How long do LED shop/ceiling lights really last at full output anyway?

How long do LED shop/ceiling lights really last at full output anyway?

In another thread, the topic came up that LED lights may not last as long nor as bright as claimed on the package:

Lights of America exaggerated LED light bulb performance

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Since the failure mechanism is electronic as much as it's the fact that LEDs diminish in light output over time, I wondered how long the LED lights (the entire unit, including electronics) really last, and, what "rules" were in place for the claims on the package (since I never get the life that the fluorescent or incandescent bulbs claim either).

As just one (admittedly egregious) example, the bulbs referenced above:

CLAIM: Replaces light output from a 40 Watt bulb (aka 400 lumens) TESTS: The F.T.C. found the bulbs produced only 74 lumens of light

CLAIM: The LED bulbs in question would last 30,000 hours TESTS: They lost 80 percent of their light output after only 1,000 hours

That didn't even cover sudden failure from the electronics.

So, I wonder aloud ... How long do LED shop/ceiling lights really last at full output anyway?

Reply to
Algeria Horan
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Doing some due diligence, I find that there *are* rules in place.

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The Lighting Facts label contains:

  1. a bulb?s brightness,
  2. energy cost,
  3. life,
  4. light appearance,
  5. and wattage

Specifically:

  1. The brightness in average *initial* lumens rounded to the nearest 5
  2. Annual *initial* energy cost at a low 3h/day at an unrealistic 11¢/kWH
  3. Life in years, rounded to 1/10th based on a low usage of only 3h/day
  4. Color in Kelvin ranging from 2,600K on the left to 6,600K on the right
  5. Wattage in average *initial* wattage

Note that, for LEDs, the "initial" specs are almost certainly going to be vastly different than the actual specs over time, so, already, the label has to be taken with a grain of salt.

Also note the highly unrealistic 11¢/kWH (which is essentially unattainable, where I live).

But at least we know what the LEDs are supposed to deliver, initially.

So now we need to figure out what typically happens to these LED light bulbs over time, mostly in terms of light output & when the lifetime brightness cutoff point has been reached.

Reply to
Algeria Horan

Put one in, and leave it on so it runs up the hours, and see when light diminishes.

Most of us haven't had LED bulbs long enough to have any feel for their lives.

I'd also point out that if you read the fine print on the LED bulb packages, the number of years they last is based on a limited number of hours every day. So they may try to make the figures look good, but the actual hours may be okay, if somewhat low. I leave the ceiling light on all day, that will diminish the numver of years the bulb lasts if I look at the stated "number of years".

On the other hand, prices are dropping, I just got a "100W" LED for 7.99 rather than the regular 19.99, and the lower wattage LED bulbs are already going to lower regular prices. And I'm using something like 19Watts (I think actually less) compared to the 100W of an incandescent bulb, so power usage is down.

Michael

Reply to
Michael Black

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Reply to
Scott Lurndal

That's effectively what most of you have done, since many of you have LED lights (I only have one, which I bought from Costco about two months ago, to replace a non-standard bulb ceiling fixture).

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I have the box in my hands. Here's what it says on the box:

Light Output: 1,495 lumens (remember, that's only the *initial* output!) Watts: 21Watts (remember, that's only the initial watts) Lumens per watt: 71.19 (why is this even there?) Color Accuracy: 82 CRI color rendering index (whatever that means) Light Color = 3000K "Bright White" (which isn't white on the scale)

They do reference more information: Web:

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Telephone: 800-787-1021x4

Going to that web site and typing in the model number of "AL-3151" was a wasted effort as they have just the label that is already on the package.

Calling that number was also a waste of time, because the customer support guy said "it lasts more than 5 years because that's the warranty if the driver fails", which is also a stupid answer (they can give me a warranty of

500 years and it still doesn't answer the question).

I pressed for a real answer, and the guy said "50,000 to 60,000 hours", to which I was incredulous. So I simply asked where he got that figure, and he said that's what he says for all questions.

Obviously he was blowing smoke at me, so I asked for someone who actually wasn't gonna just make this stuff up, so he transferred me to his "technical support" guy, whose email is apparently gmijangos at jimway.com so I left him a message to let me know what the *tested* lifetime of the lamp is.

