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We are all familiar, by now, with CFLs, or compact flourescent lamps. I have several in outdoor light fixtures. In the cold wheather, they are not as bright as in the warmer months. They normally take a minute or two to come to full brightness, even when they are used for indoor fixtures.

My question is, when they are outside and turned on in the cold winter nights, and never reach their full illumination as they do in the summer, are they drawing more power trying to get their ballast to a normal operating temperature? If so, how can that additional power draw be measured?
 

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I have noticed this also, and if you do some research you will find the do not become efficient if used for less then about 20 minutes, so for many applications they waste power. Places like the closet, or bathroom. When I am going to be in and out of my shed doing yard work, I just leave them on. I've never put a meter on one to see what the power draw is, so I have no way of knowing if they perform as advertised. I will say I like that they don't produce as much heat.
 

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I've noticed the same thing regarding the cooler the temperature the less efficient the operation, and when you consider that I live in Florida my level of cold isn't anywhere what others encounter. Then there is the concern regarding what happens when you break one, not to mention what the overall cost to the individual will be when all the incandescent lamps are replaced and the CFL's (Compact Fluorescent Lamp) are starting to be replaced at the end of their life cycle.
 

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And just what is their life cycle. I have had to replace way over 5 already and I haven't been using them for 5 years yet. The manufacturers life cycle always seem to be over-zealously stated.

Reminds me of the sintered iron rollers on cam contact followers. The company said they would last lots longer than the roller bearing cam followers they were replacing. Unfortunately, the new ones would seize, stop rolling, and the sintered iron became rough cutting files that filed off the cam lobes which required very expensive replacement of all the cams.


Life testing? Not an exact science.


Art
 

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Posted By Schlosser on 12/07/2008 10:33 AM

Life testing? Not an exact science.


Art

As far as I've ever seen "Life testing" falls squarely into the realm of a SWAG (i.e. scientific wild-a__ed guessed)!
 

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As I understand CFL operation, CFLs use the same amount of energy whenever they are on. While there's a thing inside called a ballast, it's NOT a transformer ballast like old fluorescent lamps help. What's inside is an electronic circuit called an oscillator that generates a signal that causes the gas in the tube to fluoresce. It runs all the time and produces little heat...unlike the older ballasts...heat that wastes energy. The gas, on the other hand, is sensive to temperature...and that sensitivity can be seen in terms how many lumens it will produce given the temperature of the gas. Lower temps mean lower lumens. That's why they "warm up" when turned on...and perhaps NEVER come to full brilliance in cold weather.

While I've read that CFLs are sensitive to the number of cycles they go through...I flat don't understand why. I have CFLs in virtually all my lights...even the motion detection ones. I've got a good test going though...the front lights turn on and stay on all night...to light my American Flag. The ones on the side of the house are motion activated...and don't come on often...and run short periods. I'll be interested to see how long they last relative to the ones in front. For sure these bulbs have lasted FAR longer than the old 700 hour incandescents that used to be in those fixtures. I really did wear out the front bulbs every 90 days or so.
 

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Guys,

Have you noticed the dark are @ the end of the standard flourescent bulbs.. That is the from them starting to light @ turn on.. There is only so much of that material & then be bulb will not light.. This is where the # of off/on cycles comes from.. If you turn them on & off a lot you defeat the purpose of the bulb..

Mike,

If you had bought higher voltage bulbs, say 140 volt, you would not have had the failurers every 90 days.. If you drop the voltage to a bulb to about 85% of the bulbs rating, you will increase the life of the bulb from about 700 hours to around 30,000 hours.. My #'s may be off some as it has been 10 + years since I studied bulbs..

BulletBob
 
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CFL's are typically rated at 10,000 hours. This is based on long term life testing of the gasses and phosphors that are used. This is the same rating that you will find on conventional florescent lamps and cold cathode lamps found in many LCD display panels.


However, the dominant failure mechanism seems to be the electronics that drive the actual tube. These have variable life, and from my experience, many of them don't get close to 10,000 hours. Some of them don't make 100's of hours.


Further, running them from a dimmer or triac based switch, as found in IR activated outdoor lights, can materially degrade the lifetime of the electronics in the bulbs. They can fail from the first turn on or anytime thereafter. The waveforms generated by the electronic switches seems to be really hard on the CFL's electronics.

For any application NOT driven from a conventional light switch or a relay, I use standard incandescent bulbs.


The efficiency issue is real during warm up. However, they are still more efficient that a standard bulb if the amount of light produced is sufficient to get the job done. They don't draw more power during warmup, they just put out less light. As measured with a light meter, they increase about 2 EV values (4x) in light intensity from turn on to full brightness in an indoor environment. In a cold environment, they will not reach full intensity, but they will still consume relatively little power.

I just ran a quick test with a 60 watt conventional bulb and a "60" watt CFL. The conventional bulb drew 58 watts at a 99% indicated power factor. My spot light meter indicated an EV value of 17-2/3 (it's marked in 1/3 EV steps).


