*Years *ago, there were problems with CFLs. No longer. They last much longer than incandescent bulbs.
Soon, we’ll be using LEDs.
I just bought some “daylight” CFLs yesterday. Wow! What an amazing light they produce. Perfect for reading.
One good anecdote deserves another. I have been using one for over a year with good performance.
Sometime last year I discovered “daylight” color temperature CFLs. For the same wattage as “soft white”, they appear much brighter to me.
I don’t have any three-ways in use, but the entire house is using CFLs. They seem to last forever.
CFLs are so 2008…
LEDs are the future.
But seriously, You will always be able to get specialized lighting for stuff like lava lamps. You might have to special order it, but you can get it.
I dont think I have a single incandescent light in my 4bdrm home. Its all CFL or LED.
I don’t like the way CFLs light - they start dimmer and warm up to full brightness.
LEDs are still expensive, but there’s virtually no energy wasted generating heat. (Which makes them totally useless as a lava lamp light/heat source)
This is not true.
Incandescent bulbs are grossly inefficient, but LED’s are still nowhere near 100% efficient at converting electricity; the best LED’s convert about 50% of input power to light, and dump the other 50% as heat.
If you buy an LED lamp that has the same output rating as the original incandescent bulb, the LED will consume a lot less power, but it’s still wasting plenty of that power as heat.
Example:
A 100-watt incandescent bulb consumes 100 watts of electrical power, and puts out maybe 10 watts as light, 90 watts as heat.
A “100-watt-equivalent” LED lamp, with its much higher efficiency, only needs ~20 watts of electrical power, but puts out the desired 10 watts of light (thus being “equivalent” to the 100-watt incandescent), and only 10 watts of heat. So while it’s much better than the incandescent, it’s still wasting about half its input power as heat.
high output LEDs do need big heatsinks.
CFL are best used for long duration use so a minute warmup isn’t much of a problem. for short duration use like a stairway or closet then it is best not to use a CFL.
The most efficient LEDs are just starting to beat CFLs in efficiency.
Pro electronic designer with an intimate knowledge of these hateful things signing in.
Yes, CFLs will last longer positioned glass envelope uppermost (as others have pointed out) because the electronic drive circuit in the metal base won’t run as hot. Usually it’s the electrolytic capacitor that fails first, as their lifetime is seriously reduced by running at high temperatures. These capacitors normally have one of three upper temperature ratings: 85 deg. C (commercial), 105 deg. C (industrial) and 125 deg. C (military). You can safely bet it’s a cheap commercial grade in that CFL.
From electricity in to light out it goes like this:
- Electromagnetic interference (EMI) filter.
- Full-wave rectifier.
- Electrolytic capacitor.
- 2-transistor switched mode power supply (SMPS).
- Fluorescent bulb.
There has been a race-to-the-bottom with CFL prices as they have to compete with cheap and simple incandescents, so the components used are the cheapest the OEM thinks they can get away with. Early (more expensive) CFLs were better quality, produced less radio interference, and lasted longer. Now the EMI filter stage is either very rudimentary, or is missing altogether.
The rectifier and electrolytic capacitor turn the AC mains supply into a (high) DC voltage, which is then chopped up by the SMPS (which also produces the unwanted EMI) in a moderately efficient way to provide current for the fluorescent bulb part. This current is internally regulated, which is one reason (there are others) why normal CFLs can’t be used on dimmers.
The main reason the electrolytic capacitors fail is that the electrolyte dries out over time, and this process is accelerated by raised temperatures. These electrolytics also give rise to a large current surge when the CFL is turned on, and again, this shortens the life of both the CFL and the light switch contacts. Incandescents also produce a current surge on power-up as cold tungsten filaments have a much lower resistance than white hot ones, but this is nowhere near as high as a CFL current spike.
The lifetimes of the other electronic components are also reduced by heat (the transistors are the next most susceptible devices), but these rarely get a chance to die as the electrolytic invariably croaks first.
