Fluorescent bulbs

A fluorescent lamp is a low-pressure mercury electric-discharge lamp in which a fluorescent coating (phosphor) transforms some of the ultraviolet energy generated by the discharge into light. [1] Compact Fluorescent Lamps (CFLs) have been available for residential use for about 30 years, with recent advances increasing their quality and popularity. They are the most energy-efficient choice readily available on the market for homes today. CFLs use gases and phosphor inside the lamp to create light. CFLs come in screw-in or pin-based configurations, in many sizes and shapes. Screw-in lamps fit into almost any fixture that accepts standard bulbs. Pin-based CFLs plug directly into a dedicated energy-efficient fixture. All indoor and most outdoor ENERGY STAR® qualified light fixtures are designed to accept only pin-based CFLs. CFLs last longer and use fewer watts than incandescent and halogen lamps to provide the same amount of light. They operate at a low temperature and come in ‘warm’ and ‘cool’ colors. Most CFLs do not operate well on remote or dimmer switches, though specialty dimmer-compatible and 3-way switch CFLs are beginning to appear on store shelves. Because CFLs contain a small amount of mercury, they should always be disposed of responsibly, ideally recycled. Linear Fluorescent Lamps are most often used in residential garages and basements for general lighting. They are highly efficient and long-lasting. More stylish fixtures that use this

technology can be found for use indoors, such as for kitchen ceiling lights.[2]

A comparison of lighting technologies[3] would be most helpful to establish the facts below.

Technology		CRI1		Efficacy2 (lumen/W)		Lifetime (hours)		Color Temperature3 (Kelvin)
Compact Fluorescent		80-90		60-70		6,000-10,000		2700-6500
Incandescent		100		12-18		750-1500		2400-2900
Linear Fluorescent		70-90		80-100+		20,000		2700-6500
Halogen		100		16-29		2000-4000		2850-3200
White LED		65-90		20-50		Up to 100,000		2700-6500

¹Color Rendering Index (CRI) is a comparison of a light source's ability to accurately render the color of an object to that of a standard reference light source. The CRI scale is from 0 to 100, with a value of 100 indicating excellent color rendering. Sunlight and most incandescent lamps have CRI values of 100. Only compare the CRI values of light sources of roughly the same color temperature. ²Efficacy is a measure of light output (lumens) per watt of electrical power needed by the lamp. Lumens measure how much light is emitted. Watts indicate how much electrical power is consumed. ³Color Temperature is a way to compare the color of light from different types of lamps. It is often referenced as cool (slightly blue) or warm light (slightly orange). Incandescent lamps and candles give off warm color temperatures, while sunlight and some fluorescent lamps emit cool color temperatures.

• Only 10% of the energy consumed by incandescent bulbs is released as light; 90% is heat. Fluorescents cost more initially, but they last up to 12 times longer..

• Since they use about 1/4 of the energy of incandescent bulbs they are a key part of efforts to fight climate change

• They're not cheap, these energy saving light bulbs, but over their lifetime they'll save you 65 quid and a lot more besides.

• And we're not just talking about the pain of getting the wobbly step ladder out from under the stairs but the environmental saving this small action can make.

• Most of us use light bulbs designed about 100 years ago, inefficiently producing nearly as much heat as light. And it doesn't end there, along with heat they produce carbon dioxide the nasty little gas that helps cause global warming.

• In fact if every British household fitted just three bulbs enough energy would be saved to supply the entire country's urban lighting. (who does work this stuff out?). So lower bills over a year and a cleaner planet... err, why wouldn't you adopt this action?

We are what we do

[edit] Choosing the right fluorescent bulb for you

Image from www.energystar.gov's Choose a Light Guide

• Use A-shaped bulbs if you prefer the look and feel of incandescent bulbs. A globe-shaped bulb is a spiral bulb with a decorative cover while the sleek shape of candle bulbs makes it ideal for tight fitting light fixtures.

