“HE DIRECTED”. When it comes to lighting, you’re hearing these three letters over and over … you see them posted on all lighting websites and they start to bother you. It seems to be an exciting new trend … some kind of innovative new light … but you have no idea what it is. You would like to know what everyone is talking about, what is fashionable? LEDs – Light Emitting Diodes – Simply put, LEDs are diodes that … (huh?) Hang, I’ll explain: a diode is the simplest type of semiconductor device. (What’s that?) Wow, you’re impatient: a semiconductor is a material with the ability to conduct electrical current. Basically, instead of emitting light from a vacuum (as in an incandescent light bulb) or a gas (as in a CFL), the LED emits light from a piece of solid matter, its semiconductor. Put very simply, an LED produces light when electrons move within its semiconductor structure.
They tell you when to stop and when to go. They have ruled your driving, saved your life countless times, and that little red man made you wait until you could cross the street. That’s right: the red, yellow, and green at the traffic lights are LED lights that are right in front of his nose. In fact, light-emitting diodes have been around for some time, conceptualized in 1907. However, it wasn’t until the 1960s that practical applications were found and LEDs were first manufactured. LED used to be used exclusively for traffic signals, brake lights and headlights in luxury cars and indicator lights in home appliances. You probably didn’t even know that LED lights were lighting up your digital clocks, flashlights and telling you when you had a new voicemail message on your cell phone. Expensive at first, as applications grew, benefits were discovered and manufacturing costs fell. According to the American Lighting Association (ALA), lighting manufacturers have invested a considerable amount of time, effort and research to adapt this super energy efficient technology for home use. The technology has advanced enough to gain approval from the popular and respected government Energy Star® program. So here is why:
They do more for less. LEDs are efficient and produce a lot of light with little power. For example, a 5-watt LED can produce more light (measured in lumens) than a standard 75-watt incandescent bulb. The 5 watt LED could do the work of the 75 watt incandescent at 1/15 of the power consumption. LEDs save energy and therefore money. This is because in LED lights 90% of the energy is converted to light, while in incandescent bulbs 90% of the energy goes to heat and only 10% to visible light. They last longer. LEDs are virtually maintenance-free – they don’t have a burning filament, so they last much longer. A standard household “long life” light bulb will burn for about 2000 hours. An LED can have a lifespan of up to 100,000 hours! According to some sources, LEDs can last up to 40 years. Imagine not having to change a light bulb for years. There are LED products available this year that will make frequent bulb changes during the 20th century. How it really works … (skip this part if you really don’t care) Light is a form of energy that can be released by an atom. It is made up of many small, particle-like packets called photons, which are the most basic units of light. LEDs are specially built to release a large number of photons outward. When an electrical charge hits the semiconductor, a small electrical current, which is measured in watts (oh, that’s what they mean by low power!) Happens to through the semiconductor. material. this causes the electrons to move, become “excited” and emit photons. Almost all the energy emitted is light energy. In an ordinary diode, such as incandescent bulbs, the semiconductor material itself ends up absorbing much of the light’s energy, thus producing more heat energy than light energy. This is completely wasted energy, unless you are using the lamp as a heater, because a large part of the available electricity is not used to produce visible light. LEDs generate very little heat, relatively speaking. A much larger percentage of electrical energy goes directly to generating light, significantly reducing the demand for electricity. As you can see in the diagram, they are housed in a plastic bulb that focuses the light in a certain direction. Most of the light from the diode bounces off the sides of the bulb and travels through the rounded end. They are a better (long term) buy. Until recently, LEDs were too expensive to use for most lighting applications because they were constructed of advanced semiconductor material. However, the price of semiconductor devices has plummeted over the past decade, making LEDs a more cost-effective lighting option for a wide range of situations. While they may be more expensive than incandescent lights up front, a 60-watt LED replacement bulb costs around $ 100, and even lower-output versions, used for things like spot lighting, will cost between $ 40. and $ 80. That’s compared to a $ 1 incandescent bulb and a $ 2 fluorescent bulb. The reality is, even at $ 100 for a single bulb, LEDs will end up saving you money in the long run, because you only need one. or two every decade and you spend less money on home lighting, which can account for about 7 percent of your electric bill [source: Greener Choices]. But don’t worry, the terrifying price you have to pay up front won’t last long, the lighting industry in general expects LED costs to drop quickly. Lighting Science Group, a company that develops and manufactures LED lighting, estimates a 50 percent price reduction in two years. Looks good. The primary replacement for the incandescent bulb would be the higher efficiency compact fluorescent or CFL. However, in addition to toxic mercury in the design, it emits a strange, sometimes unpleasant color that even gives some people headaches. Not the LED – its light is easy to see even in strong sunlight and can produce the same LED Christmas Lights soft white light as a normal light bulb. (Although Energy Star recommends looking for the Energy Star label when purchasing LED bulbs, as the organization tests for color stability as part of its certification criteria.) Here’s the coolest part about LEDs – they can be lit up and their light changed to many colors including a very recent addition of white and blue. Others are green, red, orange, and amber. It is safe. The LED requires low voltage DC electrical current and can be battery operated so it is safe to touch, does not get hot. Is strong. LEDs are durable, they are not glass, but small plastic bulbs. It’s Swift. LEDs are easy to implement – they’re just tiny bulbs that easily fit into modern electrical circuits. Also, due to their size, more bulbs can be used in an electrical circuit. The fury. The LED will guide and illuminate the future. The light bulb that has lit our homes since the 19th century is officially about to disappear. The inefficient incandescent has fallen out of favor with those concerned economically and ecologically; Starting in 2012, US residents won’t be able to buy one even if they want to [source: Linden]. The government is pulling the little energy suckers off the market. “This year 2010 will be the first year that LEDs will explode in the residential market,” says architect Joe Rey-Barreau, ALA’s educational consultant and associate professor at the School of Interior Design at the University of Kentuckys. “We are already seeing incredible LED developments in all aspects of our lives, from Christmas lights to LED televisions. One area where LEDs will become predominant in 2010 is the category of desk and work lamps,” says Rey-Barreau. “Another major advance will be in replacement bulbs, as the extremely long life of an LED bulb makes it ideal for replacing recessed lights in hard-to-reach areas, such as vaulted ceilings in living rooms or kitchens.” If you’re still unsure whether you want to dedicate a large portion of your living space to technology, Rey-Barreau suggests trying under-cabinet lighting in the kitchen, a desk or task lamp, or outdoor path lighting to see if. he likes lighting. He provides before investing in a whole ceiling of recessed luminaires or a large chandelier.