphors. This produces a fluorescent type of illumination without mercury and has other application possibilities.
What all this adds up to is a tumultuous time for the lighting industry. Information overload, new regulations, futuristic sources, worldwide markets and the sincere desire to reevaluate and improve current design practices should generate excitement in those of us who embrace progress and change. With new challenges come new opportunities, and those of us working in the lighting industry will have no shortage of either.
ABOUT THE AUTHOR: MARK LIEN, LC, CLEP, CLMC, IS A LEED ACCREDITED PROFESSIONAL AND MANAGER OF SPECIFICATION MARKETING AT THE COOPER LIGHTING HEADQUARTERS IN PEACHTREE CITY, GA.
· LEED: http://www.usgbc.org/LEED
· Legislation: www.cooperlighting.com/education/legis