- Location
- Massachusetts
Out with the offensive fluorescent lamps.
- Thread starter iwire
- Start date
- Status
- Location
- Massachusetts
And I think they are messing with the TV cameras. 
big john
Senior Member
- Location
- Portland, ME
You were told LEDs suck! You just wouldn't listen! :happysad:And I think they are messing with the TV cameras.
Electric-Light
Senior Member
PR Stunt. It's a university. I bet it's heavily subsidized.
They admitted they're more expensive upfront and said savings are in maintenance. They didn't say how much these lights cost or how they calculated the maintenance savings. The article says the new system uses 310kW and the old lights used 1,240kW. A 75% reduction in field lighting load, not 75% of total energy use like the article suggests. "University of Phoenix will use 75 percent less energy to host 2015?s Super Bowl." is BS.
I've read somewhere that these have LED deterioration compensation like the nLight. Is 310kW on the day it was installed and does kW input grow with age?
http://powersource.post-gazette.com...ighting-in-sports-venues/stories/201406120322
LED lighting don't offer ad revenues from videos they playback on gigantic LED TVs... they say. :lol:
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Electric-Light
Senior Member
I watched the game at 720p.
Shadow = present.
I thought people had pinker skin than I expect... but maybe that's my cognitive bias.
Replay. Went on as usual.
yaaaawn
Shadow = present.
I thought people had pinker skin than I expect... but maybe that's my cognitive bias.
Replay. Went on as usual.
yaaaawn
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
BTW, I've asked my video-engineering friends about the LED lighting. Since two of them are on the SMPTE board of governors, they'll have some real information.
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Basically, that all came back with "it was fine":
(sez a retired NBC engineer)
and another sent me:
http://ephesuslighting.com/wp-content/uploads/2014/10/Ephesus-Case-Study-University-of-Phoenix4.pdf
Electric-Light
Senior Member
Over priced public purchasing.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
I've been biting my tongue for a while...
I have seen LED lighting 'oversold' for years. As LEDs have steadily climbed in efficiency they seem to always be sold as being better then they really are. I agree with Electric Light that they are being used faddishly even where they do not make sense.
With that said, it seems clear to me that LEDs are (and should be treated as) a real contender for many lighting applications.
1) LEDs have efficiency on par with conventional fluorescent lighting at much smaller scales. As replacements for incandescent lamps they are IMHO fantastic.
2) LEDs perform well in cold temperatures. The efficiency of conventional fluorescent lighting tends to drop as ambient temperature goes down; the efficiency of LEDs tend to go up. LEDs in refrigerated cases and freezers make good sense.
3) LEDs have much higher lumen densities than conventional fluorescent lighting; this is important for applications where the output needs to be focused.
4) As has been observed, most white LEDs are a type of fluorescent lighting, depending upon phosphors (which degrade) to get the white light. IMHO the available phosphors for solid state fluorescent devices seems to give a smoother spectrum than most fluorescent lighting.
5) LED degradation is often specified to a rather high allowed level, and this needs to be understood in the energy savings calculation.
6) LED technology is evolving rapidly, and failure modes (and rates) are not fully understood. I suspect that lots of municipalities will be surprised by the upkeep of LED street lights, for example.
7) For bulk room/office/shop lighting I think that conventional T8 lamps make far more sense than LEDs.
8) I don't think that linear LED retrofits ever make sense. Right now the conventional T8 lamps are more efficient and much less expensive, and in the future if LEDs become even better (which I expect), then a fully designed system will make more sense than a drop-in.
9) The degradation of LEDs is thermally driven. It is very easy to push an LED to operate at high power levels, if you don't mind giving up life. A great way to make a cheap product that looks good initially, but doesn't last.
10) LEDs in a sporting arena? I don't know. I guess they can fairly claim a 75% reduction in energy use, but I wonder what the reduction would be if they'd replaced with the most current HID lighting. The LEDs are not using 75% energy then the best available HID lighting with the same output. The 'restrike' time issue is a big win for LEDs... I don't think you could reasonably light a stadium with T8 lamps, however
-Jon
I have seen LED lighting 'oversold' for years. As LEDs have steadily climbed in efficiency they seem to always be sold as being better then they really are. I agree with Electric Light that they are being used faddishly even where they do not make sense.
With that said, it seems clear to me that LEDs are (and should be treated as) a real contender for many lighting applications.
1) LEDs have efficiency on par with conventional fluorescent lighting at much smaller scales. As replacements for incandescent lamps they are IMHO fantastic.
