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Compact flourescent lights/dim at startup

Posted by wianno (My Page) on
Wed, May 2, 07 at 13:34

Do all CF turn on dim and brighton as they warm up? This is what prevents me from using them.

I have a few now but want to remove them becuase of this issue.


Follow-Up Postings:

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RE: Compact flourescent lights/dim at startup

They all do this, but some of them are more pronounced than others. The enclosed globes are usually the worst.

OTOH, it seems to me that the Sylvania (Osram) helicals start very close to full brightness.

I've been using CFs for almost 15 years, so by now I'm used to some of them starting a bit dim. You probably won't even notice it after a few months.

However, if you can't get used to it, one solution, albeit a somewhat wasteful one, is to buy the CFs a bit brighter than you really need - say, a 20 Watt instead of a 15 Watt. That way they're bright enough almost immediately.


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RE: Compact flourescent lights/dim at startup

Hi,

We have all CFs in the house, and none of them have a problem with being dim on startup.
I've never seen the dim at startup in the spiral type bulbs, but we did replace 4 of the globe type CFs that took 20 seconds or so to come up to full brigtness -- the replacements come up to full brightness with no delay at all.
Not sure how you determine before you buy them that you are not getting the ones that are initially dim.

Here is a side by side comparison that Pop Mech ran between an incandescent and 7 CFs:
http://www.popularmechanics.com/home_journal/home_improvement/4215199.html?series=15
Pretty interesting, every one of the CF's beat the incandescent in every category!

To me, CFs are one of those no-brainer things that not only save you lots of money but also save a lot of greenhouse gas emissions.

Gary


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RE: Compact flourescent lights/dim at startup

All the CFs I've ever used have taken a minute or two to come to full brightness. Linear fluorescents do this, too.

Some CFs are excruciatingly dim at strike, but most are just slightly so. More fall into the latter category in recent years.

Philips and Sylvania CFs seem to be the least affected. I wouldn't be surprised if they have some thermal compensation circuitry which is missing from the $2 cheapies.


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RE: Compact flourescent lights/dim at startup

I tried CFs in a couple of lamps for a year before committing the whole house to them. Now we have replaced all our incandescents with CFs throughout the house and have been very satisfied.

For example, the original kitchen ceiling fixture took 3 60 watt incandescents. After many years the plaster around the electrical box was cooked brown and crumbly. We have a new fixture (and patched ceiling) that takes 2 x 20 watt CFs. The kitchen is much brighter and cooler.

We have noted new CFs come on fast. As they age, perhaps after 6 months, it can take a little time to get to full brightness.

If the house temp is low, like 55 - 60 F, it can take them considerably longer to achieve full brightness.

CFs get dimmer towards the end of their life. I can sympathize with them.


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RE: Compact flourescent lights/dim at startup

I can't seem to figure out which CF's are best. We have one in our stairwell which is a spiral type, and comes on just about immediately. But the more typical looking CF in the bedroom closet takes forever to come on - not a good thing when trying to dress in the morning. Also, most of them are so big that they don't fit a lot of our lamps.
And now I'm hearing that they contain mercury, and so are actually more hazardous to dispose of than conventional incandescants. Does anyone know about this?


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RE: Compact flourescent lights/dim at startup

playsinthedirt20: CFs take a bit more power to start up, but far less once they are cruising. For lights that I turn on only briefly -- e.g. closet lights -- I still use incandescents which doesn't waste that much power. The CFs also won't last as long if they are flipped on repeatedly for brief periods. I first started using CFs in 2000 and they have improved a lot since that time.


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RE: Compact flourescent lights/dim at startup

The CFs also won't last as long if they are flipped on repeatedly for brief periods.

True. I have a tiny 5 watt CF in a small lamp. Long story, but we leave it on all the time - it was originally to be put on a photocell, but I never got round to it. It just keeps going and going.

This is a 6000 hour rated Lights of America brand, an older one, made in USA before they outsourced their manufacturing to some Chinese operation. It's been operating continuously now for almost 2 years - over 17,000 hours! I'm quite sure that it wouldn't have lasted this long had I cycled it every 24 hours on a timer or photocell.


