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Why LEDs Don't Beat CFLs Even Though They Should
Posted by
samzenpus
on Tue Dec 30, 2008 06:57 PM
from the light-it-up dept.
from the light-it-up dept.
TaeKwonDood writes "LEDs don't beat CFLs in the home yet, but it's not simply because PG&E is getting rich making people feel like they are helping the environment buying CFLs made in China that are shipped to the US using a lot more fossil fuels than they save. It's a problem of indication versus illumination. However, some new discoveries are going to change all that."
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Not just cost, but optics (Score:5, Informative)
LEDs are not traditionally used for illumination not only because of the costs of LEDs, but because of the complex optics required to distribute the light. it's rare to see LEDs used for illumination, though it is making an entrance for some applications, like flashlights [maglite.com] and even headlamps [motorauthority.com]. As LED prices continue to come down and LED optics technology improves and cost stabilize, conventional LED lamp retrofits will become commonplace. Take a look at LEDtronics [ledtronics.com] for some examples.
Re:Not just cost, but optics (Score:5, Informative)
Did you notice all the LED xmas lights this year?
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Re:Not just cost, but optics (Score:5, Informative)
You normally get the best deals on Christmas lights the day after Christmas
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Re:Not just cost, but optics (Score:5, Insightful)
Sorry but I don't buy the optics issue. It really can't be THAT hard to put a lens or reflector in the armature and point multiple LEDs in different directions. If anything LEDs should be preferable to incandescents because it is easier to take something very directional and spread the light than it is focus the light from a divergent source. I think the main reason LEDs are not popular yet is cost and "it's not what I'm used to". Seeing the type of crap people will buy even when there are better alternatives I simply don't believe that something as sophisticated as the beam profile of an LED will be a huge issue.
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Re:Not just cost, but optics (Score:5, Interesting)
It's actually harder than it seems. Just imagine trying to light up a room using a laser. How hard can it be, right? LEDs are *very* directional too.
It takes far more than a simple lens, or a simple reflector to manage to illuminate a workspace evenly using them. Reflectors work fine for incandescent/fluorescent and such non-directional light sources.
That's why we see LEDs thrive in many applications like flashlights and traffic lights and not others: those require directional light.
And even if you found a great way to do it, it would still add [likely significant] cost, and likely a fair amount of weight, if using optics. It would probably look like a huge catadioptric lens of a lighthouse (well, the inverse job, but a huge chunk of glass is what I meant). The best I've seen so far, is using a large number of lesser power LEDs...
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Re:Not just cost, but optics (Score:5, Insightful)
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Re:Not just cost, but optics (Score:5, Insightful)
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Re:Not just cost, but optics (Score:5, Interesting)
It does work -- somewhat! Here's proof [rei.com], a LED camping lantern that uses a standard Nalgene water bottle to diffuse its light.
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Re:Not just cost, but optics (Score:5, Interesting)
The experiance of everyone I know who has tried LED light fixtures is they simply don't have the ability to decently light a room (whether this is due to thier being simply less light output or whether it is some other characteristic of the light I don't know) while CFLs do. They are also FAR more expensive than CFLs.
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Re:Not just cost, but optics (Score:5, Funny)
Fixed that for you.
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Re:Not just cost, but optics (Score:5, Informative)
Although I agree with some points of your post, most of your belief is not quite accurate. LEDs now make the best flash light illumination, and the power drain on batteries is minimal. I've been using LED headlamps for years, so this is nothing new, as your post implies.
The problem with them being used in homes is that they direct their illumination to a specific spot. This is not a bad thing though. I've recently seen them configured as spot lamps. Perfect for recessed lighting.
The optics in LED technology can easily be modified to diffuse light to make a great replacement for CFL & incandescent. Give it time.
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Re:Not just cost, but optics (Score:5, Interesting)
Disclaimer: I have no experience with LED "lightbulbs" like those in TFA, only LED flashlights
To me, the biggest hangup on going to LED lighting from CFLs would be the spectral issue. In my experience, "white" LEDs don't actually put out true white light, but rather several distinct wavelengths that look approximately white to human eyes. IIRC they lose some definition with red/green. Not as big an issue for a flashlight, but in room lighting I'd kind of want all the colors showing up. This may very well be solved by now, however. I don't know.
