Look for bulbs with the Energy Star label, which indicates they meet at least minimal performance requirements.
Be aware that compact fluorescents can take one to three minutes to reach full brightness. This is not a defect.
The place where people are most likely to use compact fluorescents, closets, may be a poor choice. Experts at Energy Star warn that frequently turning the bulbs on and off shortens their lives, and recommend using them in fixtures “that are used at least 15 minutes at a time or several hours per day.”
The bulbs do not do well in hot places with little airflow, like recessed ceiling fixtures. They are ideal for table lamps.
Not all compact fluorescents work with dimmers or three-way sockets. Read labels.
Learning about “color temperature,” which is printed on the label of high-quality bulbs, can help consumers avoid disappointment with the color of the light. The warmest-looking bulbs generally have a color temperature less than 3,000 kelvins, with the harshest bulbs usually above 5,000.
Compact fluorescents contain mercury and should not be disposed of in the trash. Many chains offer recycling bins for the bulbs.
If you break a bulb, the the Environmental Protection Agency recommends precautions to avoid mercury exposure: Clear people and pets from the room and open a window for at least 15 minutes if possible. Avoid vacuuming. Scoop up larger pieces with stiff paper or cardboard, pick up smaller residue with sticky tape, and wipe the area with a damp cloth. Put everything into a sealed plastic bag or sealed glass jar. In most cases, this can be put in the trash, but the E.P.A. recommends checking local rules.
Keep your receipt. “Studies show that if electronics are going to fail,” the Lighting Research Center says, “it is likely to happen early on.”