The LED industry is in the midst of a rapid development cycle. In an effort to lengthen bulb lifetime, intensify colors, and create higher energy efficiencies, manufacturers are developing LEDs at an intense rate.
To help Building Team members sort through the new technological dimensions of LEDs, we asked two top-rated LED experts—John W. Curran, PhD, president of LED Transformations LLC, an LED industry consulting firm based in Stanton, N.J., and Glenn Heinmiller, principal of LAM Partners Inc., an architectural design firm based in Cambridge, Mass.—for their advice.
1. Pencil out the economics of LEDs. Building Teams should evaluate the economics of deploying LED luminaires. Cost savings come from two factors: energy efficiency and long life. The higher the electric utility rate for the application, the faster the payback. A long lifespan provides reduced maintenance costs resulting in additional savings. “The LED fixtures must last as long as assumed in the ROI calculations,” says Curran. “This is often where the economics for LED fixtures falls apart.” According to Curran, Building Teams must also be careful not to assume a lifetime that the fixtures do not deliver due to bad information from the fixture manufacturer or misapplication by the specifier or contractor.
2. Determine if LEDs are the right application for your building. “The answer depends on the specific lighting application, local electricity rates, operating hours, maintenance costs, and availability of utility incentives,” says Heinmiller. Building Teams should help owners explore the length of the payback period versus best energy performance regardless of upfront cost.
3. Consider the physical environment immediately surrounding the LEDs. Very high-temperature environments can present problems for LED technology. For example, installing highbays in an uncooled warehouse in Arizona may result in greatly reduced lifetimes for the LEDs. Those same highbays in a cold storage facility will perform much better.
4. Be aware that dimming is still a major problem with LEDs. Not all LED products can be dimmed, and those that can may not dim smoothly or to a low level. This is due to the widespread use of phase-cut dimmers in concert with conventional incandescent lighting and the drivers—the electronics—that power the LEDs. “It’s not easy to predict how a particular driver will perform against a wide range of dimmers already installed,” says Curran. Currently, there are no standards for LED dimming control, so only certain types of dimmers or dimming protocols will work with a particular LED fixture. “Dimming problems will probably improve some with technology development, but there are no signs the industry is standardizing on a dimming protocol,” says Heinmiller.
5. Test the LED color rendition. “The color rendering performance of white LED sources is generally quite good,” says Heinmiller. “Testing is important, especially for applications where color rendition is crucial, in order to make sure you are satisfied with the results.” Eventually, there will be an improved color metric that will predict quality more accurately from the specifications. Until then, Building Teams should advise clients to test color-critical applications.
6. Check out the fixtures with the manufacturer. Ask the LED manufacturer about their quality control and the type of testing done on their drivers. Deal only with reputable suppliers and manufacturers: What good is a 10-year warranty when the supplier goes out of business in a few years? Ask the supplier how they plan to provide replacement fixtures in 3 to 5 years.
7. Look for the Lighting Facts label. Go to www.lightingfacts.com to learn about a U.S. Department of Energy program that showcases LED products for general illumination from manufacturers who commit to testing products and reporting results according to industry standards. The LED Lighting Facts label can provide Building Teams with essential information for evaluating products and identifying the best options.
8. Go with a pro. For complex projects, engaging the services of a qualified professional architectural lighting designer could save your client—and you—a lot of money and grief. “It is a complex problem to determine the correct light source for the application in order to achieve the best energy efficiency and high lighting quality,” says Heinmiller. If you focus only on lower energy efficiency, you could end up with a lower electric bill but poor lighting in your building—or worse, no savings and poor lighting. For projects such as relamping existing track lighting in a retail store, working with a respected manufacturer’s representative who supports mockups and stands behind the supplier’s LED products is probably sufficient.
What are OLEDs?
Organic light-emitting diodes (OLED) are a separate branch of solid-state lighting that are beginning to have an impact on the architectural lighting industry. “The major performance difference between LEDs and OLEDs is that LEDs are point light sources while OLEDs are area sources,” says Curran, president of LED Transformations. LEDs are much further ahead in regard to cost, higher efficiencies, and longer lifetimes. Currently, OLEDs are used in cell phone displays and a small but growing number of high-end designer lighting fixtures.
Learn more about LED standards
• ANSI C78-377-2008 Specifications for Chromaticity of Solid-State Lighting Products for Electric Lamps. ANSI C78-377-2008 provides a standard for qualifying the range of colors that can be classified a particular color temperatures.
• LM 79-08 Approved Method: Electrical and Photometric Measurements of Solid-State Lighting Products. LM 79-08 gives the proper test procedure to evaluate light distribution and power consumption for an LED fixture. LED fixtures require special testing (using absolute photometry) because LED light sources, unlike traditional sources, cannot be tested independent of the fixture due to thermal effects on performance.
• LM 80-08 Approved Method for Measuring Lumen Depreciation of LED Light Sources; and TM-21-11 Projecting Long-Term Lumen Maintenance of LED Sources. LM-80-08 and TM-21-11 provide guidance on measuring and predicting the lumen depreciation of LED devices, which yields an estimate of useful lifetime.
Related Stories
Industrial Facilities | Feb 27, 2015
Massive windmill will double as mixed-use entertainment tower in Rotterdam
The 571-foot structure will house apartments, a hotel, restaurants, even a roller coaster.
Architects | Feb 27, 2015
5 finalists announced for 2015 Mies van der Rohe Award
Bjarke Ingels' Danish Maritime Museum and the Ravensburg Art Museum by Lederer Ragnarsdóttir Oei are among the five projects vying for the award.
Office Buildings | Feb 26, 2015
Using active design techniques to strengthen the corporate workplace and enhance employee wellness
The new Lentz Public Health Center in Nashville, Tenn., serves as a model of how those progressive and healthy changes can be made.
K-12 Schools | Feb 26, 2015
Should your next school project include a safe room?
Many school districts continue to resist mandating the inclusion of safe rooms or storm shelters in new and existing buildings. But that may be changing.
K-12 Schools | Feb 26, 2015
Construction funding still scarce for many school districts
Many districts are struggling to have new construction and renovation keep pace with student population growth.
K-12 Schools | Feb 26, 2015
D.C.'s Dunbar High School is world's highest-scoring LEED school, earns 91% of base credits
The 280,000-sf school achieved 91 points, out of 100 base points possible for LEED, making it the highest-scoring school in the world certified under USGBC’s LEED for Schools-New Construction system.
K-12 Schools | Feb 25, 2015
Polish architect designs modular ‘kids city’ kindergarten using shipping container frames
Forget the retrofit of a shipping container into a building for one moment. Designboom showcases the plans of Polish architect Adam Wiercinski to use just the recycled frames of containers to construct a “kids city.”
Cultural Facilities | Feb 25, 2015
Bjarke Ingels designs geodesic dome for energy production, community use
A new building in Uppsala, Sweden, will serve as a power plant during the winter and a venue for shows, festivals, and music events during the warm months.
Cultural Facilities | Feb 25, 2015
Edmonton considering 'freezeway' to embrace winter
If the new Edmonton Freezeway is constructed, residents will have an 11-km course that winds through the city and allows them to skate to work, school, and other city activities.
Building Team | Feb 24, 2015
Call for entries: 2015 Giants 300 survey
The annual Giants 300 Report ranks the top AEC firms in commercial construction, by revenue.