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Compact Fluorescents Light the Way for Energy Efficiency

March 1, 2008
As CFLs make a bid to take over the incandescent lighting market, here are the 10 things you need to know about the technology

Close your eyes and imagine the fluorescent lamp fixtures from your childhood. These lights most likely hummed, flickered, buzzed, and created harsh, unnatural light. If you stood under one of these light fixtures, you may have appeared a pale shade of green.

“The first ones that came out had old magnetic ballasts so they would go blink, blink, blink and drive people crazy,” says Russ Leslie, associate director of the Troy, N.Y.-based Lighting Research Center and professor at the Rensselaer Polytechnic Institute University. “Some of them would provide interference to your radio or TV and tended to produce a lot of cool stark white colors.”

Times have changed since the days of the noisy, flickering fluorescents. Manufacturers and research groups have spent the last decade improving the technology and performance of both the lamps and the ballasts. Fluorescents, which were first introduced in 1939 at the World's Fair in New York, are now available in compact sizes with miniaturized ballasts and lamps. Compact fluorescent lamps (CFLs) can be screwed into existing incandescent sockets or hard-wired into dedicated fixtures (Figure on page 30). CFLs were originally designed to replace conventional 25W to 100W incandescent lamps, but they now come in a variety of styles and shapes to fit virtually any lighting application. According to the U.S. Department of Energy (DOE), CFLs last up to 10 times longer, use a quarter of the energy, and produce 90% less heat than standard incandescent bulbs. This article will discuss 10 things every electrical professional should know about CFLs.

Long-term energy savings outweigh the initial cost

Consumers can buy a four-pack of incandescent light bulbs for $1 at their local supermarket, while CFLs cost about $4 to $5 for a single bulb. The higher initial cost of CFLs, however, is offset by the lamp's reduced maintenance requirements and longer life. A typical CFL lasts for about 10,000 hours compared to an average of 1,000 hours for an incandescent. As a result of the shorter life of incandescents, Americans throw away more than 1.6 billion standard incandescent bulbs every year. Some building owners and facilities managers are starting to see the light when it comes to energy-efficient CFLs, but the majority are still focusing on the bottom line, says Craig DiLouie, principal, Zing Communications, Inc.

“Many owners still do not regard life-cycle cost, energy savings, and return on investment as more important than initial cost during lighting equipment selection,” DiLouie says. “The result is they install equipment that is cheaper to purchase but much more expensive to own and operate over its life.”

CFLs now emulate the warm color of incandescents

Sidebar: Cost Comparison

When they were first introduced to the market, CFLs emitted a cool white light. Through technological advances, CFLs can now offer warm light similar to the illumination from incandescents. Jeff McCullough, senior research engineer with the DOE's Pacific Northwest National Laboratory (PNNL), says the benchmark for rating the color of lighting is determined by the color of iron when it's heated in a furnace. A piece of iron that's heated to 2,700K exhibits a yellow, or what is called a “warm white” color, which is the color of the typical incandescent light. As you heat an iron rod to 4,000K, it gets more blue and white, which is a “cool white” color. For compact fluorescent technology, manufacturers and researchers are trying to target products in the 2,700K to 3,100K range to emulate the color of incandescents.

Leslie says the Lighting Research Center conducts third-party testing on CFLs to ensure that the products meet their stated specifications.

“We've run demos where the colors between incandescents and CFLs are indistinguishable,” Leslie says. “You wouldn't be able to pick out which one was the CFL.”

  • CFLs are smaller, thinner, and come in a variety of shapes

    The flickering and buzzing fluorescents are now a technology of the past. Manufacturers have since developed thinner, more energy-efficient CFLs to illuminate commercial and industrial facilities. CFLs consist of two parts — a gas-filled tube and a magnetic or electronic ballast. When electricity flows through the ballast, the gas inside the tube glows and the white phosphor coating emits visible light. Leslie says CFLs are often bigger than incandescent lamps because they need a larger surface area in order to operate. To make CFLs that are small enough to fit incandescent applications, manufacturers have designed screw-in CFLs in twisted shapes and triple loops.

    Ron Paduchak, CFL product manager for the commercial and industrial market for GE Lighting, says lighting manufacturers have been able to solve many of the challenges faced during the early years of the CFL technology.

    “The advances in electronics with the ballasts have allowed us to make the lamp smaller and increase the lamp's life,” he says.

  • Not all CFLs are dimmable

    All incandescents can be installed in dimming circuits because of the way they're designed, but only select CFL models are dimmable. Paduchak envisions technological advances that will allow a person to use any CFL on any type of dimming circuit with the pinpoint control of an incandescent in the future.

    In the meantime, electricians need to make sure they have the right product for the right application. For example, one of Paduchak's customers called to complain that the CFLs were flickering and not operating properly. After further discussion, he discovered that his client was trying to install a non-dimming CFL in a dimmable lighting application. To make sure the CFL will dim properly, check the packaging for language stating that the CFL is for use on dimmable circuits. The “CFL Installation and Specification” sidebar on page 35 offers more tips.

