Energy efficient light bulbs used to be limited in the color they produced; most came in bleach white with a bright glow limiting their use by consumers and designers. This is no longer the case. New CFL’s, halogens, and LED’s are now offered in a variety of color temperatures. The development of these new and efficient lighting options creates more opportunity for the use of energy efficient lighting.
The color produced by a light bulb is a direct result of the amount of Kelvins associated with the lighting source. A Kelvin is a unit of measure for temperature which measures the shade of light in a bulb. The light color given off by a particular bulb ranges from yellow to blue. Bulbs with a low amount of Kelvins produce a more yellow or orange hue. At the other end of the scale, bulbs with a high amount of Kelvins give off a white or blue light. A typical energy efficient light bulb producing a white light has approximately 3500-4100K, while the bulbs producing the blue hue range from 5000-6500K.
ENERGY STAR bulbs are designed to produce light that closely matches that of natural light sources because they must have a high Color Rendering Index (CRI). CRI is a measure of a bulbs ability to show colors “realistically” or “naturally” when compared to natural light sources and incandescents. A maximum CRI of 100 for a lighting source produces extremely natural looking light, while a CRI level below 50 have poor color quality. ENERGY STAR CFL’s are required to have a CRI value of at least 80.
There are some fun, interactive websites available for consumers to test different lighting schemes in the household. Lowe’s has dedicated a whole portion of their website to help customers choose the right lighting. Visitors can view and compare a variety of lighting sources ranging from low to high on both a Kelvin scale as well as different levels of lumens and watts. The site also provides information relating to bulb choices, lighting information, and potential energy savings.
ENERGY STAR also has a very user-friendly portion of their site dedicated to lighting. They provide an interactive tool that lets you click on different lighting sources relating to various applications in the home. The consumer can click on different lighting sources and visually compare how different bulbs produce different amounts of light. After clicking on a particular type of bulb a short description of the bulb as well as some application examples are provided. There is also an option to choose between different mood lighting such as soft white, bright white, and daylight.