Light bulb Facts

Almost half of the electricity used by industry is for lighting. In homes, up to 25 percent of our electric bill is for lighting. Most of the light is produced by incandescent light bulbs, using the same technology developed in 1879 by Thomas Edison. These bulbs are surprisingly inefficient, converting up to 90 percent of the electricity they consume into heat.

If the country converted to new technologies, the electricity consumed to produce light could be reduced by up to 70 percent! This would lower carbon dioxide emissions equivalent to removing one-third of the nation's cars from the highways. Reducing the electricity consumed by just one percent would eliminate the need for an average-sized power plant.

Recent developments have produced compact fluorescent lights (CFLs) that are four times as efficient as incandescent bulbs and last up to ten times longer. These new bulbs fit almost any socket, produce a warm glow and, unlike the earlier models, no longer flicker and dim.

Over the life of the bulbs, CFLs cost the average consumer less than half the cost of traditional incandescent bulbs for the same amount of light. In addition, CFLs produce very little heat, reducing the need for air conditioning in warm weather.

Why doesn't everyone use CFLs?

Few people realize that converting to CFLs can save so much money and electricity. Many people see the price tag and think they're getting a great bargain when they buy 10 incandescent for the same amount of money. They don't understand that they can reduce their electric bills by about 75% percent with CFLs.

There are many myths about CFLs; we’ve tried to answer most questions about CFLs below:

How does a CFL work?
How much energy does it takes to turn on a CFL, compared to leaving it on?
Can I turn my CFL on and off frequently?
Do compact fluorescent bulbs (CFLs) use less energy than incandescent bulbs when you consider the energy required to make the bulbs?
Will CFLs fit into my existing fixtures?
Can CFLs be used in 3-way bulbs?
Can CFLs be used in recessed cans, outdoor lights, or track lighting?
Can CFLs be used horizontally?
Can CFLs be used with dimmer switches?
Can I use a CFL with a timer?
Can I use a CFL with an electronic control such as an electronic timer, photo sensor, motion sensors, touch lamps, and remote light control?
Can I use Compact Fluorescent Light Bulbs (CFLs) in the bathroom?
Does temperature or humidity affect the life of a CFL? For example, would a CFL work in extremely cold temperatures, or extremely wet climates?
Can I use my CFL in a totally enclosed fixture?
If a light fixture is rated for a maximum 75 watts with an incandescent bulb, does that mean I am limited to a CFL with the equivalent light output to a 75-watt incandescent? Or, can I use a CFL that is the equivalent to a 100-watt incandescent as long as it uses less than 75 watts of power?
I hear CFLs will be required by 2012. Is that true?
Are there any Compact Fluorescent Light Bulbs (CFLs) manufactured in the US?
Do CFLs contain mercury?
Do Compact Fluorescent Light Bulbs (CFLs) cause electromagnetic interference?
Do Compact Fluorescent Light Bulbs (CFLs) produce a hazardous amount of UV light?
Is any mercury released when a CFL burns out? I had a lamp burn out and noticed a bad smell -- was that mercury?
Is the proposed phase-out of inefficient lighting bad news for people who suffer from migraine headaches?
I have heard that CFLs can overheat and smoke - should I be worried? Why would this happen? Are these bulbs a fire hazard?
How should Compact Fluorescent Light Bulbs (CFLs) be disposed? Do they need to be recycled?
How should I clean up a broken compact fluorescent light bulb (CFL)?
How does a CFL work?
CFLs produce light differently than incandescent bulbs. In an incandescent, electric current runs through a wire filament and heats the filament until it starts to glow. In a CFL, an electric current is driven through a tube containing argon and a small amount of mercury vapor. This generates invisible ultraviolet light that excites a fluorescent coating (called phosphor) on the inside of the tube, which then emits visible light.
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How much energy does it takes to turn on a CFL, compared to leaving it on?
Even when turned on and off frequently, a CFL uses less energy than an incandescent of the equivalent wattage. While there is a brief surge in energy use when a CFL is turned on, that surge usually lasts about a tenth of a second and consumes about as much energy as five seconds of normal operation.
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Can I turn my CFL on and off frequently?
Turning a CFL on and off frequently can shorten its life. To take full advantage of the energy savings and long life of CFLs, it is best to use them in light fixtures you use the most – lights you leave on for at least 15 minutes at a time.
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Do compact fluorescent bulbs (CFLs) use less energy than incandescent bulbs when you consider the energy required to make the bulbs?
Yes. CFLs use substantially less energy (and cause fewer emissions of greenhouse gases) than an equivalent incandescent even when the energy necessary to manufacture the bulbs is considered. It takes much less energy to manufacture a CFL than the energy it will use over its lifetime.
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Will CFLs fit into my existing fixtures?
CFLs can replace regular, incandescent bulbs in almost any fixture. They come in a wide variety of sizes and shapes including globe lamps for your bathroom vanity, chandelier bulbs, lamps for recessed lights (now commonly found in kitchens, hallways, and more), and larger or more compact standard light bulbs.
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Can CFLs be used in 3-way bulbs?
It is best to use only qualified CFLs that are specifically designed for 3-way sockets. Even if you are only using the lamp at the highest level, to ensure optimal product quality we recommend using a 3-way CFL.
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Can CFLs be used in recessed cans, outdoor lights, or track lighting?
Yes! Always read the packaging of the CFL to be sure of its proper use, but there are a wide variety of CFLs that are designed for use in most fixtures in your home, including recessed cans, outdoor lights, and track lighting.
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Can CFLs be used horizontally?
CFLs generally can be used both horizontally and vertically. The position of a CFL can affect how well the lamp performs, which can affect the product’s light output, but the difference generally is so small that it would be unnoticeable.
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Can CFLs be used with dimmer switches?
Yes, certain CFLs are made to work on dimmers. Be sure to check the fine print on the back of the packaging to see if there are any restrictions on the product’s use. Dimming a CFL that is not designed to work with a dimmer switch can shorten its life significantly.
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Can I use a CFL with a timer?
While CFLs can be used with mechanical timers, electronic or digital timers may cause interference with the electronic ballast, and can affect product performance. Typically, CFLs used on electronic or digital timers won’t last their full lifetime.
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Can I use a CFL with an electronic control such as an electronic timer, photo sensor, motion sensors, touch lamps, and remote light control?

