# Propose an LED based general lighting



## Curt (Sep 16, 2007)

I have been doing a lot of led swaps for fluorescent lighting at a local university.. So far though it has been for exit signs and some hallway lights with a few outside walkway lights thrown in.. The main advantage for them has been lower operating cost and far less maintenance and upkeep by their crew.. Exit signs have been a constant repair issue.. Since we installed the led retrofit kits in the exit signs about a year ago the repair time for these lights have been zero.. Their hallways had mr16 bulbs above all the dorm doors.. These went out regularly due to the doors vibrating the lights when closing.. We changed to led mr16 and so far have had no failures in six months.. They do have their purpose even though their cost is higher.. At least their maintenance costs have dropped due to these lights.. Another factor to consider might be heat.. Multiply the bulbs by its heat output and ac costs would drop.. As with a mr16 replacement.. Take a look at the new led flashlights if you are in doubt about light output.. They now have 2 and 5 watt bulbs that beat any other flashlight out and battery life is far greater.. Just can't comment on cost as that isn't my end..


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## B4T (Feb 10, 2009)

I think LED's are still being developed and I would not install a light fixture using them.

IMO if customer hates the light output, your screwed unless they supplied the fixture


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## mikeh32 (Feb 16, 2009)

once they are able to convert the led 1/3w technology into home use i see it going much larger. right now its too much money. 

I do a lot of LED work for cars like you said, just nothing in homes


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## Curt (Sep 16, 2007)

Check out the halo retrofit led lights.. Google has a good pdf for download.. Tried to put it here but was too big.. These are here now and will become more popular as time goes on.. I have done these too and are a breeze to install and color is whatever you want.. These are 3000k temp with cri over 80.. As far as cost is concerned they make the comparison in their brochure..


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## Electric_Light (Apr 6, 2010)

Curt said:


> I have been doing a lot of led swaps for fluorescent lighting at a local university.. So far though it has been for exit signs


I don't disagree with you there that LEDs have specialty application, particularly colored lights, like signs. This isn't even remotely close to "general lighting" though. 



> and some hallway lights with a few outside walkway lights thrown in.. The main advantage for them has been lower operating cost and far less maintenance and upkeep by their crew.. Exit signs have been a constant repair issue.. Since we installed the led retrofit kits in the exit signs about a year ago the repair time for these lights have been zero.. Their hallways had mr16 bulbs above all the dorm doors.. These went out regularly due to the doors vibrating the lights when closing.. We changed to led mr16 and so far have had no failures in six months..


I suppose MR16 could be used as general lighting in residential, but they're usually used for accent lighting, art lighting and not as general illumination. 



> They do have their purpose even though their cost is higher.. At least their maintenance costs have dropped due to these lights..
> Another factor to consider might be heat.. Multiply the bulbs by its heat output and ac costs would drop.. As with a mr16 replacement..


You're comparing against incandescent lights. I have no doubt they can meet or exceed the efficacy of incandescent lamps. Compared to fluorescent, LED systems don't quite have the system efficacy of fluorescent.

Remember, wattage maybe lower, but if it's not providing a comparable output, its not really a fair comparison. Half the light output and half the heat output is nothing to call home about. Light output should be not what you get immediately after you turn on, but after its been allowed to heat up to operating temperature and energy consumption should be what goes into the power supply, not what power supply feed the lamps. 



> Take a look at the new led flashlights if you are in doubt about light output.. They now have 2 and 5 watt bulbs that beat any other flashlight out and battery life is far greater.. Just can't comment on cost as that isn't my end..


LEDs are efficacious in the low single figure wattage range, put the plateau is reached quickly. They don't really gain anything by scaling up. If you can get 50lm/W at 1W, that's amazing. If you get 65lm/W at 32W, that's unacceptable. 

A 1W fluorescent or incandescent would have horribly low lm/W and MH can't be made to work at such a low power. 

Using 48" lamps, linear fluorescent systems can reach around 100 lm/W

http://www.standardpro.com/sheets/pdf/07_167_LED_MR16_En_LR_web.pdf 15.7 lm/W for warm white. That's about as good as a naked 100W A19 lamp. With a incandescent lamp, reflector would have to be rigged, so it would win over them, but a CFL would surpass them. 

http://www.goled.com/T8Spec2.pdf
"comparable to 2,400 lm". This is what I call fluffing. It either puts out 2,400 lm or it doesn't. 

http://assets.sylvania.com/assets/documents/RETRO019.f3798a4b-4cc0-47ef-addb-525622a58c99.pdf
Osram-Sylvania makes quite a few too. 
The efficacy is around 50lm/W, again pretty bad. 
The MR16 is rated at 35,000 hours to 70% output. So, beats CFLs, but linear fluorescent lamps are available in 40,000+ hrs with 90+% maintenance. You can't buy close to 3,000 lumens in LED lamps for $5 _AND_ have them all be covered under warranty for 3 years.


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## Bob Badger (Apr 19, 2009)

We did this large supermarket that is 100% LED. You cannot tell ... or at least the average person can't.

http://vmsd.com/content/star-market-chestnut-hill-mass


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## Electric_Light (Apr 6, 2010)

Bob Badger said:


> We did this large supermarket that is 100% LED. You cannot tell ... or at least the average person can't.
> 
> http://vmsd.com/content/star-market-chestnut-hill-mass


50% reduction in consumption relative to what? 