  • Use a three-to-one ratio when replacing incandescents with CFLs

    Electrical engineers and contractors may encounter problems if they specify a CFL that doesn't meet the client's lighting requirements. Leslie advises the electrical industry to abide by the 3:1 rule when replacing incandescent light bulbs. For example, electricians would need to purchase a 33W CFL to replace a 100W incandescent.

    “A three-to-one ratio seems to work for maximum satisfaction,” Leslie says. “You won't disappoint someone for the amount of light coming out if the position is tilted or it's a little slow in achieving the full light output.”

    To monitor the light output of the CFLs, third-party testing labs and the Energy Star program, which was developed jointly by the DOE and the Environmental Protection Agency, are making sure that the product's performance is consistent with the packaging. Dave Geraci of Technical Consumer Products (TCP) says CFLs may have been developed nearly 25 years ago, but the technology didn't start to substantially improve until the last five years.

    “Early in the category's life, most of the products didn't perform up to what manufacturers stated they would with regards to life and light output,” Geraci says. “I think the early users or adopters of CFLs became disenchanted with them and that's why they didn't take off early. I think the better technology is the main reason for the growth of CFLs.”

  • Look for the Energy Star label

    CFLs were once only available through traditional distribution channels, but now consumers can buy them at hardware stores, home improvement retailers, and even dollar stores. However, Leslie cautions electricians to be careful about buying CFLs that are sold at rock-bottom prices.

    “There are some inexpensive products that clearly don't perform as well as the ones that have the Energy Star label,” Leslie says. “I would take caution when buying these products.”

    The Energy Star program, which was started in 1992 to reduce greenhouse emissions, labels both energy-efficient buildings and products. Commercial facilities that rank in the top 25% in terms of energy efficiency are awarded the Energy Star label (“Lighting Up Hospitality Applications” on page 34). About 164 CFL manufacturers also participate in the Energy Star labeling program for products. CFLs that earn the Energy Star rating must have an operating life of at least 6,000 hours compared to incandescent bulbs that last 1,000 hours. Most CFLs have rated lifetimes of 8,000 hours to 10,000 hours, equating to seven to nine years of use at three hours per day. The Energy Star specification also requires a minimum efficacy level defined as the amount of light output (lumens) per unit of electricity consumed (watts). Incandescent bulbs only produce about 15 lumens/W while Energy Star-qualified CFLs produce 40-60 lumens/W. They must also comply with other operating characteristics and meet safety and reliability guidelines.

  • CFLs don't operate well in temperature extremes

    Incandescent bulbs can be installed in just about any environment, but hot temperatures reduce the life of CFLs. For example, compact fluorescents tend to overheat in residential recessed downlight applications. “The operating temperature in a recessed can get very hot as opposed to a regular table lamp, floor lamp, or porcelain fixture,” Geraci says. “Heat really kills the life of the product.”

    PNNL estimates that about 350 million recessed cans are currently installed in the United States, and 20 million are sold each year. To help solve the problem of heat in recessed cans, PNNL, on behalf of the DOE, launched a technology procurement program in 2002. PNNL sent out a request for proposals, and seven manufacturers submitted 18 different models. Through both long-term and short-term testing, PNNL narrowed the field down to three manufacturers and seven models. Many of the products were weeded out in the initial phase of testing due to high ballast temperatures.

    The three companies that successfully survived the testing in a simulated insulated ceiling environment are now beta testing their products in both residential and commercial applications. The recessed downlights will be sold at a fixed price through the DOE's technology procurement program.

    In addition to the recessed downlight program, PNNL is also testing reflector CFL lamps, which currently face many technological challenges — shorter operating lives, reduced light output, and a larger size than traditional incandescent reflector lamps.

    “If the lamp is turned upside down, the cathodes are in close proximity to the electronics,” McCullough says. “When you put the lamp in an insulated can, it's not a good recipe for success. We're trying to encourage manufacturers to build a new generation of reflector lamps that will provide their rated light and meet the 6,000-hour requirement in an insulated ceiling environment.”

    The DOE is currently testing the products and will announce the finalists on its Web site at www.pnl.gov/r-lamps later this year. Through its technology procurement programs for both recessed downlights and reflector lamps, PNNL is striving to overcome technological challenges and make the products more affordable for consumers.

  • CFLs aren't suitable for all lighting applications

    While you may be tempted to replace all incandescent light bulbs with CFLs in order to cut energy costs, first evaluate the lighting needs of your facility. CFLs are designed for applications where they're on for three or more hours at a time. For that reason, they're often used in wall sconces, ceiling-mounted fixtures, and ceiling fans. To create products that can handle being switched on and off frequently, manufacturers are researching cold cathode fluorescent technology. The cold cathodes are not as bright as the CFL and are suitable for decorative lights like blunt tips, torpedoes, or exit lighting. Rather than using a filament, the product uses a high-voltage strike to start up the light. As a result, it can last twice as long as a CFL but has a lower lumen output.