Disgusted, I called the Costco Wholesale number on the package,

800-774-2678, x3, product information, x1 product information and they took down my information and said they'd get back to me on the L70 lifetime.

One thing the operator had handy, which is more smoke blown in our faces, but which she kindly stated it was all she had, which was "LED *chips* last

50,000 hours, 34 years@4 hours/day).

That's not what we're asking, since we know two things: a. The LED chip output diminishes from day 1 b. The driver is the weakest link with respect to lifetime

The problem with *everything* on the planet where there is a choice, is that the MARKETING people only talk about the good stuff (e.g., FWD slides straight in the snow, for a hilarious example), but they don't talk about the BAD STUFF (e.g., weight ratios and working in the engine bay are atrocious for most FWD cars).

So, the problem that I see with the LED marketing is that people are only talking about the good stuff, which is all fine and dandy.

But I'm looking for information on the bad stuff too.

Like the fact that the output decreases the moment you plug it in,

Apparently, it's based on 4 hours per day, based on what I wrote above.

I'm not sure why the total number of hours would be different if you use the light for 4 hours a day or for 24 hours a day, but apparently it is.

On the bulbs you just bought, what's the L70 time period?

Reply to
Algeria Horan

Thanks for that url. Here's a relevant set of snippets from:

Understanding the Cause of Fading in High-Brightness LEDs By Steven Keeping Contributed By Electronic Products, 2012-02-21

LED failure? is most likely to be the result of light output falling below an acceptable threshold (typically 70 percent of the initial output.

The primary cause of that fading (or ?lumen failure?) is triggered (for the most part) by the minute threading dislocations introduced to the chip during wafer manufacture.

Threading dislocations are a major problem...where threading dislocations are vertical micro-cracks caused by strain generated by the mismatch in InGaN and Sapphire or SiC crystal lattices .. and where ... things get worse over time, as the rate of degradation is directly related to the initial density of threading dislocations and the heat to which the LED is subjected ... all of which gets worse ... due to heating during operation, thermal expansion and shrinkage when the LED is turned on and off, and mechanical stress such as vibration.

Worse yet ... as the chip ages, it will run hotter and hotter ... due to an increased number of phonons, accelerating the formation of dislocations and the device?s eventual demise.

------------------- So now we know what kills LEDs to the 70% level (which is the formal definition of dead), which is that inherent cracks between crystals form over time, just as mud cracks as it dries at the bottom of a pond.

The fundamental problem is cracks between crystals only gets worse. b. Heat makes things worse even faster c. On/off cycles makes things worse even faster d. Vibration makes things worse even faster

So, given they don't heat/vibrate/cycle the LEDS (other than the 4 hours per day), you'll likely never get the advertised L70 lifetime in the real world.

But what do you get for a 70%-illumination lifetime in the real world?

Reply to
Algeria Horan

I forgot to mention that none of what kills the LED over time discusses the frail electronics, which also fail.

So, we need to know how long the "LED drivers" last too.

The life of the fixture is the shorter of the two failure modes: a. Inherent cracks between crystals get exponentially worse over time b. The drivers suddenly fail at any time

So, we still don't have any decent grasp on how long LED fixtures last, in the real world.

Reply to
Algeria Horan

Dunno. Your real world LED application is not the same as my real world LED application and the science fiction world of marketing tech products.

Perhaps you might be interested in "lumen depreciation", L90, L80, L70, TM-21, LM-80, LM-40, etc. There are some interesting methods of calculating LED life such as: "Reported TM-21 values have an upper limit of 6-times the number of LM-80 test hours. So if an LED chip is tested for 6,000 hours, its max reported TM-21 lifetime would be 36,000 hours. If the chip was tested for 10,000 hours, its max reported TM-21 would be 60,000 hours." Magic is a reallly nice way to produce bigger numbers.

One can also be devious: "It?s worth noting that there are two different types of TM-21 ratings, "reported" and "calculated" ratings." Sigh...