Does it provide the same luminance throughout the area compared to the previous setup? If the luminance is lower, then you can create the same reduction using a fluorescent system using low output ballasts with energy saving lamps and achieve the same using the same or less energy compared to the LED setup at significantly lower cost.

Then finally, and most importantly, lets talk about COST compared to going with the latest fluorescent setup.


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## Bob Badger (Apr 19, 2009)

Electric_Light said:


> 50% reduction in consumption relative to what?


Relative to other stores in the same chain that use HIDs and fluorescents I also suspect some media fluffing going on. 



> Does it provide the same luminance throughout the area compared to the previous setup?


This a new store, there was no previous set up. 



> If the luminance is lower,


The store is bright.




> then you can create the same reduction using a fluorescent system using low output ballasts with energy saving lamps and achieve the same using the same or less energy compared to the LED setup at significantly lower cost.


They have already been doing those things for years. Electrical costs are a major part of supermarkets expenses.


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## Electric_Light (Apr 6, 2010)

Bob Badger said:


> Relative to other stores in the same chain that us HIDs and fluorescents.


They could still be magnetic ballasts with cool white lamps. There's a drastic efficacy difference in the latest fluorescent system vs the old system. So, 50% reduction compared to a legacy fluorescent setup along with a "not noticeable, but measurable" reduction in luminance is nothing special. 

LED people tend to reference their best LEDs available against 1960s fluorescent system rather than the best available fluorescent. 




> The store is bright.


Maybe so, but unless the system is using less energy than what it takes to provide the same level of luminance using the state of art fluorescent system, then there is no saving. It could actually even have twice the efficacy and it would still take quite a few years to recoup the cost difference. (well, unless that cost difference is allocated to marketing & advertisement expense for bragging and publicity purpose) 



> They have already been doing those things for years. Electrical costs are a major part of supermarkets expenses.


Yep, it is, but I'm not convinced that LED system is more efficacious compared against the top of the line fluorescent system and even less convinced that they provide lower cost of ownership.


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## Bob Badger (Apr 19, 2009)

Electric_Light said:


> They could still be magnetic ballasts with cool white lamps.


No. T-8s or T-5s with electronic, most chains have already retrofitted the old T-12s




> LED people tend to reference their best LEDs available against 1960s fluorescent system rather than the best available fluorescent.


That is not the case here. 



> Yep, it is, but I'm not convinced that LED system is more efficacious compared against the top of the line fluorescent system and even less convinced that they provide lower cost of ownership.


Modern electronic fluorescent ballasts fail at incredibly high rates, figure that into your thoughts as well.

Push this ahead to the 3:40 to see the store.


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## Electric_Light (Apr 6, 2010)

Bob Badger said:


> Modern electronic fluorescent ballasts fail at incredibly high rates, figure that into your thoughts as well.


Figure that an LED system have switching power supplies too, just like fluorescent ballasts and computers. Just what's an "incredibly high failure rate" and why do you feel that LED power supplies are somehow less susceptible to failure than computer and fluorescent electronic power supplies? 

A 2000 case study on 4,000 lamps found "90%+ system survived" after ~37,000 hrs of use. 
http://www.nam.lighting.philips.com/us/ecatalog/casestudies/p-5472.pdf

An older study found ballast failure rate as low as 0.5% to 1% in a sample size of at least 4,000. They did report that dimming type had a high failure rate of 6+% but then, that was 18 years ago when dimming ballasts were not quite refined. 
http://www.lrc.rpi.edu/programs/NLPIP/PDF/VIEW/SREB2.pdf



> Push this ahead to the 3:40 to see the store.


I did. Video cameras & cameras have an automatic aperture adjustment, so if the lighting level was 10% higher, or 10% lower, its automatic exposure compensation would adjust for proper exposure. What a nightmare it would be using one if they didn't have it!

Long life T8 lamps are rated around 46,000 hrs(to 50% failure) @ 12 hrs a day use on PRS ballast, which is the type for dimming ballast and output loss is only 6%. If the LED system is 50,000 hours to 70% output, remember that more power increase is necessary over the lifetime compared to T8 FL system to maintain the same output. 
If it's running 10kW now on dimmed setting, it would have to be gradually raised to 14kW by end of life to to maintain the same output at 70% maintenance, so if the system is designed to provide design luminance until end of life, they'll just start off dimmed, then gradually raised up over time to offset the reduction in lamp performance. 

On a T8 system, the increase from 10kW to maintain the same output is around 10.6kW near the end of life.


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## Bob Badger (Apr 19, 2009)

Electric_Light said:


> A 2000 case study on 4,000 lamps found "90%+ system survived" after ~37,000 hrs of use.
> http://www.nam.lighting.philips.com/us/ecatalog/casestudies/p-5472.pdf
> 
> An older study found ballast failure rate as low as 0.5% to 1% in a sample size of at least 4,000. They did report that dimming type had a high failure rate of 6+% but then, that was 18 years ago when dimming ballasts were not quite refined.



You are not seriously trying to tell me that electronic ballasts do not have high failure rates are you?

Because if you are your creditability is shot.



> Figure that an LED system have switching power supplies too, just like fluorescent ballasts and computers. Just what's an "incredibly high failure rate" and why do you feel that LED power supplies are somehow less susceptible to failure than computer and fluorescent electronic power supplies?


