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dimmable fluorescent lighting?

Posted by tcjohnsson (My Page) on
Thu, Jul 6, 06 at 8:46

I've been doing some research on indoor LED lighting and I found that the technology is not there in terms of correct color rendering and light output (per watt). The trusty CFL still wins across the board in every area... but one - they can't be dimmed. Does anyone know of a dimmable CFL that can be used with standard lighting including recessed applications? I really need to have them dimmable to create the special mood every now and then. And dimmable lights ultimately save more energy. Thanks in advance.


Follow-Up Postings:

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RE: dimmable fluorescent lighting?

Compact fluorescents do exist, however, they leave much to be desired. You should be able to examine them for yourself at your favorite big box store. Dimmable 48-inch florescent tubes, on the other hand, do exist and their effect is quite dramatic.

IMO

SR


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RE: dimmable fluorescent lighting?

I have a great source for compact fluorescent bulbs--it's Energy Federation, Inc. The website is energyfederation.org or efi.org. Go to 'Consumer Division' then 'Lighting' then 'Bulbs.' They have every imaginable compact fluorescent bulb with good information about warm v. cool v. daylight, efficiency, and life on each bulb they sell. I bought dimmable c.f.'s there that work great and have a nice warm color. They cost $6.50 each for 15 watts (60 watt equivalent) or $6.75 each for 20 watts (75 watt equivalent). I also bought a terrific floor lamp there that has a very bright circular fluorescent bulb. Oh, yes, I bought candelabra-base bulbs there for my dining room light fixture.
Rose


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RE: dimmable fluorescent lighting?

I replaced as many bulb as I could with CFLs this year, including dimmable bulbs. All in all, I'm happy with them, though the bulbs do not produce as much light as I expected. Also, the flood CFLs in the kitchen (non-dimmable) are dim when first switched on, then brighten over a minute or two. I also have one dimmable bulb that flickers.

I have not been entirely happy with the light quality on any of the CFLs. They basically come in 2 colors based on Kelvins. "Warm White" is too yellow for me, and "Cool White" is too harsh. But energy reduction was my New Year resolution this year, and I'm willing to put up with it.

A good source is 1000Bulbs.com

I also got some R-20 LEDs and they are awful. --Kris


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RE: dimmable fluorescent lighting?

Hello,
One problem with flourscent fixtures, is the constant drain of electricity from the ballast. This is never changed with a dimmer switch. Unlike a incadescent bulb that you can vary the input voltage.

LED lights will soon be available. They will typically use 1/10 of the power of incadescent and be varible without wasting much energy. The life will be much longer?


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RE: dimmable fluorescent lighting?

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"One problem with flourscent fixtures, is the constant drain of electricity from the ballast."

I know of NO fluorescent ballast; electronic or otherwise; that consumes ANY power when turned off. It draws power when and only when it's on.

I'm a big fan of LED's for lighting . . mostly because of their exceptional lifetime ( 100,000 hours if you treat them nice thermally ) and relatively low power requirements. However; when looking at power consumption of a "light" of any kind; one must keep in mind the light output. That is, after all; the main purpose of any light.

While LED's draw in some cases VERY small amounts of power; that statement is meaningless by itself. One must consider the LIGHT output of a given amount of power; to say whether or not the efficiency is any better. Last time I checked; any reasonably available LED ( cost-wise at least ) put out NO more light per watt; than a decent fluorescent. To compare apples with apples; you HAVE to look at light output per watt . . .

LED replacements for fluorescents / general lighting; simply aren't there yet in terms of anything we'd care to pay for right now . . . they will be; but aren't right now . . .

They're great for certain dedicated tasks where optics can help things along . . . like taillights, traffic signals etc . . . where the area of needed light is very well defined in terms of direction / angles. General lighting just ain't happenin' yet with them . . . .

Bob


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RE: dimmable fluorescent lighting?

Hello,
I agree with your comments. I guess that I left out a couple of words that would change the message to the constant drain of electricity from a ballast when it is dimmed, because of the transformer effect of the ballast. when dimming a ballast, the wacveform is clipped on the output of the ballast?

If I can afford to design with LED's then it is a matter of time before the big boys have product on the shelf. I can almost retail a 4 ft LED lamp for less than 50. I hope it will last 20 years, but I need testing.


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RE: dimmable fluorescent lighting?

I fail to see how the above statement about dimmers and CFLs having no effect on the CFL's electrical usage due to the ballast. If the dimmer is cutting the electricity to the bulb -- CFL/ballast or incandescent/no ballast -- the bulb is consuming less electricity. NO??!!

We have replaced all the R40 spots in our home with Greenlite dimmable CFLs -- they are awesome and can be found here (cheapest I have found): http://www.imagineenergy.net/shop.php?action=cat&id=4

Did the same with the 60 watt bulbs in all the bathroom fistures, lamps etc. The one thing I noticed is that you want to go up a few watts on the CFL to get similar lumen output to the incandescent you are replacing. So, for example, all the 60 watt R40's were replaced with 23 watt R40 CFLs, even though websites say that a 20 watt gives you the same lumens.

An added benefit people often forget is much less heat output (watts are measures of the bulb's heat output, after all -- lumens is the light output), so less heat to remove with the A/C.

Finally, have you noticed lately that your local Walmart now has displays of CFLs everywhere? The link below explains why. I'm not a huge Walmart fan, but in this case, more "power" to them! I just wish more of them were the dimmable type. ;-)

Excerpt:
"Last year, conversations started in Wal-Mart around the potential of swirls to save customers money on utility bills. "Somebody asked, 'What difference would it make if we changed the bulbs in the ceiling-fan display to CFLs?'" says Kerby. A typical Wal-Mart has 10 models of ceiling fans on display, each with four bulbs. Forty bulbs per store, 3,230 stores.