Few run 30,000 hr tests. At 8,760 hrs/year, it would take over three years to run the test, by which time the product is obsolete and replaced by something new and improved. Instead, they run a HALT (Highly Accelerated Life Test), which is faster, and presumably produces the necessary inflated figures: The basic idea is to test the LED at various elevated temperatures, connect the dots on a graph, and extrapolate to how long it might last at some specified operating temperature. At 25C it will last nearly forever, which assumes that the LED has some form of cooling system. One can generate amazingly large and impressive numbers this way. Despite my derisive comments, it does work quite well when performed honestly and where the test parameters are sane.

For example, IEC 62717 and IEC 62722 LED life testing standards both demand 6,000 hrs of test time, with total output in lumens recorded every 1,000 hrs. Measuring lumens accurately requires an integrating sphere: which might explain why they don't just use a common light meter and why there are so few measurement points. Some detail on how Luxo specifies its lifetimes: I doubt if we will ever see detailed life test results from Costco LED's as you might from higher priced LED luminaires.

Reply to
Jeff Liebermann

They were probably using the US Total All Sectors figure from this page:

Reply to
Neill Massello

Thanks for finding that.

Oh, to live in Louisiana, at less than 10¢/kWH.

California is listed at double that, at 19¢/kWH, but even that must be some kind of wacko average as we pay a tiered system, where, in practice, the first tier is used up in the first week of the month, the second tier by the third week, and the next tier for the end of the month.

It goes up precipitously with each tier, and the tiers are the same for everyone, so they do NOT take into account anything specific like the number of bedrooms or bathrooms or square feet or even the number of people.

Reply to
Algeria Horan

Yikes Jeff!

You would bring up *more* complex LED-lifetime terms to figure out!

And, you would also find MARKETING BULLSHIT in the mix!

LM-80 = a standard for measuring LED lumen maintenance & depreciation LM-40 = time for 50% of the lamps in a large group to burn out L70 = time to degrade to 70% of its original lumens L80 = time to degrade to 80% of its original lumens L90 = time to degrade to 90% of its original lumens Reported TM-21 = predicts lifetime using LM80 + optimistic magic math Calculated TM-21 = predicts lifetime using LM80 + more optimistic magic math

Hence the "magic math" on the lifetime figures...

Seems to me that the "LED lifetime" figure everyone is quoting in this thread and in other threads is total bullshit, so far...

Well, I was sick of replacing very expensive non-standard Philips fluorescent bulbs, so I bought the LED light fixture from Costco just to get rid of the non-standard wacko shaped bulbs that kept burning out anyway.

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I asked Costco and the manufacturer to provide the information on the lifetime of the LED light that I did buy.

I didn't get anything more than "hey, the warranty is 5 years so that's how long it lasts".

What irks me is that they seem to never have run into someone who doesn't accept that bs as an "answer" to the question of how long the light fixture is expected to last.

I'm guessing the LED light fixture I bought lasts no longer than a couple sets of incandescent bulbs would have.

Time will tell.

Reply to
Algeria Horan

root,

Believe it or not, the tests are designed to reflect real world usage.

You keep implying that there is something wrong with all advertised LED bulb lifetimes. Then you tell us you need to Google search to find out if that's true.

...

Jeff,

Actually, 3 years wouldn't be useful for anything but the decidedly "not realworld" test case of continuous use.

It would take considerably more than 3 years to test the common on at night, off during the day test case.

You could have left the word "inflated" out of that sentence. It's an insult to the rather clever testing that you described.

... snipped test description.

Reply to
Dan Espen

Read the full report Appendix C. Then come back and tell us how unrealistic their numbers are.

Reply to
Dan Espen

On Tue, 1 Nov 2016 02:38:44 +0000 (UTC), Algeria Horan wrote in

Cali has a billing system designed to obfuscate the cost of electric power. The easiest way around that is to take the $tot$Amt of the bill and divide it by the total number of kwhs used. For about 99% of residences it will come out around $0.26/kwh.

Reply to
CRNG

Real world seems to *always* be less than advertised lifetime. At least for me they seem to be.

I'd be pleasantly surprised if LED bulbs last 5 years.

What fails? a. The electronics! b. The bulbs.

We know the manufacturers lie, or, more accurately, the MARKETING people, who make the labels, say only what they want you to think.