The CFL started out at an EV of 16, 11 watts and a 58% PF. After a two minute warm up, it had stabilized at an EV of 17-2/3, 12 watts and a 58% PF.

It appears to be doing what it is advertised to do at beginning of life. I just don't expect that it will be doing it that for 10,000 hours.
 

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Posted By Road Foreman on 12/07/2008 12:11 PM
Guys,

Mike,

If you had bought higher voltage bulbs, say 140 volt, you would not have had the failurers every 90 days.. If you drop the voltage to a bulb to about 85% of the bulbs rating, you will increase the life of the bulb from about 700 hours to around 30,000 hours.. My #'s may be off some as it has been 10 + years since I studied bulbs..

BulletBob


I hear ya...I had some of those bulbs on my outside lights...and they did last longer. But...at this point, it's kind of futile to change. I'm not sure what has happened...but both Home Depot and Costco now carry almost all CFS...no incandescents in general bulb sizes. Perhaps there has been some law or regulation passed here in California (likely)...don't know. I just know that the selection of bulbs I have now is MOSTLY CFLs. I just put 30 4" can lights into the house during the remodel...and the only reflector bulbs HD sold to fit were CFLs.
 
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IMHO, CFL's are a stopgap measure. They contain trace amounts of mercury and are thus "toxic waste." They don't handle dimmers and other electronic switches well so they cannot entirely replace incandescent bulbs.

LED prices have been plummeting and performance has been increasing at an amazing rate. They are practical for lighting now, especially in the warm white version but the cost is still a little high. Their lifetime ought to be very good AND they should work with dimmers and other electronic controllers. LED lighting is several times more efficient than even CFL's.


LEDs are still made with toxic materials, but at least those materials are encased in plastic. Indium, Gallium and Arsenic are all used in some versions of these LEDs in very small quantities. Indium is not particularly bad but Gallium is very corrosive in it's metallic form (it eats aluminum for lunch) and Arsenic is toxic in it's own right. Eventually, SiC will find it's way into useful LEDs. Silicon and Carbon are not considered toxic.
 

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I have CFL's going on their 3rd year here...I have replaced ALL incandescent lamps here...Yes I have had I think, 3 early failures and I am certain those were all due to faulty electronics...I get the bulbs in packs of 10 from SAMS CLUB and the cost is not much more than $1 apiece...The savings on my electric bill was immediately apparent and these lights have not only paid for themselves already, they have significantly lowered my overall electric bill...

I can't wait for LED lighting to come out at as reasonable a cost per light...

Is this the same George Schreyer of the LS tips site??? If so...Glad to see you here!!! We communicated years ago when i bought the last of the streamliner lowering bolsters...
 
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Is this the same George Schreyer of the LS tips site??? If so...Glad to see you here!!! We communicated years ago when i bought the last of the streamliner lowering bolsters...



the same... for better or worse
 

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I am fairly certain that incandescent lights will be either outlawed completely or severely taxed in a few years.


LEDs will have to improve immensely before they will be good for general lighting. They have too narrow of spectral (frequency) bands for the colors they put out... basically just 2 to 4 colors, depending on the type, in VERY narrow bands... whereas incandescents and CFLs have broad spectral bands of colors. I have a dozen different LED flashlights and although they are very bright to look directly at, the frequencies of light reflecting off of objects from their light is so narrow in spectral density as to make it very difficult to actually SEE anything. Great for "signaling" at a distance, but near useless for "READING" anything but jet black type on pure white background and even then it is very tiring to read by their light.

I have a small "button" device that sticks on the bottom of a light bulb between the contact at the bottom of the socket and the contact on the bulb. It contains a diode to reduce the AC to a pulsed DC and that cuts the voltage in half. Stick it on a 100 W bulb and it lights like a 50 W bulb (or dimmer) but lasts MUCH longer. I have one on my porch light and it extended the life of the bulb to nearly 10 years, whereas the previous bulb without the device lasted only a few months. Unfortunately, when I put first installed it, all I had was a 25 W bulb (refrigerator bulb) and so my porch light was REALLY REALLY dim until a few weeks ago when it burned out and I replaced it with a 75 W one. At least now the neighbors no longer knock on my door to tell me I have something wrong the the wiring to my porch light! These things will not work on a CFL.

As for the definition of "SWAG"... that is a "Scientific Wild-A**ed Guess" and must not be confused with the "SWAG" as in "Silly Wild-A**ed Guess". They are not the same and should never be used interchangeably.
 

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Posted By gwschreyer on 12/07/2008 12:35 PM
that actually translates to "silly wild a**ed guess"
To each his own, George
 

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Guys,

I had an insurance agent that had 250 volt / 150 watt bulbs on a 120 volt circuit in the night lights @ his office on a timer, 14 hours on & 10 hours off.. Had 1 bulb go bad after 7 years of use.. I lost track after 10 years & no other failures..

BulletBob
 

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I learned "WAG" as wild ass guess.... I learned SWAG as "super" wild ass guess.

But I think George is from aerospace, and I was from HP, so who knows...

And my CFL failures were all before the "warranty" and were the electronics...

Regards, Greg
 
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