I don't know that LED drivers will do well, I do know electronic ballasts do poorly and I am willing to wait and see how the LED drivers do. 

I do not see computer power supplies failing at anywhere near the rate of T-8 T-5 ballasts.


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## Bob Badger (Apr 19, 2009)

Electric_Light said:


> I did. Video cameras & cameras have an automatic aperture adjustment, so if the lighting level was 10% higher, or 10% lower, its automatic exposure compensation would adjust for proper exposure. .


No kidding? A modern marvel.

I have been in the store, it is bright, but of course my eyes have automatic aperture adjustment as well.

I bet the up front costs where much higher, but if that is outweighed by reduced maintenance remains to be determined.


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## electricmanscott (Feb 11, 2010)

That store looks great Bob. Nice to see an example of mainstream LED finally becoming reality. Next time I'm in that area I'm going to go in and check it out. Do those snooty bastards require you to show a W2 before you come in?

I think you will not succeed in convincing somebody of the benefits when they start out with and already made up mind.


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## Bob Badger (Apr 19, 2009)

electricmanscott said:


> Do those snooty bastards require you to show a W2 before you come in?


:laughing:

No comment. 




> I think you will not succeed in convincing somebody of the benefits when they start out with and already made up mind.


I really do not know if LEDs will be the next big success or not but I do know if people do not try new things we will not get anywhere. T-8s and T-5s where new technology at some point people had to make the gamble and try them out as well.


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## B4T (Feb 10, 2009)

I was in a PVC fence showroom on Saturday that had (10) 8' 4 lamp T-8 fixtures installed last year.

Lights were installed in (2) rows with romex connectors used as nipples to connect fixtures.

Then the guy ran 14/3 through the fixture, but first stripped off the outer sheath, to alternate the switching 

I had to change all the ballasts in one row, they all failed... WTF??


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## Electric_Light (Apr 6, 2010)

Bob Badger said:


> No kidding? A modern marvel.
> 
> I have been in the store, *it is bright*, but of course my eyes have automatic aperture adjustment as well.


As are Wal-Mart store. They are lit by T8 system. You can't claim an LED system that puts out 10% less measured output(whatever the exact benchmark was in your case...) and claim 10% energy saving was realized just like you can't claim the same with fluorescent system that was dimmed down 10% after you left, because you didn't "notice the difference" the very next day. 



> I bet the up front costs where much higher, but if that is outweighed by reduced maintenance remains to be determined.


Warranty picks up new ballasts and labor on fluorescent system for the first five years or so, therefore, that cost can't be included in "maintenance expense" from operations point of view. Warranty picks up the lamp for two or three years(but not labor). So, unless the lamp replacement cost on fluorescent system exceeds the initial cost difference in first 3-5 years, then you're screwed. 





Bob Badger said:


> You are not seriously trying to tell me that electronic ballasts do not have high failure rates are you?
> 
> Because if you are your creditability is shot.


Perceived failure rate and real failure rate are different things. If you've got thousands of them in operation with some units starting to hit end of useful life and you starting finding one failing after another, it might "feel" like they're failing at a high rate, but this isn't objective. 



> I don't know that LED drivers will do well, I do know electronic ballasts do poorly and I am willing to wait and see how the LED drivers do.
> 
> I do not see computer power supplies failing at anywhere near the rate of T-8 T-5 ballasts.


Where do you see hundreds of computer power supplies used in same facility to allow you to determine failure rate in a large sample other than call centers? They also live an easier life, because they run cooler thanks to fan cooling. They don't live inside luminaires running at 170F all day long.


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## Bob Badger (Apr 19, 2009)

Electric_Light said:


> As are Wal-Mart store. They are lit by T8 system. You can't claim an LED system that puts out 10% less measured output(whatever the exact benchmark was in your case...) and claim 10% energy saving was realized just like you can't claim the same with fluorescent system that was dimmed down 10% after you left, because you didn't "notice the difference" the very next day.


I spend most of my time in facilities lit by T8s and 5s, I really have no issue with those lamps only the ballasts.

Floresents dim as they age so I guess I am missing your point.




> Warranty picks up new ballasts and labor on fluorescent system for the first five years or so, therefore, that cost can't be included in "maintenance expense" from operations point of view.


Where do you live? On Pluto?

Do you have any idea what the real chances of me being able to get labor covered in the first year never mind the forth year. 






> Perceived failure rate and real failure rate are different things. If you've got thousands of them in operation with some units starting to hit end of useful life and you starting finding one failing after another, it might "feel" like they're failing at a high rate, but this isn't objective.


Buddy the real failure rate of electronic ballasts greatly exceeds that of any of the old magnetic.

Where is you experience coming from. It sure sounds to me like you live in an office and believe all that you read with no real hands on experience.





> Where do you see hundreds of computer power supplies used in same facility to allow you to determine failure rate in a large sample other than call centers?


Fidelity Investments, Call centers, Data rooms, Monster.com I could go on for a very long time.




> They also live an easier life, because they run cooler thanks to fan cooling. They don't live inside luminaires running at 170F all day long.


So basically we all should just deal with the failure rate because they live a hard life. 


Lets get down to it.

Who do you work for?

What is your beef?


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## jwjrw (Jan 14, 2010)

I have replaced at least half of all the electronic ballasts I've put in within the first year at my cost (warranty).

