Compact fluorescent lamp
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A compact fluorescent lamp (CFL), also known as a compact fluorescent light or energy saving light (or less commonly as a compact fluorescent tube), is a type of fluorescent lamp. Many CFLs are designed to replace an incandescent lamp and can fit into most existing light fixtures formerly used for incandescents.
Compared to general service incandescent lamps giving the same amount of visible light, CFLs use less power and have a longer rated life. In the United States, a CFL has a higher purchase price than an incandescent lamp, but can save over US$40 in electricity costs over the lamp's life time.[2] Like all fluorescent lamps, CFLs contain mercury, which complicates their disposal.
CFLs radiate a different light spectrum from that of incandescent lamps. Improved phosphor formulations have improved the subjective color of the light emitted by CFLs such that some sources rate the best 'soft white' CFLs as subjectively similar in color to standard incandescent lamps.[3]
History
The parent to the modern fluorescent lamp was invented in the late 1890s by Peter Cooper Hewitt.[4] The Cooper Hewitt lamps were used for photographic studios and industries.[4]
Edmund Germer, Friedrich Meyer, and Hans Spanner then patented a high pressure vapor lamp in 1927.[4] George Inman later teamed with General Electric to create a practical fluorescent lamp, sold in 1938 and patented in 1941.[4] Circular and U-shaped lamps were devised to reduce the length of fluorescent light fixtures. The first fluorescent bulb and fixture were displayed to the general public at the 1939 New York World's Fair.
The spiral tube CFL was invented in 1976 by Edward E. Hammer, an engineer with General Electric,[5] in response to the 1973 oil crisis. While it met its design goals, it would have cost GE about US$25 million to build new factories to produce them and the invention was shelved.[6] The design was eventually leaked out and copied by others.[6] It was not until 1995 that spiral lamps manufactured in China were commercially available;[7] spiral lamps have steadily increased in sales volume.
In 1980, Philips introduced its model SL, which was a screw-in lamp with integral ballast. The lamp used a folded T4 tube, stable tri-color phosphors, and a mercury amalgam. This was the first successful screw-in replacement for an incandescent lamp. In 1985 Osram started selling their model EL lamp which was the first CFL to include an electronic ballast.[8]
Ellis Yan, a Chinese immigrant to the United States who runs a lighting business in China, decided to improve on the CFL design in the 1990s. Chinese workers bent the glass by hand, but the results were "expensive, clunky and flickered when turned on."[9] Yan continued his efforts and the business became a success; by 2010, one-fourth of all bulbs sold in the United States were CFLs, with Yan claiming he made over half of those.[9]
Development of fluorescent lamps that could fit in the same volume as comparable incandescent lamps required the development of new, high-efficacy phosphors that could withstand more power per unit area than the phosphors used in older, larger fluorescent tubes.[8]
Construction
The most important technical advance has been the replacement of electromagnetic ballasts with electronic ballasts; this has removed most of the flickering and slow starting traditionally associated with fluorescent lighting.
There are two types of CFLs: integrated and non-integrated lamps. Integrated lamps combine a tube, an electronic ballast and either an Edison screw or a bayonet fitting in a single unit. These lamps allow consumers to replace incandescent lamps easily with CFLs. Integrated CFLs work well in many standard incandescent light fixtures, reducing the cost of converting to fluorescent. Special 3-way models and dimmable models with standard bases are available.
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Non-integrated CFLs have the ballast permanently installed in the luminaire, and only the lamp bulb is usually changed at its end of life. Since the ballasts are placed in the light fixture they are larger and last longer compared to the integrated ones, and they don't need to be replaced when the bulb reaches its end-of-life. Non-integrated CFL housings can be both more expensive and sophisticated. They have two types of tubes: a bi-pin tube designed for a conventional ballast, and a quad-pin tube designed for an electronic ballast or a conventional ballast with an external starter. A bi-pin tube contains an integrated starter which obviates the need for external heating pins but causes incompatibility with electronic ballasts.
Components
CFLs have two main components: a gas-filled tube (also called bulb or burner) and a magnetic or electronic ballast. For their principles of operation, see Fluorescent lamp.
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Standard shapes of CFL tube are single-turn double helix, double-turn, triple-turn, quad-turn, circular, and butterfly.
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Electronic ballasts contain a small circuit board with rectifiers, a filter capacitor and usually two switching transistors connected as a high-frequency resonant series DC to AC inverter. The resulting high frequency, around 40 kHz or higher, is applied to the lamp tube. Since the resonant converter tends to stabilize lamp current (and light produced) over a range of input voltages, standard CFLs do not respond well in dimming applications and special lamps are required for dimming service. CFLs that flicker when they start have magnetic ballasts; CFLs with electronic ballasts are now much more common.
CFL power sources
CFLs are produced for both alternating current (AC) and direct current (DC) input. DC CFLs are popular for use in recreational vehicles and off-the-grid housing. There are various aid agency led initiatives in developing countries to replace kerosene lanterns (with their associated health hazards) with DC CFLs (with car batteries and small solar panels or wind generators). [10]
CFLs can also be operated with solar powered street lights, using solar panels located on the top or sides of a pole and light fixtures that are specially wired to use the lamps.
Comparison with incandescent lamps
Lifespan
The average rated life of a CFL is between 8 and 15 times that of incandescents.[11] CFLs typically have a rated lifespan of between 6,000 and 15,000 hours, whereas incandescent lamps are usually manufactured to have a lifespan of 750 hours or 1,000 hours.[12][13][14]
The lifetime of any lamp depends on many factors including operating voltage, manufacturing defects, exposure to voltage spikes, mechanical shock, frequency of cycling on and off, lamp orientation, and ambient operating temperature, among other factors. The life of a CFL is significantly shorter if it is turned on and off frequently. In the case of a 5-minute on/off cycle the lifespan of a CFL can be reduced to "close to that of incandescent light bulbs".[15] The US Energy Star program suggests that fluorescent lamps be left on when leaving a room for less than 15 minutes to mitigate this problem.