• Look for products with ENERGY STAR label on it. Learn how a product get this label. In the European Unioun nations, there is the EU energy label or rating. In the UK, there is the Energy Saving Recommended label. For Australia, there is the Top Energy Saver Award (TESAW) label.

• Read the product packaging as not all CFLs work in all sockets. You may also read if the product causes electromagnetic interference. It may also state whether the product is designed for outdoor use.

• Follow the fixture manufacturer's specifications for light bulb wattage, voltage, and bulb shape.

• There are spirals for dimmers and three-way switches (chek the label). Spirals also come in a variety of colors like soft white, natural light, or daylight.

• The color of the light affects the brightness of the bulb. CFLs produce a brighter light because it is not yellow, unlike that produced by incandescent lamps.

• Choose the right wattage for your desired light brightness^[4]

Incandescent bulbs (watts)		Minimum Light Output (lumens)		ENERGY STAR qualified light bulb (watts)
40		450		9 to 13
60		800		13 to 15
75		1100		18 to 25
100		1600		23 to 30
150		2600		30 to 52

• Regular fluorescent light bulbs used in your home and office do not produce a hazardous amount of ultraviolet light (UV). But if you're looking for a low-UV bulb for an especially sensitive area (like a photography dark room), try specialized incandescent bulbs that block most ultraviolet light emissions.

• Compact fluorescent light bulbs may generally be used in enclosed fixtures as long as the enclosed fixture is not recessed. Totally enclosed recessed fixtures (for example, a ceiling can light with a cover over the bulb) create temperatures that are too high to allow the use of most compact fluorescent bulb. Use incandescent bulbs, reflector CFL bulbs or halogen bulbs for this purpose^[5]. See various CFL models that passed tests for recessed fixture use.

• It is not recommended to use CFLs in vibrating environments. Vibration can cause the electronics in the CFL to fail. There is one GE CFL bulb (FLE11) that is available for use in a ceiling fan. Check the package for this application.

• Here is a short list of CFL retailers:

• Ace Hardware offerings and store locator
• Amazon.com
• Home Depot offerings and store locator
• Do It Best offerings and store locator
• IKEA Offerings and locator
• Lowes offerings and locator
• Office Depot offerings and locator
• Sam's Club offerings and store locator
• Sears offerings and store locator
• Staples offerings and store locator
• Target offerings and store locator
• True Value
• Walmart offerings and store locator

[edit] Disposing of fluorescent bulbs

• CFLs (compact Fluorescent Lights) contain trace amounts of mercury. The amount is not large enough to pose a hazard to users, but it does become a concern at landfills and trash incinerators where the mercury from many bulbs can escape and contribute to air and water pollution.

• If you do break a fluorescent bulb (CFL or other type of fluorescent) you need to follow safe disposal procedures. The amount of mercury in a typical CFL is only 1/100th of that in a mercury-based thermometer but still enough to cause some harmful health effects. Is the mercury in fluorescent lights dangerous?

• Safe disposal requires storing the bulbs unbroken until they can be processed. Consumers should seek advice from local authorities. Usually, one can either:
  • 1. Bring back used CFLs to where they were purchased, so the store can recycle them correctly;
  • 2. Bring used CFLs to a local recycling facility. For UK, visit recycle-more.co.uk and select gas discharge lamp (WEEE) recycling. For Aussies, visit www.environment.gov.au.

• The first step of processing involves crushing the bulbs in a machine that uses negative pressure ventilation and a mercury-absorbing filter or cold trap to contain and treat the contaminated gases. Many municipalities are purchasing such machines. The crushed glass and metal is stored in drums, ready for shipping to recycling factories.

• Note that coal power plants are the single largest source of mercury emissions into the environment. According to the Environmental Protection Agency (EPA), (when coal power is used) the mercury released from powering an incandescent bulb for five years exceeds the sum of the mercury released by powering a comparably luminous CFL for the same period and the mercury contained in the lamp.

[edit] References

1. Wikipedia.org
2. US Environmental Protection Agency
3. EnergyStar
4. General Electric's CFL Facts