Compact Fluorescent Lights - FAQ
Where should I start with CFL's?
Depending on your budget and desire to make sweeping changes, you can start by deciding to replace one incandescent bulb with a CFL. Hopefully you will do more. Typically, you would select bulbs which burn the most hours in your home. These are often hallway lights, kitchen lights and porch lights. It's also common to begin with bulbs which are difficult to change. Switching to a CFL means you won't have to change that bulb again for 5 years or more.
NOTE: Bulbs on dimming circuits or 3-way bulbs require CFL's specifically designed for those purposes. Using a standard CFL in a dimming circuit is a fire hazard. You'll need a dimmable or 3-way CFL for the appropriate application and they are a little more difficult to find. If it's not clearly marked for dimming do not use the bulb in a dimming circuit, even at full brighness. The same applies for a 3-way bulb -- it should be clearly marked -- if not, don't use it.
To realize more advantages quicker, it's best to begin by replacing standard on/off bulbs which typically burn for a couple hours at a time, in your home or office.
Where do I buy them?
Compact fluorescents are increasingly available in retail stores and home centers. There are also many sources available for online ordering. If you're replacing many bulbs, you may be interested in our bulk CFLs shopping page.
How are they packaged?
CFL's are commonly sold in single packages, packages of 4 (or 6) and are also available in bulk for large conversions.
Is it difficult to switch to CFL's?
No, it's simple. In the vast majority of conversions, it's as easy as screwing in a new light bulb. In some instances, recessed lighting may require the base to be adjusted or extended. It depends on the reflector and the original adjustment of the base in most cases.
What should I look for when purchasing a CFL bulb?
In the U.S., we recommend bulbs which are ENERGY STAR qualified. They can be identified by the Energy Star label on the package. These bulbs tend to be of reliable quality. That's not to say bulbs without this rating are inferior, it's simply that Energy Star bulbs have met current federal energy efficiency standards.
You'll need to know the wattage of the bulb you're replacing, and it's equivalent in a CFL.
What wattage should I buy?
If you're replacing a 40 watt incandescent bulb, use a 9-12 watt CFL.
If you're replacing a 60 watt incandescent bulb, use a 13-18 watt CFL.
If you're replacing a 75 watt incandescent bulb, use a 19-24 watt CFL.
If you're replacing a 100 watt incandescent bulb, use a 25-30watt CFL.
You should also consider the color temperature of the bulb.
What is the color temperature?
The color temperature of light is rated in degrees Kelvin (K). For example, a candle is rated at 1500 degrees Kelvin and produces a "warm" light with a red tint. The typical incandescent bulb is 2700 degrees Kelvin and produces a more "yellow" light. At 4000 Kelvin, a "Cool White" Fluorescent light is considered neutral. A "daylight" fluorescent light is rated at 6500 Kelvin and provides cool light with a blue tint.
Typically, you'll find the color temperature of the bulb rated on the package in degrees Kelvin or as Cool, Neutral or Warm. To stay close to the light you're accustomed to from incandescent bulbs, you'll want to purchase CFL's in the 2700 Kelvin (or neutral) range. Some people prefer cool bulbs for reading lamps.
Do CFL bulbs flicker?
The better quality compact fluorescents produce no noticeable flicker. Lesser quality CFL's may flicker or delay a bit at startup. It's advisable to test a brand and bulb model before you purchase replacements for all the bulbs in your home.
How does more efficient lighting reduce pollution?
Replacing a 75-watt incandescent bulb with a 20-watt CFL will reduce your consumption of electricity by roughly 550 kilowatt-hours -- over the life of that bulb. In relation to a coal-fired power plant, this amounts to nearly 500 pounds of coal (about the size of a couple garbage cans) that didn't need to be burned to power your bulb. That reduction translates to 1,300 pounds LESS carbon dioxide and 20 pounds LESS sulfur dioxide released into our atmosphere. This is one bulb. Multiply this by all the bulbs in your home, then by all the homes in your neighborhood -- think of the savings. You'll see how small, easy changes, can make a huge difference in the future of our planet.
Do it for the kids.