CFLs produce less light later in their lives than when they are new. The light output decay is exponential, with the fastest losses being soon after the lamp is first used. By the end of their lives, CFLs can be expected to produce 70–80% of their original light output.[16] The response of the human eye to light is logarithmic (a photographic 'f-stop' reduction represents a halving in actual light, but is subjectively quite a small change).[17] A 20–30% reduction over many thousands of hours represents a change of about half an f-stop. So, presuming the illumination provided by the lamp was ample at the beginning of its life, such a difference will be compensated for by the eyes, for most purposes.[18]
Energy efficiency
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For a given light output, CFLs use 20 to 33 percent of the power of equivalent incandescent lamps.[19] Since lighting accounted for approximately 9% of household electricity usage in the United States in 2001, widespread use of CFLs could save as much as 7% of total US household usage.[20]
Electrical power consumption Watts (W) |
Minimum light output[21] lumens (lm) | |
---|---|---|
Compact fluorescent [citation needed] |
Incandescent[21] | |
8–9 | 40 | 450 |
9–15 | 60 | 800 |
15–20 | 75 | 1,100 |
20–25 | 100 | 1,600 |
25–45 | 150 | 2,600 |
Heating and cooling
If a building's indoor incandescent lamps are replaced by CFLs, the heat produced due to lighting will be reduced. At times when the building requires both heating and lighting, the heating system will make up the heat which, depending on the structures heating system, can actually increase total greenhouse gas emissions. In British Columbia, Canada the provincial power authority estimated that greenhouse gas emissions would increase by 45,000 tonnes annually as a result of adopting CFL lighting[22]. In colder climates this loss of heat can actually translate in to increased total energy costs. In warmer climates where the building requires both illumination and cooling the opposite effect is observed as CFLs reduce the load on the cooling system compared to incandescent lamps, resulting in savings in electrical power. Overall energy cost saving depends on the climate; increased heating energy demand offsets some of the lighting energy saved.[23]
Efficacy and efficiency
Because the eye's sensitivity changes with the wavelength, the output of lamps is commonly measured in lumens, a measure of the power of light perceived by the human eye. The luminous efficacy of lamps refers to the number of lumens produced for each watt of electrical power used. A theoretically 100% efficient electric light source producing light only at the wavelength the human eye is most sensitive to would produce 680 lumens per watt.[24]
The typical luminous efficacy of CFL lamps is 60 to 72 lumens per watt,[25] and that of normal domestic incandescent lamps is 13 to 18 lm/W.[24] Compared to the theoretical 100% efficient lamp, these figures are equivalent to lighting efficiency ranges of 9 to 11% for CFLs (60/680 and 72/680) and 1.9 to 2.6% for incandescents (13/680 and 18/680).[24]
Embodied energy
While CFLs require more energy in manufacturing than incandescent lamps, this embodied energy is more than offset by the facts that they last longer and use less energy than equivalent incandescent lamps.[26]
Cost
While the purchase price of an integrated CFL is typically 3 to 10 times greater than that of an equivalent incandescent lamp, the extended lifetime and lower energy use will more than compensate for the higher initial cost.[27] A US article stated "A household that invested $90 in changing 30 fixtures to CFLs would save $440 to $1,500 over the five-year life of the bulbs, depending on your cost of electricity. Look at your utility bill and imagine a 12% discount to estimate the savings."[28]
CFLs are extremely cost-effective in commercial buildings when used to replace incandescent lamps. Using average U.S. commercial electricity and gas rates for 2006, a 2008 article found that replacing each 75 W incandescent lamp with a CFL resulted in yearly savings of $22 in energy usage, reduced HVAC cost, and reduced labor to change lamps. The incremental capital investment of $2 per fixture is typically paid back in about one month. Savings are greater and payback periods shorter in regions with higher electric rates and, to a lesser extent, also in regions with higher than U.S. average cooling requirements.[29]
The current price of CFLs reflects the fact that nearly all CFLs come from China, where labor costs less. In September 2010, the Winchester, Virginia General Electric plant closed, leaving Osram Sylvania the last company to make standard incandescent bulbs in the United States. At that time, Ellis Yan, whose Chinese company made the majority of CFLs sold in the United States, was interested in building a United States factory to make CFL bulbs, but he needed $12.5 million to do so, and the U.S. government had not helped with this. Yan said stores wanted American-made bulbs, which would be 45 to 50 cents more each, but Yan said consumers were willing to pay this much.
General Electric had considered changing one of its bulb plants to make CFLs, but even after a $40 million investment, wage differences would mean the bulbs would cost one and a half times those made in China.[9]
Starting time
Incandescents reach full brightness a fraction of a second after being switched on. As of 2009[update], CFLs turn on within a second, but many still take time to warm up to full brightness.[30] The light color may be slightly different immediately after being turned on.[31] Some CFLs are marketed as "instant on" and have no noticeable warm-up period,[32] but others can take up to a minute to reach full brightness,[33] or longer in very cold temperatures. Some that use a mercury amalgam can take up to three minutes to reach full output.[32] This and the shorter life of CFLs when turned on and off for short periods may make CFLs less suitable for applications such as motion-activated lighting.