  • Research rebate programs

    To save on energy costs and encourage consumers to help protect the environment, electric utilities offered rebates, enabled consumers to buy the CFLs at a reduced rate, or gave them away in the ‘90s. During the energy crisis of 2001, electric utilities in Oregon, Washington, and Idaho gave away 1.3 million CFLs, according to the Zero Waste Alliance. Some utilities are still sponsoring programs today.

    “When the utilities were in the heyday of their demand side management programs, CFLs were subsidized in the interest of residential energy conservation,” Leslie says. “The focus was largely on the residential market because of the dominance of incandescent lighting.”

    For the commercial market, many of the state energy codes limit the widespread use of incandescent lighting. Instead, they encourage the installation of dedicated fixtures designed for CFLs. With a screw-in CFL, users can always switch back to an incandescent. Specifying dedicated fixtures prevents the possibility of “snap back,” in which energy users revert back to the old tried-and-true technology.

  • Remember to recycle

    Electrical contracting firms that are switching out large quantities of compact fluorescent bulbs can't toss the old lights into the dumpster. Unlike incandescents, CFLs contain about 5 mg to 15 mg of mercury per bulb, which is essential to the lamp's operation. Because mercury is a toxic substance that's harmful to the nervous system, electricians must be careful not to crush the lamps. They must also carefully transport them to a recycling center or hazardous waste collection site where they can be disposed of properly.

  • Each state has different guidelines on the recycling of CFLs, and the electrical industry needs to become aware of the policies in their area. About 34 states currently regulate the disposal of CFLs, while the remaining states permit the disposal of CFLs in a regular waste stream. For example, Florida and Minnesota require companies that dispose of more than 10 lamps a month to use a recycling program. A Portland, Ore.-based conservation group called the Zero Waste Alliance is also spearheading a residential CFL recycling program to prevent the release of mercury into the environment, encourage the safe use of energy-efficient products, and work with retailers to establish CFL collection sites.

    Some manufacturers are trying to reduce the mercury content in their CFL products to make them safer for the environment. These companies are also inventing new ways to help the nation lower its $75 million lighting bill through energy-efficient lighting. According to the Energy-Efficient Lighting Association, less than 10% of the 70 billion square feet of the country's commercial floor space had been upgraded with energy-efficient lighting by 2001. This opens up a wide market for electrical contracting and engineering firms, who can save energy and make a difference — all by just changing a light bulb.

    Incandescent bulbs may carry a lower sticker price, but they need to be replaced more often, leading to higher maintenance, operation, and life cycle costs. The following table assumes that the light is on for six hours per day, and the electricity rate is 10 cents/kWh.

    Hotel guests often leave the lights on in their rooms, which burns energy and generates heat in incandescent lighting applications. One hotel's annual energy bill even topped $400,000 due to the amount of energy consumed in the guest rooms. To lower its electricity costs, the hotel replaced its incandescents with compact fluorescents. As a result, the facility saved $30,000 in energy bills.

    “When you knock out that much cost out of a $400,000 bucket just by changing a lightbulb, that's significant,” says Chris Forti of GE Lighting. “Hoteliers really see compact fluorescents as an opportunity to reduce their expenses.”

    Many of these hotels are installing CFLs in order to qualify for the Energy Star for Buildings rating. Commercial buildings must measure the energy use of their entire building and compare this information to a national database. If their facility ranks in the top 25% in terms of energy efficiency, they're awarded the Energy Star label.

    “You now have an opportunity on the commercial side of the business to get the recognition for energy efficiency,” Forti says. “It gives you the opportunity to say something to the customers that you're working with the top 25% of energy savings and have a progressive energy program.”

    Craig DiLouie, principal, ZING Communications, Inc., identifies the following application issues that electrical professionals should understand when specifying CFLs.

    Light output. Few CFLs produce enough light for high ceiling (above 12 feet) ambient lighting applications.

    Light quality. CFLs are linear sources while incandescent lamps are point sources. Therefore, they soften objects in the space and minimize shadowing and sparkle. If shadows and sparkle are desired for certain accent lighting applications, incandescent lamps will work better.

    Size and shape. Today's compact fluorescent lamps come in a variety of shapes and sizes, including spirals, circle-line, double/triple/quadruple tubes, bullets/torpedoes, and globes. A major application issue involving CFLs is what happens when an incandescent fixture designed optically for incandescent lamps is retrofitted with a compact fluorescent with very different characteristics like size and shape. When choosing the CFL for a retrofit, a lamp should be chosen that's as similar as possible in size, shape and light output as the replaced incandescent. Recessed downlights can be replaced using retrofit kits that include a CFL in a complete fixture designed specifically for such uses. The kit that's right for the application will depend on the ceiling height and required light output and light distribution.

    Cold temperatures. Many compact fluorescent lamps either won't start or will start slowly in cold temperatures. Check the manufacturer for starting temperature specifications and be aware of the historical temperature low ranges for the application.

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