What Do the Terms on Energy-Saving Light Bulbs Mean?

Scott Olson, Getty Images
Scott Olson, Getty Images

There's a reason your parents used to scold you for not turning off a light when you left a room. According to the U.S. Department of Energy, an average American household uses up to 5 percent of their total energy expenditure on lighting. Living rooms get flooded with light. Dining rooms and dens are full of lighting accents. Motion lights, hallway lights, bathroom vanity lights, lamps—we like our lives to be nice and bright.

Fortunately, energy-saving lighting sources have largely replaced the conventional incandescent bulbs that once used up a substantial amount of power. Those bulbs heated up a coil, or filament, of tungsten wire that gave off light. Roughly 90 percent of the energy they passed on was in the form of heat, which siphoned off energy and kept utility bills inflated. Today's bulbs brighten without the waste. That's the good news. The bad? The varieties of bulbs can be confusing. If you've ever been lost in the fixtures section of the hardware store, here's a quick primer on what these terms mean.

Halogen Incandescent:

These are incandescent light bulbs that contain a halogen gas-filled capsule around the filament to help increase energy efficiency. While cheaper to operate than a conventional incandescent bulb—they use 25 to 30 percent less energy—they don't produce as much of a cost savings as other options. On the plus side, they reach full brightness immediately. Other choices may take time to warm up.

Compact Florescent Lamp (CFL):

When you see a coiled light bulb, it’s likely to be a CFL, which is simply a downsized version of the tubular florescent lighting seen in commercial spaces. Instead of an electric current traveling through a filament like in an incandescent bulb, the current goes through a tube containing argon and mercury vapor. The resulting ultraviolet light activates phosphor inside the tube, which emits light. It uses one-third of the energy of a halogen incandescent. The downside? They can take a little time to warm up, especially if used outdoors. They also contain mercury, a potential health hazard if the bulb breaks. (See the "mercury" entry below.)

Light Emitting Diode (LED):

This type of bulb uses a semiconductor to convert electricity into light. In addition to being energy-efficient, they usually last eight to 25 times longer than halogen incandescent bulbs and four to eight times longer than CFLs—perhaps as long as 18 to 46 years. You'll probably pay more up front, but the expense is offset by their durability. Most LEDs are compatible with dimming switches, too. Most CFLs aren't, so if that's important to you, you'll want to stick with LED.

Energy Star:

A bulb with an Energy Star label was evaluated by a third party to make sure its energy-saving claims are accurate, and they'll typically have a longer warranty than bulbs without the endorsement.

But what about the "nutritional label" style information box that appears on light bulb packaging? Let's take a closer look.

An example of a label that appears on energy-efficient light bulb packaging is pictured
Federal Trade Commission

Brightness:

You have probably inferred that brightness refers to the light output given off by a bulb. This is measured in lumens and rounded off to the nearest five. (A bulb will never be 822 lumens. It's 820.) The higher the number, the brighter the bulb. Since you're probably used to shopping by wattage, consider that a bulb with 800 lumens is roughly the equivalent of a 60-watt incandescent. A 1100 lumen bulb will resemble a 75-watt bulb.

Estimated Energy Cost:

This is a rough estimate of much it will cost an average household to operate the bulb. What's average? The wattage of the bulb is calculated with three hours of daily operation at a cost of 11 cents per kilowatt. Your actual cost will go up or down whether you use it more or less or pay your energy supplier a different amount.

Life:

This is how long the bulb is expected to last based on the same usage estimated for the energy cost and rounded to the nearest tenth of a year.

Light Appearance:

This refers to the color temperature of the bulb measured in Kelvin, a temperature scale measuring light color. The range is from 2600 K (yellow and warm) to 6600 K (blue and cool). Bright white is about 3500 K. You should probably avoid anything above 3000 K for any interior room.

Energy Used:

This is how much energy the bulb will require and is measured in watts. The lower the wattage, the cheaper it costs to operate. This is where the energy savings materializes, as a 10-watt LED bulb may give off as much light as an old 60-watt incandescent.

Color Rendering Index (CRI):

It's not on all bulb packaging, but if you see it, it refers to how accurate colors will appear under the bulb's light on a scale of 0 to 100. Halogen incandescent bulbs score high. CFLs and LEDs aren't quite as accurate, though they may still get the job done. Try to get a high CRI if you'll be using the bulbs in a bathroom, as skin tone can appear off with lower CRI numbers.

Mercury:

You might see some CFL bulb packaging with a mercury disclosure. This isn't an issue if the bulb remains intact, but if it breaks, it might release potentially hazardous mercury vapor and the introduce the very small possibility of mercury poisoning. Avoid using CFL bulbs in kids' rooms if there's potential for knocking over a lamp or light. Broken bulbs that contain mercury should be cleaned up by following Environmental Protection Agency guidelines—picked up with tape, not vacuumed—and disposed of properly. Old bulbs should be recycled.

