Conventional LEDs have been used for indication and display applications for several decades. The inherent benefits of LED technology are well-known and documented, and include, maintenance and power savings, as well as performance features that are taken for granted by electronics-savvy consumers such as durability, reliability, longer life span, and consistent color and brightness levels. These benefits, combined with society’s growing environmental concerns and subsequent demand for green, energy-efficient products, have continued to drive the development of LEDs for challenging new industries and markets, such as general illumination for commercial and residential adjustable downlight buildings. With the escalating demand for solid-state lighting, LED manufacturers are motivated to develop high-lumen LEDs while LED lighting companies are working hard to integrate the latest technology into retrofit packages and luminaries. However, new perspectives may be necessary for people to adopt LED technology as an illumination source in new installations, or incorporate LED technology in existing light fixtures.
Are LEDs suitable for commercial and residential lighting applications?
LEDs are arguably the most energy-efficient light source available. Case in point, LEDs have created upwards of 80 percent energy savings in the traffic signal industry. However, in this application, the LEDs had two natural advantages:
1. LEDs are monochromatic, so almost all of the light adjustable hotel downlight generated is used. In contrast, the white light generated by an incandescent bulb needs to transmit through a colored filter. Light outside of the frequency of the colored lens is wasted.
2. LEDs are directional, so almost all of the light generated was emitted towards the lens. In contrast, light from an incandescent bulb needed to be reflected toward the lens, resulting in loss of efficiency.
Commercial and residential lighting applications stand to gain similar, if not more, energy-savings by converting to LEDs. However, most applications are not as straight-forward as stuffing a PC board with a bunch of directional red, amber or green LEDs. LED light fixtures and retrofit packages have to be designed to distribute the directional light generated by the LED over wide areas. Moreover, white LED technology, while continuously improving, does not yet have the optical color and brightness that consumers have become accustomed to with incandescent lights. However, the power savings can be significant, for example, in California the energy commission has adopted efficiency standards for residential and commercial buildings. These standards, Title 24, have accelerated development of LED illumination technology.
Why LEDs are not in your house?
Unlike incandescent bulbs, high-power LEDs cannot be simply plugged into a wall socket. Several companies are working to overcome the technological and economic challenges by developing LED light fixtures and retrofit LED lighting products using high-power LEDs. Thermal management, complex drive circuitry, optics, and packaging are challenging hurdles for developers to contend with. There are also educational barriers to overcome in the development of commercial LED illumination products. Getting users to adopt new types of fixtures, understand the illumination characteristics of LEDs, choose the appropriate viewing angle for a given application, select the appropriate intensity for a given application, and understand the limitations of LED color temperatures are pivotal to developing the market for LED technology in commercial and residential lighting.
For the past couple of centuries, traditional luminaries have consisted of a light bulb and lamp socket that enables consumers to continually replace bulbs that have burned out. Whether it is an incandescent, compact fluorescent or fluorescent light bulb, it will simply screw or drop into an industry-standard socket and the luminary will continue to be operational. A few LED lighting companies have developed high-flux LED bulbs that retrofit into existing sockets; but this approach is less than ideal. For example, a traditional light bulb socket provides a very poor thermal path for cooling an LED light source. Incandescent light bulbs are basically heaters that produces visible light, and the socket it is screwed into is designed to protect the lamp base and wiring from that heat. With high-power LEDs, most of the wattage consumed is converted to heat and, if it can’t be dissipated through the lamp socket, will dramatically shorten the LED life.