Home / Professional / Hospitality / Technology Guide Technology Terms and Descriptions Your Smart Guide for Lighting Terminology Compact Flourescent Light (CFL) Bulbs CFLs provide substantial benefits over incandescent bulbs, including lasting 8 to 10 times longer, producing 90% less heat, using 75% less electricity and producing about four times as many lumens (brightness) as an incandescent bulb of the same wattage. Traditionally spiral in shape, these bulbs now also come in a variety of shapes and sizes to accommodate more sophisticated design needs. CFLs already make up 25% of the U.S. light bulb market – and that number is expected to grow. Lumens: Light Output vs. Energy Consumed For decades, consumers have purchased light bulbs based on their wattage – shopping for a 150-watt, 100-watt, 60-watt, etc. pear-shaped general incandescent bulb. As CFLs begin to grow in popularity, shopping based on wattage will be replaced with a more accurate measurement of brightness/light output: LUMENS. In fact, a light bulb’s wattage is the amount of electricity it consumes, not the brightness of the light it produces. The brightness of any light is measured in lumens, so the higher the lumens, the brighter the light. New Labels for Bulb Light Packaging Bulb Life Expectancy How can consumers and professionals shop for light bulbs based on lumens? New light bulb package labeling will help. The Federal Trade Commission (FTC) is already working with light bulb manufacturers to help change the consumer mindset from wattage to lumens. In 2012 manufacturers will begin using new Lighting Facts® labels that list a light bulb’s lumens prominently on a package with wattage listed as "energy used." The labels will also list helpful information such as estimated annual energy cost and bulb life expectancy. Color Rendering Index (CRI) CRI is another measure of the quality of the light and gives a good indication of color accuracy. More specifically, CRI is how a light bulb’s light interprets the color of the objects it illuminates. CRI is measured on a scale of 0 to 100, with 100 being the best. Both CRI and Kelvin Temperature come into play when assuring that colors come alive in their natural tones – reds are red, greens are green. Illuminating Engineering Society of North America (IESNA) LM-79-2008 IESNA LM-79-2008 is a standardized industry test conducted on all light fixtures and light sources, and measures qualities such as lumens, energy consumed, CRI and color temperature. It allows for a true comparison of energy efficiency regardless of the light source and is the standard test used for creating Lighting Facts® labels. Light Appearance/Color Temperature When people talk in terms of light feeling warm or cold, what they’re really referring to is a light’s Kelvin temperature or color temperature. "Cool" colors, like blue, have higher Kelvin temperatures (5,500 K and up) and “warm" colors, like yellow, have lower color temperatures (4,000 K and below). Sunlight is always the best way to see an object’s “true color” and measures somewhere in the middle – at about 5,000 K. New labeling will clearly list a bulb’s light appearance – also known as color temperature – helping consumers and professionals choose a bulb that enhances an environment.