Comparison with alternative technologies
Solid-state lighting has already filled a few specialist niches such as traffic lights and may compete with CFLs for house lighting as well. LEDs providing over 200 lm/W have been demonstrated in laboratory tests[34] and expected lifetimes of around 50,000 hours are typical. The luminous efficacy of available LED lamps does not typically exceed that of CFLs. DOE testing of commercial LED lamps designed to replace incandescent or CFL lamps showed that average efficacy was still about 31 lm/W in 2008 (tested performance ranged from 4 lm/W to 62 lm/W).[35]
General Electric discontinued a 2007 development project intended to develop a high-efficiency incandescent bulb with the same lumens per watt as fluorescent lamps.[36] Meanwhile other companies have developed and are selling halogen incandescents that use 70% of the energy of standard incandescents.[37]
Other CFL technologies
Another type of fluorescent lamp is the electrodeless lamp, known as Magnetic Induction Lamps, radiofluorescent lamp or fluorescent induction lamp. These lamps have no wire conductors penetrating their envelopes, and instead excite mercury vapor using a radio-frequency oscillator.[38] Currently, this type of light source is struggling with a high cost of production, stability of the products produced by domestic manufacturers in China, establishing an internationally recognized standard and problems with EMC and RFI. Furthermore, induction lighting is excluded from Energy Star standard for 2007 by the EPA.
The Cold Cathode Fluorescent Lamp (CCFL) is one of the newest forms of CFL. CCFLs use electrodes without a filament. The voltage of CCFLs is about 5 times higher than CFLs, and the current is about 10 times lower. CCFLs have a diameter of about 3 millimeters. CCFLs were initially used for document scanners and also for backlighting LCD displays, but they are now also manufactured for use as lamps. The efficacy (lumens per watt) is about half that of CFLs. Their advantages are that they are instant-on, like incandescents, they are compatible with timers, photocells, and dimmers, and they have a long life of approximately 50,000 hours. CCFLs are a convenient transition technology for those who are not comfortable with the short lag time associated with the initial lighting of CFLs. They are also an effective and efficient replacement for lighting that is turned on and off frequently with little extended use (e.g. a bathroom or closet).
A few manufacturers[39][40] make CFL-style bulbs with mogul Edison screw bases intended to replace 250 watt and 400 watt metal halide lamps, claiming a 50% energy reduction; however, these lamps require slight rewiring of the lamp fixtures to bypass the lamp ballast.
Spectrum of light
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- Compact Fluorescent: General Electric, 13 W, 6,500 K
- Incandescent: Sylvania 60 W Extra Soft White
- Compact Fluorescent: Bright Effects, 15 W, 2,644 K
- Compact Fluorescent: Sylvania, 14 W, 3,000 K
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CFLs emit light from a mix of phosphors inside the bulb, each emitting one band of color. Modern phosphor designs are a compromise between the shade of the emitted light, energy efficiency, and cost. Every extra phosphor added to the coating mix causes a loss of efficiency and increased cost. Good quality consumer CFLs use three or four phosphors to achieve a 'white' light with a CRI (color rendering index) of around 80, where 100 represents the appearance of colors under daylight or a black-body (depending on the correlated color temperature).
Color temperature can be indicated in kelvins or mireds (1 million divided by the color temperature in kelvins).
Name | Color temperature | |
---|---|---|
(K) | (Mired) | |
Warm/soft white | ≤ 3,000 | ≥ 333 |
(Bright) white | 3,500 | 286 |
Cool white | 4,000 | 250 |
Daylight | ≥ 5,000 | ≤ 200 |
Color temperature is a quantitative measure. The higher the number in kelvins, the more blue the shade. Color names associated with a particular color temperature are not standardized for modern CFLs and other triphosphor lamps like they were for the older-style halophosphate fluorescent lamps. Variations and inconsistencies exist among manufacturers. For example, Sylvania's Daylight CFLs have a color temperature of 3,500 K, while most other lamps with a daylight label have color temperatures of at least 5,000 K. Some vendors do not include the kelvin value on the package, but this is beginning to change now that the Energy Star criteria for CFLs is expected to require such labeling in its 4.0 revision.
Some manufacturers now label their CFLs with a 3 digit code to specify the color rendering index (CRI) and color temperature of the lamp. The first digit represents the CRI measured in tens of percent, while the second two digits represent the color temperature measured in hundreds of kelvins. For example, a CFL with a CRI of 83 and a color temperature of 2,700 K would be given a code of 827.[41]
CFLs are also produced, less commonly, in other colors:
- Red, green, orange, blue, and pink, primarily for novelty purposes
- Blue for phototherapy
- Yellow, for outdoor lighting, because it does not attract insects
- Black light (UV light) for special effects
Black light CFLs, those with UVA generating phosphor, are much more efficient than incandescent black light lamps, since the amount of UV light that the filament of the incandescent lamp produces is only a fraction of the generated spectrum.
Health issues
The cost effectiveness of battery-powered CFLs is enabling aid agencies to support initiatives to replace kerosene lamps, the fumes from which cause chronic lung disorders in typical homes and work places in third world countries.[10]
According to the European Commission Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) in 2008, the only property of compact fluorescent lamps that could pose an added health risk is the ultraviolet and blue light emitted by such devices. The worst that can happen is that this radiation could aggravate symptoms in people who already suffer rare skin conditions that make them exceptionally sensitive to light. They also stated that more research is needed to establish whether compact fluorescent lamps constitute any higher risk than incandescent lamps.[42]
If individuals are exposed to the light produced by some single-envelope compact fluorescent lamps for long periods of time at distances of less than 20 cm, it could lead to ultraviolet exposures approaching the current workplace limit set to protect workers from skin and retinal damage.[42]
The UV radiation received from CFLs is too small to contribute to skin cancer and the use of double-envelope CFL lamps "largely or entirely" mitigates any other risks.[42]
Environmental issues
Mercury emissions
CFLs, like all fluorescent lamps, contain small amounts of mercury[43][44] as vapor inside the glass tubing. Most CFLs contain 3–5 mg per bulb, with the eco-friendly bulbs containing as little as 1 mg.[45][46] Because mercury is poisonous, even these small amounts are a concern for landfills and waste incinerators where the mercury from lamps may be released and contribute to air and water pollution. In the U.S., lighting manufacturer members of the National Electrical Manufacturers Association (NEMA) have voluntarily capped the amount of mercury used in CFLs.[47] In the EU the same cap is required by the RoHS law.