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RE: Compact flourescent lights/dim at startup

I didn't know about them not lasting as long if they were cut off and on a lot. I generally turn mine off and on three to four times a day when I'm at home all day, but only twice when I'm not.


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RE: Compact flourescent lights/dim at startup

another option is LED lights. they are bright from the start, and use less energy than a CFL. plus they last longer.


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RE: Compact flourescent lights/dim at startup

The latest CFL that we got is "instant on", comes up to full brightness very quickly after power is applied.

On the other hand, we have a couple of ceiling fixtures that are about 55W. D-type flourescents that take about 30 seconds to come up to full brightness. Which doesn't bother me, since full brightness is quite bright for the space.

Aren't LED lights pretty expensive?

-Roger


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RE: Compact flourescent lights/dim at startup

Based on their advertised useful life - I've recently seen a unit which claims a "design life" of 50,000 hours to 70% of rated light output - LEDs are still more expensive per hour of use than CFs. A typical good CF will provide 10,000 - 12,000 hours of service with 10-20% loss of output. The best linear fluorescents will provide 20,000 - 30,000 hours of service. (Instant start is toward the low end of this range and programmed rapid start toward the high end.)

More to the point, LED units available for real world use are still less efficient than good CFs. In fact, some are barely any more efficient than incandescent lamps. Many don't achieve California Title 24 requirements.

They also are dim. You'll see LED downlights advertised that can supposedly replace 100 watt incandescents. However, when you really dig into the published specs, you find that these "100 Watt equivalents" barely provide as much light as a 40 watt bulb.

LEDs are improving, however. In another 5 years I think they're apt to match or even exceed the efficacy of CFs. They might even beat the best linear fluorescents, which would be quite an accomplishment.

I expect it will take yet another 5 years beyond that to get LEDs' price down to where they will become cost effective for residential use. If researchers can stretch LEDs' service life further, the break-even point may happen somewhat sooner for commercial settings where relamping labor is an issue.


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RE: Compact flourescent lights/dim at startup

well, the only LED's i have experience with are on top of towers. they starting using themm a few years ago in place of the strobe lights. they require less juice and last much longer.

i did not know that they were not as good as a CFL for regular use, i had heard otherwise. but yes, they are more expensive to purchase.


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RE: Compact flourescent lights/dim at startup

I have replaced some of my bulbs with CFL and am quite satisifed with the spirals. I have one in a stairway that is not a spiral, ( I don't know the type but it looks like a regular bulb, except a bit larger) It takes quite a long time to come up.

I have several celing fixtures that I would like to convert. They all have glass globes over the bulbs. Is there a particular type of CFL that I should be looking for?


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RE: Compact flourescent lights/dim at startup

I have found GE bulbs to be very good. But have also found White Westinghouse & Maxlite to be junk as the both have very short lives. White westinghouse replaces for free but maxlite make you send in old one and pay shipping for new one which costs more then going to the store for a new one.


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RE: Compact flourescent lights/dim at startup

bonelady- we put in several dedicated fluorescent surface-mount ceiling fixtures during our remodel. They're in hallways and closets, mostly. HD carries several that look like traditional fixtures, including the "mushroom" type that was original in other parts of our house. I think Progress is the brand, and they're typically sequestered off with the fluorescent shop lights. These are using 4-pin bulbs rather than screw-base CFLs. The light color is good, and they seem to have very little lag in brightness when you turn them on.

FWIW, earth911.org is a great place to look up local CFL-recycling options. Our only easy/free option intown in ATL is to take them to Ikea.


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RE: Compact flourescent lights/dim at startup

Thanks everyone. I replaced 12 bulbs over the week end in celing fixtures. I found the "mini" bulbs at Menards and they fit quite well inside of the globes. They are still 60W and made by Sylvania. I am looking forward to not having to drag out the step ladder to change these bulbs every few weeks !


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