Compact Fluorescent Light Bulbs - the GEM of Energy Savings

Replacing standard incandescent bulbs with compact fluorescent light bulbs(CFL bulbs) is probably one of the lowest hanging fruit on the tree of energy savings.

Compact fluorescent bulbs have come down in price dramatically over the last few years, and offer huge benefits. They are ideal for a first home energy saving project. Below are some pros and cons.

CFL bulbs:

  • Typically consume 50-80% less energy than incandescents and last about 8 -10 times longer.
  • Are versatile, and can be applied in nearly any type of fixture that incandescents are used. Dimmable (for use with newer dimmer switches) and 3-way CFLs and are now available on the market, along with bulbs that can be used on timers (though still for a premium price).Remember to read the labels on the CFL, dimmer or timer packages to check for compatibility before installing dimming CFLs.
  • Provide high quality warm light, as compared to regular fluorescent fixtures. Refer to choosing CFLs below.
  • Are much less expensive to operate in the long run, despite the higher up front cost; they last much longer and use much less electricity, therefore need less replacement. One compact fluorescent can save more than10 times its initial cost over its life (depending on your average electric rate)
  • Reduce greenhouse gas emissions through reduced electric use. One CFL can save a half a ton of CO2 over its lifetime. Less electric use means diverting the need for new power plants.

Still, there are drawbacks to compact fluorescent light bulbs making them unsuitable for certain applications or shorten their lifespan.

  • Compact fluorescent light bulbs are generally temperature sensitive. Heat is the most often cause of CFL failure, particularly low air flow or heat build up in recessed light fixtures.Also, check labels to see if the bulb is suitable for outdoor use where it will be exposed to the elements and large temperature variations.
  • Frequent on-off switching or cycling affects bulb life. CFLs perform best in areas where the light stays on for steady, and longer periods
  • Most CFLs are not suitable for dimmers, 3-way switches and timers. Check package labels for compatibility.
  • Compact fluorescents have a "warm up" time, typically about a minute, before reaching full brightness.
  • Compact fluorescent lights are best for general area lighting; not too effective as focused beam or spot lighting.
  • The mercury content of CFLs, although a fraction of that in a tooth amalgam (1/100th) or a watch battery (1/5th), still requires proper disposal protocols (drop off at the Home Depot or other participating home centers, recycling or hazardous waste centers, or scheduled community hazmat pickup dates).

Disposal of Broken CFL Bulbs
Due to their trace amounts of mercury, CFLs need to be disposed of through recycling hazardous material handling centers. Also, many home centers such as The Home Depot accept spent bulbs from customers.

If you should break a CFL, follow these precautionary steps:

  • Ventillate and vacate the room for 15 minutes or more
  • Use a wet rag to clean up and dispose of the bulb pieces, and the rag, in a plastic bag
  • Place that bag into another sealed bag
  • Call your local recycling center for proper disposal information. You may also put it in your local trash.
  • Wash your hands afterward.

Choose the Right CFL bulb
The light output or lumens of compact fluorescent light bulbs are rated by their Kelvin (K) temperature rating (or the absolute temperature at which that color brightness is emitted).

Low K numbers between 2700-3000 have a soft, warm light comparable to incandescent bulbs. The brightness for Higher K numbers increases and approaches a bright, cool, bluish hue, similar to sunlight (K nubmer between 3000-6000).

When choosing CFLs to match the brightness of your incandescents bulbs, match the lumens to the lumens of the bulbs you are replacing (not the watts or energy use). Also, match the shape of the bulbs so that they fit in the fixtures.

Below is a chart that matches the most common incandescent light bulbs, their light output in lumens and their wattage to comparable CFLs.

Incandescent WattsLumensCFL Replacement Watts

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