Light-emitting diode (LED) technology enables the lighting industry to reimagine the lighting fixture in bold new ways. Another approach is to design replacement sources for existing conventional fixtures as a way to save energy and gain other potential benefits, including long service life, long mean time between failures, reliable operation in colder temperatures, and resistance to vibration. These general-service lamp replacements are typically integrated products, similar to self-ballasted compact fluorescent lamps (CFLs).
This approach is not as effective as a good purpose-built fixture, and overall, the lamp technology has progressed slower than the fixture side; however, manufacturers are making significant progress with LED directional and omnidirectional lamps. Discerning electrical contractors can use the state of current developments and tools to protect themselves and their customers from poor product.
The entire market is poised to experience a boom as the Energy Independence and Security Act of 2007 (EISA) takes effect in 2012. LEDs stand a chance to fill the vacancies of obsolete lamps in the coming years.
As inherently directional sources, LEDs are ideally suited to track and downlighting. Consider, for example, that there are more than 500 million recessed downlights installed just in U.S. homes, according to the Department of Energy (DOE). These are proven applications for LED directional lamps offered by manufacturers.
Legislation is creating demand for energy-efficient alternatives to incandescent reflector lamps that will accelerate in the near future. EISA and subsequent DOE regulations are eliminating many inefficient incandescent and halogen reflector lamps from the market. Compliant alternatives include halogen-infrared, ceramic metal halide, compact fluorescent and LED.
But how do LEDs stack up against other alternatives? Round 11 of the DOE’s independent CALiPER LED product testing—the most recent round as of the time of writing—shows LED PAR30 and PAR38 lamps exceeding the benchmark halogen infrared lamp in terms of light output and efficacy but not yet achieving equivalency with metal halide (see Figure 1). The testing also showed improvement in center beam candlepower, a critical metric with this lamp type (see Figure 2). All four of the tested PAR30 and PAR38 products surpassed the curve representing minimum requirements for equivalency with a 50-watt (W) halogen lamp—one borders on the limit for 75W halogen, and another even surpasses the mark for 75W halogen—while using 70–80 percent less energy. However, none of the four achieve the level of the 25W metal halide, which is compared in package labeling to a 90W halogen PAR38.
While manufacturers continue to make significant progress with LED directional lamps, contractors should remember that white-light LED is still a young technology. Manufacturers are still inflating sales claims and offering poor-performing products. To protect themselves, contractors should evaluate all aspects of products, not just watts, to determine suitability, and look for products that are recognized by independent testing and labeling such as Lighting Facts and Energy Star. Additionally, contractors should sample the product before committing to it.
In the latest round of CALiPER testing, the DOE found that products with Lighting Facts labeling—meaning the manufacturer is a member of the Quality Advocates Initiative and follows certain guidelines and labeling to report product performance—were more likely to have accurate sales claims (see “Quality Assurance,” page 66, for more on the Lighting Facts label). As of the time of writing, there were more than 2,400 products approved for the label, of which nearly 1,100 are replacement lamps.
Another important tool for identifying suitable products is the U.S. Environmental Protection Agency’s Energy Star product labeling program, which announced criteria for LED directional lamps effective Aug. 31, 2010. The Energy Star mark asserts that a product has been tested and determined to perform as well as an incandescent/halogen lamp while being more energy-efficient.
The criteria for LED directional lamps cover BR, ER, K, MR16, PAR16, PAR20, PAR30, PAR30LN (long neck) and PAR38 lamps. The product must produce an equivalent center beam candlepower using a calculator that is based on wattage and beam angle. It must also produce minimum light output of 10 times the wattage of the lamp intended for replacement. If the lamp is 2½ inches in diameter or smaller, it must operate at an efficacy of 40 lumens per watt (LPW); if larger, 45 LPW. Finally, the lamp must be available in a color temperature of 2,700K, 3,000K, 3,500K or 4,000K, have a CRI rating of at least 80 (R9 > 0), and a rated life of 25,000 hours. A significant number of directional LED lamps already carry the Energy Star mark on their labeling.
Compatibility with dimmers, particularly existing line-voltage incandescent dimmers, is a sensitive area. Neither Lighting Facts nor Energy Star indicate whether a product is dimmable. As a control effect for LEDs, dimming may increase efficacy and life. However, not all LED lamps are dimmable, and those that are dimmable may not be compatible with all dimmers.
Until the Solid-State Lighting 6 standard, covered on page 64, is widely accepted, it is recommended that contractors ensure the selected LED lamp and given controls are compatible. Assume they are not unless specifically stated.
LED omnidirectional lamps are now catching up to the rapid progress directional lamps have made, providing a proven alternative to decorative lamps and lower wattage A-lamps and beginning to be offered as replacements for wattages as high as 60W and 75W. The market potential here also is enormous. Consider, for example, that approximately 425 million 60W incandescent lamps are sold each year. ESIA, which will take effect in 2012, will eliminate the common 40–100W incandescent general-service lamps, putting hundreds of millions of sockets up for grabs.