Why Are Poinsettias Associated with Christmas?

iStock
iStock

Certain Christmas traditions never seem to go out of style. Along with wreaths, gingerbread cookies, and reruns of A Christmas Story sits the poinsettia, a red-tinged leafy arrangement that’s become synonymous with the holiday. Upwards of 100 million of them are sold in the six weeks before December 25.

Why do people associate the potted plant with seasonal cheer? Chalk it up to some brilliant marketing.

In 1900, a German immigrant named Albert Ecke was planning to move his family to Fiji. Along the way, they became enamored of the beautiful sights found in Los Angeles—specifically, the wild-growing poinsettia, which was named after Joel Roberts Poinsett, the U.S.-Mexican ambassador who first brought it to the States in 1828. Ecke saw the appeal of the plant’s bright red leaves that blossomed in winter (it’s not actually a flower, despite the common assumption) and began marketing it from roadside stands to local growers as "the Christmas plant."

The response was so strong that poinsettias became the Ecke family business, with their crop making up more than 90 percent of all poinsettias sold throughout most of the 20th century: Ecke, his son Paul, and Paul’s son, Paul Jr., offered a unique single-stem arrangement that stood up to shipping, which their competitors couldn’t duplicate. When Paul III took over the business in the 1960s, he began sending arrangements to television networks for use during their holiday specials. In a priceless bit of advertising, stars like Ronald Reagan, Dinah Shore, and Bob Hope were sharing screen time with the plant, leading millions of Americans to associate it with the holiday.

While the Ecke single-stem secret was eventually cracked by other florists—it involved grafting two stems to make one—and their market share dwindled, their innovative marketing ensured that the poinsettia would forever be linked to Christmas.

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Why Does Santa Claus Live at the North Pole?

allanswart/iStock via Getty Images
allanswart/iStock via Getty Images

As children settle in for a restless night’s sleep this Christmas Eve, they’ll no doubt be picturing Santa Claus on his way from the snowy ’scapes of the North Pole to deliver them Star Wars LEGO sets, Frozen 2 dolls, and everything else on their wish list. They picture Santa at the North Pole, of course, because they’ve seen him living there in numerous Christmas movies, books, and television specials, from perennial Rankin/Bass programs to more modern classics like 2003’s Elf.

While it might seem a little more magical if we told you that nobody really knows why Santa lives there, there is a relatively traceable paper trail: The first known reference to Santa’s North Pole residence is in an 1866 cartoon from Harper’s Weekly.

According to Smithsonian.com, famed political cartoonist Thomas Nast—who was also responsible for establishing the donkey and elephant as the symbols for the Democratic and Republican parties, respectively—first started creating Harper’s Weekly Christmas cartoons as Union propaganda for the Civil War in January 1863. Borrowing imagery from Clement Clarke Moore’s (alleged) 1823 poem “A Visit From St. Nicholas” (which you’d probably recognize as “’Twas the Night Before Christmas”), Nast developed the white-bearded, rosy-cheeked, all-around jolly guy that we know today, and showed him passing out gifts to Union soldiers, climbing into a chimney as a soldier’s wife prays, and more.

harper's weekly santa claus at camp by thomas nast
Thomas Nast, Harris Brisbane Dick Fund, Wikimedia Commons // Public Domain

The cartoons became so popular that Nast branched out from his source material and began inventing his own details to add to Saint Nick—like where he’s from, for example. A December 29, 1866 issue of Harper’s Weekly debuted a multi-image cartoon titled “Santa Claus and His Works,” which includes a small inscription along the circular border that reads Santa Claussville, N.P. According to The New York Times, we don’t know exactly why Nast chose the North Pole (or if it was even his own idea), but there are a few reasons it made sense for the time period.

For one, Santa Claus was already widely associated with snow because most of the publishing companies producing Christmas cards and other content were located in New England, where it actually snows around Christmas. Furthermore, the 1840s and 1850s were partly characterized by high-profile—and ill-fated, in the Franklin expedition's case—attempts to explore the Arctic, and the public was generally interested in the mysterious, poorly-charted region. Because the Pole was unoccupied, Santa and his elves could toil the year away without interference from prying eyes; and, because it was unclaimed, Santa could remain a bastion of benevolence for every nation.

merry old santa claus by thomas nast
"Merry Old Santa Claus," perhaps Nast's most famous illustration of Santa, from the January 1, 1881 edition of Harper's Weekly.
Thomas Nast, Wikimedia Commons // Public Domain

Though we’ll likely never know Nast’s personal rationale behind placing Santa Claus in the North Pole, one thing’s for sure: At this point, it’s hard to imagine him living anywhere else. It’s also hard to imagine him riding a broom, wielding a gun, or smoking cigarettes (find out the stories behind those early Santas here).

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