What is LED? The Flagship Article
Author: Dorothy Winslow
You know those light bulbs that you buy that are 60 watts? And the spiral ones that buzz and take a while to light up? Those are incandescent and compact fluorescent lamps, and they are yesterday’s news. Everybody is talking about LED now. What is LED, you might ask? LED stands for Light Emitting Diode. In general terms, it’s made from the stuff the swamp monster was wearing in that one episode of Scooby Doo. It’s a piece of metal with a phosphorous that glows. We now grow it in scientific labs, so no more swamp monsters. They have no mercury and are environmentally friendly since they last an incredibly long time.
Some people do not like LED lamps. They say they are too pricy, the light is too blue, they are too bright, and they do not dim well. Those are problems based off of old technology. LEDs have changed a lot in the past few years, so they look like regular ‘warm’ lighting and do not cost very much, as prices have gone down. There are different qualifications that define LEDs. These explain why some are more expensive or look different than others.
What makes a lamp yellower, whiter, or bluer? That is the color of the light, or color temperature. An incandescent lamp, the one we screwed into the sockets as kids, has something called a 2700 Kelvin temperature. This means it looks yellower, or ‘warmer’. A whiter light is like what you see in your local supermarket in those hanging fluorescent fixtures. They have what is called 4100 Kelvin temperature.
There’s also something that helps us distinguish color called CRI, or Color Rendering Index. It’s a fancy term for which colors show up in the light. The scale is 0-100, 100 being the best. If it’s lower on the scale we can’t see that many colors. There is also something called the R9 value. R9 is the red color that CRI does not include. For example, if meat is put under a lamp which does not have R9, the meat looks brown like it is already going bad. When meat is put under a lamp that has R9, it shows its natural vibrant red color (way more appetizing to buy and eat!).
You know those incandescent lamps I keep talking about? When we go to buy them, we have to know what wattage they are. Usually we buy 60 watts for our home. For those lamps, that means it’s very bright and uses A LOT of power (way more money on your electric bill!). My mom always had me turning off the lights when I left a room, did yours? LEDs do not use as much power to give that much brightness. So for LEDs we describe brightness in a term called lumens. LEDs only need 7 watts (WAY less than incandescents!) to make the same amount of light that the 60 watt incandescent makes. So if your kid accidentally leaves the lights on all weekend, that’s not even a blip on your electric bill.
Lumens, CRI, and color are some of the categories that LEDs are sorted into. In the science labs we talked about, the LED sorting is called binning. Like when you win tickets at Chuck E Cheese, you have to pick from the bins that you have enough tickets for. LEDs get tickets too, and the LEDs with more tickets for those categories are higher quality. These higher quality LEDs are used in museums and art galleries. LEDs that do not get as many ‘tickets’ are put into the low quality bin. Manufacturers, like Toys R Us, pick from the low bin to light up the sirens in their toy cars.
There is one more thing that makes one LED lamp different from another. This is called the driver. No, not that crazy taxi driver back in NYC that almost drove you into a hot dog stand. This driver is a little machine that controls and regulates the power going into the LED. This is like a ballast for a fluorescent lamp (in those fixtures in your supermarket). Some drivers are made to dim, other are not. Different drivers can handle different LED loads (amount of power) for different lengths of time. These also factor into the price of LED lighting.
All of these qualities factor into the price and quality of LED lighting. When picking out LED lamps or fixtures for the home, it is best to look at what the lighting will be used for. Invest in a high end LED light bulb for displaying art, and a lower quality bulb for a broom closet, since nothing is being displayed or worked on in such a place (unless you have Harry Potter living there). In the following weeks we will be going in depth into each of the above subjects to help broaden our reader’s knowledge on the LED scale.
About the author, Dorothy Winslow is a sales associate for CES Santa Barbara and has been with the company 4 years. She specializes in LED lighting and Energy Management. She is also a San Francisco Giants fan and an avid dog lover.