Specifying LEDs For Commercial Use
The philosopher Albert Borgmann said, “Technology is most celebrated when it is most invisible—when the machinery is completely hidden, combining the simplicity of godlike effortlessness with blissful ignorance about the mechanisms that operate.”
Lighting, essential to see or do anything for life, work, or play, is such a basic technology. Today it is expected to be present everywhere, including the still-in-use 30 million commercial/ institutional structures erected in the United States prior to 1940, and even more residential units of that age. It is also the easiest discipline with which to conserve energy and reduce CO2 emissions. Unfortunately, lighting is often the last considered in planning and the first to be jettisoned in the budget crunch, when it should be designed as early as possible.
Good lighting enhances all design, conserves energy, and increases productivity, safety, security, personal comfort, sales, attendance, and profit. On the other hand, artificial illumination could consume up to 40% of a commercial structure’s energy, and prolonged exposure to harmful infrared (IR) and ultraviolet (UV) rays emitted by all light, natural and artificial, could accelerate disintegration of fugitive organic material components and contents (anything that once grew, like wood, paper, textiles, leather, ivory, lacquer, feathers, or bone).
In lighting, one size/type does not fit all. There are many tools of differing energy efficiency available for the lighting designer. However, only if all the most energy-efficient technologies best suited to the particular application are known and used, can affordable, sustainable sophisticated illumination be created within the increasing energy conservation regulations. The best practice: Keep the design of task and atmospheric lighting as simple as possible.
Advances in lighting
Every day, there are many revolutionary developments in lighting. Light-emitting diodes, or LEDs, are one. Semiconductor LEDs are solid state lighting (SSL) and, like glass fiber optics (GFO) functional architectural lighting, based on total internal reflection, they differ completely from conventional incandescent, fluorescent, halogen, and metal halide lamps.
LEDs are no longer an evolving topic but are now becoming mainstream for commercial or retail use, such as colleges/universities, data centers, laboratories and research facilities, high-rise multipurpose buildings, offices, hospitals, hospitality, recreation, factory/storage facilities, theaters/assembly, museums, water features, landscapes, libraries, retail stores, and other nonresidential facilities.
Illumination with LEDs could be functional (task, display, ambient, architectural features) or decorative. It may be interior or exterior, directional (spotlight), or ambient (general); automated or manually operated; wireless or wired; individually or centrally controlled with adjacent systems; or have special effects of color, motion, and dimming. Existing lighting fixtures may be retrofitted or historic light levels and colors recreated.
Sustainability is based on each component’s life expectancy, not just that of the chip. Binning (assembly of chips) determines distance of light thrown, resolution, and angle of visibility.
Color temperature of light is crucial. Higher Kelvin temperatures (4,100 K) allow older eyes to see better with less energy consumed. The color temperature selected depends upon the décor, with lower Kelvin degrees (2,700 K) to enhance warm colors (red/yellow/orange), and higher ones for cool colors (blue/green, etc.). A new Color Rendering Index (CRI) from the National Institute of Science and Technology (NIST, part of the U.S. Department of Commerce) is based on vibrant rather than pastel colors.
With LEDs, the metric sought is lumens (visible light output) rather than wattage (energy consumed). Lighting designers also should learn the light distribution, color quality and appearance, and shape and size of the bulb if retrofitting into an existing socket, as well as electrical compatibility with an existing system (transformer, dimmer, and connected load).