LED Lighting Facts
What are LEDs?
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LED stands for light emitting diode. LED lighting products produce light approximately 90% more efficiently than incandescent light bulbs. How do they work? An electrical current passes through a microchip, which illuminates the tiny light sources we call LEDs and the result is visible light. To prevent performance issues, the heat LEDs produce is absorbed into a heat sink.
How is LED lighting different than other light sources, such as incandescent and CFL?
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- LED lighting differs from incandescent and compact fluorescent lighting in several ways. When designed well, LED lighting can be more efficient, durable, versatile and longer lasting.
- Common LED colors include amber, red, green, and blue. To produce white light, different color LEDs are combined or covered with a phosphor material that converts the color of the light to a familiar “white” light used in homes.
- LEDs are directional light sources, which means they emit light in a specific direction, unlike incandescent and CFLs, which emit light – and heat – in all directions. For this reason, LED lighting can use light and energy more efficiently in many applications.
LED Basics
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The useful life of LED lighting products is defined differently than that of other light sources, such as incandescent or CFL. This is because LEDs typically do not “burn out” or fail. Instead, they experience ‘lumen depreciation’, wherein the brightness of the LED dims slowly over time. Unlike incandescent bulbs, LED “lifetime” is established on a prediction of when the light output decreases by 30 percent.
LEDs and Heat
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LEDs use heat sinks to absorb the heat produced by the LED and dissipate it into the surrounding environment. This keeps LEDs from overheating and burning out. Thermal management is generally the single most important factor in the successful performance of an LED over its lifetime. The higher the temperature at which the LEDs are operated, the more quickly the light will degrade, and the shorter the useful life will be.
LED products use a variety of unique heat sink designs and configurations to manage heat. Today, advancements in materials have allowed manufacturers to design LED bulbs that match the shapes and sizes of traditional incandescent bulbs. Regardless of the heat sink design, all LED products that have earned the ENERGY STAR have been tested to ensure that they properly manage the heat so that the light output is properly maintained through the end of its rated life.
- *Source — energystar.gov