willrock
New Member
Can I use a dimmer switch on CFL's????
CFL's
- Thread starter willrock
- Start date
Only if the bulb is designed for it, and don't expect it go to super-low either- most go to ~20-30% of perceived brightness and blink out. It's better if you figure out the light level you need, and buy the CFL that delivers it, or have switchable banks of lights for different levels.
Trying to design the electronics of a CFL ballast via cheap incandescent-dimmer waveforms or raw power-in is really tough task- too tough to fit in the li'l screw base where it has to live. Pin-base CFLs designed to fit into ballasted fixtures can dim quite nicely, with good efficiency over the dimming range. Most require special dimmers though.
Some of the better LED bulbs like the CREE LR6 (PAR/R30 bulb replacement) do a lot better, since there's more room to work with, and the luminous device itself runs at much lower voltage, with brightness determined by a single factor (junction current), whereas CFLs need to balance filament current, strike voltage and tube current for dimming. You'll pay quite a chunk o' change for dimmable LEDs that have any efficiency though. (Most don't come close to CFL efficiencies, hyperbole notwithstanding, but a few do.)
Trying to design the electronics of a CFL ballast via cheap incandescent-dimmer waveforms or raw power-in is really tough task- too tough to fit in the li'l screw base where it has to live. Pin-base CFLs designed to fit into ballasted fixtures can dim quite nicely, with good efficiency over the dimming range. Most require special dimmers though.
Some of the better LED bulbs like the CREE LR6 (PAR/R30 bulb replacement) do a lot better, since there's more room to work with, and the luminous device itself runs at much lower voltage, with brightness determined by a single factor (junction current), whereas CFLs need to balance filament current, strike voltage and tube current for dimming. You'll pay quite a chunk o' change for dimmable LEDs that have any efficiency though. (Most don't come close to CFL efficiencies, hyperbole notwithstanding, but a few do.)
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Jimbo
Plumber
The BULB itself must specifically be rated as dimmable. Some are, most are NOT. Here is the kicker: the DIMMER device must also specifically be rated as capable for electronic ballast fluorescent. If you paid less than $100 for the dimmer, it is probably not rated!
Both CFL and LED are difficult and expensive to dim. You either need to get dimming out of your lifestyle, or think about options such as turning off individual fixtures in groups of multiples, to lower light levels.
Both CFL and LED are difficult and expensive to dim. You either need to get dimming out of your lifestyle, or think about options such as turning off individual fixtures in groups of multiples, to lower light levels.
Runs with Bison
Member
As Dana said, CFL's only really work right with dimmers if they are designed and sold as dimmable. And even then they can be disaapointing. I tried some of the GE dimmables for ceiling cans and found the turndown was far less than I anticipated, so I returned them. These two cans are the last remaining incandescent fixtures inside my home (excluding appliance bulbs in the fridge, microwave, and oven.) They are rarely used, but when they are it is typically during the heating season, when the extra heat is beneficial in that portion of the home (basement corner.)
On the other hand, I have a double-circline fluorescent torchiere that has about 4:1 turndown. It works well for the application but it would not be enough turndown for someone wanting very dim lighting.
I agree with Jimbo that if you value dimming, grouping fixtures is an approach to consider. Being able to do some sort of sequenced dimming with several pairs might make sense. If you had 4:1 turndown on 3 pairs of low wattage then you could effectively acheive 12:1 this way.
On the other hand, I have a double-circline fluorescent torchiere that has about 4:1 turndown. It works well for the application but it would not be enough turndown for someone wanting very dim lighting.
I agree with Jimbo that if you value dimming, grouping fixtures is an approach to consider. Being able to do some sort of sequenced dimming with several pairs might make sense. If you had 4:1 turndown on 3 pairs of low wattage then you could effectively acheive 12:1 this way.
Jimbo
Plumber
Wow, that is one I have not seen. Did not know you could get dimmable circlines. I have a circline torchiere, and the switch is 1 bulb on/other bulb on/both bulbs on. So it gives three discrete light levels, which works fine for me.
Runs with Bison
Member
It's pretty cool. It has a heavy torchiere base with dimmer switch. Best part was that I got it for free...actually a little better than that. We were buying some sorely needed furniture and were close to the point that a substantial discount would kick in. We had been admiring this lamp as a potential solution to a lighting issue in the living room, when it dawned on me that if I added it to the total our "out the door cost" would be less than if I didn't buy it.
I've seen what appears to be the same double circline bulb at Home Depot for ~$10, but am not certain that dimming will work with the replacement.
Scuba_Dave
Extreme DIY Homeowner
I have one dimmable CFL bulb as a test in my dining room
It does dim with reg dimmer - BUT probably only because there are 4 other incandescent bulbs still there
The bulbs were on clearance at a local store - .99 each
I only bought 4...dining room takes 5
I plan on using them somewhere else - 2 sets of 2
It does dim with reg dimmer - BUT probably only because there are 4 other incandescent bulbs still there
The bulbs were on clearance at a local store - .99 each
I only bought 4...dining room takes 5
I plan on using them somewhere else - 2 sets of 2
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