Editing Compact fluorescent lamp (section)

{{Short description|Fluorescent lamps with folded tubes, often with built-in ballast}}
{{Multiple image
| direction         = vertical
| width             = 250
| header            = Compact fluorescent lamp (CFL) examples
| image1            = Energiesparlampe 01 retouched.jpg
| caption1          = The tubular-form CFL is one of the most popular types in Europe.
| image2            = Compact fluorescent light bulb with GU24 connector.png
| caption2          = CFL with [[GU24 lamp fitting]]
| image3            = Compact fluorescent light bulbs 105W 36W 11W.jpg
| caption3          = Comparison of CFLs with power ratings of 105&nbsp;W, 36&nbsp;W, and 11&nbsp;W
}}
A '''compact fluorescent lamp''' ('''CFL'''), also called '''compact fluorescent light''', '''energy-saving light''' and '''compact fluorescent tube''', is a [[fluorescent lamp]] designed to replace an [[incandescent light bulb]]; some types fit into [[light fixture]]s designed for incandescent bulbs. The lamps use a tube that is curved or folded to fit into the space of an incandescent bulb, and a compact [[electronic ballast]] in the base of the lamp.

Compared to general-service incandescent lamps giving the same [[Luminous flux|amount of visible light]], CFLs use one-fifth to one-third the electric power, and last eight to fifteen times longer. A CFL has a higher purchase price than an incandescent lamp, but can save over five times its purchase price in electricity costs over the lamp's lifetime.<ref>{{cite web |title=Compact Fluorescent Light Bulbs |publisher=Energy Star |access-date=2010-09-30 |url=http://www.energystar.gov/index.cfm?c=cfls.pr_cfls |archive-date=2008-09-16 |archive-url=https://web.archive.org/web/20080916035448/http://www.energystar.gov/index.cfm?c=cfls.pr_cfls |url-status=dead }}</ref> Like all fluorescent lamps, CFLs contain toxic [[Mercury (element)|mercury]],<ref>{{cite web |title=CFL Bulbs Have One Hitch: Toxic Mercury |publisher=National Public Radio |access-date=2007-02-15 |url=https://www.npr.org/templates/story/story.php?storyId=7431198}}</ref> which complicates their disposal. In many countries, governments have banned the disposal of CFLs together with regular garbage. These countries have established special collection systems for CFLs and other hazardous waste.

The principle of operation remains the same as in other [[Fluorescent lamp#Principles of operation|fluorescent lighting]]: electrons that are bound to mercury atoms are excited to states where they will radiate ultraviolet light as they return to a lower energy level; this emitted ultraviolet light is converted into visible light as it strikes the fluorescent coating.

CFLs radiate a [[spectral power distribution]] that is different from that of incandescent lamps. Improved [[phosphor]] formulations have improved the perceived color of the light emitted by CFLs, so that some sources rate the best "soft white" CFLs as subjectively similar in color to standard incandescent lamps.<ref>{{Cite news |last=Masamitsu |first=Emily |date=May 2007 |title=The Best Compact Fluorescent Light Bulbs: PM Lab Test |work=Popular Mechanics |access-date=2007-05-15 |url=http://www.popularmechanics.com/home_journal/home_improvement/4215199.html |url-status=dead |archive-url=https://web.archive.org/web/20070426184034/http://www.popularmechanics.com/home_journal/home_improvement/4215199.html |archive-date=April 26, 2007}}</ref>

White [[LED lamp]]s compete with CFLs for high-efficiency lighting.<ref name="popularmechanics.com">Amber Angelle, "Will LED Light Bulbs Best Your CFLs and Incandescents?" [http://www.popularmechanics.com/science/environment/will-led-light-bulbs-best-cfls-and-incandescents ''Popular Mechanics'' August 4, 2010] accessed May 30, 2011</ref> [[General Electric]] has since stopped production of domestic CFL lamps in the United States in favour of LEDs.<ref name=":0">{{cite web|title=Say Goodbye. Say Hello.|url=http://www.gereports.com/say-goodbye-say-hello-ge-stops-making-cfls-says-go-go-go-to-leds/|access-date=2016-12-19|date=February 2016|archive-date=2016-10-22|archive-url=https://web.archive.org/web/20161022112541/http://www.gereports.com/say-goodbye-say-hello-ge-stops-making-cfls-says-go-go-go-to-leds/|url-status=dead}}</ref>