Ask Pl’us’: Shedding Light on Bulb Selection

Ask Pl’us’ is a blog feature in which we’ll utilize CDFL’s Power of Plus to share some of our experts’ opinions on landscaping, how to get the most of your space, lighting, and more. If you have questions you’d like answered by our architects, engineers, interior designers, or landscape architect, please email horlansky@cdfl.com.

Question: My favorite light bulbs seem to have disappeared, and the available bulbs don’t emit the kind of light I prefer. Where have they gone and what do I do now?

Ron Fender, CDFL Principal and Electrical Engineer: Generally, light bulbs are not something people spend a lot of time thinking about; that is, until they go out and need changing. More and more, however, people are talking lighting and bulb selection due to the major changes in the industry. In December 2007, the federal government enacted the Energy Independence and Security Act (EISA). While this legislation stretches beyond just lighting, the impact on Thomas Edison’s electric light bulb, our beloved incandescent, is devastating.

The EISA requires roughly 25% greater efficiency for light bulbs to be phased in between 2012 and 2014, causing domestic manufacturing and importing of conventional incandescent light bulbs to cease. Beyond that, roughly 200% greater efficiency is required for lighting sources by the year 2020. Appliance lamps, specialty lights, 3-way bulbs, plant lights, and candelabra lights under 60-watts are counted among for exceptions to the efficiency requirement. The incandescent light bulb, however, will go the way of the dinosaur. The 100-watt and 75-watt light bulbs are already gone, and the 60-watt and 40-watt are next to go.

The next logical question is, “what is the best choice to use for a replacement?” As we’ve all likely gone to a major retail or home improvement store in the last year, we’re well aware that there are MANY choices. As consumers, we’re in a great position. The new lighting sources use less energy to produce the same lighting levels, resulting in saved energy. The estimated annual operating cost for a 60-watt incandescent bulb is $7.23 (3 hours use per day) as compared to $1.81 for compact fluorescent and $1.14 for LED. The new light sources also have a longer life, so we have to replace them less often. The estimated life for a 60-watt incandescent is approximately 0.9 years as compared to 9.1 years for compact fluorescent and 22.8 years for LED. Of course some of these figures have yet to be proven, as some of these products are new to the market. Even with their higher initial cost, it’s easy to see that the lower operating cost and longer life make compact fluorescent and LED light bulbs a better value.

Perhaps most of concern to consumers is the kind of light emitted from these new bulbs. There’s nothing quite like the warm glow of incandescent lighting, and some of the earliest compact fluorescent and LED lamps had a much cooler appearance – even appearing bluish to some. A light bulb’s appearance can be determined by a characteristic of the lamp called the Color Correlated Temperature (CCT), which is sometimes referred to simply as the color temperature and is identified on the light bulb packaging. The value is measured in Kelvin (K) and generally ranges between 2500 K and 6500 K. The lower the number, the warmer (closer to incandescent) the light will appear. It follows that the greater the number the cooler/whiter the light will be. Lamps with CCT numbers in the 6000 K range are considered to be full spectrum and tend to more closely imitate natural light than incandescent sources. Some stores have helpful displays demonstrating the effect of CCT on the surroundings. And while many early compact fluorescent and LED lamps had CCT values that were not as warm as incandescent sources, there are now so many choices that this is much less of an issue.

Here’s hoping this information sheds some light on bulb selection and replacement. Because of the many changes to the industry, manufacturers are working hard to ensure it’s easier to compare different light sources for brightness, power usage, and color. At the end of the day you may just want to pick up a few different types and see what you like best. That way, you’ll know you like them before you spend the next 22.8 years cranky.