Yesterday I was in an achingly beautiful 19th century building that I frequent, and was as encouraged as I was disconcerted to see a glaring compact fluorescent light bulb doing its mini-spiral from the base of an antique sconce. Yes, this is great, I thought; eeew, that looks awful, I countered. Every list of tips to save the planet pleads with us to switch our light bulbs—but nobody tells us how to do that without sacrificing beauty, warmth and ambience. It’s time for some practical tips about the nuances of compact fluorescent light bulbs and how to use them for the best lighting.
OK, OK. We know already. If every American home replaced just one light bulb with a compact fluorescent light bulb (aka CFLs): we’d save enough energy to light more than 3 million homes for a year; we’d save more than $600 million in annual energy costs; we’d prevent greenhouse gases equivalent to the emissions of more than 800,000 cars. Yes, we know! So we go to the store and buy an armful of CFLs, go home replace all of our incandescent bulbs, shudder at the soul-baring glare, remove CFLs, reinstate incandescents, and banish the CFLs to a nice drawer somewhere.
The problem is that without a little know-how, energy saving light bulbs are not a very elegant replacement for incandescent bulbs. (Incandescent bulbs are the standard light bulb we have been using since Thomas Edison invented them in 1879.) The first thing to know is that there are two families of commercially available energy-saving light bulbs: Light emitting diodes (LEDs) and CFLs.
Light Emitting Diodes (LED)
LED bulbs have been around for a while and have been traditionally used for electronics and flashlights. They are now being made into consumer light bulbs, and last a whopping 10 times longer than a CFL, and more than 100 times longer than an incandescent. This writer has a few in her house and can’t recommend them enough—but since CFLs are more readily available (and affordable), that’s the bulb we’ll tackle today; we’ll look at LEDs down the road.
TIP: For more information and to order LED bulbs, go to the website of C.Crane.
Why Compact Fluorescent Light Bulbs?
In an effort to hold your attention, we will skip the technical issues here—filaments and the release of thermally equilibrated photons and so on. We will say that incandescent bulbs are highly inefficient since the light they generate is really just a by-product of heat generation. According to the Federal Trade Commission, incandescent bulbs lose 90 percent of the electricity consumed as heat and only last 750-1000 hours, whereas CFLs use 75 percent less energy for the same amount of light (producing no heat) and last 10,000 hours. For the homeowner this means a savings of $30 or more over each bulb’s lifetime, not to mention the significant decrease of millions of tons of global warming pollution.
Shining the Light on Brightness
The first mistake most people make is in buying CFLs that are way too bright. Light is measured in lumens, but we have come to quantify brightness by watts, which is actually the amount of power a bulb uses. Since 90 percent of the watts used to light an incandescent bulb go to producing heat, these bulbs require a lot of watts to create their light output (lumens). A CFL requires much fewer watts to create the same amount of lumens. So if you buy a 60 watt CFL, it is the equivalent of a 150 watt incandescent bulb!
To find the equivalent brightness, the rule of thumb is: CFLs use about a quarter of the wattage to produce the same light. (EG, to replace a traditional 60-watt bulb, look for a CFL that’s about 15 watts.)
Correlated Color Temperature (CCT)
The color of light is important in creating ambience—you wouldn’t want your dining room table lit with the same eerie orange glow that comes from a parking lot light. The color of light in a bulb is measured by its Correlated Color Temperature (CCT) which is a measure of how warm or cool light is and designated by Kelvin (the scientific measure of temperature). Most CFLs come in 2700K, 3000K, 3500K and 4100K—which range from warm white to a bluish white. Too high a CCT (above 3500K) and your light will look blue and feel cold; these products are usually identified by labels stating “bright white,” “natural” or “daylight.”
For a color match closest to incandescent bulbs, try a CCT range between 2700K and 3000K, this may be labeled as “warm white.”
