CFL vs Incandescent

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Given, CFL's are thought to be more energy efficient than incandescent bulbs. But I heard they use more energy to turn on.
What if it is in a room that is used infrequently, a closet or guest room for instance. In other words a room in which you would go in and out of pretty quickly.
How long would a CFL have to be left on to realize the net energy savings.
thanks for your input, bonnie
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Mythbusters did a segment on that. The break-even point was something like 6/10ths of a second.
The better question is, is this really a question considering that you aren't going to be able to buy incandescent lights next year.
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Pat wrote:

The ban does not kick in until 2012, and only affects general service ones of a certain range of brightness. Even then, ones that achieve some higher efficiency standard are exempt. I got just an hour ago a couple that I believe will get around that ban by using "halogen infrared" technology.
These are Philips Halogena Energy Saver. I got them from Home Depot. They look like ordinary soft white incandescents, of the squarish shape used by some Philips lightbulbs in North America (and Westinghouse before they sold their lamp division to Philips).
There is a 70 watt one with light output fully on par with a 1500 hour (double life) soft white 100 watt incandescent, and a 40 watt one with light output fully on par with a 60 watt 1500 hour soft white incandescent. Both of these are rated to last 3,000 hours and are rated to be fully dimmable.
- Don Klipstein ( snipped-for-privacy@misty.com)
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On Sun, 27 Apr 2008 22:57:41 +0000 (UTC), snipped-for-privacy@manx.misty.com (Don Klipstein) wrote:

We have many recessed floods on dimmers. Dimmable CFL's are WAY too expensive right now. I sure hope that changes before anyt kind of ban on them.
And I hope something improves with the "warmup" time. I now have all CFL floods in my kitchen. When I'm ready to make dinner, I have to pre-heat the lights and the oven at the same time. :)
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On Mon 28 Apr 2008 05:53:02a, told us...

Mitch, the CFL floods I have in my kitchen take 5-7 seconds to reach full brightness.
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Wayne Boatwright
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What are you doing here? :-)
Mine take about 3-4 minutes! I have various brands (10 lights total), and they all take that long.
What kind do you use? I want those!
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Yours must just be very old. I have lots of kinds and brands, and they all come up to full strength in less than 10 seconds. The only one that takes minutes is a bulb in a closet that's been there for more than 5 years.
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On Mon, 28 Apr 2008 12:19:58 -0400, <h> wrote:

Not at all. My oldest are no more than 2 years old. The most recent were purchased within the past 2 months.
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On Apr 28, 11:19am, <h> wrote:

I have new HDs that take minutes
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On Mon, 28 Apr 2008 10:31:19 -0700 (PDT), ransley
It's kind of funny, because you can watch the light slowly spiral down the tube.
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On Apr 28, 12:19pm, <h> wrote:

My Sylvania floods are just a few weeks old and take up to 3 minutes to reach full brightness. I'll still have the package and receipt. They're going back and I'm gonna try the Philips Halogena "Energy Saver" floods that Don mentioned.
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On Mon 28 Apr 2008 09:06:06a, told us...

I have twelve in my kitchen, all the same brand, as I ordered them online. Unfortunately, I don't remember the brand, and I would need to drag out the 10 ft. ladder to check them.
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You may try replacing some of the CFL floods with Philips Halogena "Energy Saver" floods, available at Home Depot. Yesterday, I saw 40 watt ones (60-65 watt equivalent) in 2 different sizes. The larger size is BR30 (3.75 inch diameter).
They are not nearly as efficient as CFLs, but they are more efficient than ordinary incandescents. And they are dimmable.
I somewhat remember (I hope correctly) that floods are not affected by the upcoming ban.
- Don Klipstein ( snipped-for-privacy@misty.com)
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There is no Thought on if cfls are more efficent, they are in fact 75-80 % more. Replace them first where you save the most.
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The turn-on energy difference is miniscule, but each start removes about 6 minutes (0.1 hours) from a CF's typical 6000 hour lifetime at a typical $2 cost, vs a bulb's typical 750 hour lifetime at a typical 50 cent cost.

You might better ask "How long would the CFL have to be left on per start to save money over an incandescent bulb, with 1/4 the power consumption, at 10 cents/kWh?"
Nick
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That is absolutely false. It is a continuation of an old myth that fluorescents have some big surge in power consumption when they are turned on, supposedly amounting to a significant amount of energy consumption. That is simply not true.
That is a mistranslation from advice to leave fluorescents on rather than turn them off and back on, unless they will be off for a substantial amount of time - due to starting-related-wear.

This varies widely with lamp wattage, lamp cost, starting technology used, and your electricity cost rate. I would say, as a "one-size-fits-all" figure that is at best a ballpark, 5 minutes for wattages at least 10 watts.
I consider closets, refrigerators and motion sensor lights to not be candidates for CFLs.
There are cold cathode ones that do not experience starting-related wear. However, they cost more, are less widely available, available only in lower wattages mainly 8 watts and less, are less efficient than the usual hot cathode ones, and still need to warm up to achieve full light output. Cold cathode CFLs are best for frequent on-off use. They take too long to achieve payback when they are off 98-99% of the time.
- Don Klipstein ( snipped-for-privacy@misty.com)
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Look at your question this way, you have an incandescent in a spare room that you energize for a total of 60 minutes per year. If it is a 100 watt bulb and you pay 15 cents per kilowatt hour, you use 1 1/2 cents worth of electricity per year. Not much of a savings to be had.
OTOH if you have a bulb you burn for 6-8 hours per day, CFL wins hands down.
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About the time I had mastered getting the toothpaste back in the tube, then
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On 4/27/2008 2:11 PM bonnie spake thus:

The initial inrush (or surge, if you prefer) current that you're talking about is pretty small. Leave the CFL on a minute and any energy cost from turning it on is negligible.
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