Use of Light Emitting Diode (LED) Lighting
(Description: Bryan standing in well-lit kitchen)
Bryan: One of the greatest things we could say a person with a visual impairment needs is illumination. Illumination. Illumination.
(Description: Shows close look at LED lamp inside package)
Bryan: One of the most exciting categories of lights is LED lamps. “LED” stands for “Light Emitting Diodes.”
(Description: Shows more lamps in packaging with different diodes and chips )
Bryan: However, LEDs may be more than a single diode. They may have numerous diodes, or even a chip or multi-chip, sometimes in several layers.
(Description: Packaging showing that the bulb saves $121 in energy)
Bryan: Three main features of LEDs are that they are extremely energy efficient to operate,
(Description: LED bulb coming on immediately when turned on)
Bryan: they achieve full brightness instantaneously,
(Description: Packaging shows that the bulb has 33 times longer life expectancy)
Bryan: and they have an incredibly long life expectancy. LEDs may last for at least 50,000 hours,
(Description: Woman looking down with an LED lamp shining over her shoulder)
Bryan: which may equate to an effective life of several decades of use.
(Description: Packaging of fluorescent and incandescent bulbs showing comparison of life expectancy)
Bryan: Compare this to a life expectancy of about 7,500 hours for compact fluorescent bulbs, or about 1,000 hours for an incandescent bulb. Extreme temperatures or failure of the semiconductor (which happens very rarely) may reduce their life.
(Description: Row of a variety of LED light fixtures; different colored LED lamps, their construction; and packaging showing Kelvin ratingsand life expectancy of bulbs)
Bryan: LEDs are made with a variety of phosphors, rare earth elements, scintillator crystals, and/or quantum dots. They come in a variety of colors and Kelvin ratings. Interestingly, they can either have very low Kelvin ratings, such as 2,700, or very high, such as 6,500.
(Description: Variety of LED packages indicating different Kelvin ratings)
Bryan: If you are concerned about lamps with a high Kelvin rating, and the fact that they may emit blue light and/or ultraviolet rays, check the Kelvin rating of an LED lamp or bulb. Surprisingly, two LED bulbs can be advertised adjacently on the same page of a catalog, or alongside each other on a store shelf and have the same manufacturer, cost and specifications except for their Kelvin rating. One with a “warm” Kelvin rating would be a lamp of 2,700K (more yellowish) to 4,500K (more white). One with a “cool” or “daylight” rating would be above 5,000K (more bluish in color). With the fairly recent development of “white” LEDs, and considering their longevity and energy efficiency, LEDs are increasingly taking over the market formerly held by incandescent and fluorescent lamps. Another feature to consider with LEDs is the “spread” of the light delivered by LEDs.
(Description: Woman walks down corridor using flashlight with wide spread of beam)
Bryan: Some may seem to have a fairly narrow spread or beam,
(Description: Lamp with narrow beam spread)
Bryan: while others have a wider distribution of light across the surface to be illuminated.
(Description: Picture of two flashlights beaming against wall to show differences in beam spread)
Bryan: You may want to compare several LED lamps to find one with the spread of total beam angle that you desire. LED bulbs have no mercury, unlike CFLs,
(Description: Woman knocks LED bulb on table to show hardness of bulb)
Bryan: and are encased in hard plastic covers, as opposed to most conventional bulbs that are in glass. Therefore, they will not cause damage to the environment upon disposal, and will not break easily if dropped.
(Description: Woman writes using LED lamp)
Bryan: At present, a very helpful use of LED lighting for people with vision loss is as a desk or floor lamp for the home, office or school, providing “task lighting.”
(Description: Woman replacing compact fluorescent bulb with LED bulb with Edison base that will screw into standard lamps and light fixtures.)
Bryan: LED bulbs now come in an Edison (E-26 or E-27) base, and can be purchased to replace other bulbs in existing light fixtures, including those using incandescent and fluorescent bulbs. They will work in all household lamps, flood lamps and light fixtures
(Description: Man turns on LED lamp to light a counter)
Bryan: and can be even used for under cabinet lighting or for lighting stairways.
(Description: Can of chicken noodle soup being read under LED lamp)
Bryan: They work best when the source is close to the surface you are trying to illuminate. The LED gooseneck lamp shown here can be used for reading, writing, sewing, repairs and other daily living activities that require good lighting. It is easy to adjust and therefore, can be positioned where you need it.
(Description: Man adjusts flexible led desk lamp; same man struggling to use screw to adjust swing arm lamp)
Bryan: This is also available in a swing arm LED desk lamp, shown here, or in an LED floor lamp. This lamp may be a bit more difficult for a person with hand-strength problems since it involves turning a screw to adjust the position.
(Description: Man walking down a dark hallway with LED lantern)
Bryan: Some LED lamps are even available as battery operated, making them very portable to carry around the house to help give light for various tasks. Other LED lamps include personal headlamps, flashlights, stick-on lights for a closet, cupboard or workspace, LED keychains and even night lights. Some LEDs can be used with a dimmer switch. Check the packaging to determine if the lamp you purchased can be dimmed and that the switch can be used with LEDs. In the future, room or large area lighting may become available through the use of organic LEDs (OLEDs), which create light on an ultra-thin sheet. OLEDs are already being used in television screens, computer monitors, and small portable system screens such as mobile phones and even handheld video magnifiers. Unlike other bulbs, LEDs do not burn out or just quit working, they merely become dimmer with age and use. Therefore, to measure the useful life on an LED A level of acceptable lumen depreciation must be chosen.
(Description: Screenshot of website: Lighting Research Center, www.lrc.rpi.edu)
Bryan: The Lighting Research Center recommends defining useful life for general LED lighting as the point at which light output has declined to 70% of initial lumens. Most manufacturers of high-power white LEDs estimate a lifetime of around 30,000 hours to the 70% lumen maintenance level.
(Description: Close up of LED in package followed by color-changing LED plugged into a wall outlet)
Bryan: However, LED durability continues to improve, and some LEDs are rated to last at the 70% level to 50,000 hours.
(Description: Woman knits using adjustable floor lamp)
Bryan: If used an average of three hours a day, this would mean a useful life of 27 to 46 years, allowing for the 30% lumen depreciation.
(Description: Woman reads canned good label under LED lamp)
Scott: You do not have to go to a specialty lighting store to purchase LED lamps or bulbs.
(Description: LED’s are displayed on retail shelf)
Scott: They are now readily available at many retail outlets and hardware stores, such as Lowe’s, Home Depot, Wal-Mart and other places. With their very long life and energy efficiency, they are a good option and alternative to other types of lamps and bulbs such as incandescent, which are being phased out.
Copyright 2013 by American Foundation for the Blind.