In areas with coal-fired power stations, the use of CFLs saves on mercury emissions when compared to the use of incandescent bulbs. This is due to the reduced electrical power demand, reducing in turn the amount of mercury released by coal as it is burned.[48][49] In July 2008 the US EPA published a data sheet stating that the net system emission of mercury for CFL lighting was lower than for incandescent lighting of comparable lumen output. This was based on the average rate of mercury emission for US electricity production and average estimated escape of mercury from a CFL put into a landfill.[50] Coal-fired plants also emit other heavy metals, sulfur, and carbon dioxide.
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In the United States, the U.S. Environmental Protection Agency estimated that if all 270 million compact fluorescent lamps sold in 2007 were sent to landfill sites, that this would represent around 0.13 metric tons, or 0.1% of all U.S. emissions of mercury (around 104 metric tons that year.)[51]
Broken and discarded lamps
Health and environmental concerns about mercury have prompted many jurisdictions to require spent lamps to be properly disposed or recycled rather than being included in the general waste stream sent to landfills. It is unlawful to dispose of fluorescent bulbs as universal waste in the states of California, Minnesota, Ohio, Illinois, Indiana, Michigan, and Wisconsin.[52] In the European Union, CFLs are one of many products subject to the WEEE recycling scheme. The retail price includes an amount to pay for recycling, and manufacturers and importers have an obligation to collect and recycle CFLs. Safe disposal requires storing the bulbs unbroken until they can be processed. In the US, The Home Depot is the first retailer to make CFL recycling options widely available.[53]
Special handling instructions for breakage are currently not printed on the packaging of household CFL bulbs in many countries. The amount of mercury released by one bulb can temporarily exceed U.S. federal guidelines for chronic exposure.[54][55] Chronic however, implies that the exposure continues constantly over a long period of time and the Maine DEP study noted that it remains unclear what the health risks are from short-term exposure to low levels of elemental mercury. The Maine DEP study also confirmed that, despite following EPA best-practice cleanup guidelines on broken CFLs, researchers were unable to remove mercury from carpet, and agitation of the carpet—such as by young children playing—created spikes as high as 25,000 ng/m3 in air close to the carpet, even weeks after the initial breakage. Conventional tubular fluorescent lamps have been in commercial and domestic use since the 1930s with little public concern about their handling; these and other domestic products such as thermometers contain far more mercury than modern CFLs.[56]
The U.S. Environmental Protection Agency (EPA) recommends that, in the absence of local guidelines, fluorescent bulbs be double-bagged in plastic before disposal.[57] The Maine DEP study of 2008 compared clean-up methods, and warned that the EPA recommendation of plastic bags was the worst choice, as vapours well above safe levels continued to leach from the bags. The Maine DEP now recommends a sealed glass jar as the best repository for a broken bulb.
The first step of processing CFLs involves crushing the bulbs in a machine that uses negative pressure ventilation and a mercury-absorbing filter or cold trap to contain mercury vapor. Many municipalities are purchasing such machines. The crushed glass and metal is stored in drums, ready for shipping to recycling factories.
According to the Northwest Compact Fluorescent Lamp Recycling Project, because household users in the U.S. Northwest have the option of disposing of these products in the same way they dispose of other solid waste, in Oregon "a large majority of household CFLs are going to municipal solid waste". They also note the EPA's estimates for the percentage of fluorescent lamps' total mercury released when they are disposed of in the following ways: municipal waste landfill 3.2%, recycling 3%, municipal waste incineration 17.55% and hazardous waste disposal 0.2%.[58]
Mercury poisoning of Chinese factory workers
In the past decade, hundreds of Chinese factory workers who manufacture CFLs for export to first world countries were being poisoned and hospitalized because of mercury exposure. Examples include workers at the Nanhai Feiyang lighting factory in Foshan city where 68 out of 72 were so badly poisoned that they required hospitalization. At another CFL factory in Jinzhou, 121 out of 123 employees were found to have excessive mercury levels with one employee's mercury level 150 times the accepted standard.[59]
Design and application issues
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The primary objectives of CFL design are high electrical efficiency and durability. However, there are some other areas of CFL design and operation that are problematic:[60]
- Size
- CFL light output is roughly proportional to phosphor surface area, and high output CFLs are often larger than their incandescent equivalents. This means that the CFL may not fit well in existing light fixtures.