Color Rendering Index (CRI)
Have you ever purchased an article of clothing in a fluorescent-lit store only to take it outside and discover the color looks different? Different types of lighting render color differently, and this has been codified into a numeric representation known as Color Rendering Index (CRI). The CRI rates a light bulb’s ability to show colors “realistically” as compared to a standard incandescent. The CRI scale ranges from 0 to 100—the higher the number, the closer the CFL will render color like an incandescent bulb.
TIP: For good color rendering quality, look for CFLs with a color rendering index of 80 or above.
Within each color Kelvin, there are lamps with varying ranges in the color spectrum indicted by the CRI, which ranges anywhere between 60 and 90. The high color-spectrum sources (80+) are considered full-spectrum by the lighting industry. If you opt for a 5000K lamp (that looks very blue/white) with a CRI of somewhere between 80 and 90, that’s tpically what is used to simulate natural light. Whether or not it has the ‘full-spectrum’ label depends on the manufacturer.
Full-spectrum lamps are frequently priced somewhere between 4- to 12-times higher than comparable lamps without the “full-spectrum” label. The increase in price is typically due to claims being made about the lamps: better visibility, enhanced color perception, improved health, and greater productivity.
TIP: Full-spectrum lamps have a color temperature greater than 5000K and a CRI of over 90. Whether or not they’re labeled as “full-spectrum” depends on the manufacturer.
My Friend the Dimmer Switch
Oh how I love to dim, I even like to cook by dimmed light—it’s the quickest road to ambience in my mind, and I am a glutton for atmosphere. However, only recently have CFLs been specially designed to work with dimmer switches—and they must be specifically labeled as such. CFLs still do not have the same dimming precision of incandescent bulbs, with only a range of between 20 and 80 percent of the brightness, but that’s good enough for me. (And my pal Blanche DuBois.)
TIP: Use this great chart from Environmental Defense for information on what kind of bulb to use with your dimmer switch.
The Right Bulb for the Job
CFLs were once available only in the spiral shape, but the industry has been great in responding to the needs of those of us who require some grace with our greening. One can get a traditional bulb shape, a globe and even a candelabra shape CFL now. In terms of which type to use where, usually a certain type of CFL can be used in a variety of fixtures. CFLs fall into three categories: bare (like the spiral), covered (like a traditional looking bulb) and reflective (like flood lights).
TIP: Use this Energy Star chart for choosing the right bulb for the job.
Alas, the beloved CFL isn’t perfect. All fluorescent lights contain mercury. The good news is that the new generation of CFLs posses only a trace amount of mercury (4 mg), far less mercury than in thermometers (500 mg) or old thermostats (3000 mg). In terms of environmental mathematics, a power plant actually emits 10 mg of mercury to fuel the power needs of an incandescent light bulb compared to 2.4 mg required to produce the electricity to power a CFL for the same amount of time. There has been a lot of fear (and a few urban myths) circulated about toxins released from a broken bulb. Again, the amount of mercury is minimal, but you should take precaution in cleaning up a broken CFL.
TIP: How to clean up a broken CFL
• Using gloves, carefully scoop up the fragments and powder with stiff paper or cardboard and place them in a sealed plastic bag. DO NOT USE A VACUUM!
• Place all cleanup materials in a second sealed plastic bag.
• Take to a recycling center.
How to Recycle CFLs
Well, I have been using these bulbs for years and haven’t had to replace one yet (you gotta love that seven-year life span). But when the time comes to dispose of a CFL, it’s important to note that some states, cities and counties have outlawed putting CFL bulbs in the trash, but in most states the practice is legal. (Which just doesn’t seem right.) Recycling is the best option. But even most cities that have curbside recycling won’t take the bulbs and they must be brought to a hazardous-waste collection day or a special facility. Some retailers will take them for recycling: IKEA, bless those green-hearted Swedes, accepts them. And the EPA is working with Wal-Mart to establish a similar program.
TIP: Find recycling options near you by going to earth911. Select “Fluorescent Bulbs” from the “Find a Recycling Center” drop-down menu at the top of the page and enter your zip code. This page will identify the nearest mercury recycling or disposal facilities near you.