What you need to know about CFLs

Jan. 22, 2010

By Kevin Henry, Managing Editor, Dental Economics

One of the most common questions I hear when I travel across the country speaking on “going green in the dental office” deals with compact fluorescent light bulbs (CFLs). CFLs are something most dental professionals have heard about, but don’t seem to understand. Exactly what are CFLs? What are their advantages? Are they really worth the cost? These are questions I hear often and answer in my lectures. I will also answer them in this article that will help you on the path toward practicing "green dentistry."

Exactly what are CFLs?
Essentially mini versions of the large overhead fluorescent lights found in office buildings and schools, most CFLs last roughly 10 times longer than incandescents, at a quarter of the cost per hour. They also produce 70% less heat than incandescents while illuminated, so heat waste is a nonissue.

Are they really worth the cost?
There’s no question that CFLs are an investment. CFLs do cost between $5 and $15 per bulb, while some incandescents can be purchased for as low as 50 cents each. But given their longer life and energy savings, the cost of CFLs is worth it. It is estimated that by replacing just five incandescent lights with CFLs, a standard office could save up to $60 per year. Over the span of 10,000 hours, a CFL can cost less than half of an incandescent.
Traditional incandescent lights are incredibly inefficient. For every watt of energy consumed, only 10% is used to produce light — that means the remaining 90% is released as heat. It's a waste of power and a fire and burn hazard due to the heat generated.

The EPA estimates that the average household spends close to 20% of its annual electricity bill on lighting. Now think about your practice … According to energystar.gov, qualified commercial products use at least 75% less energy and last 35 times longer than incandescent lighting. Imagine the energy savings for your practice with a switch to CFLs, plus you’ll be helping the environment. Don’t forget that by generating electricity to illuminate our homes and offices, power plants release soot and other pollutants into the atmosphere. The less electricity used, the less pollutants in our air.

A good way to maximize the lifetime savings and effectiveness of your CFLs is to keep them on for 15 minutes or more at a time. Yes, CFLs need a little more energy when they are first turned on, but once on, they use about 75% less energy than incandescent bulbs.

How do I know which CFL to choose?
Picking the brightness can be tricky. Incandescent energy is measured in watts while its output is measured in lumens. If you want the same brightness from a CFL bulb, look for one with a lumen output comparable to the bulbs you normally use. Another way is to pick a CFL that is about 25% of wattage of the incandescent you are replacing.

For example…
CFL watts ... Incandescent watts
9-13 ... 40
13-15 ... 60
18-25 ... 75
23-30 ... 100
30-52 ... 150

Remember to think 25% … CFL watts are about a quarter of wattage of the incandescent being replaced.

How do I dispose of CFLs?
Please remember that all types of bulbs contain a small amount of hazardous waste. CFLs contain mercury, and incandescent bulbs and LEDs contain lead. For this reason, don't toss burned-out bulbs into the regular trash; these toxic substances are best kept out of the landfills. Treat burned-out bulbs as hazardous waste — dispose of them at your local hazardous waste site or seek out recycling centers that accept light bulbs. The Web site earth911.org can help with this.

Tips to remember about CFLs
** Not all CFL bulbs come with dimmer switches. If you want dimmable lights, be sure to check the label to see if the CFL bulb can do that. Likewise, you'll need to buy special three-way CFL bulbs if you want to use them in three-way lamps.

** Make sure the CFL will not touch the surrounding shade. If your lamp clips onto the bulb, you'll need to buy a covered CFL to use with these shades.

** Not all CFLs work with motion sensors.

** Do not use a CFL in an enclosed space. CFLs are very sensitive to temperature, so if your CFL is used in a light fixture that does not have an opening to allow for natural cooling, it’s not a good idea to use a CFL.

** CFLs are a good start to going green in your practice and home. There are plenty of ways you can minimize your carbon footprint and save money. Drop me an e-mail at [email protected] for ideas and I'll be glad to help.

Kevin Henry is the managing editor of Dental Economics and is becoming one of the nation's leading experts and speakers on ways to become more environmentally conscious in the dental office. He can be reached at [email protected].