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Re:Mod parent up! (Score:5, Informative)
I've got a nice, tungesten-coloured LED right here that emits nearly omnidirectional light if I just remove the lens that comes with it. I don't think directionality is really any kind of inherent problem, just a manufacturing issue.
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Re:Mod parent up! (Score:5, Interesting)
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Re:Not just cost, but optics (Score:5, Insightful)
It was a bit off-topic, but it's not viral marketing, I'm an actual customer of theirs.
You are a customer talking about a product you use. That is one of the forms of Viral Marketing.
Back since I was a youngster, we just called it "word of mouth". Worked pretty well for good companies.
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Re:Not just cost, but optics (Score:5, Insightful)
That article repeats a bunch of CFL myths. I find it amazing to watch some in the geek crowd glob onto any "science" related conspiracy ("global warming is fake", "the Hindenburg didn't burn from hydrogen", etc) the same way tin-foil hat people glob onto the "moon hoax" or "there was no plane crash at the Pentagon on 9/11".
We even were treated to one in the header of this article:
"CFLs made in China that are shipped to the US using a lot more fossil fuels than they save."
Oh, really, is that so? Shipping cargo takes about one gallon of gas per ton of cargo per 500 miles [google.com]. Shanghai is ~6500 miles from LA. Thus, 154 pounds can cross the Pacific per gallon of diesel. A gallon of diesel contains 130MJ. A CFL weighs perhaps a quarter pound. Therefore, it takes 211kJ of fuel energy per bulb. If we assume the big diesel engine is roughly as efficient as a power plant's electricity generation, we can compare them directly. 211 kilojoules is 0.05 kilowatt hours. If usage that bulb reduces 60 watts down to 15, thus saving 45 watts, it'd take barely over an hour to pay off the energy used in shipping it.
Of course, you also need to include train shipping energy consumption to get it to and from the ports, which is more like one gallon per ton per 300 miles, but that too is trivial to pay off.
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Riiight (Score:5, Insightful)
CFLs made in China that are shipped to the US [use] a lot more fossil fuels than they save.
'Cause incandescents are all made in the US and don't share nearly the same shipping costs.
Re:Riiight (Score:5, Insightful)
But what if you had to ship 6 lights for every one due to lifespan differences?
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Re:Riiight (Score:5, Informative)
You are either buying CFLs from a completely incompetent manufacturer, or simply have a bizarre situation where reality is bending around you.
I replaced all bulbs in my home with CFLs three years ago. None have burned out to date, and I saw a small but measureable decrease in home energy use, as my home energy costs are very stable. Everyone I know who has replaced all or some of their bulbs have had the same experience.
There's demonstrable energy savings to be had, and a measureable lifespan increase simply due to the physics of CFL versus incandescent.
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15 years. (Score:5, Informative)
I have had the CFL in my hallway for 15 years.
I haven't changed a lightbulb in at least five, and even that was because somebody hit it with a broom handle. I don't remember much from when I was a kid but those other types of lights would die every now and then.
You're doing it wrong.
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Re:15 years. (Score:5, Insightful)
Have you done it recently? The CFLs I bought in the nineties are still working. The ones I bought last year aren't measurably any longer lasting than the few incandescents I still use. I suspect that now everyone has jumped on the bandwagon, there are a lot of crappy cut-rate CFLs being made. And I'm pretty sure that this isn't being taken into account in figuring overall real-world environmental impact.
Contributing to this, as Fred and Ethyl Mertz buy eight-packs of CFLs at Costco, they're certainly using them in situations where they don't work well -- like areas where the lights go on and off frequently. (I made this mistake initially -- couldn't figure out why CFLs were lasting months rather than years in the bathroom.) Which, as you point out, really is doing it wrong. CFLs work well in narrowly-defined environments -- they're not a replacement for every bulb in the house. The general public doesn't appear to realize this, and the retailers are in no hurry to correct their misunderstanding.
