REALISTIC performance of your old T8 systems faced vs LED T8 retrofit dilemma

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Electric-Light

Senior Member
Intro
Electricians, utilities, facility owners and anyone interested in realistic performance of the typical existing T8 lighting systems and retrofit, modification and upgrade options should read this post for continuing education or as a resource to help make an informed decision. This post is compiled from realistic stuff. It doesn't go along with the interest of LED Sales Representatives looking for ways to get LEDs to move through the pipes or sell LED installs. Sidenote: LEDs did make huge improvements in the past few years.

Average existing T8
Snapshot of a system representative of overwhelming majority of T8 systems

Baseline
Efficiency for 2 lamp system using the basic model ballast and cheap lamps from early 2000s.

About 85 LPW with new lamps. About 80 LPW maintained.
About 90/(85) for 4 lamp systems.

Wattage input for basic early 2000s systems with 32W lamps

1L: 30W 2L: 59W 3L: 86W 4L: 112W

Existing T8 Ballasts:
Vast majority of T8 lights use an instant start electronic designed to run lamps to push 87-89% of their spec lumens. Best efficiency ballasts sold today are a couple percent more efficient than the typical ones from early 2000s. Not that much. +4-5% more efficient for 2 lamp. +2-3% for 4 lamp.

Sales managers from "rewire LED" shops can probably track down a magnetic ballast for two F32T8 that draws 75W and rated 1.0BF. Such a ballast exists in catalog, but they are RARELY used.

Existing T8 Lamps

The cheapest basic lamps: 700 series 32W 78 CRI, 4100K.
Philips... in 2002 catalog: 2850, 2710@8000hrs. 20K hr life.
Sylvania in 2010 catalog: 2800, 2520@10000hrs. 25K hr life.

Worse lamps exist if you look hard.

Fixtures
Fixtures can range anywhere from 50-95% efficient depending on light pattern. Example for modern high efficiecy recessed type. Kenall 1x4 CSEFO14P is at 83.4%. 2x4 @ 85% using fluorescent lamps. These are ITL Boulder tested values, so I trust it. http://www.kenall.com/Kenall-Files/Product-Files/specificationsheets/CSEFO14P.pdf

Deteriorated reflectors and fixtures that don't do a good job of directing the light from upper half of the lamps to where it's needed unduly favor LEDs retrofits.

Upgrade options for indoor use
Premium T8 drop in.
Wait until you need to replace the lamps.
No change in light pattern for fluorescent drop-ins.

Material: $4.16 to 5 per lamp
Labor: none if you wait until you're due for re-lamp. Additional if the fixtures are dirty and need cleaning.

  1. 28W drop-in A very close match for basic 32W 700 series lamp.
    About 12% reduction in watts, same output.
    Power usage(typical) 52W for 2lamp. 98W for 4L.

  2. 25W drop-in. Reduction to about 2000-2100 lumens per lamp.
    about 10% reduction in light.
    About 22% reduction in watts.
    Typical watts: 46W for 2L, 87W for 4L.

    Good: economical. Unparalleled lumen maintenance. 94% lumen maintenance after 40,000 hr burn time.

    Bad: Not for use below 60F.

$4.16/ea for 32,000/38,000hr rated (3 hr per start, 12hr per start)
$5/ea for 40,000/46,000 XLL. Competitive with LED's life.
(HOME DEPOT online in case quantity, delivered. 30/cs)

I think its more reliable than LED claims. We've had T8s since 1990s and tens of thousands of real life usage, so I think there's enough data to support the light loss prediction.

LEDs are only tested to 6,000 hrs. Engineers think that deterioration settle down after those 6,000 hours and the rated life is EXTRAPOLATED to guess how many hours it takes to drop to 70% of new output. I don't know of any GSFL linear lamps that lose anything close to 30%.
 

iwire

Moderator
Staff member
Location
Massachusetts
I think you have been preaching to the wrong audience.

