What is an LED and how does it work?
Light Emitting Diodes (LEDs) are
solid state semiconductors that emit light when current passes through them. Today LED bulbs and fixtures can be used in
many common applications in your home or business. When well designed, LED lighting can be
efficient, durable, versatile and long lasting, offering many unique money and
energy saving benefits. When an electrical current passes through a semi-conductor material that illuminates
the light source we call LED, it produces a very bright and efficient
light. The heat produced is absorbed
into a heat sink; the LED itself is very cool to the touch. Heat is the number one cause of LED failure,
the better the Heat Sink the longer the LED will last.
LED’s have historically been used
in sources other than Commercial and Residential lighting sources. Most commen LED sources include colors such
as amber, red, green and blue. To get
the LED to produce the white light that we would use in homes and offices, different
color LEDs are mixed or covered with a phosphor material that converts the
color of the light.
LEDs are a directional light source
unlike traditional incandescent, halogen or (HID) High Intensity Discharge
lamps which emit light and heat in all directions. For this reason LEDs can produce as much
light as its counterpart very efficiently and at a highly reduced wattage,
helping you save energy and cutting down on wasted light.
Why are LEDs becoming
Most LEDs in today’s market
will last up to five times longer than (CFLs) Compact Fluorescents and up to
twenty times longer than an incandescent or HID bulb or fixture. The average life span for an LED is 40,000 to
50,000 hours and can last up to 15+ years depending on amount of usage. A typical LED light that burns eight hours a
day can last about 17 years before it needs changing. In a residential application this long life
means saving money and time not having to replace or purchase lamps as often. In commercial or Industrial applications
means less time on a ladder, lower labor maintenance costs for businesses.
High Quality Light
Getting the right quality of
light is crucial when it comes to home décor and a comfortable office environment. Today’s LEDs can produce a broad range of
color temperatures from 2700K to 5000K and higher.
lights generate almost no heat or UV rays, which can reduce air conditioning
costs and keep fabrics and furnishings from fading.
In accordance to the Energy
and Security Act of 2007, incandescent bulbs started phasing out in 2012 and
will be completely phased out in 2014. A
popular alternative to this phase out has been the (CFL) Compact Fluorescent
lamp. Although CFL’s are more energy
efficient than an incandescent there are some downfalls. One is they contain
toxins and it could be illegal in your state to be thrown away with your
regular trash. The reason for this is
the damage the mercury can do to your health and our environment. Other reasons include shorter life span,
worse color temperature and they are not in short light, most CFL’s can take a
minute or two to get to full brightness.
Reduces your Power
can provide greater energy savings by using up to 80% less energy than it’s
incandescent or HID counterpart.
Although CFL’s can save you energy when comparing to an LED, you can use less wattage with an LED and get more light output, a better light and longer
output of an incandescent lamp can produce extra heat in your home or place of
business. An incandescent can waste as
much as 80% of the energy it uses at an extremely high heat. This means that not only can you save money
on the energy portion of your bill, your air conditioner won’t have to run as
hard to keep your home or business at a comfortable temperature.
Safe & Non-Toxic
LED’s do not contain mercury
like it’s CFL counterpart therefore it is cleaner and better for our environment. The biggest drawback to CFL’s is the fact it
contains mercury and just dropping and breaking one CFL can release enough of
the chemicals to be harmful to your health.
Most states don’t allow you to just throw away your old CFL’s, it is
illegal in 10 states and more are getting on board.
Basics of Picking the
Lumen output is the SI derived
unit of luminous flux, a measure of the total amount of visible light emitted
by a source. What this means to picking
the proper LED bulbs or fixtures.
fixture or lamp has a lumen output rating.
Because LED fixtures and lamps have a directional light source they can produce
more light at a lower lumen output than incandescent or HID’s. This means there is less wasted and unusable
output is measured in photopic and scotopic lumens; however, it is the scotopic
lumens that enhance the visibility as seen by the human eye. LED’s produce light energy that is more
favorable to the scotopic response of the eye allowing a brighter appearance.
Lamp Comparison in Lumens:
Color temperature is a measurement
in degrees Kelvin that indicates the hue of a specific light source. Picking the right color temperature can be
the most important decision when buying a LED light source. LED’s come in many different Kelvin
temperatures and if you are not familiar with temperature ratings you can make a wrong decision when buying LED products.
products come in many various shades from bright white, which can almost look blue, to a soft white
like you would put in a table side lamp.
A good rule of thumb is to use soft white (2700-3000K) indoors and
bright white outdoors (3500-5000K).
These numbers are known as the Kelvin Temperature Rating, the higher the
number the brighter the shade of white light produced and the lower the
yellower or warmer the light produced.
Refer to this chart:
Lifetime of LEDs
The lifetime of LED light
sources can vary quite a bit, therefore you should observe this closely when picking
out an LED product. LEDs can range from
20,000 hours up to 60 and even 70,000 hours of lifetime. This could potentially mean that your LED
bulb or fixture could last up to 15+ years if burning a reasonable amount each
Example: Burning 8 hours a day is 2,920 hours a year, if
your LED product has a 50,000 hour lifetime that would be over 17 years.
the individual LED itself is what will shorten the life of the LED bulb or
fixture. The better the heat sink or
heat dissipation the longer the LED is going to last. Most LED bulbs can’t get the heat away from
the LED, so most lamps have a shorter life span than a fixture that would have a
better heat sink and therefore have a longer life span. Most LED bulbs are not rated to go in an
enclosed fixture, so be sure to check this because it can drastically reduce
lifetime of the LED.
Lighting Facts Guide
Lighting Facts is a program of the US Department of Energy. Information contained on the lighting facts label has been verified by an approved independent testing laboratory. Purchasing LED fixtures or lamps without a Lighting Facts label results in customers depending on unverified and inaccurate performance data.
Buying a Quality Product
There seems to be an unlimited supply of manufacturers producing LED bulbs in today's market. Some of these manufacturers can produce false information leading to you buying an inferior LED product. There are several things you can do to protect yourself from this happening.
Buying from a reputable company
Buying from a reputable company is the key to a successful investment in LED lighting. We have found that some off brand LED manufacturers can sell an inferior product while telling you that it is not. This is truly where you will find the old saying "you get what you pay for" to be true.
Also, a lot of LED manufacturers may not be around in the near future like a major manufacturer like Philips Lighting. The importance of this is that most LED manufacturers offer a 5 year or more warranty on their LED products, if by chance you had a problem with your product, the warranty is voided once they are out of business. Plus a lot of LED purchases will be bought in phases and not all at once, you should buy the same brand to keep the visual appeal consistent throughout your home or business. If the manufacturer is out of business, you will not keep this consistency.
Look for the lighting facts label
On your next LED lighting purchase, look for the lighting facts label and read it carefully. The United States Department of Energy wants to keep you informed about LED lighting you purchase and how it will perform. Lighting Manufacturers that display this label on their products agree to meet government regulated criteria in the following areas.
- Correlated Color Temperature (CCT)
- Color Rendering Index (CRI)
Do your research
There are things you can look for to help you make a successful purchase:
- Look for a reputable manufacturer
- Look at color temperature
- Look at Lumen output and lumens per watt
- Be sure they have a lighting facts label