c. CFL Light Info

The Compact Fluorescent Lamp (CFL) is a smaller version of the classical fluorescent tube with the drivers (ballasts) integrated into the socket.

Fluorescent light is a chemical-based, gas discharge light, produced by exiting mercury vapour into producing ultra-violet light, which causes a phosphor-mix to fluoresce and give visible light.

- The composite nature of fluorescent light creates a spiky light spectrum.

- Lower colour accuracy (CRI 80-83) means a flat light with visibly duller colours.

Higher and lower colour accuracy
Image from www.cielux.com

- Poor contrast and unclear light may cause eye strain and headaches.

- May take time to reach full brightness. Newer CFLs of leading brands are often quicker to light up than older models and no-name brands, though consumer tests keep finding variations even in models of known brands.

- Only a few models are dimmable. These have a much higher price and dim strangely (= may flicker and the light gets more grey-blue).

- Fluorescent light is most effective in linear tube shape. The mini tube or spiral CFL (compact fluorescent lamp) is less effective due to its suboptimal shape where it easily gets overheated. The enclosed CFL bulb (a CFL spiral in a frosted outer bulb) has even lower performance for this reason.

- CFLs will get continuously dimmer over time, with light losses up to 30%, according to consumer tests. The enclosed bulb type tends to lose more, and sooner, than naked stick and spiral types.

- Durability varies between models, brands and individual lamps. "Rated life 8 000 hours" means "the time by which 50% of the lamp samples in a test must still be burning". Actual life also depends on where they are used, how often they are switched on-and-off, and quality of that particular bulb.

- Most CFLs are sensitive to cold temperatures, which makes performance poorer and startup even slower if used outdoors in countries with cold winters, unless specifically designed for outdoor use.

- Easily get overheated, especially in recessed or closed fixtures, which can shorten lamp life.

- Sensitive to frequent switching, which can shorten lamp life down to 1% of rated life!

- High-frequency (24-100 kHz) flicker may cause headaches, concentration difficulties and other problems in sensitive individuals.

- Lower power factor creates dirty electricity and degrades the power grid.

- Ultraviolet radiation leakage from naked tubes through cracks in the phosphor coating. Can be "strong enough to burn skin" and even "cause melanoma" (according to latest studies and earlier studies). May also cause cataracts and adverse health effects (some very serious) on a long list of UV sensitive patient groups (see Health page for details). 

  Fluoresent lamps, including CFLs, contain toxic mercury! 

Risk of mercury poisoning if accidentally broken! (See separate Mercury Spill Instructions page for advice on what to do if a CFL breaks at home or at work.)

Mercury is the third most toxic substance on earth. Symtoms from inhalation of high concentrations of mercury vapour include headaches, tremors, neuromuscular changes, emotional labiliby, insomnia, memory loss, and diminished cognitive function. Even small doses can be harmful.

Especially dangerous to children and pregnant women!

Therefore, this lamp cannot be considered a green replacement and is not recommended.

NOTE: On January 19th, 2013, the UN Minamata Convention agreed on a global treaty to phase out household mercury products, including some CFLs.

CFL Lamp Models 

Note:

These are some of the basic models. There may be other models and variations in shape and size.


• Avaliable in light colours from warm white to cool white.

Incandescent lamp vs 5 CFLs
Image: Wikimedia Commons

• Exact colour for "warm white" CFLs may vary between models and brands and is never an exact copy of incandescent light.

 • CFLs must be taken to recycling stations for hazardous waste or left to special CFL collection centers! 

• Never throw in out with regular trash!! They will either break during handling and may harm recycling workers, or end up in landfills and contaminate the environment.

• Never throw in glass recycling bins!!! Doing so will contaminate all the glass in that bin with mercury and may harm recycling workers.