Most of us don't specify or choose the lighting fixtures we install at least not in any kind of large quantities. Most of us make money by installing what has already been specified by others.

So bring on LEDs and I will make money and when those are deemed undesirable by the paying customers I will make money again installing the replacements.

I would say that over the last year at least 60% of on the clock time has been installing LEDs.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
a lot of people are looking at LED not for the energy savings but because of the wild claims of lifetime that may reduce the need to replace them down the road and thus reduce ongoing labor costs.

there is also the problem with some of the annoying issues with fluorescents when they get to end of life with flashing. LEDs tend to just get less bright or fail completely. A fixture that is flashing is almost impossible to work under. A fixture with reduced lighting is not something that has to be tended to immediately.
 

Electric-Light

Senior Member
T8 vs LED

T8 vs LED

Most of us don't specify or choose the lighting fixtures we install at least not in any kind of large quantities.

I come across a lot of questions asking about LED ' upgrade ' such as drop-in or rewire LED T8s, so maybe we have guests that wonder those things too and research places like here before specifying LEDs or allowing that stuff to become specified for their property. I believe myths and pure non-sense perpetrated by LED sales industry play a role in causing LEDs to become specified on false premises. LED sales people generally over-inflate the performance of LEDs significantly and cast T8 under unfavorable view using unrealistic values to project the ROI, carbon foot print, PBP and those things bean counters are enlightened about. Knowing realistic values for the average T8 system will help them make more informed decision and not get sold into unnecessary LED change outs.

Anyone considering LED retrofits should make the LED vendor produce answer to every one of these questions and make them stand behind them with further warranties. http://energy.gov/eere/ssl/what-ask

a lot of people are looking at LED not for the energy savings but because of the wild claims of lifetime that may reduce the need to replace them down the road and thus reduce ongoing labor costs.
This is very true. There are many spurious claims perpetrated by LED sales people. Many, even those in the trade do not really understand what lamp life ratings really mean.

"Conventional lamps, like T8 fluorescents, have regular and predictable catastrophic failure mechanisms. Thus, lighting specifiers can be confident that maintenance personnel will be alerted to the need to relamp" (This statement from a US Department of Energy technical report PNNL-22727 )

Fluorescent T8 lamps are used in a quantity in commercial lighting and just as they say, their failure pattern is very accurately predicted with statistics. You can go for more percent of rated life today than when F40T12s dominated. This is because F40T12 lamps are usually wired in series in a pair. This means that two lamps shut off for every lamp failure. Most F32T8 systems are parallel wired, so only the failed lamps shut off.
This is probably something ignored by LED sales people.

When LEDs decay 25%, the objective performance decay is comparable to after 1 in 4 fluorescent lamps have burned out. When one lamp burns out, the power input drops on a fluorescent system. Performance decay on LEDs do not reduce power use. I suppose the aesthetic advantage of dimming instead of visible dead lamps attest to the Light Emitting Decorations aspect.

Here's the fluorescent failure curve:
LDTl5Pw.png

Image courtesy: GE Lighting

Lamp life has been defined the same way for many decades, however many people incorrectly interpret their ratings. If they see "2,000 hours" many think that each and every is expected to last a minimum of 2,000 hours.

LED lifetime is GUESSED. LM-80 test conditions only require testing to 6,000 hours and rest are speculated under imaginary conditions. The real life results can be worse, or potentially better. It's a wild guess. Lumen maintenance of fluorescent lamps are proven through extensive field experience.

GKg1zLE.png

Image courtesy: PNNL

LED performance maintenance is still unpredictable. If the design is to allow for 30% depreciation, the initial lumen must be oversized 42%, so that 143% x 0.7 =100% (target level). The over sizing factor is under 10% with the fluroescent technology.

Matching the initial performance of LEDs with the existing system performance is NOT the correct way. The standard life rating for LEDs is based on predicted life to 70% of original output.