Most electronic controls such as electronic timers, photo sensors, motion sensors, touch lamps, and remote light controls are designed to work with the simple technology of an incandescent rather than the complex technology of a CFL. The result is that operating CFLs on controls can significantly shorten the lifespan of the product.
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Can I use Compact Fluorescent Light Bulbs (CFLs) in the bathroom?
You can use CFLs in bathrooms; however, high humidity can shorten the life of CFLs. To avoid moisture problems, control humidity in your bathroom by running your ventilating fan or opening a window during and 15 minutes after showers and baths.
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Does temperature or humidity affect the life of a CFL? For example, would a CFL work in extremely cold temperatures, or extremely wet climates?
Extreme temperatures can affect CFLs. Some CFLs can be used outside in temperatures down to –10 degrees Fahrenheit and up to 120 degrees Fahrenheit, though when it is very cold they may take longer to reach full brightness. There are some CFLs that are weatherproof and can be used outside where exposed to rain, so check for “weatherproof” models before installing it in your outdoor spot light.
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Can I use my CFL in a totally enclosed fixture?
Before using a CFL in a totally enclosed fixture, you should consult the product packaging. CFLs that are not designed for totally enclosed fixtures will state that on the package. Because totally enclosed fixtures do not allow air to circulate around the lamp, it causes heat to build up, which can lead to performance issues.
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If a light fixture is rated for a maximum 75 watts with an incandescent bulb, does that mean I am limited to a CFL with the equivalent light output to a 75-watt incandescent? Or, can I use a CFL that is the equivalent to a 100-watt incandescent as long as it uses less than 75 watts of power?

As long as you do not exceed the recommended wattage for a particular fixture, you can use any CFL wattage up to the limit. For example, if a light fixture is rated for 75 watts of power, you can use any light bulb with a rated wattage of 75 or less. While you could use a 75-watt equivalent CFL, if you want more light in this fixture, then you could use a 100-watt equivalent CFL. Most 100-watt equivalent CFLs use between 23 and 30 watts of power, much less than the 75-watt rating of the fixture. That's the great thing about CFLs you get more light for less power!
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I hear CFLs will be required by 2012. Is that true?
The Energy Independence and Security Act of 2007 requires all light bulbs use 30% less energy than today’s incandescent bulbs by 2012 to 2014. It’s not entirely correct to say "CFLs will be required" or “incandescents will be phased out” because the standards set by the bill are technology neutral, and by 2012, a next generation of incandescent bulbs could satisfy the 30% increased efficiency. There are also other lighting technologies, such as halogen and LEDs that will be able to meet the new requirements and are expected to both increase in performance and drop in cost over the next few years.

