Lighting

Dim and Dimmer

CFLs are great! Dimmers are great! Together? Not always.

Why the big jump? Better light. The new generation of ENERGY STAR qualified CFLs turn on instantly, produce no sound, and are available within a warm color range, as well as cooler color tones. Of course, they also provide the same amount of light, and last up to 10 times longer, which saves $30 or more in energy costs over each bulb's lifetime

CFLs, also known as compact fluorescent light bulbs, are red hot. Well, not literally. CFLs generate little heat and use at least two-thirds less energy than standard incandescent bulbs.

But when it comes to the marketplace, CFLs are increasingly popular. The sales of ENERGY STAR® CFLs nearly doubled in 2007, according to Environmental Protection Agency (EPA) estimates. In 2007, 290 million CFLs were sold, and the energy-saving bulbs now account for approximately 20 percent of the American light bulb market. That’s up from 11 percent in 2006.

Get Dim

Dimmer switches are a good energy-efficient option over traditional flip switches. And it’s not just about mood lighting. Dimmer switches allow one fixture to serve several lighting functions, such as task lighting when at full illumination and decorative or safety lighting at lower settings.

Dimming increases lamp life and saves energy because less electrical wattage is used. For example, a light that is dimmed by 25 percent uses about 20 percent less electricity and the bulb's life is increased fourfold.

CFLs and Dimmers

CFLs are good. Dimmer are good. So together, they’re a winning team for energy efficiency, right? Not so much.

Dimmers work by sending intermittent charges of electricity to the light fixture. That’s fine for a filament bulb, as it simply reduces the amount of heat generated by the light bulb. But CFLs don’t work that way.

Standard CFLs regulate power through a tube, which is not compatible with regular electricity interruption. As a result, a dimmer can shorten a CFL’s life, effectiveness, and in rare cases, it can pose a fire hazard.

The Continuing Lighting Evolution
Approximately 40 ENERGY STAR qualified CFLs are specially designed to work with dimmers and say so on the label, but they usually come at a greater cost. And in addition to being more expensive, dimmable CFLs may have some other shortcomings. First, they only dim to about 20 percent of the rated lumens. Secondly, unlike an incandescent, the dimmed lighting does not get softer. So while dimmable CFLs have plenty of uses, don’t count on them for setting that romantic mood.

It can be a similar story for photocells, which is the technical term for those really cool light-sensitive switches that automatically turn on at dusk. One solution is to find a compatible timer, which usually works with CFLs. Otherwise, you could try a dimmable CFL. In all cases, read product details for your dimmers and CFLs carefully to make sure they are compatible.