This is something I found online. I believe it's a good example of misunderstanding of lamp life: "We now sell LED, because we have seen how the T8 bulbs that we warranted for 3 years are failing at 2.5 years. They were supposed to last 40,000 hours, well beyond 3 years, but we had several fail at 2.5 years. We recently went back to warranty some bulbs that had burned out, which were minimal but still a nuisance. We just happened to be 6 months past the warranty date."

Exact quantities or hours/start weren't mentioned, but sounds very much normal and within the mortality curve.

there is also the problem with some of the annoying issues with fluorescents when they get to end of life with flashing. LEDs tend to just get less bright or fail completely. A fixture that is flashing is almost impossible to work under. A fixture with reduced lighting is not something that has to be tended to immediately.

The behavior you mentioned is very common with traditional magnetic rapid start ballast systems, the most common type with F40T12 lamps. They can exhibit flashing for a very long time. The duration (in days) and probability of such flashing is much less with T8 systems which predominantly use electronic ballasts. Fixture level outage due to driver/ballast failure is something shared between both technologies and even CREE admits that driver is the weak point in LED systems.
 
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Electric-Light

Senior Member
Example of unrealistic LED claims

Example of unrealistic LED claims

Let's take a look at an example LED product:
Philips InstantFit 4' T8 drop-in rated at 1600 lumens 14.5W
Product # 9290002841

This is a drop-in T8 substitute for fixtures with an instant start electronic ballast. It costs $20 to $25 a piece. It does not work with some programmed start ballasts.

Box claims...

-55% energy savings when operated on a 0.88 BF compared to a baseline of 32W F32T8 on 1.0BF ballast.


-"same foot candle level as 32W 2800 lumen T8 lamp when used in bare batten" under hypothetical conditions of unknown height or reflectivity of the room surfaces and unknown ballast factor.

Realistic comparison:
Lumen comparison using MEAN lumens (0.94 LLF for FL, 0.70 LLF for LED)
RE80 T8 with standard T8 ballast: 59W, 4,930 lm
25W T8: 48W (81% of base): 4,200 lm(85% of base)
LED: 38W(65% of base): 2,240 lm (45% of base..)

Philips used a NEMA Premium ICN-2P32-N ballast to establish performance of their LED drop-in which came out to 3210 lumens output and 34.8W input running two lamps.

To make their claim "55% energy savings valid" true, the baseline power consumption has to be 77.3W. (77.3W x (1-0.55) = 34.8W). This is unrealistically high. The average power consumption of existing T8 is about 59W.

So, in your standard efficiency electronic ballast, when you switch to LEDs, I think realistic expectations are 35% power reduction with 55% loss in maintained lumens.

The non LE Decoration option provides much closer match on lumen output even though the input is 45W(+2-3W for standard eff ballast) Lamp rated life is 40,000 hr @ 3h on IS.
 
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mirawho

Senior Member
Location
Sun Valley, CA
I will say that I was never impressed with LED's until recently. They just did not produce the fc needed for the projects we did. Most electricians deal with product replacement LED's and not anything that is a new design. I am in the entertainment industry and we look at lighting from a very different perspective (I have also been a commercial/residential electrician so I am aware of those aspects). LED manufacturers have spent a lot on R&D for our industry, not for product replacement like in commercial lighting, but in new innovative products. There was a certain amount of product replacement (like camera lights) but most of it was new. LED's have yet to come up with a satisfactory replacement for old standards like the studio fresnel (1K, 2K etc.) but when it comes to intelligent lighting, they are surpassing the old technologies with new simplicity. Example would be a 1200w HMI intelligent light (moving). For starters, the HMI needs a start up period like any HID/HMI light needs. The 1200 needs color wheels to be able to change the colors which creates another mechanism in the light that can fail. The HMI lights are heavy because of the mechanical and electrical devices contained in the instrument. LED's, on the other hand, are instant on. You are outputting full fc's right off the bat. LED's come in white, RGB and RGBW so the lighting colors can be blended without introducing a mechanical means into the picture. Also, there is a tremendous amount of green in fluorescents and HID/HMI lighting. Most LED manufacturers try to get their CRI's in the low to high 80's. It is so much easier on the eyes.

