More on CFLs

The information that you give on CFL safety is partially incorrect. It's amazing how hard it is to get the proper safety information through the public hysteria.

a) The mercury level in the CFL is extremely low. By comparison, one old mercury switch (like in an old thermostat) equals 1,000 CFLs. That silly woman in Maine sounds like the classic self-terrifying idiot who cannot grasp the concept of acceptable levels of toxic substances, and demanded that the government "do something".

b) The safe method of cleanup is a broom and gloves, followed by letting the room air out. The gloves are more for broken glass safety than for mercury risk. Vacuums are specifically a poor idea because they cause immediate mercury vaporization and dispersal of the mercury vapor into the room while you are there. You are probably safe even with your personal dose maximized, but why maximize it unnecessarily. Opening the windows and letting it disperse is a small step, reduces your personal dose, and still exposes the neighborhood by less than the airborne mercury emissions associated with coal powered incandescents.

See http://www.nema.org/lamprecycle/epafactsheet-cfl.pdf for official sagety practices.

As for lighting quality, there are significant variations and issues. There are a variety of phosphors used for CFLs, each of which gives a different color balance. CFLs are generally not a good choice when color is significant and must be manipulated. I personally use daylight CFLs extensively, and they give definitely different colors than incandescents. They match a north light (not a direct sunlight) very well. I determine this from a room with a good strong north light, where turning on or off the CFLs is hard to notice during the day because there is no lighting shift. With incandescents or warm-white CFLs (warm white is the most popular phosphor choice) you do see an immediate change when the lights are turned on and off.

The warm-white phosphor (and you must check the labels to get the phosphor that you want) is a reasonable match to warm-white incandescents for most purposes.

For retail color control I would stick to halogens and incandescents until LED lighting is cheaper. At the high end - where you hire a color lighting consultant and control everything about the display - LED lighting is gaining ground. LED lighting is much more expensive to install, but the lights last 50,000 hours and the color temperature can be fine tuned on a bulb by bulb basis and dynamically adjusted for daytime vs nighttime. This kind of expense is justified in some retail environments by the cost savings from the 50,000 hour lifetime (and LEDs use about 1/3 the electricity of incandescents). They never need to shut down the sales operation for bulb replacement and can put the lights anywhere the consultant wants, without much regard for the difficulty of replacing bulbs. But LED lights with color controls cost 10-20 times what a CFL costs. LED lights are still cheaper than color consultants, and their tunability reduces the color consultant time charges significantly.

In many states, however, retailers aren't free to use whichever bulbs they like. Electric bills are, of course, a major cost of operation, giving businesses plenty of incentive to cut costs. One of these days, LEDs will be affordable and people won't understand lightbulb jokes.