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Re:15 years. (Score:4, Informative)
>> couldn't figure out why CFLs were lasting months rather than years in the bathroom
You bought crappy CFLs. CFL's don't have a problem with on/off as long as you're not running a disco or something. My 5 round CFL bulbs in the bathroom are going strong after 2 years. Same for everyone else in the family.
I agree that CFLs aren't for every possible use, but they are great for almost everything. The only thing they're not great for is decorative lamps (although you can get different shapes of CFLs) and outdoor lamps that aren't always on in cold environments (takes too long to warm up and produce full light).
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Re:Riiight (Score:5, Interesting)
I've seen similar issues with specific outlets in my house. CFLs last about 2 months and incancesdents a year or two. The problem appears to be fluctuating power supplies. Our house's power isn't very stable... the vacuum cleaner, dryer, and other devices cause lights to slightly dim or flicker. I've solved most of it by separating the circuits, but the CFLs seem to be VERY sensitive to fluctuating electricity.
A CFL on its own circuit seems to last a long time.
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Re:Riiight (Score:4, Informative)
CFL bulbs will give you 10+ years of service if you leave them on for at least 30 minutes everytime you turn one on. Not good for use in bathrooms or inside refrigerators.
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Commercial shipping (Score:5, Informative)
Except that commercial shipping is usually done by volume not weight. Only if the weight is extremely excessive does it matter for pricing. Shipping containers are usually charged by the container, not by the weight. They have a weight *limit*, but that is not the same thing. I can't imagine hitting the weight limit of a container with any kind of light bulb.
Trucks are the same way for large quantities.
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Re:Commercial shipping (Score:5, Funny)
I can't imagine hitting the weight limit of a container with any kind of light bulb.
What about HEAVY bulbs?
BADDUMM TISH!
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same thing! (Score:4, Insightful)
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Re:Riiight (Score:5, Informative)
Then there is something seriously wrong with your wiring or the bulbs you buy. The claims are sometimes overdone on the packaging, but it was much worse back in 2001 than now. Also, some manufacturers are more reliable than others (feit electric at Costco and Sylvania at lowes, other places, seem to be good for certain models). The Walmart brand Great Value seems to be horrible, at least in my experience.
I've had enclosed Par 38 CFLs (23w) die on me with some regularity although it has gotten a little better the last year. OTOH the enclosed Par 20 (13w CFL) have been absolutely solid since 2004, after a bad first run.
My longest lasting lights about 10 regular 13 watters --60w equivalent-- enclosed exterior ones. They started in all temps from (-5F to 100F). They used to be dusk to dawn for the first 3 years, so I guess 12 hours a day on average through the year, then the solar cell went bad on several 2 3-lamp posts and so 6 lights were running continuously for about a year (busy year). When I fixed that, put a timer in to start at dusk and turn off rougly midnight.
Through those 6 years, about 5 lights went bad. Keep in mind, they were running around probably 4,380 hrs a year. One year it was the max 8,760 with no breaks. And now, it's down to 2,190. This is probably due to them being on for extended periods and not constantly switched on and off which wears on a ballast and kills the shoddy ballasts fast.
CFLs are a type of fluorescents, and if the ballast is shoddy, you can forget it. Also had to replace every fluorescent ballast in a section of newly constructed office space once as one in an entire row (same manufacturer) went bad one at a time in a short period. Doesn't meant fluorescent tech is bad, means it was either a bad manufacturer or bad run. BTW, there can be bad fluorescent tubes as well, Philips seems to be good while the much cheaper Sylvania contractor packs are shit.
Just how it goes. Go to some CFL forums and learn. Have no experience with dimmers though. Don't have a one.
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Re:Riiight (Score:4, Insightful)
As other's have mentioned, you must be fantastically unlucky to be getting those failure rates. I haven't had to replace a single one of the 10 bulbs I put in 2 years ago. Maybe your power is unstable? I've heard that CFLs tend to not like uneven power.
Also you mention rising electricity bills, but of course that has nothing to do with CFLs. They use less power, so you're doing something else to make up the difference. Not "probably" as you say, but absolutely certainly.