Margery Conner over at EDN has some definitive articles on the subject:
This Was Not The Right Application for a CFL
Utilities Suffer from CFLs Poor Power Factor
Governments, Measurements and CFLs
This is about 0.01% of the contempt I have for CFLs, and the disingenuous way they have been foisted upon us. But on the bright side (unlike a CFL, say) they’ll only be around for a few more years before being made obsolete by LEDs, which will be superior in every respect.
I wouldn’t be so sure. Current regulations in Australia ban the sale of all general-purpose incandescent bulbs except for halogen bulbs. Decorative incandescents will be phased out over the next couple of years.
it does say that below 25W there is no set phase out date for pilot lamps. i see no listing for appliance bulbs which are often about 10 or 15W. currently there is no substitute for use in things like cooking ovens or clothes dryers.
Ah, that would be really nice, wouldn’t it? However, we’re far more likely to see cars that run on wishes and dreams than a government that has any sense.
Not to mention that flourescent tubes and CFLs are classified as hazardous materials and must be disposed of/recycled accordingly.
I did not have good luck using CFLs in a socket operated by a timer. It would physically come on but apparently was always drawing some current and this threw the timer off by up to hours per day.
if the timer switched the load off the light would not always be drawing some current. if your timer was off by hours everyday i would think it likely broken. set the correct time on the timer and let it run with nothing plugged into it and find out if it keeps time.
That’s electromagnetic interference wreaking havoc right there, most likely when the CFL turns on. Timers only have little relays in them, and the current they state they can handle is for a purely resistive load like… well, an incandescent really, and not much else. For reactive (capacitive and/or inductive) loads the current they can cope with is much reduced, and the lifetime of the relay will be diminished.
Capacitive loads, like a CFL or a CRT TV, will have a big current surge on power-up, and this can be enough to spot-weld the relay contacts shut. Inductive loads, like a motor, kick back a high voltage (“back EMF”) on power-down, and this will spark erode the contacts away in time.
Either a high current surge or a high voltage spike can easily scramble the microcontroller in a timer - I’ve seen it happen plenty of times. Some models are more susceptible than others. The way around it is to use the timer to operate a much meatier relay, and have some interference suppression components judiciously applied.
The CFL shouldn’t be drawing any current when the timer is off unless the timer relay is welded shut, in which case it will be on permanently. Unless the relay contacts have an RC snubber circuit across them (they shouldn’t do, as this doesn’t provide full electrical isolation, though it does protect the contacts from back EMF erosion). If this is the case then there should be enough current bleeding through to slowly charge up the CFL capacitor to the point where the voltage is high enough to operate the CFL circuit, which then dumps the energy into the bulb to give a brief flash, discharging the capacitor as it does so. It should flash once every few seconds/minutes, depending.
Actually, with the exception of a few very infrequently used bulbs (garage, etc.), my entire house has been using CFL’s for years. I once did an analysis of the return on investment for these bulbs,and got around 140%. Unfortunately, your maximum investment is sort of limited.
Fridgemagnet and johnpost, here’s a prior thread on this. Basically, I had an incandescent bulb in an outdoor fixture controlled by a Triac timer. Worked fine until I replaced it with a 40 or 60 watt CFL. Sometime after that I noticed the timer wasn’t operating properly. I replaced that timer twice before considering it might be the bulb. When I went to replace the CFL back with an incandescent I noticed that even though the timer was off the CFL had a tiny bit of sputtering light at the tip of the bulb. Now that the incandescent is back in the timer again works perfectly. Last week I had an electrician out to do some other work and asked him about the pairing, Triac timer with CFL. He agreed there was an issue but didn’t go into detail as to its nature.
Thanks for your input. While I’ve tried to distribute CFLs throughout my house, this was one instance in which I have noticed a problem.
How long will “regular” bulbs be available in the U.S. ?
What about those bulbs used in chandelier-like fixtures that look kind of like Christmas tree bulbs with a pointy end?