I know this kind of seems off topic here for the T8 thread you started here, but it does have something to do with this. One site you quoted on T8 efficiency was actually a site that was promoting LED's instead of T8's. And, one thing that is not mentioned here is that T8', like all fluorescents, incandescent and HID lighting is the amount of heat the lights put out. When you install LED's in a residential or commercial setting, you decrease the amount of heat that is produced by the actual light itself. In an area where there is a lot of lighting, the AC works harder trying to cool an area that is light by conventional lighting as opposed to LED's. It is easy to start to calculate the savings with an LED as there are hidden savings that most don't consider. We did a Hi Bay retrofit in our warehouse and it made a large difference in temperature. It takes a good 5 minutes for parts of a fluorescent fixture to cool down before you can service it. Since most LED replacements have been rewire projects, it is a matter of just changing the lamp. You don't have a hot ballast to remove (unless you are using one of the direct replacement lamps they are now making).

Another plus of LED's over T8's is environmental. The T8 uses mercury in the lamp. They have to be disposed of properly, you just cant throw them in the trash (though most do). LED's do not create any contaminants.

And, they don't give off any UV, so, all in all, LED's are a much better product than T8 lamps. I think when the technology gets developed a little more, we might the see the end of days for fluorescent. I always stay open minded about this industry and I think that LED's will, at some point, replace all of the standard lighting. If you drop or break a fluorescent lamp that is ceiling mounted, you are going to have shards of glass everywhere that are hard to find. You don't have that problem with LED's.

Again, I am one of the last hold-outs at our office when it comes to conventional studio lighting. But I have been coming around and have started to use a lot of LED lighting as it is more efficient and is becoming more reliable. It was actually me that headed up our Hi Bay retrofit project and we are extremely pleased with the outcome.
 
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Electric-Light

Senior Member
LED's have yet to come up with a satisfactory replacement for old standards like the studio fresnel (1K, 2K etc.) but when it comes to intelligent lighting, they are surpassing the old technologies with new simplicity. Example would be a 1200w HMI intelligent light (moving). For starters, the HMI needs a start up period like any HID/HMI light needs. The 1200 needs color wheels to be able to change the colors which creates another mechanism in the light that can fail. The HMI lights are heavy because of the mechanical and electrical devices contained in the instrument. LED's, on the other hand, are instant on.
I wouldn't disagree with you that Light Emitting Decorations do well in decorative lighting and special effects.

Also, there is a tremendous amount of green in fluorescents and HID/HMI lighting.
White LEDs have a tremendous level of potentially retina damaging blue.

Most LED manufacturers try to get their CRI's in the low to high 80's. It is so much easier on the eyes.
Which is about the same as RE80 T8s.

one thing that is not mentioned here is that T8', like all fluorescents, incandescent and HID lighting is the amount of heat the lights put out. When you install LED's in a residential or commercial setting, you decrease the amount of heat that is produced by the actual light itself.

That's an urban legend. The truth is watts in = heat out. Given the same input wattage, LEDs produce the most conducted heat that must be dissipated by the heat sink. Total BTUs is the same if the input wattage is the same regardless of lighting technology. Law of Physics.

In an area where there is a lot of lighting, the AC works harder trying to cool an area that is light by conventional lighting as opposed to LED's. It is easy to start to calculate the savings with an LED as there are hidden savings that most don't consider. We did a Hi Bay retrofit in our warehouse and it made a large difference in temperature.

The heat output is all about the watts input. As LEDs decay, the light output drops without a drop in heat output. So, the lumens per watt declines. LED life is rated to 30% decay. MHs decay more. T8s decay only 6-8%.

Another plus of LED's over T8's is environmental. The T8 uses mercury in the lamp. They have to be disposed of properly, you just cant throw them in the trash (though most do). LED's do not create any contaminants.

