CFLs use more energy than indicated

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Twice as much.
"Every CFL light contains a small ac-dc power supply with reactive components in it that will affect the CFL's power factor (PF) - that is, the load presented to the ac line. The closer the PF is to 1, the better. A load with low power factor (<.85) draws more current and is less efficient than a load with a high power factor for the same amount of useful power. ... These power losses don't show up directly on our electricity bill, but the utilities sure see the effects.
"I put one of my home CFL bulbs on my Kill-O-Watt power meter recently and measured its power factor: It was .57. This is lousy. "
http://www.edn.com/blog/1470000147/post/450043045.html
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The good point is I save the money running cfls.
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Is the reactive portion of the load capacitive or inductive?
Jimmie
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JIMMIE wrote:

With the usual low power factor electronic-ballasted CFLs, most of the "non-real" portion of the current is neither inductive nor capacitive, but in the form of harmonics.
- Don Klipstein ( snipped-for-privacy@misty.com)
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ransley wrote:

Of course. Even with poor PF, if the light output(Lumen) is higher for the power consumed compared to old incandescent bulbs.
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that is pretty crappy, even old style fluorescent fixtures are generally 0.8 or better.
Now I'm going to have to try that when I get home to satisfy my curiosity.
nate
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One reservation we have about the use of CFLs is that since we heat most homes here with electricity (hydro generated) anyway and never need, in this climate AC, the so-called wasted heat from cheap (25 cent) incandescents (when on at night for example) is merely an alternative to our electric heating! One place that CFLs do make sense is outside, where they are sometimes left on at night for safety and insurance reasons. But CFLs in very cold climates do not seem to be always the best choice and ot you have to buy expensive ones to get good starting and colour! Also CFLs do not seem to be a good or necessary choice for locations where they are flipped on for a short time, such as stairs, cupboards etc. they supposed to be used (like strip fluorescents) where they will be left on continuously. We have a bunch of those, with electronic ballasts, (from a school renovation) in our workshop. Interesting finding; what about switching power supplies also?
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stan wrote:

It is true that the old incandescent bulbs do provide heat, however, like resistance heat, they are very inefficient. IIRC a good heat pump will provide about four to six times as much heat as a resistance heater or incandescent for the same power consumption.
EJ in NJ
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Ernie Willson wrote: ...

While I'm not going to say lighting is the ideal way to heat, and there's truth to the heat pump, it achieves such efficiencies only when source temperatures are relatively high whereas the resistance heater is the same irregardless.
--
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Robert Neville wrote:

Which is probably 95% of the time here in Seattle.
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On Thu, 09 Apr 2009 15:16:37 -0400, Ernie Willson

I think what you meant to say is that using electricty only** is a very expensive way to make heat. That doesn't meant that incandescent light bulbs are an inefficient way to provide heat. I believe that they are 100% efficient, in that all the electric power that is used is converted to heat and light, and the light is converted to heat when it lands on a surface (except for the light that that gets out through a window.)
Light is absorbed by a black surface and converted to heat at that time. Light is partially reflected from a white surface, so part of the energy is converted and part is reflected. You can tell that not all of the light is reflected because if it were, when the light source is turned off in an all white room, there would still be light inside the room, when in fact it goes dark almost instantaneusly.
**As opposed to using electricity to power a heat pump or an oil furnace.

That's because the heat pump brings heat from the outside to the inside, and the electricity just powers the process. An electric powered coal stoker, that brought coal from a coal pile to a coal furnace would generate even more heat per KWHour, although I don't know that people would call a coal stoker an even more efficient means of heating. Although maybe they would.

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I thought it was 2-3 times as much.
- Don Klipstein ( snipped-for-privacy@misty.com)
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Don Klipstein wrote:

15 or 20 years ago that was the range IIRC.
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How is it inefficient if that heat is kept inside the house?
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On Apr 9, 7:36 pm, snipped-for-privacy@privacy.net wrote:

You can look at an incandescent bulb as being something like 99% efficient compared to an ideal resistive heater, meaning that 99% (and I'm pulling that number out of the air) of the electricity that passes through the bulb is eventually converted to heat. Some of it is initially radiated as visible light, but most of that is eventually absorbed by some surface and converted to heat (sort of). I think the only real loss is any visible light that goes out through a window, for instance.
But he's comparing it to a heat pump which, rather than converting the electricity into heat, is using the electricity to move (pump) existing heat from outside the building to inside. Basically, an air conditioner in reverse. Supposedly, under the right conditions, this can bring in more heat than what would be produced by converting 100% of the electricity it uses directly into heat.
I personally know nothing about how much more or under what conditions.
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Duh... Now that I think about it, I'm sure the reason a heat pump can be so efficient is because if the compressor is inside, most of the electricity it uses is also converted to heat inside the house on top of what it brings in from the outside...
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And of course, you're wrong. As someone explained very well earlier, a heat pump is efficient because it's MOVING heat, rather than generating it. Modern heat pumps can generate more heat for the same Kwh than resistance heaters, even when the outside temp drop into the teens. BTW, the compresors in the ones I've seen are outside.
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On Apr 10, 8:32 am, snipped-for-privacy@optonline.net wrote:

I understand what they do, and I said I knew nothing about how efficient they were at doing it (for the sake of argument, not taking anyone's word as correct on that). My point was that even if one happened to be very inefficient at moving heat, it would be, at worst, atill be functioning as a pretty good radiant heater (as does almost anything else that uses electricity).
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The heat pump is OUTSIDE. You'd have to stand there to get any radiant heat from it. And anything that uses electricity is NOT necessarily a pretty good radiant heater or even a radiant heater at all. The common electric water heater being one good example, which heats via conduction.
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On Apr 10, 8:25 pm, snipped-for-privacy@optonline.net wrote:

My mistake, but ideally if you were using the heat pump for heating only, you could make the system more efficient by putting the pump inside. Probably too much of a noise issue for most people though.
An electric water heater heats the water by induction, but when the water is not being used most of that heat eventually radiates out into the home. It's not an effective radiant heater, but still an efficient one when you're not carrying that heat away for other uses.
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