A Consumer's Guide to Compact Florescent Light Bulbs

With a federal mandate in place to phase out the sale of incandescent light bulbs in the US by 2014, you may want to know more about one of your energy efficient alternatives, the compact florescent light bulb (CFL). Here are some useful facts that will help you make a smooth transition to more efficient lighting.
Environmental Impact - 20% of the average American household's energy bill is for lighting. That's why replacing energy hungry incandescent lights with energy effiecient CFL's makes sense for both your wallet and the environment. Although the initial upfront financial cost for the CFL's are slightly more, over the bulb's lifespan, its total financial cost to the consumer is significantly less than incandescent (where total financial cost = its purchase price + cost of energy consumed). That's because CFL's last up to 10 times longer and use up to 75% less electricity than the traditional incandescent light bulb.
Usage and Limitations - CFL's provide the most energy savings and last the longest when used in fixtures that are regularly illuminated for 15 minutes or more. The federal government's Energy Star guidelines suggest using CFL's in open fixtures that allow airflow, such as table and floor lamps, hanging lamps, wall sconces, and outdoor fixtures.
There are some limitations when using CFL's. Using the bulbs in enclosed fixtures or vibrating fixtures, such as fans, will shorten their lifespan. Also, the bulb’s light output is decreased by cold temperatures. Lastly, specially marked CFL's are required for use with dimmers.
Light Quality - One of the common complaints about CFL's is the quality of the light that they produce. Choosing the right bulb can mitigate this concern. Most people are looking to replace the traditional incandescent bulb with a CFL bulb that closely mimics the incandescent’s color of light. For the best results, follow these simple tips:

• Check the bulb's kelvin (K) rating listed on the package or bulb base. Bulbs with a lower K rating (2,700-3,000K) offer a soft, warm light similar to an incandescent and are suitable for living rooms, bedrooms, etc. These bulbs may be identified as "soft white". Incandescent lights typical have a rating of 2,700K .
• Bulbs with a higher K rating (3,500-6,500K) offer a cooler, white or bluish-white light that may be identified as "bright white" or "daylight". You may want to choose this type of bulb for task lighting.
• Remember that CFL's can take from 30 seconds to 3 minutes to reach their full lighting potential after you turn the lamp on.

Mercury and Recycling - Mercury in CFL's is a concern for some consumers, but the concern should not prevent you from utilizing them. CFL's contain a small amount of mercury sealed within the glass tubing. This amount is usually less than 5 milligrams per bulb. While no mercury is released when the bulb is intact or in use, mercury can be released if the bulb’s glass is broken. Therefore, avoid using CFL's in lamps that may be knocked over by pets or children. Also, avoid disposing of CFL's in your regular trash. They should be recycled (see more about this below).
Some critics of CFL's will suggest that because they contain mercury, they are actually worse for the environment. This simply is not true. Electricity use, through the burning of fossil fuels, is the main source of mercury release into the environment. The power production required to light an incandescent bulb releases significantly more mercury into the air than the power production required to light a CFL bulb. Even if the CFL bulb is sent to a landfill and its mercury is released, the bulb’s overall mercury footprint is still less than the mercury footprint of using an incandescent bulb for the same amount of time
Because CFL's contain a small amount of mercury, to obtain their maximum environmental benefit, they should be recycled. This will prevent the unnecessary release of mercury into the environment. All Home Depots offer CFL recycling (usually next to the return counter). To find other businesses and municipalities that offer CFL recycling, visit http://www.epa.gov/epawaste/hazard/wastetypes/universal/lamps/index.htm

by Pat McGannon

Sources for this article:

1. EPA at http://www.energystar.gov/index.cfm?fuseaction=find_a_product.showProductGroup&pgw_code=LB
2. Tennesse Valley Authority http://www.tva.com/cfl/index.htm