Monday, February 21, 2011

The Sustainability Review – LED and Dimmable Efficient Lighting

By Mike Forbes, Co-op volunteer writer


I’ve owned every sort of efficient lighting that has existed in the recent past. Always I am searching for a dimmable light bulb that closely emulates the standard incandescent light but offers lower energy use. Recently there have been large improvements in design that make these bulbs worth looking at but still there are issues. In this article I’ll talk about what is readily available and my perception of the technology.

First, LED lighting is making a step into lighting market. Until recently LED lights cast a very blue light and were very expensive ($50-$100/bulb). The advantage they have is the lowest energy use and ridiculously long life (50,000 hours+, that’s 5-1/2 years of continuous 24hr/day use). They currently cost approximately $18/bulb and use about ½ the power a compact fluorescent (CFL) does and 80% less than an incandescent. As a bonus, many are dimmable and are not affected by the cold as CFLs can be.

Let’s talk dimming. Incandescent bulbs are known for their smooth dimming, where as CFL and LED bulbs tend to be a bit more “jerky” in their dimming. This is due to the CFL & LED using electronics to control the light output. Older CFLs were horrible at dimming, they’d buzz loudly and cast a purplish, cold light unless they were on full. There is talk out there that you need a special dimmer for CFL/LED bulbs yet Consumer Reports did some testing on this with various bulbs and found no difference in performance.

The newer CFLs don’t buzz as much and dim much smoother but still don’t provide that infinite adjustment that the incandescent does. The light quality is good however on the whiter side. It is common to have the typical warm-up time that most CFLs have in varying degrees, gone is the startup flicker.

I purchased several LED dimmable bulbs and found them to behave and look very similar. There was a slight buzz, noticeable only when your head was next to the lamp, and they exhibited some of the jerky dimming but easily adjustable to various levels. The biggest drawback is that they don’t provide the warm, glow of the incandescent even thought the package claims to provide that color (soft white). I found the color of the bulb to be very cold, similar to the daylight bulbs out there.

Are they worth it? If you are concerned about energy use then you cannot beat the LED. If you are more concerned about nice, warm ambiance of a dimly lit room you might want to pass at this time. If I were looking for lights in my office, workroom, or any place I wanted a good, bright worklight, I’d definitely consider the LED lights. I think you’ll continue to see the price of these lights drop in the near future.

Mike welcomes questions and can be reached at mike@technicalrescue.net

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