2) LEDs perform well in cold temperatures. The efficiency of conventional fluorescent lighting tends to drop as ambient temperature goes down; the efficiency of LEDs tend to go up. LEDs in refrigerated cases and freezers make good sense.
3) LEDs have much higher lumen densities than conventional fluorescent lighting; this is important for applications where the output needs to be focused.
4) As has been observed, most white LEDs are a type of fluorescent lighting, depending upon phosphors (which degrade) to get the white light. IMHO the available phosphors for solid state fluorescent devices seems to give a smoother spectrum than most fluorescent lighting.
5) LED degradation is often specified to a rather high allowed level, and this needs to be understood in the energy savings calculation.
6) LED technology is evolving rapidly, and failure modes (and rates) are not fully understood. I suspect that lots of municipalities will be surprised by the upkeep of LED street lights, for example.
7) For bulk room/office/shop lighting I think that conventional T8 lamps make far more sense than LEDs.
8) I don't think that linear LED retrofits ever make sense. Right now the conventional T8 lamps are more efficient and much less expensive, and in the future if LEDs become even better (which I expect), then a fully designed system will make more sense than a drop-in.
9) The degradation of LEDs is thermally driven. It is very easy to push an LED to operate at high power levels, if you don't mind giving up life. A great way to make a cheap product that looks good initially, but doesn't last.
10) LEDs in a sporting arena? I don't know. I guess they can fairly claim a 75% reduction in energy use, but I wonder what the reduction would be if they'd replaced with the most current HID lighting. The LEDs are not using 75% energy then the best available HID lighting with the same output. The 'restrike' time issue is a big win for LEDs... I don't think you could reasonably light a stadium with T8 lamps, however
-Jon
Electric-Light
Senior Member
I think it's just another form of a light emitting product. The typical marketing and special treatment they're getting need to get addressed. People generally don't understand lighting in depth. LED or fluorescent, and the fact that most LED lighting are solid state fluorescent lamps. Everything should have descriptive names and condensed into slangs rather than some word games to beat around the bush. LED marketing go through a great length to disassociate and avoid any connotation with fluorescent lamps.
pcLED, blue pumped Phosphor coupled LED, remote phosphor LED, solid state lighting just to avoid the words "fluorescent" and "ballast" to get people to think they have almost nothing in common. Solid state fluorescent lamp, LED activated fluorescent lamp are much more accurate.
"I thought LEDs are always more efficient..." "I thought LEDs make almost no heat" "LEDs have no ballast to fail". LED sales reps are misinformed about both LEDs and fluorescent. Many decision makers, such as board of directors of small organizations are excessively dependent on sales reps for information and they often don't have straight forward information on all available means of lighting to chose from.
"fluorescent lighting requires compromise in almost every way: from flickering and inadequate dimming to mercury use and poor-quality "
This is a quote from Cree's Product Portfolio Manager, Jeff Hungarter. Many in the field have never even seen 0-10v dimming. When these people hear something like that from a Cree factory dude, they tend to believe it just based on his credentials. So it's very disturbing that someone speaking for Cree has no clue what he's talking about. T5, T8, T12 and CFL all dim very well without flickering in the context of commercial lighting which is what the article is about.
https://www.creelink.com/exLink.asp?19706952OV78E19I37602548
I suppose.
What's conventional? CFLs tend to be less efficient largely because of trapped light from inner facing section of spiral. For 800 lm and above, they're still not competitive without a subsidy.
LED bulbs have been going downhill in the last few months and they are still very expensive costing $7-10 for the basic 60W equivalent lamp. Single packs often cost less per lamp than four or six packs probably due to subsidies. First generation Cree bulb was 84 LPW. Second generation slouched down to 75 LPW while 13W CFLs are 62 LPW. Keep in mind that these are initial performance. These consumer LEDs are rated 25,000 hr to L70 30% decay and we are seeing 10-12,000 hr rated CFLs, so the life advantage gap for LEDs is shrinking. The solid state compact fluorescent lamp is projected to degrade to 56 LPW, so they still have a miniscule advantage over traditional CFLs, but at three times the price.
LED is the clear leader in relatively low light output requirement like display cases. Although the advantage is not so clear for higher output lighting such as high bay in refrigerated storage as F54T5HO run at high enough power density that they can actually keep themselves warm enough for full performance within enclosed fixtures.
Conventional fluorescent lamps are essentially useless for that. So, incandescent and HIDs dominate those applications and solid state fluorescent lamps as well as high(er) intensity gaseous fluorescent lamps such as electrodeless lamps have potential.
