LED lighting [View all]

[sendero]

When I moved to this house 3 years ago I installed CFL light bulbs in almost every fixture. CFLs are OK, if you get the right ones they put out a nice light and clearly use a lot less power and throw off a lot less heat than incandescents.

However, I've had a pretty good failure rate with these things. And they are toxic, so you cannot (or shouldn't at least) toss them in the trash.

The wife picked up a couple LED bulbs at the local home-improvement store on our last visit. I was skeptical, but decided to try one out.

I was impressed. This "60W equivalent" puts out as much light as my 100W equivalent CFL. (I can tell because I have two fixtures on my ceiling, one with each). This got me excited about the prospect of changing out most of our lights to LED.

But man, once I started looking into it I realized that using LED lights is a lot more complicated than I imagined.

I'm sure some of you already know all of this but for those who don't here goes:

1) Color - Like CFLs, LEDs have a "color". This color ranges roughly from almost bluish (almost useless in a home setting IMHO) to a warm yellow. The color is expressed in a number like 3000K or 5000K, which is actually a specification for the wavelength of the light. I like 3000K, a soft yellowish light that is very close to incandescent. Your mileage may vary but be sure you know what you are buying.

2) Dimmable - most LED lights, like CFL, will not work properly on a dimmer. You can get one that will but it will cost you more. I only need dimmers on about 1/3 of the lights in my house so I'm going to buy dimmable bulbs for those fixtures only.

3) Wattage equivalent - there is apparently no standard (as there seems to be on CFL bulbs, at least a de facto one) as to how many watts of LED light equal how many incandescent watts. I see bulbs called "60W equivalent" that use from 8 to 13 watts! I suppose the wattage does not tell the whole story so best to look at lumens, the actual light output of the bulb. Clearly it is better to have a bulb that uses 10 watts and produces 800 lumens than to have one that uses 13 watts and produces 800 lumens. You have to pay attention to all of these numbers!

4) Heat - LED bulbs are supposed to last a long time but many suffer from early failure. Some of these failures are probably related to poor/new/unseasoned designs but some are almost certainly related to heat. You are NOT SUPPOSED TO USE A LED BULB IN AN ENCLOSED FIXTURE! This present a problem for me because all of my ceiling fixtures are enclosed. If you install a LED bulb into an enclosed fixture IT WILL RUN HOT and IT WILL NOT LIVE A NORMAL LIFESPAN.


LEDs themselves (the actual semiconductor diode) are pretty cheap. What you are paying for in the (still a bit high) price of an LED bulb is the electronics required to convert 120 volts AC into a low DC voltage. Since this part (the power supply) is also a semiconductor device (at least most of it) the price will go down as volume is ramped up. I do not expect LED lights to ever be as cheap as CFLs or incandescents, but I think the price will halve or so over the next few years as more and more folks start using them. Please buy some and help get the volume up and cost down!