There are many types of incandescent bulbs that are exempt from this law: any kind of specialty light (ie. bulb in refrigerator), reflector bulbs, 3-way bulbs, candelabras, globes, shatter resistant, vibration service, rough service, colored bulbs (i.e. "party bulbs"), bug lights, plant lights.

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Are there any Compact Fluorescent Light Bulbs (CFLs) manufactured in the US?
No, there are not currently any CFLs manufactured in the US.
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Do CFLs contain mercury?
CFLs contain a very small amount of mercury sealed within the glass tubing - an average of 4 milligrams - about the amount that would cover the tip of a ballpoint pen. By comparison, older thermometers contain about 500 milligrams of mercury - an amount equal to the mercury in 125 CFLs. Mercury is an essential part of CFLs; it allows the bulb to be an efficient light source. No mercury is released when the bulbs are intact (not broken) or in use.
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Do Compact Fluorescent Light Bulbs (CFLs) cause electromagnetic interference?
Similar to fluorescent lighting and other electronics, it is possible for CFLs to cause electromagnetic interference (EMI). Electromagnetic interference is regulated by the Federal Communications Commission (FCC), and ENERGY STAR includes these requirements by reference for CFLs. In addition, ENERGY STAR requires CFLs to use ballasts that operate at greater than 40 kHz, which limits the potential for interference.
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Do Compact Fluorescent Light Bulbs (CFLs) produce a hazardous amount of UV light?
Regular fluorescent light bulbs used in your home and office, including CFLs, do not produce a hazardous amount of ultraviolet light (UV).
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Is any mercury released when a CFL burns out? I had a lamp burn out and noticed a bad smell -- was that mercury?
As long as the glass tube remains intact, no mercury is released from a CFL when it reaches its end of life. In some rare cases, when a fluorescent bulb reaches it end of useful life, the arc contained in the tube may increase the temperature of the housing plastic near one end of the tube. This high temperature, although it is short lived, may produce some limited smoke and odor from the plastic housing or coatings. Although the odor may have a bad smell it is not harmful - it's just the burnt plastic. The smoke does not contain any mercury as long as the glass tube remains intact.
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Is the proposed phase-out of inefficient lighting bad news for people who suffer from migraine headaches?
Although fluorescent lights have long been blamed for causing or intensifying migraine headaches, technology improvements have largely addressed this problem, especially for CFLs.
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I have heard that CFLs can overheat and smoke - should I be worried? Why would this happen? Are these bulbs a fire hazard?
Unfortunately, there have been some instances of CFLs smoking or smoldering. While this usually occurs when the product is defective or installed improperly, it is nonetheless a concern. ENERGY STAR qualified CFLs currently meet UL safety standards, which require the materials to be self-extinguishing. So, although the base or glass tubing may darken, an ENERGY STAR qualified CFL should never catch on fire. CFL manufacturers recommend that you install and remove CFLs by grasping the plastic portions of the base only. If you have a product that does begin to smoke or smolder, immediately shut off the power to the CFL and, once it has cooled, remove it from the light socket.
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How should Compact Fluorescent Light Bulbs (CFLs) be disposed? Do they need to be recycled?
Because CFLs contain a small amount of mercury, EPA recommends that consumers take advantage of available local recycling options for CFLs. Consumers can contact their local municipal solid waste agency directly, or go to epa.gov/bulbrecycling or www.earth911.org to identify local recycling options. The Home Depot and IKEA stores take back used, unbroken CFLs for free. Bring the CFLs to the returns desk.

If your state or local environmental regulatory agency permits you to put used or broken CFLs in the garbage, seal the bulb in two plastic bags and put it into the outside trash, or other protected outside location, for the next normal trash collection. Never send a fluorescent light bulb or any other mercury-containing product to an incinerator.

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How should I clean up a broken compact fluorescent light bulb (CFL)?
Link to http://juniorenergy.org/mercuryinfo.aspx to find out how to clean up a broken compact florescent light bulb.
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Source: The NEED project and EnergyStar

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