LED is short for light-emitting diode.
LEDs are notable for being extremely long-lasting products. Many LEDs have a rated life of up to 50,000 hours. This is approximately 50 times longer than a typical incandescent, 20-25 times longer than a typical halogen, and 8-10 times longer than a typical CFL. Used 12 hours a day, a 50,000 bulb will last more than 11 years. Used 8 hours a day, it will last 17 years!
They can be used almost anywhere. LED replacements are already available for bulb types such as A-shape, PAR reflectors, MR reflectors, decorative, undercabinet, and more. When used on dimmers, particularly dimming systems that support many bulbs, we suggest testing a few LEDs first to test compatibility.
Enclosed fixtures are defined as not only air tight, but also are fixtures that are enclosed on the side, rear and open in the front, such as many track heads. LEDs that are used in fixtures where there's less than 1/2" around the circumference of the lamp when installed in the fixture are also considered an enclosed application. If you plan to use LEDs in these types of applications you should use an LED that's rated for enclosed fixtures. Using an LED lamp not rated for enclosed fixtures in this type of application may cause the LED lamp to flicker and will dramatically reduce the life of the lamp.
Bulbs.com now offers a wide assortment of enclosed rated LEDs in many different lamp shapes. LEDs not rated for enclosed fixtures should only be used in fixtures open in the front, where the lamp's lens is open on the sides and the rear, and should have at least 1/2" space around the circumference of the lamp.
The advantages of switching to LED are numerous. Here are just some of the benefits: LEDs use much less electricity than other bulbs, have extremely long rated lives, produce very little heat, do not emit UV or infrared, contain no mercury, are resistant to shock and vibration, and can operate effectively in extremely cold environments. For more information the advantages of LED, see LED: Is It Right For You?.
LED is still a new technology, and the expense of producing quality product is still high. However, pricing has come down dramatically from just a few years ago and prices are expected to continue to drop. In terms of whether LEDs are worth the extra cost, it's helpful to look at the cost to operate a bulb in addition to the up-front cost. The energy savings realized in a switch to LED means that the extra up-front cost is often paid back rather quickly, and you'll wind up saving money over the life of the bulb. If you'd like to see this in action, check out our Energy Savings Calculator. Here is an example: for a residential customer who may have the light on for just 10 hours per week ñ the payback is over 10 years. On the other hand, a retail or restaurant client who is burning lights for 90-100 hours per week will calculate their payback on a $70 LED PAR to be less than 18 months. Taking a look at your payback estimate should definitely be a consideration when deciding if LED is right for you.
Yes. LEDs are very similar to consumer electronics and quality really matters. In order for an LED to function properly and provide an acceptable light output, all of the components must be built to last. It's always a good idea to buy from a manufacturer and retailer that you're confident will stand behind the product. If you'd like to learn more about the components and how cheaply-made LEDs stack up against top-quality product, check out A Tale of Two Bulbs.
For most applications, yes. Off-the-shelf LED products are now reliably replacing incandescent equivalents of up to 100 watts, and specialty products are available to replace even higher wattages. If you'd like to learn more about LED light output, take a look at this article on light output.
If you buy quality product, the light quality is excellent. Color Rendering Index (CRI) is generally used to measure light quality on a scale from 1-100. Most LEDs have a CRI rating of at least 80, and many are rated 90 and above.
LEDs are very green. For starters, they use much less electricity than many other lighting products. This means that less electricity has to be produced to operate them, and resulting in lower emissions from power plants, especially in areas where coal-fired plants are common. Unlike CFLs, they contain no mercury. Because of their long life, they also reduce solid waste: If you replace an incandescent bulb with an LED, you will prevent fifty 1,000 hour incandescent bulbs from being thrown away. Additionally, they produce very little heat and can reduce energy usage related to HVAC. The U.S. Department of Energy has estimated that increased adoption of LEDs over the next 15 years would also reduce electricity demands from lighting by 62 percent, prevent 258 million metric tons of carbon emissions, and eliminate the need for 133 new power plants.
Usually, yes. Many LEDs are specifically listed as being dimmable. Some dimming systems work with LEDs better than others, so it's best to test one or two before completely re-lamping a space.