Volume 13, Issue 01
The PEACEKEEPER
Page 3
BULB continued from pg. 2
ons may look like familiar light bulbs and some may not but can be er match the performance of tradi onal light
bulbs. Some LED light fixtures may have LEDs built–in as a permanent light source.
LEDs are “direc onal” light sources which means they emit light in a specific direc on, unlike incandescent
and compact fluorescent bulbs which emit light — and heat — in all direc ons. For this reason, LED ligh ng is able to
use light and energy more efficiently in many applica ons.
Incandescent bulbs produce light using electricity to heat a metal filament un l it becomes “white” hot or is
said to incandesce. As a result, incandescent bulbs release 90% of their energy as heat.
In a CFL, an electric current flows between electrodes at each end of a tube containing gases. This reac on
produces ultraviolet (UV) light and heat. The UV light is transformed into visible light when it strikes a phosphor
coa ng on the inside of the bulb. Learn more about how CFLs work.
LED Basics
The useful life of LED ligh ng products is defined differently than that of other light sources, such as incan‐
descent or CFL. This is because LEDs typically do not “burn out” or fail. Instead, they experience lumen deprecia on,
where the amount of light produced decreases and light color appearance can shi over me. Instead of basing the
useful life of an LED product on the me it takes for 50% of a large group of lamps to burn out (as is the case with
tradi onal sources), LED product “life me” is set based on a predic on of when the light output decreases 30 per‐
cent.
LEDs and Heat
Because LED ligh ng systems don’t radiate heat the way an incandescent or halogen light bulb does, the heat
produced from the power going into the product must be drawn away from the LEDs. This is usually done with a
heat sink, which is a passive device that absorbs the heat produced and dissipates it into the surrounding environ‐
ment. This keeps LEDs from overhea ng and burning out. Thermal management is probably the single most im‐
portant factor in the successful performance of an LED product over its life me because 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 configura ons to manage heat, so they may look
very different from each other. 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.
Why should I choose ENERGY STAR cer fied LED ligh ng products?
There are more ligh ng choices available on store shelves than ever before. Even with all the new choices,
it’s s ll simple – look for the ENERGY STAR label. ENERGY STAR means high quality and performance, par cularly in
the following areas:
COLOR QUALITY: Consistent white light over the rated life
LIGHT OUTPUT: Light must meet minimum levels for replacement claims and is maintained through the end
of rated life
EFFICACY: More light (lumens) for less wa s, 75% or more
WARRANTY: 3 year minimum warranty.
See BULB continued on pg. 4