"Someone went off and did the math," says Kerby. "They told me we could save $6 million in electric bills by changing the incandescents to CFLs in more than 3,000 Wal-Marts. I couldn't believe it. I didn't know I was paying $6 million to light those fixtures. I said, that can't be right, go back and do the math again." The numbers came out the same the second time: savings of $6 million a year. "That, for me, was an 'I got it' moment." "

Here is a link that might be useful: Fast Company CFL Article


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RE: dimmable fluorescent lighting?

Dimable fluorescent bulbs are just not available here in Europe. Those swirl bulbs have only just turned up on the market. Things have got better, but we're far behind the technology you have available.

When I changed my lighting for almost entirely fluorescent bulbs a couple of years back I had a very small selection of brands, sizes and wattages. Nor could I dim any of them.

I replaced a number of fixtures so the bulky (at the time) bulbs would fit and removed dimmer switches all over the house. My lighting plan has never worked better. This is partly because it was the first time I really thought about lighting.

I find that the best thing is to have a good number of different light sources that are individually switched. Lots of table lamps, task lighting for desks/counters, as well as wall lights and ceiling lighting. I can choose where I want light, the type of light, and how bright it is by how many lights I turn on. It's far more flexible than a dimmer switch.


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RE: dimmable fluorescent lighting?

I have dimmer switches in almost every room of my house coupled with a lot of recessed lighting. I would really like to switch to cfl where I can, but the dimmable bulbs are prohibitively expensive.

I would be willing to forego the dimming feature on the switches and use non-dimmable cfl's until dimmable cfls become more cost effective, but does this work? Does it damage the switch or fixture somehow? Or will it just not turn on at all if one tries to use the dimming function?

I want to order some new recessed lights, can someone enlighten me? Thanks a bunch.


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RE: dimmable fluorescent lighting?

Hello, DB
I did not say CFL's in my statement about dimming flourscent bulbs. The typical dimming circuit uses a large heat sink that dissiapates the electricity thru a resistor. The is not energy reduction, just diversion of electricity.

As to dimmable CFL's; It requires extra circuitry in the electronivcs to allow the bulb to function and be dimmable.

Flourscent lighting needs a minimum of voltage to fire the circuit, a typical dimming switch lowers the voltage, below the level required to fire the bulb.


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RE: dimmable fluorescent lighting?

On the question about using florescents in a dimmed light but not dimming it. It doesn't work. I tried it in my kitchen and they flickered and produced an annoying atmosphere and then they kicked in less than a week.

By the way Ikea has some nice non-dimmable florescents that look (almost) like a regular lightbulb, are cheap, and you can put the clip on kind of lamp shade on them. My husband says he actually likes reading with them better than with the old ones.


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RE: dimmable fluorescent lighting?

I've been looking at the dimmable fluorescent swirl light on http://www.imagineenergy.net/shop.php?action=detail&id=72&PHPSESSID=4611974287518e46aae2937de5ba41d2. Does anyone know if these lights can be dimmed with a regular (as in bought at Home Depot) wall light dimmer switch without flickering? I bought 3 dimmable compact fluorescent swirl lights from a Litetronics distributor and they flicker badly when I dim the bulbs.

Thanks,
John
jlabiak@ameritech.net


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RE: dimmable fluorescent lighting?

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I don't know of ANY CFL's or fluorescents of any type; which can be dimmed with a conventional dimmer. Most I've seen strictly warn AGAINST doing so . . . there is a real hazard in doing so; the potential of fire. At best you'll likely GREATLY shorten the life of any fluorescent by trying to dim it with ANYTHING other than a specifically recommended dimmer for that bulb. The CFL's I've looked at all do VERY well with reduced voltage like line sag and such; but dimming them with a conventional dimmer is a VERY different thing to a CFL . . . for your safety; do NOT do it . . .

Bob


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RE: dimmable fluorescent lighting?

I know of at least 4 brands of dimmable CFs.

Osram-Sylvania make screw-in retrofit CFs which can be dimmed with conventional triac dimmers. They dim down to 10%. I have used these CFs and find them satisfactory, though the dimmed light is a bit greyish.

Also, someone on one of these forums (either this one or the lighting forum) has mentioned obtaining good results from Greenlite brand dimmable CFs.

TCP and Litetronics also manufacture (or import) dimmable CFs, but I have no experience with them. I'm sure there are others, though you may not find them in your local hardware store. Try some of the online sources, such as 1000 Bulbs and Service Lighting.

The key is to purchase CFs which specify that they can be dimmed with a conventional electronic dimmer. They usually cost a bit more than other CFs of similar quality.


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RE: dimmable fluorescent lighting?

Yup... Greenlite has been the best from our experience. We have 18 of their dimmable R40 floods, 23W, 2700k in kitchen, hallway, a loft and the master suite. They smoothly dim down to 20% and no "greyish" light. All on ordinary triarc dimmers -- it's what they are made for.

And, they seem to be on backorder all the time now -- glad they last so long! ;-)


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RE: dimmable fluorescent lighting?

I'd like to put regular fluorescent bulbs on my ceiling fans, but was advised not to do so. Are there any dimmable bulbs that can be used for said purpose?


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RE: dimmable fluorescent lighting?

Are you dimming the light kits on the fans? If not, I don't see any reason you can't use ordinary retrofit compact fluorescents there. They're very resistant to vibration, so they're a good choice for fans.


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RE: dimmable fluorescent lighting?

Bumping this thread to see if anyone can recommend a good dimmable fluorescent light bulb. Thanks!


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