LEDs maybe considered hazardous waste depending. The manufacturing process of LEDs may not be environmentally friendly either.

And, they don't give off any UV, so, all in all, LED's are a much better product than T8 lamps. I think when the technology gets developed a little more, we might the see the end of days for fluorescent.
Which means fabric brighteners or anything that rely on UV content to contribute to appearance won't work.

Comparing brand new LEDs against decayed HIDs is not the right way to do it. The decayed LED output should be used to ensure sustained lighting level. The amount of LED performance decay is only predicted. The real life lumen maintenance still have to be proven by actual use.
LEDs require 1.43x oversizing to ensure light output is acceptable throughout the useful life if you're using conventional L70 as the useful life. If 1 is the required FC target, brand new LEDs have to be 1.43 times, because, 0.7*1.43 = 1. If brand new LEDs are rated 40,000 hours to 70% and you're barely meeting the required level when new, the lighting level will fall short of required performance during useful life.

I always stay open minded about this industry and I think that LED's will, at some point, replace all of the standard lighting. If you drop or break a fluorescent lamp that is ceiling mounted, you are going to have shards of glass everywhere that are hard to find. You don't have that problem with LED's.
That's why there are coated lamps for those applications requiring shatter resistance.

Again, I am one of the last hold-outs at our office when it comes to conventional studio lighting. But I have been coming around and have started to use a lot of LED lighting as it is more efficient and is becoming more reliable. It was actually me that headed up our Hi Bay retrofit project and we are extremely pleased with the outcome.

LEDs, electrode-less fluorescent/induction or conventional fluorescent basically all beat the decay rate of traditional metal halide. MH lamps, especially probe start ones decay quite steeply. Conventional metal halides should go in its own class as it decays so much.
 
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mirawho

Senior Member
Location
Sun Valley, CA
Its obvious you do not like LED's and when someone comes the table with a closed point of view, nothing will change what they believe, even if its true. There will always be a rebuttal. Like I said, it was hard for me to become interested in LED's, not for the reasons you point out, but for ones I had mentioned in my post. I actually have had retina surgery from lighting damage from exposure to HMI/HID, neon and fluorescent lighting. Fluorescents have ultraviolet emissions that are eye damaging when you are in the light field. This has been slightly decreased with gas changes (argon to krypton) but you still have the ultraviolet emissions. LED's do not have a "tremendous" amount of eye damaging blue light. They emit a blue light that could be (key words "could be") retina damaging at close exposure. Tests were done with LED white light on albino rats with the lighting right next to them. Any light you put right next to your eye could be retina damaging. There is a big difference between a known fact and something that could be. LED's can kill you if you swallow enough of them at one time.

Your first reply to my post
I wouldn't disagree with you that Light Emitting Decorations do well in decorative lighting and special effects I would just like to correct. This isn't decorative lighting or special effects. We are using LED's to replace most of the standards in show lighting. This is not decorative lighting or special effects. The standard stage wash was achieved with PAR cans (500 - 1000w). The standard LED replacement is called a Colorblast which allows you to tie the units into a multiple unit driver that is controlled though DMX for the higher light functions. A Color Kinetics PDS-750 will control 12 units at 750w total load. 12 lights for the load of 1? We save our clients money on power distribution. Also, some of the LED's are competing with 1200w HMI luminaires. So, this isn't decorative lighting. These are powerful units used in concerts that people sitting a distance away can see the effects.

The RE80's you mentioned are in that CRI range at a temperature 5000K+. Most homes and businesses use fluorescent lighting in the 3200K range.