I believe led technology will surpass t-5 and t-8 sooner rather than later.
I just added A LED "bullet" to my web site with an explanation of what they are and where I feel they work well at this time. Will the drivers last???I don't know. I doubt they will be as bad as the t-8's.

And B4T all you have to do is send your customer to the lighting showroom you deal with, then let them decide if leds put out enough 
light for them. You buy them mark them up they have to live with them.


I've never seen a t-8 bulb last anywhere near what they claim they do. Are the LED manufactures lying also? Don't know but I am willing to let time tell as I usally install regular cans on my jobs. But if a customer goes to my web site they will see I am trying to embrase "green" technology whether I agree with that crap or not.


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## Electric_Light (Apr 6, 2010)

> And B4T all you have to do is send your customer to the lighting showroom you deal with, then let them decide if leds put out enough
> light for them. You buy them mark them up they have to live with them.


Like you said, "embracing" something for making the sale is different from actually believing in it. This is no different from a car salesman selling a car from offering a test drive and persuade them on just that first impression. 

LEDs *CAN* make the same output as fluorescent just like incandescent lamps. Can they do that using lesser power? Obviously no for incandescent. 




> I've never seen a t-8 bulb last anywhere near what they claim they do.


So, a case study showing 90% survival after ~37,000 hrs on a sample size of 4,000 lamps isn't good enough? Unless they're lying, I think that's a decent sized sample. 

It also remains unknown that the aforementioned supermarket's LED system is actually more efficacious than a fluorescent setup making the same measured output.



> Buddy the real failure rate of electronic ballasts greatly exceeds that of any of the old magnetic.


We're comparing electronic LED vs electronic FL. The RPI study also shows that the failure rate was higher for electronic ballasts than magnetic. Well, I don't know about you, but I just don't have three Super Wal-Marts with 4,000 lamp setup thats been around for three years to be able to provide first hand experience on, so I had to rely on external resource for that. If you have first hand hard data on failure rate (as opposed to "high") on such large installs thats been in use, then please share.

Anyways, the criteria in the first post are mandatory. Does that supermarket one meet ALL of them? 
Relative to what can be accomplished using fluorescent system...

Shall provide a comparable output, as measured. No "scotopic" and subjective fluffing allowed
Shall have a comparable of better efficacy and CRI
Shall have a similar cost and payback period





Bob Badger said:


> I spend most of my time in facilities lit by T8s and 5s, I really have no issue with those lamps only the ballasts.
> 
> Floresents dim as they age so I guess I am missing your point.


Wal-Mart was quoted as "over 90% of *lights* were functional after ~37,000 hrs" as opposed to "lamps". This can be open to interpretation, but I imagine by "lights" they mean the entire fixture including the lamps. Yes, it's *possible* that failed ballasts were changed out, original lamps put back in and not counted toward failure... 

As for dimming, I meant that it is not a balanced comparison to claim xx % energy saving when there's no objective measure of light output. Say I manually dim down fluorescent lighting by 10% using the dimming control after employees leave. Even if nobody notice it the next day, I can't claim the energy was saved due to improved efficacy. So, if the LEDs are not putting out exactly the same measured output as whatever fluorescent system that it was compared to, the use of LEDs over fluorescent can't given credit for making the 50% energy saving. The way it was presented, it seemed like LED technology was given credit for reduction in power. 

"well its bright" sounds like "output is lower, but nobody noticed" 

Power reduction through output reduction is a technique that is used. The F32T8/25W is an example of such. They fit into existing fixtures. Power consumption reduction is credited to reduced output, not the new "innovative highly efficient bulbs". 



> Buddy the real failure rate of electronic ballasts greatly exceeds that of any of the old magnetic.
> 
> Where is you experience coming from. It sure sounds to me like you live in an office and believe all that you read with no real hands on experience.


I don't just happen to have first hand experience with three sets of 2,000 ballasts in operation for two years at Super Wal-Mart stores to provide data from, so I had to rely on external resources. If you happen to have first hand hard data(i.e. 2,000 units installed in Dec 2003 and failure rate of 5.3% of original units as of Dec 2008) on large installations like that, please share. I'm interested.


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## Curt (Sep 16, 2007)

At the university we have racks set up because we have to burn in the fluorescent bulbs for 100 hours at full brightness as per manufacturers specs or they will will fail prematurely when dimming.. Regarding bulb life.. Companies here make a living out of changing tubes once a year because of loss of light and failure.. We also replace a ton of the new electronic ballasts on the sconce lights here.. Also rated life is quoted at 10000 hrs for the pl series lights.. I think 37000 hours is just advertising hype not really attainable in the real world.. Would like to see the lumen output of any of those long life bulbs and also the cost per bulb.. The university here would jump at the idea anything would be so reliable having tried just about everything here to lower costs.. I still believe down the road maintenance costs are critical as well as heat output.. Leds will be the future because they are easily dimmable, produce less heat and you get full brightness on startup unlike most smaller residential bulbs..


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## bobbyho (Oct 15, 2007)

Not to mention that they can be thrown out. The cfl's are being jammed down the throats of the public and they are not aware of the downsides. The mercury in these fixtures will be a problem in the ground water at some point. I am confident the LED will easily replace the cfl in the not too distant future. I certainly hope so because the average Joe tossing these cfls away without regard to the hazardous ramifications will do a lot of damage. I have young kids and the potential hazard in our well water is something I do think about.