- End of life
- In addition to the wear-out failure modes common to all fluorescent lamps, the electronic ballast may fail since it has a number of component parts. Ballast failures may be accompanied by discoloration or distortion of the ballast enclosure, odors, or smoke. The lamps are internally protected and are meant to fail safely at the end of their lives. Industry associations are working toward advising consumers of the different failure modes of CFLs compared to incandescent lamps, and to develop lamps with inoffensive failure modes.[61] New North American technical standards aim to eliminate smoke or excess heat at the end of lamp life.[62]
- Incandescent replacement wattage inflation
- An August 2009 newspaper report described that some manufacturers claim the CFL replaces a higher wattage incandescent lamp than justified by the light produced by the CFL.[63] Equivalent wattage claims can be replaced by comparison of the lumens produced by the lamp.[64]
- Dimming
- Only some CF lamps are labeled for dimming control. Using regular CFLs with a dimmer is ineffective at dimming, can shorten bulb life and will void the warranty of certain manufacturers.[65] Dimmable CFLs are available.[66] There is a need for the dimmer switch used in conjunction with a dimmable CFL to be matched to its power consumption range, many dimmers installed for use with incandescent bulbs do not yield acceptable results below 40W, whereas CFL applications commonly draw power in the range 7-20W. The marketing and availability of dimmable CFLs has preceded that of suitable dimmers. The dimming range of CFLs is usually between 20% and 90%.[67] However, in many modern CFLs the dimmable range has been improved to be from 2% to 100%, more akin to regular lights. There are two types of dimmable CFL marketed: Regular dimmable CFLs, and "switch-dimmable" CFLs. The latter use a regular light switch, while the on-board electronics has a setting where the number of times the switch is turned on & off in quick succession sets a reduced light output mode. Dimmable CFLs are not a 100% replacement for incandescent fixtures that are dimmed for "mood scenes" such as wall sconces in a dining area. Below the 20% limit, the lamp remain at the approximate 20% level, in other cases it may flicker or the starter circuitry may stop and restart.[68] Above the 80% dim limit, the bulb will generally glow at 100% brightness. However, these issues have been addressed with the latest units and some CFLs may perform more like regular lamps. Dimmable CFLs have a higher purchase cost than standard CFLs due to the additional circuitry required for dimming. A further limitation is that multiple dimmable CFLs on the same dimmer switch may not appear to be at the same brightness level. Cold Cathode CFLs can be dimmed to low levels, making them popular replacements for incandescent bulbs on dimmer circuits.
- Perceived coldness of low intensity CFL
- When a CFL is dimmed the colour temperature (warmth) stays the same. This is counter to most other light sources (such as the sun or incandescents) where colour gets warmer as the light source gets dimmer. Emotional response testing suggests that people find dim, bluish light sources to be cold or even sinister. This may explain the persistent lack of popularity for CFL's in bedrooms and other settings where a subdued light source is preferred.
- Heat
- Some CFLs are labeled not to be run base up, since heat will shorten the ballast's life. Such CFLs are unsuitable for use in pendant lamps and especially unsuitable for recessed light fixtures. CFLs for use in such fixtures are available.[69] Current recommendations for fully enclosed, unventilated light fixtures (such as those recessed into insulated ceilings), are either to use 'reflector CFLs' (R-CFL),[70][71] cold cathode CFLs or to replace such fixtures with those designed for CFLs.[70] A CFL will thrive in areas that have good airflow, such as in a table lamp.[72]
- Power quality
- The introduction of CFLs may affect power quality appreciably, particularly in large-scale installations.[73][74] In such cases, CFLs with low (below 30 percent) total harmonic distortion (THD) and power factors greater than 0.9 should be used.[75][76]
- Infrared signals
- Electronic devices operated by infrared remote control can interpret the infrared light emitted by CFLs as a signal, this limits the use of CFLs near televisions, radios, remote controls, or mobile phones.[77]
- Iridescence
- Fluorescent lamps can cause window film to exhibit iridescence. This phenomenon usually occurs at night. The amount of iridescence may vary from almost imperceptible, to very visible and most frequently occurs when the film is constructed using one or more layers of sputtered metal. It can however occur in non-reflective films as well. When iridescence does occur in window film, the only way to stop it is to prevent the fluorescent light from illuminating the film.
- Use with timers, motion sensors, and other electronic controls
- Some electronic (but not mechanical) timers can interfere with the electronic ballast in CFLs and can shorten their lifespan.[77] Some timers rely on a connection to neutral through the bulb and so pass a tiny current through the bulb, charging the capacitors in the electronic ballast. They may not work with a CFL connected, unless an incandescent bulb is also connected. They may also cause the CFL to flash when off. This can also be true for illuminated wall switches and motion sensors. Cold cathode CFLs avoid many of these problems. Check with the timer manufacturer if their products are approved for use with CFL bulbs, for some control the main load ON/OFF function using a solid-state relay without any leakage current and do not interfere with the proper operation or lifespan of the ballast.
- Fire hazard
- When the base of the bulb is not made to be flame-retardant, as required in the voluntary standard for CFLs, then the electrical components in the bulb can overheat which poses a fire hazard.[78] The latest ENERGY STAR CFL specification (which went into effect December 2, 2008) requires all ENERGY STAR qualified CFLs to incorporate end-of-life requirements and higher safety standards.[79] The Electrical Safety Authority of Canada has stated that certified bulbs do not pose a fire hazard as they use anti-fire plastics.[80]
- Outdoor use
- CFLs are generally not designed for outdoor use and some will not start in cold weather. CFLs are available with cold-weather ballasts, which may be rated to as low as −23 °C (−10 °F).[81] Light output drops at low temperatures.[82] Cold cathode CFLs will start and perform in a wide range of temperatures due to their different design.
- Differences among manufacturers
- There are large differences among quality of light, cost, and turn-on time among different manufacturers, even for lamps that appear identical and have the same color temperature.
- Lifetime brightness
- Fluorescent lamps get dimmer over their lifetime,[83] so what starts out as an adequate luminosity may become inadequate. In one test by the US Department of Energy of 'Energy Star' products in 2003–04, one quarter of tested CFLs no longer met their rated output after 40% of their rated service life.[84][85]
- UV emissions
- Fluorescent bulbs can damage paintings and textiles which have light-sensitive dyes and pigments. Strong colours will tend to fade on exposure to UV light. Ultraviolet light can also cause polymer degradation with a loss in mechanical strength and yellowing of colourless products.[86]
Efforts to encourage adoption
Due to the potential to reduce electric consumption and pollution, various organizations have encouraged the adoption of CFLs and other efficient lighting. Efforts range from publicity to encourage awareness, to direct handouts of CFLs to the public. Some electric utilities and local governments have subsidized CFLs or provided them free to customers as a means of reducing electric demand (and so delaying additional investments in generation).