The substandard threshold is probably used to evade warranty obligations while they're testing the water, which is not acceptable. The risk needs to remain with the manufacturer in order to have a predictable ROI. Old F40T12/CW is rated 20,000 hr average life. 3050 initial and 2680 lm after 8,000 hrs or 88% "mean lumen". RE80 T8s hold over 90% over the entire useful life.
The depreciation amount is well documented and understood. Solid state lighting interest group lowered the bar to 70% for LEDs. LED life is *ESTIMATED* hours until 30% output loss, however, this is usually also the warranty threshold, so a decay to 75% within the first year and gradually losing the remaining 5% over the rest of life would not be covered under warranty. This level of depreciation is totally unacceptable for any fluorescent substitute.
30% decay allowance is worse than a freaking F40CW. It's only beat by quartz metal halide. It falls short of HPS, LPS as well as the latest CMH technology.
I think they're starting to understand it better and with better understanding, I think they're stretching the limits of 70% loss and making faster decaying LEDs to lower production cost. Even A19 bulbs cost several times the cost of CFLs at 60W size. 75W and 100W sizes have an even larger gap.
The tremendous unsubsidized cost of fixtures having a maintained efficacy over 80 LPW (power wires to out the fixture efficiency) would not yield an acceptable ROI over T5 or T8. The standard I use is 10% rate of return with 3 year PBP.
Thermal and current. Given the same junction temperature, LEDs degrade faster at higher current. Also, higher ambient air will increase decay rate of plastic encapsulation. LED encapsulation yellows. Fluorescent lamp glass does not. Glass encapsulated LEDs are prohibitively expensive.
However, electrodeless HIDs are a real possibility such as Luxim electrodeless metal halide and LG's suflur lamp.10) LEDs in a sporting arena? I don't know. I guess they can fairly claim a 75% reduction in energy use, but I wonder what the reduction would be if they'd replaced with the most current HID lighting. The LEDs are not using 75% energy then the best available HID lighting with the same output. The 'restrike' time issue is a big win for LEDs... I don't think you could reasonably light a stadium with T8 lamps, however
-Jon
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Electric-Light
Senior Member
The spectrum of phosphor converted electric discharge lamp depends mainly on the phosphor and there are many different types of phosphor blends. The low pressure mercury discharge is very stable in spectrum, but this isn't the same for the blue LEDs used to drive phosphor converted solid state fluorescent lamps called LED lamps. They're are inconsistent from chip to chip and they continue to struggle with chromaticity consistency from brand to brand, model to model, lot to lot.
There's a gap between the pumping light and the beginning of converted output, so there's a gaping hole between blue and green in current LED lights. Some Cree based technology dope the output with a huge spike of red to raise the CRI and R9 score.
Any light source that is dependent on phosphors is a fluorescent lamp. Some colored LEDs like the Philips Luxeon Rebel lime used in Philips Hue lamps use a phosphor, so it's still a fluorescent lamp. The exceptions are for LED lights that do not use pcLED (phosphor converted) technology whatsoever. Those are truly exceptions.
Hmmm Cree sure have all kinds of patents on LED powered fluorescent lamps for a comany that viciously hate fluorescent lamps. http://www.ledsmagazine.com/article...e-phosphor-led-technology-space-magazine.html
This Philips solid state fluorescent lamp was apparently licensed by Cree.
mirawho
Senior Member
- Location
- Sun Valley, CA
Do you know what an LED is? It is a diode. It is a semiconductor. Do diodes build up a tolerance to electricity over time????
You have any idea how many devices use semi-conductors? I guess after a couple of years we might as well throw out the TV and the radio since they are built with solid state technology. Oh, and what about solid state drives? Better go back to old fashion hard drives. Wait, they have semi-conductors too. We better go back to tape drives. The unfortunate thing you do is provide half cocked info regarding LED's. You obviously are more knowledgeable than the engineers at Philips lighting (a company which makes a boatload of money off of T5 & T8 lamps). But wait, I forgot, engineers that represent fluorescent lighting are engineers and engineers that represent LED lighting are salesmen. Whats that old adage? Oh yeah, you can lead a horse to water but you can't make it drink.
mirawho
Senior Member
- Location
- Sun Valley, CA
Hmm....must be online trying to find a way to defend that remark. Sometimes, as much as I swear I come here as a person with a lot of knowledge that would like to help in the education process, I think there are times I am mainly here for the laughs! :lol::roll:
Electric-Light
Senior Member
I apologize if my wording was confusing. Lighting products that are nominally called "LED lighting" are generally a type of electric fluorescent lamps. This type uses one or more light emitting diode chips in one or more packages to produce the light energy used to activate the fluorescent phosphor material.