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## Bob Badger (Apr 19, 2009)

Electric_Light said:


> Like you said, "embracing" something for making the sale is different from actually believing in it. This is no different from a car salesman selling a car from offering a test drive and persuade them on just that first impression.
> 
> LEDs *CAN* make the same output as fluorescent just like incandescent lamps. Can they do that using lesser power? Obviously no for incandescent.
> 
> ...


So you are not going to come clean and tell us which ballast manufacturer you work for?

You think a failure rate of 5.3% is a good thing?

That crap costs ECs money.


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## s.kelly (Mar 20, 2009)

bobbyho said:


> Not to mention that they can be thrown out. The cfl's are being jammed down the throats of the public and they are not aware of the downsides. The mercury in these fixtures will be a problem in the ground water at some point. I am confident the LED will easily replace the cfl in the not too distant future. I certainly hope so because the average Joe tossing these cfls away without regard to the hazardous ramifications will do a lot of damage. I have young kids and the potential hazard in our well water is something I do think about.


I have not figured out why the public is suddenly so worrried about mercury. How many times have you seen 4' or 8' tubes tossed in the past? How about the mercury put out by coal fired power plants. 

Sure it is an issue, but there are other sources of mercury that everyone forgets about. I think resistance to change is an issue here more than anything.

And if we are going to talk about groundwater pollutuion, how about the circutry on LED's. Heavy metals and plastics. They are not good for groundwater either. 

All that said, I am all in favor of lighting technology. I had a cfl in the 80's before anyone had heard of them. Though most of the Chinese mfg CFL's today are crap and do not last. I think LED's will be the wave of the future, but certainly need some work, particularly on cost per lumen.


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## Electric_Light (Apr 6, 2010)

Curt said:


> At the university we have racks set up because we have to burn in the fluorescent bulbs for 100 hours at full brightness as per manufacturers specs or they will will fail prematurely when dimming..


Does Lutron still prescribe that? In either case, I don't see the point of the rack. Why not just burn them four days straight in fixtures with dimming set to 100% manual override? 



> Regarding bulb life.. Companies here make a living out of changing tubes once a year because of loss of light and failure.. We also replace a ton of the new electronic ballasts on the sconce lights here.. Also rated life is quoted at 10000 hrs for the pl series lights..


What exactly are "PL" lamps? There are a few. If you mean the Phillips PL-C or PL-L, then 10,000 is about right. Osram-Sylvania Dulux D (CFxxDD) are 12,000 @ 3 hrs and 20,000 @ 12hrs and this is assuming operation using programmed start ballast. If they're burning 24/7 and you're expecting near zero failures, then annual replacement is about right. 

rated life in industry means(for both fluorescent and incandescent) average life for 50% failure to occur in a large sample, so scheduled re-lamping at 50-60% is necessary unless spot replacements are acceptable. 
http://www.gelighting.com/eu/resources/firstlight/module05/07.html

Most of light loss occurs in first 5-10% of use in T8 & T5, but only loses 5-6% over the entire useful life, unlike 30% or so for LEDs, HIDs, some CFLs and older fluorescent lamps. 



> I think 37000 hours is just advertising hype not really attainable in the real world.. Would like to see the lumen output of any of those long life bulbs and also the cost per bulb.. The university here would jump at the idea anything would be so reliable having tried just about everything here to lower costs.. I still believe down the road maintenance costs are critical as well as heat output.. Leds will be the future because they are easily dimmable, produce less heat and you get full brightness on startup unlike most smaller residential bulbs..


Well, it seems like the benchmark for fluorescent technology has shifted towards expectations for CFLs in this discussion. Linear lamps are cheaper and have favorable life and cost, so they're common for general lighting. 

I'm not aware of CFLs rated over 20,000. 

Philips special extended life is rated at 36,000(3hr cycle) to 40,000(12hr cycle) to 50% failure on instant start. raised to 40,000/46,000 on programmed start. The case study was based on linear lamp that are hardly ever cycled (24/7 super Wal-Mart)



Bob Badger said:


> You think a failure rate of 5.3% is a good thing?


The 5.3% was just tossed up there as an example of "hard data" I'm looking for, not anything real. Please share your failure rate, the duration in use, and sample size. Don't tell me just "high".


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## Lighting Retro (Aug 1, 2009)

interesting stuff here, but it does appear the OP has an axe to grind with LED. 

I personally do not pitch LED for Fluorescent tube replacements because the return is not there. At $50-$100 a lamp, the wattage difference is not significant enough to make the payback worthwhile. 

YET

It is predicted that with the advancements in LED technology, that the upper limits of LED performance will be in the 400-500 lm/watt range. That will change the game, especially when you factor in no mercury. it's a bit early yet for tube replacements, but I would not doubt it's there in a year or two. 

Until then, it is correctly stated that T8 technology can now last 40,000 plus hours using the Extra Long Life products, etc. We only buy the Cadillac of lamps, so we do not experience the failures that some here have mentioned. As a matter of fact, it is VERY rare for us to ever see a ballast fail within 3 years. We buy the good stuff though, and I don't know if those that dislike the product are buying the cheapest thing off the shelf or not. 

I can tell you that electronic ballasts do not handle dirty power as well as magnetic ballasts, so if you are in a poor grid area, the electronics will be more likely to fail. That's a bummer, but it is what it is. 

In short, LED is coming, but not there from a payback perspective for us YET. Those using LED tubes are on the bleeding edge. I like to wait until it's cutting edge.


