Q about dimmable CFLs vs Non-dimmable ones

[Ashton Crusher]

I replaced the incandescent bulbs in a 6 bulb fixture with non-dimmable CFLs. I didn't realize it at the time I did it that the switch was a dimmer switch. Realizing it was a dimmer switched circuit I tried dimming them. Didn't work, they were either on or off. So just to see what would happen I took out two of the CFLs and put regular incandescent back in. With the inc bulbs there the dimmer would dim the non-dimmable CFLs. Not as well as real dimmable CFLs but certainly enough to be dim enough to satisfy my needs in the dimming department. there is a slight buzzing when I dim this setup but it's not enough to be a problem to me for the few times I want to dim them.

So what's different about the dimmable CFLs compared to the non-dimmable ones? Do they just add a resistor in parallel inside the dimmible bulbs???

[bob haller]

i was told that attempting to run a non dimable CFL off a dimmer can result in the CFL overheating and becoming a fire risk......

[hrhofmann]

Not sure, but in effect that's what is happening. I would be very leery of what you are doing, however, because it obviously is running the CFL's in a manner to which they were not designed. I would expect that any guarantee about lifetime would be out the window, and also I would be very careful to see if they overheat under that type of operation. You're taking an appreciable risk in doing what you are doing, although I have done the same thing just for a couple of 20 second experiments out of curiosity just like you did.

[N8N]

I'm not sure, but at least as of a few years ago I wasn't able to find a dimmable CFL that worked acceptably. I did notice more recently that the "big box" stores started selling dimmers that apparently were designed specifically to work with CFLs, but even the ones with displays to test out the various dimmers, timers, etc. did not have any of them installed. So, after spending lots of time and money trying to find a good dimmable CFL I just gave up and put incandescents in the few fixtures that I had that were controlled by dimmers. Fortunately I was able to return most of the CFLs that I tried.

I'll revisit it again in a few years if the stores ever let you actually see how the dimmers and CFLs work together, but my suspicion is that they'll never really work well because LEDs are the new hot thing and I suspect that they'll be ready for prime time soon enough, and apparently those handle dimming better than any fluorescent ever did.

nate

[BobR]

I have yet to find or see a truely dimmable CFL Bulb unless you want to count how long the damn things take to actually produce the rated light.

I have replaced most of the lights in my house with CFL's but have found that they don't last much longer than incadescents and cost more in the long run.

[gregz]

I bought a dim able cfl at the home depot, over 10 years ago. Worked pretty good. Really nice color temperature. There is a threshold you have to deal with. The bad part, it cost over $15. This was really cool. I modified a 500 watt floor lamp into the cfl, using the same dimmer. I broke the cfl while moving. Its steal broke.

Bought a batch of feit ceiling cfl floods, said dimmable. One blew out immediately. The others worked like shit. From costco..

Greg

[Ashton Crusher]

I have 8 of those in my kitchen on a dimmer and nothings gone wrong with them yet. They are about year old, maybe more. Their range of dimming isn't nearly as much as incandescent's but it's good enough for what I need.

[BobR]

I have tried a couple of the dimmable bulbs but was totally dissatisfied with them and am not about to pay more for the overpriced experiments that don't work. Based on the bulb price to electric savings I figure I will be dead and pushing up dasies for 20 years before I break even.

Fool me once....