As for shipping, it's incredibly unlikely that the weight is a factor in comparing traditional bulbs to CFLs. Volume is going to be a limiting factor for both of them. No way would a cargo ship have to load fewer containers of CFLs because of some weight limitation. They ship containers of steel for crist's sake.
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Re:Riiight (Score:5, Insightful)
They don't have to make such claims. If the incandescent bulbs involve the same shipping overhead as the CFLs (as the grandparent is sarcastically suggesting), then the claims that CFLs are more environmentally friendly stand up. That's the point, period. The shipping costs mentioned (without any sort of supporting data, I might add) in the summary is only a valid issue if incandescents are made locally.
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Re:Riiight (Score:5, Informative)
No, it's valid if they're both made extra-nationally, but in different places. Most incandescents are actually made in the United States by GE, but the vast bulk of the remainder are made in Mexico, and shipped up by rail, which is far more efficient than slow-boating them from China. It turns out that there are more than one country outside of America, and that those countries aren't actually all in the same location.
Of course, if anyone actually did the math, they'd find out that the energy cost of shipping is offset by the energy savings in usage in under three days; sometimes I wonder whether people have any idea how many lightbulbs fit on a large boat, or how little fuel a large boat actually needs.
But hey, made up math is great for making arguments, right?
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Re:Riiight (Score:5, Insightful)
I always laugh when people start talking about carbon footprints and all that. Currently the simplest and only real way to drastically reduce your carbon footprint is to spend less money. Things that cost more in general have a greater carbon footprint (there are exceptions to this rule, but it often holds true). So the footprint of manufacturing a new stove is roughly proportional to how much the stove costs (obviously if you're buying a gold plated stove with platinum racks this won't quite hold true). So the quickest way to halve the US's carbon footprint is to cut the US's spending power in half. Of course, with the steps the government is taking to reverse the current economic crisis, they could easily accomplish this.
Phil
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"using a lot more fossil fuels than they save"??? (Score:5, Insightful)
Seriously? (Score:5, Insightful)
You're seriously trying to claim that the savings of CFLs are offset by shipment? Really?
I would go into the obvious math or the economics, but honestly this is just simply too stupid to even deserve further comment, except that it is a completely asinine, baseless statement that I'm sure will be picked up and repeated by a lot of ignorant contrarians.
Re:Seriously? (Score:5, Insightful)
It's the hip new anti-environmentalist meme. Anything that is supposed to lessen emissions actually increases them because you have to build it!
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Re:Seriously? (Score:5, Informative)
A 20' container is approx 19' x 7' x 7' or 1.6M cubic inches (it's a bit bigger, but I left room for pallets, etc).
If a CFL + packaging is 3" x 4" x 6" = 72 in^3 then you can fit around 22,000 of them into a 20' container
This site [cypressindustries.com] claims you can ship a 20' container from China to the US for $3800 USD
Let's say that 75% of the shipping cost goes toward fuel, the rest goes to labor, paying off the ship, container rental, etc. Sounds reasonable.
I'm going to use Diesel for the energy calculations. I know that ships run off bunker fuel, not diesel, but I have to think that the cost per unit of energy for bunker fuel is cheaper than diesel since it's less refined, so by using Diesel I'm being conservative. Right now you can buy diesel for under $2/gal, so with 75% of $3800, we can buy 1425 gallons of diesel.
Diesel has 38 MJ [hypertextbook.com] of energy per liter (143 MJ/gal), or 40KWh according to the units command.
So, each light bulb uses 40KWh / 22,000 = 1.8 KWh (1800 Wh)of energy
A 29 Watt CFL can replace a 100 Watt incandescent bulb, so that's a 71 watt savings... 1800Wh / 71 W = 25 hours
Sooooo....a CFL will save the energy used to ship it in about 25 hours of operation. CFL's are supposed to last 5000 hours, so over its lifetime, it will save over 200 times more energy than used to ship it. (of course, this is only this shipping energy, and ignores the extra energy that it took to manufacture the CFL it as compared to an incadescent. I don't know how to do that math).