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## jwjrw (Jan 14, 2010)

Lighting Retro said:


> interesting stuff here, but it does appear the OP has an axe to grind with LED.
> 
> I personally do not pitch LED for Fluorescent tube replacements because the return is not there. At $50-$100 a lamp, the wattage difference is not significant enough to make the payback worthwhile.
> 
> ...


 

Ive put in lithonia, sylvania, and cooper t-8 fixtures. Within a year we replaced at least half of the t-8 electronic ballasts. I say they suck. There were 32 lay ins in each upfit. 25 upfits. After 6 months they started to fail. Went back last week and changed 2 more out.


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## Lighting Retro (Aug 1, 2009)

That would tick me off too, but the problem lies in the quality of the power, not the product unfortunately. Guarantee if you put the correct material on at the panel to clean up the power, those problems would go away. Magnetic ballasts are better at handling dirty power, so it can give a false impression it's a better product.


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## Electric_Light (Apr 6, 2010)

Lighting Retro said:


> interesting stuff here, but it does appear the OP has an axe to grind with LED.


*I have no problem with LEDs. Yes, I do have an axe to grind with how they're MARKETED* I'm not sure if those who advertise them really believe what they're singing, but I'm uncovering the stuff that usually goes unmentioned about LED's intentionally or not. 

LEDs have their purpose, but using them in general lighting in place of linear fluorescent is not one of them. If you look at the graphic, you can see that 5mm LEDs (the common bullet-tip looking ones) degrade so pathetically (50% loss in 6,000 hrs). They maybe appropriate for flashlights that may never see beyond 150 hours of use in their lifetime but completely inappropriate for general lighting that is expected to be used eight hours a day. 

I'm challenging those who believe LEDs as being truly beneficial and economically just to come up with some form of support. As in the links I provided earlier, some use BS like "comparable to xx lumens", quote the efficacy from LED manufacturers most optimistic end of range and conveniently omit loss in driver/ballast. 

Some driver/ballast/control gear/whatever you call it/ integral lamps who report honestly do not do well on brochure. Osram Sylvania reports lm/W value based on fully warmed up state. As such, efficacy value is quite a shame. It's in the range of 30-50lm/W before taking loss from long term decay into consideration. The cost follows the output unlike CFL. A 26W CFL can be had for <$5, but to get the same output from an LED lamp, its well over ten times the cost AND less efficacious. 

Linear T8 and T5s are not even in the same league. 

HIDs are hardly influenced by ambient.

Fluorescent lamps do not achieve full output until fully warmed up and output declines under extreme heat.

LEDs' drop significantly in output with heat. The datasheet reports the performance based on INTERNAL junction temperature slightly above room temperature. The internal junction is always hotter than case and ambient, of course. 

Of course, show rooms can use trickery too by leaving the lamps turned off until the appointment and showing the foot candle reading at the beginning of demonstration, but conveniently omitting what happens after they've been allowed to remain on until its completely warmed up. 




> I personally do not pitch LED for Fluorescent tube replacements because the return is not there. At $50-$100 a lamp, the wattage difference is not significant enough to make the payback worthwhile.
> 
> It is predicted that with the advancements in LED technology, that the upper limits of LED performance will be in the 400-500 lm/watt range. That will change the game, especially when you factor in no mercury. it's a bit early yet for tube replacements, but I would not doubt it's there in a year or two.


As shown in IESNA handbook, the maximum possible efficacy is 683lm/W, but that is 555nm green light source that is putting out one watt of radiant power for one watt of electrical power, i.e. 100% efficient. According to Yoshi Ohno of NIST, 400lm/W is possible for white light using RGB light sources that converts 100% of electrical energy into optical energy. But then... you can expect a significant gain from replacing the arc inside a fluorescent lamp with a process that converts 100% of energy into UV-C light. 

As with anything in real life, 100% efficient does not happen. 



> Until then, it is correctly stated that T8 technology can now last 40,000 plus hours using the Extra Long Life products, etc.


LEDs bring up a question of definition of life. In lighting industry, the definition is until "50% of sample burns out". LEDs may have a longer life until they stop working COMPLETELY, but LEDs' output decays faster than linear T8 or T5 fluorescent making them less efficacious over time. Of course, marketing literature may claim lumens at 25C junction, with 0 hours of use and don't account for driver loss. According to LRC at RPI, high output LEDs are comparable to HPS in terms of output decay. 

LEDs and HIDs have to be oversized so that output remains within the acceptable limit over its entire lifetime. Linear fluorescent requires less oversizing since the flux decay remains within a single digit percent over the useful lifetime. Many marketing literatures do not take this into consideration, or should I say, conveniently omit it. A brand new LED system that actually matches the output of a fluorescent system will fall behind. 

If the decayed output of LED system after 20,000 is considered acceptable, then a lower output fluorescent system could be used in the first place. 

We only buy the Cadillac of lamps, so we do not experience the failures that some here have mentioned. As a matter of fact, it is VERY rare for us to ever see a ballast fail within 3 years. We buy the good stuff though, and I don't know if those that dislike the product are buying the cheapest thing off the shelf or not. 



> I can tell you that electronic ballasts do not handle dirty power as well as magnetic ballasts, so if you are in a poor grid area, the electronics will be more likely to fail. That's a bummer, but it is what it is.