For example, they'll tell you an LED itself lasts 50,000 hours, but they won't tell you the "driver" lasts anywhere from zero to a couple of years.

The one thing about Jeff is that he's shown himself over the past decade to be a well-balanced person who is not swayed, like most people are, by exaggerated claims, whether they be any claim by Apple for their WiFi reception, or a bogus claim by LED manufacturers (such as the ones I received on the phone yesterday) as to lifetime.

He'll deny this though, as he doesn't like accolades, but he is always on the money, and, he almost always provides *proof*, something which you need to provide also in order for us to believe your claims (I'm not saying you didn't or don't provide proof - I'm just saying that Jeff almost always does

- so what he says carries weight).

Also, Jeff runs his own *tests* of tons of things, which are tests that most of us have never run, they're that detailed (ask him about router claims versus the real world some day!).

Jeff is like I am. We prove what we say, and we provide references, and photos and other reliable statistics. You'd need to do the same to hold water with us.

Anyway, fact is, I have a bulb, in my very hand, incandescent, that failed in two days.

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Notice the package says "1.4 year life".

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Reply to
Algeria Horan

See Appendix C as I stated in my other post. Then tell me how your methods are so superior to those used by the experts.

Do you honestly think that proves anything?

I have 3 CFLs in a lamp post since 2000. Just this year, one of them gave up the ghost. They are activated when it gets dark. So, they're on at least 12 hours a day, every day. Construct some statistics out of that.

Reply to
Dan Espen

I can assure you, we replaced incandescent floodlights back in 2010 with LEDs in one of our buildings. These lights are on 8 to 10 hours a day, if not longer and we've yet to replace any of them (over 50).

I understand your skepticism as a general consumer, but I've been experiencing the products first hand. I've been dealing with LEDs for many years and I agree, they do diminish in brightness after their manufactured rating, the quality lamps last up to their claim if not longer. Of course, we don't purchase the cheap ones you buy at Home Depot.

Reply to
Meanie

Dan, You come across as challenging the facts, but, you provide few facts on your own. It's easy to challenge, but it takes effort to back up your challenge.

I read my electricity bill. Those are "my" facts.

I don't even have to show you my bill. I'll simply point you to the PG&E Tiered Plan that I'm on:

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Do you see *anything* anywhere near 10 cents? Anything?

Look again:

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The first tier (which lasts about a week) is almost double that. The next tier is almost triple. And the fourth tier, the one that you use for the second half of the month, or the last week, if you're frugal, is almost quadruple that.

Those are facts. Do you dispute the facts?

What facts do you have for my rate that dispute that?

Reply to
Algeria Horan

I understand your point, which is that I can say it lasted 10,000 years. If I could prove it completely, and if it was worth the effort, I would, just like Jeff *proved* that WiFi reception in routers was NOT what the manufacturers claimed.

But you are like those people who say "prove it" to everything, which is fine, but *you* have to provide some semblance of a reason to go to the effort to prove things that we just have to accept on faith.

I was backing up your unproven claim that Jeff was not being balanced, in effect, when I know, from the last decade on s.e.r and a.i.w that Jeff "is" well balanced, and he proves what is worth proving.

You entirely and completely missed the point. Did you buy too many arguments this week?

All I was saying is that your claim against Jeff's veracity are completely unfounded. You're entitled to your opinion, but if I asked you to prove that you had sex with your wife five times this week, do I really expect you to prove that?

What I'm saying is simply that your criticism of Jeff was unfounded, if you look at the entire record. And, I'm saying that 11 cents per kilowatt hour is a magical number entirely unachievable by me, in California.

If you claim otherwise, I'm only asking you to attempt to back up your very own claims with fact, as I did with Jeff, and as I did with the price of electricity in California.

Reply to
Algeria Horan

That is the reason they last so long. What people don't realize is the life of fluorescent, whether tubes or CFL, is shortened when they are subject to constant on and off. They are not made for constant on/off action unless the fixture contains a "program start" ballast. Due to the cost of that ballast, they will not be within the common hardware store fixture. When fluorescent lamps remain on all day, chances are you can see 10 years on them. The average home will not see that life cycle since it's not common to leave them on all day everyday.

Reply to
Meanie

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