More controversially, some governments are considering stronger measures to entirely displace incandescents. These measures include taxation, or bans on production of incandescent light bulbs that do not meet energy efficiency requirements.
In 2008, the European Union approved regulations progressively phasing out incandescent bulbs starting in 2009 and finishing at the end of 2012. By switching to energy saving bulbs, EU citizens will save almost 40 TW·h (almost the electricity consumption of 11 million European households), leading to a reduction of about 15 million metric tons of CO2 emissions per year.[87]
Australia, Canada, and the US have also announced plans for nationwide efficiency standards that would constitute an effective ban on most current incandescent bulbs.[88][89][90]
The United States Department of Energy reports that sales of CFLs have dropped between 2007 and 2008, and estimated only 11% of suitable domestic light sockets use CFLs.[91][92]
In the USA, a subjective program called the Program for the Evaluation and Analysis of Residential Lighting (PEARL) was created to be a watchdog program. PEARL has evaluated the performance and ENERGY STAR compliance of more than 150 models of CFL bulbs.[93][94]
Labeling programs
In the United States and Canada, the Energy Star program labels compact fluorescent lamps that meet a set of standards for starting time, life expectancy, color, and consistency of performance. The intent of the program is to reduce consumer concerns due to variable quality of products.[95] Those CFLs with a recent Energy Star certification start in less than one second and do not flicker. There is ongoing work in improving the 'quality' (color rendering index) of the light.[96]
In the United Kingdom a similar program is run by the Energy Saving Trust to identify lighting products that meet energy conservation and performance guidelines.[97]
Notes and references
- ^ "Philips Tornado Asian Compact Fluorescent". Philips. Retrieved 2007-12-24.
- ^ "Compact Fluorescent Light Bulbs". Energy Star. Retrieved 2010-09-30.
- ^ Masamitsu, Emily (May 2007). "The Best Compact Fluorescent Light Bulbs: PM Lab Test". Popular Mechanics. Retrieved 2007-05-15.
- ^ a b c d Mary Bellis (2007). "The History of Fluorescent Lights". About.com. Retrieved 2008-02-13.
- ^ http://americanhistory.si.edu/lighting/20thcent/invent20.htm#in4 Inventing 6 Modern Electric Lamps, retrieved 2010 April 30
- ^ a b Michael Kanellos (August 2007). "Father of the compact fluorescent bulb looks back". CNet News. Retrieved 2007-07-17.
- ^ http://www.lamptech.co.uk/Spec%20Sheets/Philips%20CFL%20Tornado.htm Phillips CFL, retrieved 2010 May 6
- ^ a b Raymond Kane, Heinz Sell Revolution in lamps: a chronicle of 50 years of progress (2nd ed.), The Fairmont Press, Inc. 2001 ISBN 0881733784 pp. 189-190.
- ^ a b c Rourke, Matt (2010-09-10). "It's lights out as last major bulb plant falls to progress". News & Observer. Associated Press. Retrieved 2010-09-10.
- ^ a b 200 0000+ solar powered kerosene-lamp replacements assisted by aid agencies: http://www.ashdenawards.org/winners/mpgvm , http://www.ashdenawards.org/winners/Dlight10, http://www.unescap.org/esd/bazaar/documents/PPT-Sunlabob-LaoPDR.pdf
- ^ The National Energy Foundation - Low Energy Lighting - How to Save with CFLs
- ^ General Electric Incandescent lamps TP110, technical pamphlet published in 1976, no ISBN or Library of Congress number, page 8
- ^ "Osram Dulux EL Energy-Saving Lamps" (PDF). Osram. Archived from the original (PDF) on 2006-07-22. Retrieved 2007-12-24.
- ^ "IEC 60969 - Self-ballasted lamps for general lighting services - Performance requirements". Collaborative Labeling and Appliance Standards Program. Archived from the original on Feb 26, 2008. Retrieved 2007-12-24.
- ^ "When to turn off your lights". Energy Savers. United States Department of Energy. 2009-02-24. Retrieved 2009-07-03.
- ^ Performance Standard and Inspection Methods of CFL
- ^ Charles P. Halsted (1993). "Brightness, Luminance, and Confusion". Information Display. Naval Air Warfare Center Warminster, PA. Retrieved 2007-10-07.
If the luminance of a viewed light source is increased 10 times, viewers do not judge that the brightness has increased 10 times. The relationship is, in fact, logarithmic: the sensitivity of the eye decreases rapidly as the luminance of the source increases. It is this characteristic that allows the human eye to operate over such an extremely wide range of light levels.
{{cite web}}
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ignored (help) - ^ Krešimir Matković (1997). "Color Science Basics: Human Vision". Tone Mapping Techniques and Color Image Difference in Global Illumination. Institut für Computergraphik eingereicht an der Technischen Universität Wien. Retrieved 2007-10-07.
It is interesting, that despite the fact that incoming light can have a dynamic range of nearly 14 log units, the neural units can transfer the signal having the dynamic range of only about 1.5 log units. It is obvious that there is some adaptation mechanism involved in our vision. It means that we adapt to some luminance value, and then we can perceive data in a certain dynamic range near the adaptation level. One of the most important characteristics that changes with different adaptation levels is the just noticeable difference.
{{cite web}}
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ignored (help) - ^ FAQs: Compact Fluorescent: GE Commercial Lighting Products
- ^ "US Household Electricity Report". US Energy Information Administration. 2005.
