New Lighting Facts Label Makes Comparing LED & CFL Bulbs Easier

Say goodbye to watts and hello to lumens. Compact fluorescent and LED bulbs use fewer watts, or less energy, to produce the same amount of light, or lumens, as incandescent bulbs. But the color of the light varies by the type of bulb, so you need more information than just a bulb's watts to get the light you'd like.

The Lighting Facts label, patterned on nutrition labels on foods, will give you much of that information. It lists the bulb's lumens, or brightness; its estimated yearly energy cost; how long the bulb is expected to last; its appearance, from warm to cool; how much energy, or watts, it uses; and whether the bulb contains mercury. The label must be on packages starting in mid-2011, but you might see it sooner.

Anatomy of the Lighting Facts Label

Light Output/Lumens - Measures light output. The higher the number, the more light is emitted. - Reported as "Total Integrated Flux (Lumens)" on LM-79 test report.

Watts - Measures energy required to light the product. The lower the wattage, the less energy used. - Reported as "Input Power (Watts)" on LM-79 test report.

Lumens per Watt/Efficacy - Measures efficiency. The higher the number, the more efficient the product. - Reported as "Efficacy" on LM-79 test report.

IESNA LM-79-2008 - Industry standardized procedure that measures performance qualities of LED luminaires & lamps. - Allows for a true comparison of luminaires regardless of the light source.

Model Number - Unique manufacturer's model number for the product.

Type - Specific type of solid-state lighting fixture.

Brand - The brand under which each product is available.

Color Rendering Index (CRI) - Measures color accuracy. - Color rendition is the effect of the lamp's light spectrum on the color appearance of objects.

Correlated Color Temperature (CCT) - Measures light color. - "Cool" colors have higher Kelvin temperatures (3600–5500 K). - "Warm" colors have lower color temperatures (2700–3500 K).

If you’re buying CFLs or considering LEDs, look for rebates from retailers and utilities and at www.energystar.gov and www.dsireusa.org/incentives. And save your receipts in case there’s a problem. Also keep in mind:

Think about the fixture

 CFLs last longer and perform better if they’re on for 15 minutes or more. That longevity makes them good for hard-to-reach fixtures. But they take time to reach full brightness, from about 30 seconds for spirals to roughly 2 minutes for recessed bulbs and 3 minutes for outdoor bulbs, so don’t use them in staircases or other areas where you need instant brightness. If you don’t like the swirly look of CFLs, use a covered version. But those aren’t as bright, which could be a problem if your light fixture’s shades are dark, frosted, or textured. Because CFLs contain a small amount of mercury, don’t put them in lamps that children could tip over and cause the bulb to break. If a CFL shatters, don’t panic; just follow the cleanup tips athttp://www.epa.gov/cfl/cflcleanup.html.

Twelve-watt LEDs are designed for many applications, including table lamps and ceiling- and wall-mounted fixtures, much like the 60-watt incandescents and 16-watt CFLs they’re replacing. LED bulbs are even cooler to the touch than CFLs.

Note the lumens

Lumens indicate how much light the bulb provides. Buying a bulb with just the right brightness and the fewest watts saves energy and money. Energy Star suggests that a 60-watt incandescent and its CFL or LED replacements have at least 800 lumens. Our tests found that some CFLs are slightly dimmer than comparable incandescent bulbs and continue to dim as they are used.

Consider the kelvins

The color of the light is measured by its temperature in kelvins (K). To match a soft-white incandescent, get a CFL or LED with 2700 K. The light from bulbs with 3000 K is comparable to the whiter light of halogen bulbs, while bulbs with 3500 K to 4100 K give off a cool, bright white light. To mimic daylight, choose bulbs with 5000 K to 6500 K. The Color Rendering Index (CRI) ranges from 0 to 100 and indicates how accurately colors appear under the light. The higher the CRI, the better. Incandescent bulbs are near 100. Most CFLs we tested have a CRI in the low 80s. We haven’t verified the CRI of LEDs yet, but manufacturers say they will be between 80 and 90.

“Only 2% of total energy consumed by LED-based lamps is used in their production.”

When trying to determine the greenest option among products, it is important to take into account the whole life-cycle of the thing; the manufacturing process, how it is used, and the disposal at the end of its life. The U.S. Department of Energy has already released a few life-cycle assessments (LCA) of LED lights (see here and herefor a Carnegie Mellon study), and LED maker Osram has just released a new LCA study conducted by the Siemens Corporate Technology Centre for Eco Innovations. Their conclusions are pretty interesting… Picture Caption: It takes 25 incandescent lightbulbs, 2.5 CFLs and 1 LED lamp to reach the 25,000 hours benchmark.

Conclusion: LEDs are Competitive, a Takeover is Imminent

So for now, the conclusion is that based on life-cycle assessments, LEDs are about as energy efficient as CFLs when you take into account their whole life-cycle. But that seems likely to change since LED lighting technology is still maturing and improving quite fast and fluorescent technology is unlikely to improve enough to catch up.