Compact fluorescent lamp

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Compact fluorescent lamps are smaller versions of standard fluorescent lamps. They consume between 5 to 27 watts, and have a brightness and color interpretation that is equivalent to incandescent lights. Unlike standard fluorescents, they can directly replace standard incandescent bulbs. Compact fluorescent lamps (CFLs) combine the energy efficiency of fluorescent lighting with the convenience and popularity of incandescent fixtures.

Working of CFL[edit]

Compact fluorescent lamps work to a great extent like standard fluorescent lamps. They consist of two parts:

  1. A gas-filled tube
  2. Magnetic or Electronic ballast

The gas in the tube glows with ultraviolet light when electricity from the ballast flows through it. This in turn excites a white phosphor coating on the inside of the tube, which emits visible light throughout the surface of the tube. Compact fluorescent lamps with magnetic ballasts flicker slightly when they start. Besides, they are heavier than electronic ballasts. Electronic ballasts are more expensive than magnetic ballasts. However, they are more efficient especially at low temperatures. Most currently available CFLs have electronic ballasts.

Main Features[edit]

  • Compact fluorescent lamps are most cost effective and efficient in areas where lights are on for long periods of time.
  • Since compact fluorescents do not need to be changed frequently, they are perfect for hard-to-reach areas.
  • Compact fluorescent lamps are designed to operate within a specific temperature range. Temperatures below the range results in reduced output. Main CFL models are available for indoor use but few of them are available for outdoor use too.
  • Fluorescent lamps are available typically in three color temperatures. They are: Warm white (2700K), Cool white (4000K), Daylight (6000K).
  • CFLs can be installed in regular incandescent fixtures, and they consume less than one-third as much electricity as incandescent lamps do.

Types of Compact Fluorescent[edit]

CFLs are available in following styles or shapes:

  1. Twin-tube integral
  2. Triple-tube integral
  3. Integral model with casing that reduces glare,
  4. Modular circline and ballast
  5. Modular quad-tube and ballast

Some models have two, four, or six tubes while others have circular or spiral-shaped tubes. The size or total surface area of the tube determines how much light it produces. Some CFLs have the tubes and ballast permanently connected whereas other CFLs have separate tubes and ballasts which enables us to change the tubes without changing the ballast. There are also types enclosed in a glass globe.


Compact fluorescents offer following advantages over incandescent light bulbs:

  • Lower power consumption i.e. CFL consumes 1/4 the energy, and produce 90% less heat as compared to incandescent lamps.
  • Longer lifetime (last up to 10 times longer than incandescent lights)
  • Produce more light


  • Longer starts
  • More expensive than incandescent lamps owing to their higher initial cost.
  • CFLs are physically larger than incandescent lamps which may make them difficult to use in some light fixtures.
  • Fluorescent tubes contain a microscopic amount of mercury. It is such a small amount that disposal is not generally regulated as with full size fluorescents. Hence we should use caution to avoid crushing the tubes, and dispose of them safely.