- ^ a b http://www.energystar.gov/index.cfm?c=cfls.pr_cfls_lumens
- ^ http://www.cbc.ca/canada/manitoba/story/2009/03/04/mb-light-bulbs.html
- ^ http://www.cmhc-schl.gc.ca/odpub/pdf/65830.pdf
- ^ a b c Keefe, T. J. (2007). "The Nature of Light". Community College of Rhode Island. Retrieved 18 September 2010.
- ^ "Conventional CFLs". Energy Federation Incorporated. Retrieved 18 September 2010.
- ^ Compact Fluorescent Light Bulbs – A Tale From Dust to Dust retrieved June 15, 2008
- ^ Long Island Power Authority News | LIPA Encourages All Long Islanders to Join in the Change a Light, Change the World Campaign
- ^ FAQ: The End of the Light Bulb as We Know It. US News & World Report, 19 December 2007.
- ^ Chernoff, Harry (2008-01-23). "The Cost-Effectiveness of Compact Fluorescents in Commercial Buildings". EnergyPulse. Retrieved 2008-03-21.
- ^ "Why does my compact fluorescent light bulb flicker or appear dim when I first turn it on?". Compact Fluorescent Light Bulb (CFL) FAQs. GE Lighting. Retrieved 2009-06-15.
- ^ "GE Lighting Frequently Asked Questions - Compact Fluorescent (CFL): 4. Can I use a CFL in applications where I will be turning the lights on/off frequently?". Retrieved 2007-04-13.
- ^ a b "I've noticed some CFLs need a few minutes to warm up, or reach full brightness..." Customer Help FAQ. Energy Star. Retrieved 2009-06-15.
- ^ "Why does it take time for CFL bulbs to come up to full brightness?". Efficient Lighting FAQs. City of Fort Collins. Retrieved 2009-06-15.
- ^ "Cree Breaks 200 Lumen Per Watt Barrier". LIGHTimes Online. February 4, 2010.
- ^ DOE Solid-State Lighting CALiPER Program Summary of Results: Round 6 of Product Testing (PDF). U.S. Department of Energy. September 2008.
- ^ GE Suspends Development of High efficiency Incandescent, retrieved July 25, 2009
- ^ "Incandescent Bulbs Return to the Cutting Edge". The New York Times. 2009-07-06. Retrieved 2010-04-30.
- ^ "RF Lighting Tunes in Improved Illumination".
- ^ www.nexstarlighting.com retrieved January 5, 2009
- ^ http://www.maxlite.com/PDFs/FocusSheets/HighMax.pdf retrieved March 29, 2009
- ^ Color Temperature and CRI of Energy Saver Lamps
- ^ a b c "Energy-Saving Lamps & Health". GreenFacts Website. Retrieved 2009-06-10.
- ^ "Mercury Content Information Available for Lamps on the 2003 New Jersey Contract T-0192". Retrieved 2007-05-15.
- ^ "Canada-Wide Standard for Mercury-Containing Lamps" (PDF). 2001. Retrieved 2007-03-23.
- ^ "Frequently Asked Questions Information on Compact Fluorescent Light Bulbs (CFLs) and Mercury June 2008" (PDF). 2008. Retrieved 2008-08-31.
- ^ "Mercury in Fluorescent Lamps". FAQ. Energy Federation Incorporated. Retrieved 2009-07-02.
- ^ "NEMA Lamp Companies Announce Commitment to Cap CFL Mercury Content". Retrieved 2007-03-23.
- ^ Compact Fluorescent Bulbs and Mercury: Reality Check. Popular Mechanics, 11 June 2007.
- ^ "Frequently Asked Questions, Information on Proper Disposal of Compact Fluorescent Light Bulbs (CFLs)" (PDF). Retrieved 2007-03-19.
- ^ http://www.energystar.gov/ia/partners/promotions/change_light/downloads/Fact_Sheet_Mercury.pdf Frequently Asked Questions Information on Compact Fluorescent Light Bulbs (CFLs) and Mercury July 2008, accessed 2009 Dec 22
- ^ What are the mercury emissions caused by humans? Do CFLS that wind up in a landfill contribute to these emissions? retrieved January 5, 2009
- ^ http://www.epa.gov/waste/hazard/wastetypes/universal/lamps/index.htm[failed verification]
- ^
Rosenbloom, Stephanie (2008-06-26). "Home Depot Offers Recycling for Compact Fluorescent Bulbs". The New York Times. Retrieved 2008-06-26.
{{cite news}}
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ignored (help) - ^ Daley, Beth (February 26, 2008). "Mercury leaks found as new bulbs break". The Boston Globe. NY Times Co. Retrieved 2009-03-07.
- ^ "Maine Compact Fluorescent Lamp Breakage Study Report". State of Maine, Dept of Environmental Protection. February 2008. Retrieved 2009-03-07.
- ^ "Compact Fluorescent Light Bulb (CFL) FAQs: Is it true that CFLs contain mercury?". General Electric Company. Retrieved 2009-03-07.
- ^ "Mercury - spills, disposal and site cleanup - what to do if a fluorescent light bulb breaks". U.S. Environmental Protection Agency. 2007-10-25. Retrieved 2008-01-15.
- ^ "Compact Fluorescent Lamp Recycling Project Phase I Draft Report Background Research and Program Options" (pdf).
- ^ 'Green' lightbulbs poison workers, Times Online, May 3, 2009
- ^ Stefan Fassbinder. How efficient are compact fluorescent lamps? Leonardo-Energy.Org
- ^ National Electrical Manufacturer's Association NEMA, Failure Modes for Self-Ballasted Compact Fluorescent Lamps, white paper no. LSD 40, retrieved 2008-06-26.