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i didnt buy CFL/LED bulbs to save the world (Score:5, Interesting)
As the tag says, lumen per watt (Score:5, Interesting)
an directionality. It's hard to beat CFLs and moreso some good quality fluorescent tubes get slightly more lumens per watt (although I saved 100 watts per hour in the kitchen - 200 instead of 300- by going with directed CFLs that shine line exactly where needed vs previous central flourescent tubes that were lighting from the center trying to sloppily spill light everywhere).
Since every Home Depot now takes any CFLs, the disposal is actually better than fluorescent tubes. Considering most electricity comes from coal, you prevent mercury release in the air vs incandescents. And no, you don't need a specialized clean up crew if a CFL breaks: http://www.snopes.com/medical/toxins/cfl.asp [snopes.com]
Except for the oven, fridge, and flashing lights - CFLs are appropriate for most applications.
I would love to have LEDs. But they need to raise their efficiency. They don't generate heat as such, but AC->DC conversion does, index of refraction of the casing material presents a problem, as well that leds don't generate white light by themselves (they use phosphor?) and all that reduces the light given off.
It would be cool if those were solved one day, where they got near 90% theoretical max lumens/wax (683 lm/wt), where a 3 watt LED would give off the same light as a ~100 watt incandescent or ~23 watt CFL. Even 150 or 200 lm/wt would be a revolution. But it will take 5-10 years I suppose.
Re:As the tag says, lumen per watt (Score:4, Informative)
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Uh (Score:5, Insightful)
Wow. Way to sneak in that lie under the radar. Politically motivated, or just simple ignorance?
In any case, no, the manufacturing and transport of CFL bulbs absolutely does not generate more CO2 than that saved by using them (assuming coal/natural gas powered, the only logical comparison in this case). Let's run some simple numbers.
Assuming an average 60-watt equivalent (12 watt nominal) CFL bulb with a lifespan of 10,000 hours, it will draw 120kWh over the course of its life. The 60-watt incandescent, if it lasted as long, would draw 600kWh. Of course, it doesn't last as long, but rather an average of 1/5 as long.
So the savings are roughly 480kWh for an 800lm fixture. That's the equivalent of over 400 liters of gasoline burned in an internal combustion engine, and that doesn't include the fuel used building, shipping and shopping for replacement incandencents, which as mentioned burn out far more frequently.
Now for some logic. How is it that a bulb which apparently requires >480kWh of energy to build/ship ($48 at $0.10/kWh) sells for a few dollars? Hint: it doesn't require >480kWh of energy to build/ship, or anywhere near that.
CFLs offer a massive net efficiency gain, and by extension, a net reduction in CO2 emissions. Even factoring in disposal costs at 5 times the manufacturing cost (silly), CFLs are a net win. So please don't spread that tripe!
Shipping Costs (Score:5, Informative)
If a shipping vessel can hold 35,000 tons of cargo and the shipping weight of a CFL is 1/2 pound, the vessel can hold 140 million bulbs. Of course there is not enough space for them all, but they can ship with heavier items, and I am assuming costs are allocated by weight.
If a 7,000 mile journey burns 875 tons of fuel, or 15.75 million gallons, then each bulb is allocated
Therefore, the shipping costs don't even come close to negating the energy savings.
Most incandescent bulbs are made in China (Score:5, Interesting)
The vast majority of light bulbs are imported from China. Incandescent, halogen, fluorescent, CFL, you name it, it's likely made in China. I own a hardware store and have watched over the years as production of GE bulbs has shifted from the US to Mexico to China. It was interesting to note that some of the specialty bulbs (for example, a bulb called Lumiline [servicelighting.com]) had very high defective return rates when produced in Mexico, so GE moved manufacturing back to the US for a while until the bugs were worked out.
Anyway, this transportation cost objection is bogus IMHO. Incandescents weigh slightly less than CFL's, but they take as much "cube" space in container loads so the cost to transport is probably similar to CFL's.
