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Compact Fluorescent Lighting

CFL's are four times more efficient and last up to 10 times longer than typical incandescents

We are living in a new era when it comes to lighting our homes. No longer is it enough for fixtures to be beautiful and illuminate our spaces. Now, we also expect them to use energy as efficiently as possible to help conserve the limited supply of available energy. In some areas of the country, energy efficient lighting is now required in new and remodeled homes.

Compact fluorescent lamps are simply miniature versions of full-size fluorescent lights. They use an arc discharge through a phosphor-lined tube instead of heating a resistance filament which is used in incandescent light bulbs. A CFL consists of a lamp, lamp holder, and ballast. The ballast provides the electrical control to strike and maintain the arc. Historically, fluorescent lighting’s bluish hue has turned people away from using the energy-efficient lighting in living spaces. However, the warm tones of newer compact fluorescent lighting make it almost indistinguishable from incandescent lighting.

Compact Fluorescent Lights (CFLs) are up to four times more efficient (using 50 to 80 percent less energy) and last up to 10 times longer than incandescent bulbs. A 22-watt CFL has about the same light output as a 100-watt incandescent. .

To optimize the value of CFLs, it is best to use them in areas that are lit for relatively extended periods of time (15 minutes or longer). This could include the outdoor fixtures, the kitchen, family room, and bedroom. Switching a CFL on and off too frequently will shorten its life.

CFLs contain small amounts of mercury, so they should not be placed in regular disposal in order to keep their contents from seeping into a landfill. They should be taken to a qualified disposal facility. These sites can be found through local or regional waste management resources.

Energy Efficiency

Fluorescent lamps use about one-quarter the electricity of an equivalent incandescent lamp. In hot climates, they provide a further benefit by reducing the heat output from the lamp.

Quality and Durability

Fluorescent lamps last about five or more times longer than incandescent lamps. Their high-quality light output improves the lighting quality within the home over standard fluorescent lighting.


There is widespread availability of compact fluorescent lamps. To best choose a lamp, first determine if the bulb is used for period of 15 minutes or more at a time. Then, determine what type of light fixture it is (recessed, dimmer, pin, or typical screw-base type fixture). No additional tools or training are required for installation of CFL bulbs.

CFL bulbs can range from $4 to $15 depending on their type. This is much more than typical incandescent bulbs, but their lifetime and energy savings are significant.

Because CFLs use up to 80 percent less energy than typical incandescent bulbs, they are less expensive to operate. Lamp life is about five times that of incandescent lighting, potentially savings on replacement cost.

As with any electrical device, CFLs must be listed for use such as with a testing laboratory label. CFLs are not specifically referenced in building codes.

Not Applicable

No additional tools or training are required for installation of CFLs. There are three types of CFL lamp-ballast systems.

Integral: Light bulbs that combine a lamp, ballast, and standard screw base in a single sealed assembly, which must be discarded when the lamp burns out. They can be installed in any standard screw-type light fixture where incandescent bulbs are normally used.

Modular Units: This type has a separate two- or four-pin base lamp that plugs into a separate adapter or ballast. When the lamp burns out, a relatively inexpensive replacement lamp can be installed in the original ballast and pin base.

Hardwired (dedicated) Systems: These systems consist of a ballast and fluorescent lamp socket permanently wired into a fixture by the manufacturer, or as part of a retrofit kit. The lamp can be replaced with another similar pin-based CFL when it burns out.

CFLs contain very small amounts of mercury, so broken or burned out bulbs must be disposed of properly. Currently there are few recycling centers available for old or damaged CFLs, and the EPA is working to extend the network of recycling facilities. This EPA FactsheetPDF file provides recycling information and cleaning instructions for broken fluorescent bulbs.

CFLs are usually warranted for 2 years or more. If they fail before this period ends, they can be replaced by the manufacturer.


Efficient: CFL’s are up to four times more efficient and last up to 10 times longer than incandescent bulbs. A 22-watt CFL has about the same light output as a 100-watt incandescent. CFL’s use 50 to 80 percent less energy than incandescent bulbs. Standard incandescent bulbs have an average lifetime of 750 to 2500 hours, while CFLs last from 6,000 to 10,000 hours.

Expense: Although initially more expensive, you save money in the long run because CFL’s use 1/3 the electricity and last up to 10 times as long as incandescent bulbs. A single 18-watt CFL used in place of a 75-watt incandescent will save about 570 kWh over its lifetime. At 8 cents per kWh, that equates to a $45 savings for one bulb over its lifetime.

Reduces Air and Water Pollution: Replacing a single incandescent bulb with a CFL will keep a half-ton of CO2 out of the atmosphere over the life of the bulb. Saving electricity also reduces CO2, SOx, and NOx emissions from power plants.

High-Quality Light: Newer CFL’s give a warm, inviting light instead of the “cool white” light of older fluorescents. They use rare earth phosphors for excellent color and warmth. New electronically ballasted CFL’s don’t flicker or hum.

Versatile: Energy efficient CFL’s can be used nearly anywhere that incandescent lights are used. They can be used in recessed fixtures (with the exception of recessed enclosed fixtures, where temperatures may be too high), table lamps, track lighting, ceiling fixtures, and porch lights. CFLs do not create as much heat as comparable incandescent bulbs, making them idela for clostes or other applications where there is heat sensitivity. Also, three-way CFL’s are now available for lamps or fixtures with three-way settings.


Outdoor Use: Some fluorescent lamps are not suitable for outdoor use in cold climates, because they do not operate well at temperatures below 40 oF. However, some CFLs are specially designed to operate at temperatures down to -20 oF. To qualify for ENERGY STAR®, the lamp package must state the minimum starting temperatures or geographical zone of use, and any other conditions for reliable starting to meet the starting time requirements from ANSI C78.5, Clause 4.7. There are also “weatherproof” models that are ENERGY STAR qualified.

Dimming: Most CFL lamps and fixtures do not operate effectively with dimmer controls; special ballasts are needed. Only specially selected replacement bulbs and fixtures are suited for dimming, as dimming will shorten the bulb life of many CFLs. Manufacturers have developed CFLs that will work with dimming switches, and the package will note that the lamp or fixture can be connected to a dimmer. ENERGY STAR maintains a “dimmable CFL” list on their website.

Frequent On and Off Switching: Turing a CFL on and off frequently will shorten its life. For better energy savings and longer life, it is best to use them in light fixtures which will be on for at least 15 minutes at a time.

Availability: Even though integral type CFLs are very common throughout the U.S., availability of special fixtures, recessed downlights, and dimmable CFLs may be limited in some jurisdictions. However, these special bulbs and fixtures are increasingly being marketed on the web.

Disclaimer: The information on the system, product or material presented herein is provided for informational purposes only. The technical descriptions, details, requirements, and limitations expressed do not constitute an endorsement, approval, or acceptance of the subject matter by the NAHB Research Center. There are no warranties, either expressed or implied, regarding the accuracy or completeness of this information. Full reproduction, without modification, is permissible.