It’s not just about energy savings: CFL’s, LED’s and other SSL types offer aesthetic, labor-saving, and special-application advantages
Compact fluorescent, and LED and other high-efficiency lamps in the emerging field of Solid State Lighting (SSL) promise dramatic advantages in energy use and control convenience in homes, businesses and industry. Although high-efficiency has been the primary focus in promotion of these lamps, all the new technologies also claim significantly longer lamp life, as well as a variety of other advantages not widely reported.
Long lamp life, and its implications
CFL manufacturers typically claim a lamp life of 10,000 hours, which translates to almost five years for a lamp operating six hours/day year round. Compared to 1,500 hours for a basic incandescent or 2,500 hours for the highest-quality halogen incandescents, this is quite significant. LED’s typically claim a 50,000 hour life, which is more than five years of always on lamp life. In that six hour/day application, such a lamp might last twenty-two years!
The life of a lamp
Every lamp type has a different statistical failure profile and characteristic failure mode. Incandescents have a fairly steady lumen (light) output and color output for their entire life, which typically ends very suddenly, whether with a wimper or, occasionally, a bang. Typically the lamp’s filament burns out and breaks, opening the electric circuit and preventing the further flow of current and production of heat that normally causes the filament to ‘incandesce’. Sometimes, the broken filament falls loose in a way that re-connects the circuit through a fully-conductive portion of the filament assembly not designed to heat up and incandesce. The momentary unlimited current flow vaporizes the metal in a miniature arc flash that can be noisy, and may even shatter the bulb and/or burn out dimmers or switches controlling the circuit.
Fluorescent lamps’ failure mode is more progressive than filament-type lamps, but still relatively quick. It may involve a few days or months of erratic output at the end of life, and can be recognized by the scorched rings at the ends of tube type fluorescent lamps.
LED’s typically diminish in output slowly from the day you put them in service. ‘Failure’ for an LED lamp has been defined as the hour the output falls to 60% of the rated output (rated output may sometimes be lower than initial output, so that the manufacturer can claim longer life before the lamp reaches its 60%-of-rating moment. For the newest LED products (and the better ones are all new), no one has actually tested the lamp life claims being made; the lamp may have been prototyped a year ago and its lamp life is five years or more, so it’s actually impossible for anyone to test the expected lamp life before sale! Fortunately, the LED components used in the lamp have a long track-record under careful study and the slow degradation of output during the lamp’s first 1,000 hours can provide an accurate projection of its performance during the subsequent 49,000.
For very sensitive applications, you will also want to consider the color output and quality over the life of the lamp.
Lamp life and maintenance cost
One of the most important aspects of lamp life relates to the lamp application. For difficult lamp-change applications such as remote locations or high ceilings or difficult fixture or other lamp enclosures, the longer the life, the better the cost savings in re-lamping labor and/or security issues relating stemming from lamps being left unchanged due to technical difficulty, after failure.
See also:
Licensed Electrician Robert Monk Advantages of LED lamps and high-efficiency lamps Copyright Robert Monk, 2012
Source: http://www.phillylicensedelectrician.com/led-lamps-high-efficiency-lamps/
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