When I explained that LEDs build tolerance to electricity, I meant degradation of lumens/W as a chip-phosphor-package assembly rather than the semiconductor chip itself declining in mW of blue light in radiometric output per watt input.
As with electric discharge activated fluorescent lamps, the lumen/watt degradation is the combined total of all the degradations. LED activated fluorescent lamps run the phosphor layer at a much higher temperature and higher power loading density so the fluorescent phosphor has a much higher degradation rate than lower loading density electric discharge fluorescent lamps.
It's a common knowledge to LED engineers that LED driven fluorescent lamps have their life rated as the expected hours of run time until 30% of lumens are lost which far exceeds the output and efficacy loss of electric discharge fluorescent lamps.
- Location
- Massachusetts
I would love to jump in here but I am far to busy installing LEDs right now.
mivey
Senior Member
My guess would be that he has forgotten more about lighting LEDs than you know.
You were saying?
and I'm sure you do. But for this particular thing you leaped before you looked.
I too laughed when I read your post. It just struck me as funny given the extent of EL's knowledge.
Lighting LED degradation is nothing new, even for those with limited knowledge. I think you must have scanned some of the posts and had some weird misunderstanding. Just one of them days I suppose.
mivey
Senior Member
Smart-aleckI would love to jump in here but I am far to busy installing LEDs right now.
Electric-Light
Senior Member
I would love to jump in here but I am far to busy installing LEDs right now.
LED projects bring you money and for these projects to get created, LEDs have to get specified and you're honest about not really caring the politics and reasons they get installed. If they've already been specified, it's too late.
When decision makers are charged with duty of care in making purchases or specifying something in the interest of whom they're representing, they're expected to consider several points of view. LED sales people really hate it when decision makers are given opposing inputs that can not just be ignored.
I can absolutely see why you'd be supportive of LEDs and take position from emotional attributes such as "like" "easier to work under" especially when these types of inputs increase the odds of more LED installs coming your way without PROPER studies showing measurable and repeatable differences.
The subjective qualities should not be ignored but strongly challenged when these claims can influence incentive program development. You reaction to the wind knocking over a cup of beer on you and someone dumping it on you wouldn't be the same. This is a clear example of the need to isolate the cognitive bias from how it happened so it doesn't influence the research on how you feel about smelling like beer for the rest of the day.
The customer usually knows that you installed LEDs and the employees know as well. Making positive comments about boss' decision on sustainable purchase is the politically correct thing to do at work place and if it's obvious that money was spent, there's a tendency for us to believe it's doing some good. Those who have vested interest to that install such as the installer who want more leads and more LEDs getting specified would clearly want satisfied customers. That's kind of common sense, but "customer likes it", "they said it feels they work better" should not bias rebate program allotment that causes technology bias.
mirawho
Senior Member
- Location
- Sun Valley, CA
You guessed wrong. I have been in the lighting industry and have been for over 40 years. My background includes commercial lighting and signs including neon and fluorescent. I also have a strong electronics background including military communications security devices, old TTY, you name it, I have worked with it. Anytime you turn on your TV and see a movie premiere or most awards shows, you are looking at something I probably designed the lighting on and spec'd the power. We have been interested in LED's for lighting since they came out. Everyone knows about LED degradation, but that holds true for all lighting. Finding points about a type of light that is new is easy to do. But, solid state will, no matter who says what, end up at some point being the direction commercial, residential and TV lighting goes in. There is a lot of engineering involved in creating better products. In the beginning, maybe you could call them Light Emitting Decorations. But, when you have manufacturers like Philips, Lithonia and Osram developing these devices, no matter what you come up with to make them look bad, you know that they are looking at the future of lighting. Like I said before, you can lead a horse to water but you can't make it drink. According to your pal, everyone that is involved in the information trail regarding LED's is a salesperson. The exact opposite is true. We have had the leading developers come to our offices and we have spoken in length. Also, he is going online and C/P'ing others posts regarding LED's but only giving part of the info.
Just curious, ever drop a fluorescent tube, an incandescent lamp or say a 1000w MV from 30' in the air? It's not pretty and not fun to clean. I know, I have been there. Know what happens when you drop an LED?
Anyway, this is going to be another one of those posts that goes on and on and back and forth. This is a learning forum, yet it seems those that need the knowledge refuse to learn. Whatever.
mirawho
Senior Member
- Location
- Sun Valley, CA
I would love to jump in here but I am far to busy installing LEDs right now.
Love it!!! A man that knows the future.
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