LEDs should last forever but apparently don't (Score:5, Interesting)
I really want to switch to LEDs. I've become disillusioned with CFLs in recent years. The very first two CFLs we ever purchased, in the mid-nineties, -- my wife's reading lamp and the hard-to-reach light in the stairwell -- are still working. But in recent years (since maybe 2002) I've had a remarkable number of failures, often in the first month of use, and I rarely see more than a couple years of service. Oddly enough, I get longer service from the outside lights, which should be the harshest environment. The indoor CFL overhead lights (except for that stairwell light) last about a year. The worst service is from the CFL globe lights over the mirrors in the two bathrooms. I lose about one a month, and recently I've started replacing them with incandescents as they burn out.
I think part of this is due to putting CFLs in environments where they do not thrive -- anywhere you have heavy on/off duty cycles like a bathroom or occasionally used overhead. But I wonder also if CFLs in general haven't become (at least in part) victim to "value engineering", IE, making them as cheap as possible.
But anyway, what worries me about LEDs is that although they *should* give longer life, (50K hours vs 15K for CFL and 1K for incandescents) they apparently don't, judging by the LED array stoplights that have been put in all around the city. It's difficult to find one that doesn't have large parts of the array completely out or blinking madly. Around Christmas I noticed that some of them had been replaced with conventional bulbs. Looking at the technology, LEDs should do better, but it's all about implementation.
Strange... (Score:5, Interesting)
I've been using CFL's since at least 1995, probably a lot earlier. Starting with the big Philips 'jam jar' types which lasted more or less forever - I still have some of the first lamps I bought, now more than 15 years old, they still work - and gradually moving to the more recent folded tube and even more recent incandescent form factor ones I have yet to see any trouble with them. They *just work*, save a *lot* of power and hardly ever burn out.
In other words, I completely fail to grasp the reluctance to change over, leading even to conspiracy theories and pseudo-science arguments against these dependable light sources. They may not be the best choice for all applications but they are a good match for most.
Remember, LEDs last a LONG time (Score:4, Interesting)
Re:LEDs == Frustration (Score:5, Informative)
Actually, I have never found a LED bulb nor any CFLs that with a confortable color spectrum.
Also, most inexpensive CFLs lose their brightness very quickly and need to be replaced far sooner than what the manufacturer would have you believe.
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Re:LEDs == Frustration (Score:4, Informative)
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Re:LEDs == Frustration (Score:4, Insightful)
so using a 14W (75W equivalent) for reading lamps is probably a minimum.
There is one of the big problems with CFL acceptance. I don't know how they rate the lumens, but the human eye doesn't get a 75w incandescent equivalent amount of light in it from a 14w CFL. You need something more like a 27w CFL to match a 75w incandescent. So, when people buy a CFL that is 14W and claims to be a 75w incandescent equivalent, they feel like the CFLs are too dark. Better labeling would go a long way in improving CFLs reputation. Of course, they wouldn't be able to claim as great of energy savings, but 27w is still way less than 75w.
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Re:LEDs == Frustration (Score:4, Informative)
But typically LED-based "white" lighting is a series of discreet spectra between red and blue, rather than a continuous spectra from red to blue; color temperature by itself is not a sufficient metric for comparison.
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Re:CFLs still suck (Score:4, Interesting)
>Or until government regulates incandescent out of existence.
Which many of us hope will not happen. There is no suitable replacement for incandescent in MANY applications. My house has many such.
Flor is generally not dimable. Even those that claim to be really are barely and cost a fortune.
Flor saves NO MONEY when dimmed, even if you can find expensive dimable ones.
Flor bulbs do not fit in all fixtures, especially decorative ones and small ones.
Flor bulbs are UGLY in many types of fixtures, period.
Flor FIXTURES are UGLY in many types of applications.
Flor light is not pleasing to many people- it is too white/blue or harsh.
Flor fixtures often emit lots of RFI.
Flor fixtures often emit noise.
Flor lamps are not instantly on.
Flor lamps are also not instantly 100% bright, many taking MINUTES to reach full brightness.
Until you can address all or most of those issues, there are very valid reasons to prefer incandescent lighting in many situations. I, for one, have replaced about 1/3 of all my lights with flor, but the remaining can't be because of many or all of the above reasons. If anything, tax incandescent lamps to make them cost parity with alternatives, but do not attempt to eliminate MY CHOICE until there is a truly suitable replacement.
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