Plastic shot "glasses" (they use those in some places in St. Louis ) may withstand abusive use better than glass shot glasses, such as dropping on the floor. This doesn't make glass ones inferior in the realm of proper use.

Its true semiconductor components don't handle surge and transients as well. Exposing them to surge and transients is outside of normal use conditions just like dropping glassware is outside of normal usage. 

I think that LEDs and electronically ballasted fluorescent systems are on a even playground in this respect as they both operate on semiconductor controlled switch-mode power supply. 

Finally, the current white LEDs are fluorescent lamps. They excite the phosphor with a solid state blue light source rather than a mercury vapor UVC source.

It's true fluorescent lamps contain mercury. The Philips ALTO II T8 32W contains 1.7mg. It takes 1,000 to 2,000 of them to equal that of a normal old school thermostat used in homes. 

Oh, by the way, the chemicals used in semiconductor processing of LEDs aren't exactly environmentally friendly. 

Except for the "LEDs Magazine" these sources are not taking sides of either 
technology. 



References:
http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/lightfair8_richman-ies.pdf

http://www.cormusa.org/uploads/CORM...M80_and_Future_Standards_CORM_2009_Y_Ohno.pdf

http://www.cormusa.org/uploads/CORM_2009_Development_of_LED_performance_standard_Eric_Richman.pdf

http://www.ledsmagazine.com/features/2/5/4


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## Westcoast Sign Guy (Apr 27, 2010)

Electric_Light said:


> There are some who swear that LEDs are more efficient and superior to fluorescent for general lighting, but I firmly believe that LEDs just do not even come close to being competitive with fluorescent system for general lighting.
> 
> I think LEDs have an edge in single digit wattage accent lighting, car interior lighting, but they have a looong way to go before being practical.
> 
> ...



All light sources IMO have their place, and should be used according to the application, the right light sources should be used for the right job. LED's as advetised by the manufacturers are said to be one fits for all applications.

Nothing can be further from the truth. 

I'm in the electric sign business, so we use a lot of CFL, CCFL, and LED lamps. The unfortunate part for LED's is the fact that they are marketed on Guilt and Fear, and pushed by a strong environmental & safety movement being pushed across America and abroad. It's also being backed and funded by out own tax dollars in the form of stimulus and government subsidized money. The bigger picture is, the poor end client may one day be forced to pay more for everything, and we as contractors will be loose our freedoms to pick our own components.

When if comes to job specific applications LED's are great and have their advantage, but like all light sources, they have pro's and cons depending on ambient temps. You won't want to use white or colored LED's in Arizona or Vegas, and you won't want to use CCFL lamps in Minnesota or Canada for exterior applications.

LED's are great for small applications where it makes other light sources impossible, or where installation is easier, where shipping can be a big problem. 

When it comes to retrofit jobs for interior lighting (4' T-8, T12), channel letter signs, Pylon signs with HO CFL lamps, it does NOT make sense to switch the systems with LED's as a general use. When running the costs versus saving, in most cases it will take 20 years just to break even. 

The problem with all the marketing is the fact that they always state annual savings of 60%-80%. To this day, I can't find where they get these numbers, and people from GE never reply back to me. There are no savings that high. I've only seen 20% savings in most applications with a ridiculous up front cost. What they don't tell you is how you will make it back in "savings vs. initial upfront cost". 

Most figures used by these LED companies are always exaggerated, extreme and sometimes made up.

On 2 lamp fixtures for interior use.

T8 electronic ballast = 60 watts
LED system = 48 watts.

cost

T8 lamps with ballast = $30
LED modules with PS = $300.00



On Ballast life, as I've read a few posts here. I would be curious on installation pictures these fixtures. There are things you want to do and things you don't want to do that will shorten or prolong life. Don't forget like anything else, you get what you pay for. Every use Tri-Phosphor lamps instead of the typical Halophosphate? 


I'm not blasting LED's, I like them, they have their place for sure, but they are to be used liek anyother light source and not for all. On the retrofit job thing, it will make more sense down the road when they get cheaper to make, just not now.

As for Mercury in the air from broken lamps, just think of all that volcano in Iceland that no one can pronounce, that blast just but more mercury vapor in the air than man has in his lifetime. This doesn't even account for the Hg being put into our oceans by underwater volcanism. Mother earth will long outlast us.


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## Lumina Energy (May 9, 2010)

*Agreed*



Electric_Light said:


> There are some who swear that LEDs are more efficient and superior to fluorescent for general lighting, but I firmly believe that LEDs just do not even come close to being competitive with fluorescent system for general lighting.
> 
> I think LEDs have an edge in single digit wattage accent lighting, car interior lighting, but they have a looong way to go before being practical.
> 
> ...



The LED tubes are great for display applications. I sell a lot of those but when customers are looking to retrofit the office lighting, I generally point them in the direction of the induction fixtures.

I still sell the LED troffers, and they are bright, but usually only to the islands because they care more about power consumption than quality due to the extremely high power costs.


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## Electric_Light (Apr 6, 2010)

Lumina Energy said:


> The LED tubes are great for display applications. I sell a lot of those but when customers are looking to retrofit the office lighting, I generally point them in the direction of the induction fixtures.


They're expensive. What do LED tubes offer that makes them worth the cost? 



> I still sell the LED troffers, and they are bright, but usually only to the islands because they care more about power consumption than quality due to the extremely high power costs.