- ^ http://www.csa.ca/cm/ca/en/news/article/new-household-light-standard-addresses-consumer-concerns New household lamp standards, discusses co-ordinated US, Mexico and Canada standard UL 1993, retrieved 2009 Dec 3
- ^ Energy saving light bulbs offer dim future, The Telegraph, August 29, 2009
- ^ http://europa.eu/rapid/pressReleasesAction.do?reference=MEMO/09/113 Section III.3
- ^ GE Lighting FAQ for CFL retrieved 12 March 2007
- ^ BC Hydro - Power Smart for Business - Lighting Controls
- ^ Dimmable CFL's
- ^ Yau, E.K.F. (2001). Phase-Controlled Dimmable CFL with PPFC and Switching Frequency Modulation. Power Electronics Specialists Conference (PESC). Vol. 2. p. 951. doi:10.1109/PESC.2001.954241.
- ^ What Compact Fluorescents To Use Where. Accessed 1 January 2008.
- ^ a b "A Dealer Guide to Energy Star: Putting Energy into Profits" (PDF).
- ^ "CFL Reflector Products". Pacific Northwest National Laboratory. 2007-10-02. Retrieved 2007-12-24.
- ^ http://www.lrc.rpi.edu/resources/newsroom/pr_story.asp?id=162
- ^ Ph. N. Korovesis e.a., Influence of Large-Scale Installation of Energy Saving Lamps on the Line Voltage Distortion of a Weak Network Supplied by Photovoltaic Station, IEEE Transactions on Power Delivery, Vol. 19, NO. 4, Oktober 2004
- ^ J. Cunill-Solà and M. Salichs, Study and Characterization of Waveforms From Low-Watt (<25 W) Compact Fluorescent Lamps With Electronic Ballasts, IEEE Transactions on Power Delivery, Vol. 22, NO. 4, Oktober 2007
- ^ Compact Fluorescent Lamps
- ^ Anibal T. De Almeida: Understanding Power Quality, Home Energy Magazine
- ^ a b Can CFLs interfere with electronic equipment? at ConsumerReports.org. Accessed 1 January 2008.
- ^ CPSC, Teng Fei Trading Inc. Announce Recall of Energy Saving Light Bulbs. U.S. Consumer Product Safety Commission press release. Accessed 1 January 2008.
- ^ http://energystar.custhelp.com/cgi-bin/energystar.cfg/php/enduser/std_adp.php?p_faqid=3147
- ^ "THE ELECTRICAL SAFETY AUTHORITY RESPONDS TO CONSUMER CONCERNS ABOUT CFLs" (PDF). Electrical Safety Authority. 22 March 2007. Retrieved 2009-01-21.
- ^ "Coming to Terms with Energy Efficiency and the Environment". The Clean Air Partnership. Archived from the original on Oct 11, 2007.
- ^ US Dept. of Energy, Greening Federal Facilities, 2nd Edition, 'Compact Fluorescent Lighting'. DOE/GO=102001-1165 page 87. Retrieved 22 February 2007.
- ^ "Topic and Discussions on the Performance Standard and Inspection Methods of CFL" (PDF). Retrieved 2007-04-13.
- ^ "Energy Star Lighting Verification Program (Program for the Evaluation and Analysis of Residential Lighting) Semi-annual report For the period of October 2003 to April 2004" (PDF). Retrieved 2007-04-13.
- ^ "Quality Assurance in Energy Star Residential Lighting Programmes" (PDF). Retrieved 2007-04-13.
- ^ http://www.gcrio.org/UNEP1998/UNEP98p62.html
- ^ Member States approve the phasing-out of incandescent bulbs by 2012 – Press releases RAPID Mon Dec 8, 2008 Retrieved Wed December 9, 2008
- ^ Canada to ban incandescent light bulbs by 2012 – Reuters Wed Apr 25, 2007 Retrieved Tue September 16, 2008
- ^ THOMAS Record of Clean Energy Act
- ^ Phaseout of Inefficient Light Bulbs - Compact Fluorescent Lamps (CFLs) FAQs Department of the Environment, Water, Heritage, and the Arts
- ^ Leora Broydo Vestel As C.F.L. Sales Fall, More Incentives Urged, New York Times September 28, 2009, retrieved 2010 Jan 6
- ^ CFL Market Profile March 2009, retrieved 2010 Jan 6
- ^ http://www.lrc.rpi.edu/programs/PEARL/index.asp
- ^ http://www.lrc.rpi.edu/resources/newsroom/pdf/2007/PEARL8511.pdf
- ^ Energy Star Program Requirements for CFLS Partner Commitments, 4th edition, dated 03/07/08, retrieved 2008-06-25.
- ^ Energy Star List of Compact Fluorescent Light Bulbs is a list of Energy Star qualified CFLs.
- ^ Energy saving lightbulbs
External links
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- e-lumen.eu – a website from the European Commission about the second generation of energy-saving lightbulbs
- US government Energy Star's page on fluorescent bulbs
- LampRecycle.org – for information on recycling spent mercury-containing lamps
- Evolution of Compact Fluorescent Lamps
- Snopes Urban Legends Archive, regarding mercury exposure from a broken CFL
- Light Bulbs from Great Lakes Green Initiative. Differentiates various types of bulbs; considers mercury and recycling issues.
- Email sent to European Parliamentarians: About the negative health effects of low energy light bulbs / CFLs
- The European lamp industry’s strategy for domestic lighting: Frequently Asked Questions & Answers on energy efficient lamps
- A technical description of a typical CFL circuit
- Determine the benefits of Compact Fluorescents with an Energy Saving Calculator
- BanTheBulb.Org energy efficiency campaign
- Program for the Evaluation and Analysis of Residential Lighting (PEARL)
- CFL Intelligence
- National Lighting Product Information Program