A number of manufacturers creating products featuring light-emitting diode (LED) technology boast that they are offering the best in terms of brightness, efficacy, life expectancy, light output, thermal capability—the list goes on. But while LEDs currently are considered a viable alternative to incandescent or fluorescent lamps in a variety of installations, such as automobile interiors and electronic devices, issues still need to be resolved before LEDs are considered a preferred illumination source for architectural lighting applications. (See “The LED Evolution,” ARCHITECTURAL LIGHTING, Sept/Oct 2007, p. 85.)
LEDs still are seen as an emerging technology. The U.S. Department of Energy (DOE) is investing in solid-state lighting (SSL) research and in September 2007 released standards for LED lighting through its Energy Star program that will take effect Sept. 30, 2008. Major players in the lighting industry, such as Philips Lumileds, Cree, and Osram Opto Semiconductors, in addition to others, realize they cannot afford to fall behind when it comes to advancements in LED technology. But debate surrounds manufacturer claims that their LED products are the brightest or the longest-lasting based on the testing of the LED source itself, not its performance when actually installed in a manufacturer's luminaire. With new LED products being released on a regular basis, many manufacturers are quick to pronounce that their product is “a first,” “the best,” or “blowing away the competition”—but architects and lighting designers should be aware of the possibility that some of these statements might be inaccurate. While the DOE is conducting solid-state luminaire testing (the most recent results were released in August 2007), the number of manufacturers accurately reporting claims about their products has not significantly improved. The following are a handful of products either recently released or currently in development that, according to the manufacturers, are making strides with LED technology.
Philips Lumileds launched a new version of its Luxeon K2 LED featuring thin film flip chip (TFFC) technology. Overall, the manufacturer claims this cool-white LED is the first of a line of products that will lower light costs and deliver more light and higher efficacy. The TFFC technology assists in offering an improved light output, thermal capability, and optical performance. According to Philips, the Luxeon K2 with TFFC is the only LED designed, binned, and tested for standard operation at 1000 milliamps (mA), with capabilities of being driven at 1500mA. The product is best suited for security, roadway, or spot lighting applications and is designed to operate in harsh environments.
Osram Opto Semiconductors introduced the Diamond Dragon, a product that achieves a brightness of up to 250 lumens and is available in a white color temperature ranging from 2700K to 6500K, in addition to monochromatic colors. The manufacturer says it is the “brightest single-chip surface-mount LED” and that the technology is appropriate for applications such as indoor lighting and signal lighting. With an expected lifetime of 50,000 hours, the product is rated for 5W to 8W input power and is compatible with devices allowing upgrades for current Golden and Platinum Dragon users.
Another product touting enhanced brightness is Cree's green XLamp XR-E LEDs, which, according to the manufacturer, are 70 percent brighter than its previous generation of green LEDs. Now available commercially, the XR-E produces a maximum luminous flux of 87.5 lumens at 350mA. Norbert Hiller, Cree vice president and general manager for lighting LEDs, states in a press release that the product complements “the previously released blue XR-E LEDs for industry-leading performance in RGB LED applications” and allows customers to build more efficient, cost-effective fixtures using fewer LEDs.
Toronto–based GO Lighting Technologies recently introduced GO Flat LED Lighting (GO FLL) in November 2007, at the Property Management and Exposition and Conference in Toronto. Claims made by GO about GO FLL include the reduction of electrical consumption by 20 percent or more when compared with fluorescent lighting; a lifespan of up to 50,000 hours; no ultraviolet radiation or electromagnetic interference; and being fully recyclable with no hazardous disposal requirements. Sealed to keep out dust, insects, and humidity, the polycarbonate surface is resistant to temperature swings, will not become discolored, and saves on maintenance and labor costs because the need to change ballasts or replace tubes is eliminated. GO FLL fixtures can be mounted either vertically or horizontally or recessed into the floor.