What benefits do they offer over NEMA premium ballast + premium lamp fluorescent setup? I've yet to see an LED troffer that offers superior efficacy relative to premium fluorescent system.


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## Lumina Energy (May 9, 2010)

Electric_Light said:


> They're expensive. What do LED tubes offer that makes them worth the cost?
> 
> 
> What benefits do they offer over NEMA premium ballast + premium lamp fluorescent setup? I've yet to see an LED troffer that offers superior efficacy relative to premium fluorescent system.


Ok. Yes. The LED tubes are expensive. But when my customer calls me and says he wants ten, six foot LED tubes that are 4500K for his display case... I say, sure no problem. I don't ask him if he is doing it to reduce the wattage of a fixture that is on 24/7, or whether or not he is trying to save the environment and hugging a few polar bears while feeding them baby seals because in reality, he already knows what he wants and as a business owner, as well as an LD, I sell him what he wants with a smile on my face.

As I said before, when it is for an area such as a office or retail space that I am designing and specifying, then I tend to go with induction. You can not beat the life and in reality, they really aren't that expensive.

The LED troffers are selling. They are bright and they only use 64W and produce 4800lm. They do not have a ballast to go bad and they are rated to 50,000 hours before they should be replaced. That does not mean that they burn out at 50,000 hours, it means that they are only producing 70% of what they did brand new. That also means no flickering bulbs and no waiting around for the maintenance guy to replace a ballast. (many places don't have a good maint. dept.) Do I recommend them? No. But you bet I will sell them. It's just business. That is the world we live in today.


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## Electric_Light (Apr 6, 2010)

Lumina Energy said:


> Ok. Yes. The LED tubes are expensive. But when my customer calls me and says he wants ten, six foot LED tubes that are 4500K for his display case.


Agreed. They're definitely high cost, high profit, but does not compete with fluorescent on performance point of view. As a result, you'll see many people involved on the sales side of LEDs with all kinds of fluffing. I see nothing wrong with selling them as long as they're not sold using misleading claims.



> As I said before, when it is for an area such as a office or retail space that I am designing and specifying, then I tend to go with induction. You can not beat the life and in reality, they really aren't that expensive.


Induction is just a high wattage CFL that's driven by induction, so the lumen maintenance seems to whats typical of a high power CFL, then continue to decline past the point where normal CFLs have failed and discarded. 



> The LED troffers are selling. They are bright and they only use 64W and produce 4800lm.


That's 75lm/W. If this figure is for luminaire efficacy, that's about up to par with a pretty good straight fluorescent system, out of the box. 



> They do not have a ballast to go bad


 I'm assuming you mean the Cree troffer, which does have an electronic driver. Ballast or driver, matter of semantics. Since LEDs are heat sensitive and given a luxury of large heat sink in the ceiling space with HVAC airflow, driver gets to enjoy cool operating temperature too. Fluorescent ballasts are rated at 70C to 90C case temp, but the warranty is usually shortened for 90C. If the ballast is mounted on the back of the fixture, then a heatsink attached on top in free flowing air like LED and its driver or induction ballast, it would enjoy increased reliability. 



> 50,000 hours before they should be replaced. That does not mean that they burn out at 50,000 hours, it means that they are only producing 70% of what they did brand new.


One thing... LEDs have come a long way, but so have conventional fluorescent lamps. They may FAIL, but in commercial use where 12+hrs/day use is common, resistance to frequent cycling isn't such a great importance. The most advanced T8s are enjoying *95% *output at failure. 

Out of the box, fluorescent and LEDs maybe comparable, except for the price tag... 

Fluorescent would only need to be over-designed by 5.3% to compensate for loss. LEDs that loses 30% over 50,000 hrs would need to be over-designed by 42.9%. They can employ active feedback control

LED sell sheets usually conveniently omits lumen maintenance compared to best fluorescent technology.

Of course, customers are probably told 4,800 lumens, 64W, but then, if the useful life is defined as the point when it reaches 70%, then that's implying 3,360 lumens from the luminaire is acceptable. Well, a fluorescent luminaire that only puts out 3,600 lumen new would be acceptable, since it would pretty much hold 95% of if for ~40,000 hrs. 

They could be designed with active feedback controlthat works much like cruise control, but that only prevents over lighting before the LEDs have decayed, but doesn't change the fact that power consumption will increase with decay as more "throttle" is applied to compensate for it 

Lighting designers have already put in a lot of luminaires with 30% loss over lamp life into consideration so that footcandles stay above design value over the duration of lamp life. There are 25 and 28W lamps that work in existing 32W fixtures. They provide less output, but since the output is held more or less 100% of output for the entire life, it still meets the design spec. 

The induction lamp... though it may go 100,000 hours before needing replacement, it will lose around 40% of output. At 40,000 hours, 25% of output will be lost. The benchmark is 175W MH. (see attached, borrowed from Osram Sylvania Icetron induction lighting design guide, FL022R1)

Considering energy is the number one expense in many areas, if you use lamps with almost no lumen drop, they can be sized smaller to begin with, reducing not only kWh, but facility kVA demand charge as well.

In the NW where commercial electricity rate is less than a nickel per kWh and majorly dependent on hydroelectric, then the LED sales people will strongly push mercury content, maintenance cost etc. But in Hawaii where summer is hot(meaning that extra heat load into A/C is not appreciated) and each kWh is like a quarter, straight fluorescent is simply unmatched.


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