Dimmable Compact Florescent Lightbulb (CFL) Review
When we moved into our home, the kitchen had a lovely ceiling fan. It promptly broke because it wasn’t wired correctly. So, I installed a simple light fixture but never got around to removing the dimmer switch. It wasn’t really a problem except that the CFL bulbs we used are not designed (read: should not be used) with a dimmer switch.
How Dimmer Switches Work
Electric dimmer switches work by passing electricity in short bursts. These short bursts turn the light on and off so fast that the human eye doesn’t notice. Traditional, incandescent bulbs use electricity to heat up a thin filament and thereby create light. Incandescent bulbs limited by dimmer switches simply don’t heat up as much.
The Problem with Regular CFLs and Dimmer Switches
CFL’s create light in a different way. They don’t use heat or a filament to create light. CFL tubes are filled with an inert gas. The electricity excites the gas molecules and they give off energy in the form of ultraviolet light. The UV light then excites a phosphor coating on the inside of the tube which creates visible light. Unfortunately, typical CFLs are not compatible with dimmer switches. What’s the exact reason? I’m not totally sure but, I think it’s because CLFs require a minimum threshold of constant power to properly excite the gas molecules. The intermittent bursts created by dimmer switches don’t adequately maintain that threshold.
The real problem is that using regular CFLs on a dimmer can result in shorter bulb life. That means it can cancel out any potential savings. Plus, it often voids any manufacturer’s warranty. Regular CFLs can also flicker and create a noticeable hum.
ECOSMART Dimmable CFL Review
Fortunately, industry has created dimmable CFLs! I just purchased three ECOSMART brand dimmable CFLs from Home Depot. Here are the details:
- Soft white light
- 23 watts of energy used
- 90 watt equivalents
- 1400 lumen output
- 10,000 hours of life
- 9 year warranty
Pros
These bulbs are great. They put out a generous amount of light and are not harsh on the eyes. Best of all, they don’t flicker, no matter what light setting. They come on quickly and “warm-up” in about 30 seconds. Each bulb puts out about the same amount of light so there isn’t any obvious imbalance.
Cons
Dimmable CFL’s still have room for improvement. They don’t dim completely. Energy levels lower than 20% result in the CFL turning off. So, you’ll never get the ultra-low, romantic light that incandescent bulbs provide. I also noticed a slight hum when these bulbs are not on full strength. It’s slight, but still there. I plan on testing these bulbs on another dimmer switch to see if the hum persists.
What do you think? Have any dimmable CFLs? What brand do you like most?
Comments & Conversation on this Article...
5 Responses to Dimmable Compact Florescent Lightbulb (CFL) Review:
Leave a comment and join the conversation!
If you want a picture to show with your comment, go get a gravatar!
November 19th, 2008 12:08 pm
Thanks for the review. We don’t have any dimmer switches currently. We had one before I started the kitchen expansion and dining room remodel, but we never used it except at full power because it hummed even with an incandescent bulb. Of course, I wouldn’t be surprised if they’d wired it wrong.
November 19th, 2008 2:43 pm
I might give these a try. I have a ton of dimmers in my house. My major issue with CFLs is the time they take to come up to full brightness, especially if I’m only going to be in a room for a short time.
Do these CFLs work the same way? Are there “instant-on” dimmable CFLs?
November 19th, 2008 3:04 pm
@Gene, I’m not sure if the hum is from my switch or the bulbs themselves. I’ll investigate more.
@Rob, These bulbs come on very quickly. They take about 30 seconds to reach full brightness. I completely understand your reluctance. That was one of my gripes. But so far I’ve been pleased. I’m not sure if any current dimmables are supposed to be “instant-on” though.
November 19th, 2008 3:52 pm
@Rob, Not all CFLs are created equal. We have some older ones that take a while to warm up and get bright, as well as a couple of newer globe-enclosed ones that do, too. The latter are for our reading lamps over our bed, so it’s not a big deal that they take a minute.
But the one in my office lamp, for example, comes on at or near full brightness right away. It’s model EDXO-14 (14w, 60w equivalent). I think I bought it as part of a 2- or 4-pack at Home Depot. Googling suggests it would have been a Commercial Electric or more recently n:vision label. Whatever it is, there’s no hum from it, either. But unlike what Ethan reviewed, it’s not dimmable.
November 20th, 2008 11:07 am
I am using dimmable par 30 lights in the cans in my living room. The start-up time is about 30 seconds, which isn’t bad, but my lights seem to cut off at between 20-40%. I still like them, though I am curious to see how their longevity stacks up against the manufacturers recommendations.
Also, their cost is considerably higher than regular bulbs. I never did the math to see how much these lights save, but with $10 bulbs not sure I’m saving too much.