Caution: Although there has been a lot of media attention given to LEDs, far too many LEDs are not well-manufactured and too many LED lighting fixtures are not well-designed. In short, the LED lighting market is still maturing. Research continues to improve the brightness, the efficacy, and the life span of LEDs at a remarkable pace. However, Pegasus Associates Lighting continues to be cautious about which LEDs and LED fixtures it brings to the market place because we want our customers to be pleased with our LED lighting products both today and tomorrow. We suggest that you be cautious as well.
- Q) What do the letters, L-E-D, stand for?
- A) Light Emitting Diode
- Q) What is an LED?
- A) An LED is a small electronic device that emits light when electricity is passed through it.
- Q) What are the advantages of LEDs?
- A) LEDs are very energy-efficient and have very long rated lives.
- Q) What colors do LEDs come in?
- A) LEDs can be red, green, blue, or amber. Presently, a white LED is created by covering a blue LED with a white phosphorus coating.
- Q) What is the color temperature of white LEDs?
- A) White LEDs can and do vary in color temperature. Some white LEDs can be as "warm" in appearance as 3000K but most white LEDs are "cool" in appearance since white LEDs are created by putting white phosphors over a blue LED.
- Q) How bright is a high power LED?
- A) A single high power LED can produce up to about 80 lumens of light.
- Q) How does the brightness of LEDs compare with incandescent light sources?
- A) Since a standard 60W incandescent light bulb can produce about 900 lumens a single high power LED is only about 1/11th as bright.
- Q) How can LEDs be used successfully in lighting fixtures?
- A) For most LED lighting fixtures to provide adequate lighting the fixture must contain groups of LEDs.
- Q) Are LEDs efficient?
- A) Yes, LEDs now produce 25-40 lumens/watt
whereas incandescent light sources produce only about 15 lumens/watt.
- Q) Are LEDs more efficient than fluorescent light sources?
- A) Not yet. A compact fluorescent light source
(CFL) produces about 50 lumens/watt. So, LEDs presently have an efficacy (efficiency
rating) that is somewhere between incandescent and fluorescent light sources.
- Q) Will LEDs become even brighter in the future?
- A) Almost certainly. The lumen output of LEDs has almost doubled in the last two years.
- Q) Do LEDs get warm?
- A) Yes, all lighting sources generate heat including
LEDs. However, they do not get very hot, especially if the LEDs and the light fixture are
well-designed with "heat sinks" to help dissipate the heat.
- Q) Do LEDs emit infrared radiation (heat radiation) like incandescent light
sources?
- A) No, they do not.
- Q) Do LEDs emit ultraviolet radiation (UV rays)?
- A) No, they do not.
- Q) What is the expected life of an LED?
- A) The typical LED has a lifetime of about
35,000 to 50,000 hours.
- Q) Do some LEDs have a lifetime of 100,000 hours?
- A) Only in the laboratory; under real operating
conditions LEDs operate for about 50,000 hours or less.
- Q) Do LEDs ever burn out, per se?
- A) Not really. Over their lifetime LEDs simply get progressively dimmer until they do not emit enough light to be useful.