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We're
glad you asked because this one question is at the heart of
why LED lighting makes so much sense. We'll try not to get
too technical so you can put your protractor away but the
root of LED light savings rests on the efficiency of how it
works. We'll compare it with earlier and almost antiquated
technologies like incandescent and the half-way there
improvement of fluorescents. Lighting is truly ready for
the biggest revolution since the first electric light bulb
lit up the lab. Let's take a look at how LED's work.
Our
ultimate goal is to turn electricity or electrons into light
or photons. Wattage is a measure of electricity that we
used commonly on a large scale basis (such as your utility
bill) while lumens is a measure of quantity of lights and
you'll typically find this measurement on light bulb
packages. LED's are the most direct exchange of electrons
to photons on the lighting market. What is an LED? LED
stands for Light Emitting Diode. Diode is probably the
piece that might be new to most people. It's a simple kind
of electronic component. "Di" in this case means two since
a diode will have two terminals. In the case of a diode,
electrons only move in one direction and this is the key
function of diodes. It's a way direct electrons one way
which has many uses in electronics. LED's are diodes that
are made of a special kind of material. Electrons enter the
material and are absorbed by the atoms which eventually
release this extra energy in the form of photons or light.
It's a pretty lossless transfer of energy which results from
the electron make-up of those atoms. There is very little
heat actually generated from the electron/photon conversion
which is critical. Heat is the enemy of all things
mechanized and especially with electronics from computers to
cell phones to....lighting. Heat, aside from being lost
energy (outside of a heating lamp maybe) also is corrosive
to all systems. By definition, heat is an elevated level of
chaos and disorder and it loves to bring ordered systems
(like the inside of your computer) down to its level. So,
we want to keep heat away from our lighting system, right?
The
original lighting source, incandescent, practically runs on
heat which is it's big Achilles heel. Certain materials
will glow brightly when heated. These same materials resist
electric flow so when an electric current is applied to
them, they will heat up as a result of this resistance.
This energy is then converted to a small amount of light and
a large amount of heat. In fact, almost 90% of energy
output from incandescent lights is in the form of heat.
They should be called incandescent heaters in the aim of
honest advertising. So, not only is there a 90% thief of
energy at works with these lights, the heat generated will
eventually (actually relatively fast) break down the system
and destroy the filament (or material that glows when
heated). That's the pop you hear when a standard
incandescent light bulb goes. One other small note, the
whole thing has to be enclosed in a glass vacuum which
sounds like a recipe for disaster as in, "Don't drop it!".
CFL's
came along with better efficiency but not close to LED
lights. They operate by exciting certain kinds of gas which
absorb electricity and then release this energy as photons
of corresponding wavelengths. This is why fluorescents have
very funky colors and attributes to the eye. A few years
from now, CFL's and incandescent will look like blood
letting to cure the flu from the Dark Ages. With the cost
savings proposition of LED's combined with new color tuning
abilities for warmer tones, the LED works just perfectly for
our modern day lighting requirements.
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