The DOE’s CALiPER testing shows continuing improvement in light output and efficacy of LED omnidirectional replacement lamps, with products achieving efficacy levels (lumens of light output per watt of electrical input) similar to or even surpassing CFLs. Candelabra lamps provide similar performance as incandescent with 80 percent less energy. A-lamps are achieving the output and distribution characteristics of 40W incandescent lamps for up to 80 percent energy savings, according to CALiPER.
In the past year, there have been advances in the form of LED integral lamps targeted to replace 60W incandescent A-lamps. Early generations of these lamps did not match the light output and distribution of 60W lamps, but were positioned as viable alternatives for directional lighting fixtures (such as downlights) where using A-lamps typically results in fixture light losses of 30–50 percent. Round 11 of CALiPER testing, for example, included a product that, at 557 lumens, might be a viable replacement of 60W A-lamps in relatively directional applications. However, such a product might be marketed as equivalent to a 60W incandescent, which might lead some to believe it produces equal light output. As always, read the fine print.
The latest generation of 60W replacement lamps, now being introduced, are more robust, claiming 800–820 lumens of light output—about what 60W lamps produce—for 10–13W (up to 80 percent energy savings), a warm color tone and 80–84 CRI rating, dimming down to some low level such as 10–20 percent, and long rated life of 25,000–50,000 hours. Examples include the Philips EnduraLED, Sylvania A-LED, Lighting Science Group Definity A19, Switch Lighting Switch60 and a Cree 60W replacement. Switch Lighting has also announced a 75W replacement.
As manufacturers continue to push the envelope and achieve major milestones, we must remember that white-light LED is still a young technology, with the same risks and advice for caution.
As with directional lamps, Energy Star offers a tool for buyers. The criteria for LED omnidirectional replacement lamps became effective Aug. 31, 2010, and cover A, BT, P, PS, S and T lamps. The product must produce a minimum level of light output (between 200 and 2,600 lumens) based on replaced wattage (between 25W to 150W). If the lamp draws less than 10W, it must operate at an efficacy of at least 50 LPW; if 10W or larger, then 55 LPW. The lamp must have a color temperature of 2,700K, 3,000K, 3,500K or 4,000K and a minimum CRI rating of 80 (R9 > 0). Finally, it must operate at a power factor of 0.7 or greater if the lamp is larger than 5W and have a rated life of at least 25,000 hours. As of the time of writing, only one lamp, a GE product producing 470 lumens (equivalent to a 40W incandescent), qualified for the Energy Star mark on its labeling.
Additionally, Lighting Facts labeling is available for LED omnidirectional replacement lamps as it is for directional LED lamps, but may be supplanted by new lamp packaging labeling rules currently being implemented by the Federal Trade Commission. These rules, scheduled to go into effect Jan. 1, 2012, will cover similar information in a similar format, emphasizing light output as the primary metric, not watts, while providing additional information about color temperature and expected annual energy cost.
Linear LED lamps are proliferating in the market, offering direct replacements for 4-foot T8 and T12 lamps in existing troffers. They may use or bypass the existing fluorescent ballast. Sales claims include high efficiency, service life up to 50,000 hours with few spot replacements, cold-temperature operation, no mercury or lead, resistance to shock/vibration, and, in some cases, dimming on an existing dimming ballast. Two 18W LED lamps, for example, would generate up to 40 percent energy savings compared to two standard T8 lamps operated on an instant-start ballast.
Despite these claimed benefits, the current state of the technology appears to present some risks. The biggest problem is light output and resulting efficacy. The lamps produce significantly less light output. While it is true that the directionality of the LEDs results in 10–15 percent lower lighting fixture losses, it is not enough to maintain design light levels without adding lamps. Additionally, the strong directionality of the lamp distribution may negatively impact uniformity, producing dark spots between fixtures. Bypassing the ballast requires more labor in a retrofit, while using existing ballasts may reduce efficacy.
The category appears to be improving, however. CALiPER testing of 12 products up until the fall of 2010 revealed poor performance, low light output and resulting efficacy. In Round 11, six products were tested, and several performed fairly well in terms of efficacy, a big improvement. Nevertheless, none of the products tested in a parabolic troffer matched the light output, spacing criteria and light distribution produced by their fluorescent T8 competitors in the same lighting fixture. And several exhibited color qualities outside the standard tolerances for white light at their manufacturer-rated color temperatures.
“Although there may be certain situations where such products are viable alternatives, in most cases, they’re not yet competitive with their fluorescent counterparts, in terms of both cost and performance,” said Jim Brodrick, the DOE’s SSL program manager.
Although the DOE does not consider LED replacement lamps to be ready for Energy Star, it published suggested specifications for 4-foot, LED linear lamps. Available online at the DOE’s SSL website, these specifications provide a helpful tool that decision-makers can use to identify suitable products. Criteria include light output of 2,700 lumens, minimum 80 CRI, 2,700K–6,500K color temperature and a rated life of a least 35,000 hours. Clearly, LED replacements are available for a host of different lighting types. The key is trying them out and seeing what works for your application.
DILOUIE, L.C., a lighting industry journalist, analyst and marketing consultant, is principal of ZING Communications. He can be reached at www.zinginc.com.