And really, LED's could be hazardous? Like I said, eat enough LED's and they could kill you. It's obvious that for whatever reason you do not like LED's. I never thought I would say it, but I believe that LED's are the future of lighting. Lighting has come a long way since the first light bulb. I remember stores that I used to service that had the old cold cathode neon 25mil tubes. So I have seen a lot in the lighting industry. Who ever thought there would be an end to the T12? Each to his own. I wont go through all your replies. It is unfortunate when someone tries to convince people not to use something based on weak facts. I suggest to anyone that is being asked by a client about LED installation to read up on it, don't rely on opinion. When large lighting manufacturers like Philips (who has made incandescent, HMI/HID and fluorescent lamps) and is now touting LED lighting, it tells you a story about the direction they see lighting going in. Here is a link to a good read about LED lighting produced by Color Kinetics/Philips. This pamphlet will enable you to speak more intelligently to your clients. I do not work for Color Kinetics or Philips and am not touting their products, I am just trying to help in the education product. You will come to your own conclusions.

Never close your mind to technology.
 
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Electric-Light

Senior Member
Fluorescents have ultraviolet emissions that are eye damaging when you are in the light field.
If you hold a lamp up to your eyes and stare at it all day long, possibly. The glass envelope does not transmit the UVC generated inside the lamp.

LED's do not have a "tremendous" amount of eye damaging blue light.
It does in the context of your statement "fluorescent lamps have tremendous amount of green".

There is a big difference between a known fact and something that could be. LED's can kill you if you swallow enough of them at one time.
T8 lamps have 2 to 4mg of mercury. About 1/1,000 to 1/2,000 used in a thermometer. Most modern spent lamps are considered non hazmat waste in some but not all places. HIDs contain an order of two magnitudes more. 200-1,000mg range. This thread is about LEDs touted as replacement for T8 linear lamps, not HIDs (which includes HMIs)

LEDs may constitute ahazardous waste. http://www.pprc.org/research/rapidresDocs/rr-LED_lights_toxic.pdf

Your first reply to my post I wouldn't disagree with you that Light Emitting Decorations do well in decorative lighting and special effects I would just like to correct. This isn't decorative lighting or special effects.

A Color Kinetics PDS-750 will control 12 units at 750w total load. 12 lights for the load of 1?

Those are specialty lighting. LEDs do not have 12 to 1 efficacy even against incandescent lamps. A substantial portion of light is lost if you use a color wheel filter, but anything using a color wheel would be a special effects lighting.

The RE80's you mentioned are in that CRI range at a temperature 5000K+.
RE80 or 800 series are available in all sorts of color temps.
Household CFLs are RE80, 2700K.
800 series T8 lamps are readily available in 3000, 3500, 4100 and 5000. 6500 also available but not common.

RE70 T8 lamps were just banned since the efficacy is slightly lower than RE80 lamps.

It is unfortunate when someone tries to convince people not to use something based on weak facts.
Worse yet, someone like yourself steering people into LED by giving incorrect facts such as RE80 fluorescent lamps are only 5000K or higher...
LEDs produce less heat...

I suggest to anyone that is being asked by a client about LED installation to read up on it, don't rely on opinion.
I agree. I recommend reading the energy.gov and make the LED vendor produce answers to all the recommended questions in that list and if you have the time, read the PNNL report I also linked.


When large lighting manufacturers like Philips (who has made incandescent, HMI/HID and fluorescent lamps) and is now touting LED lighting, it tells you a story about the direction they see lighting going in.
The marketing literature choose applications that make the product look good.

Here is a link to a good read about LED lighting produced by Color Kinetics/Philips. This pamphlet will enable you to speak more intelligently to your clients.
Never close your mind to technology.

Pamphlets are designed to help sell the products.


For example, eW Cove Powercore, a linear LED fixture from Philips Color Kinetics, emits light in a tight 110? spread. At 177 lumens per foot, these fixtures produce much less light than a popular F32T8 lamp, which is rated at 700 lumens per foot. However, analysis shows that eW Cove Powercore delivers a comparable level of light to a target area.

Including all losses, about 85% of the F32T8?s lamp lumens leave the fixture, reducing its lumen output to 595 lumens per foot. But those 595 lumens are radiated in all directions, in 360?. Any 110? slice would contain about 30% of the lumen output, or 182 lumens ? almost exactly the same as eW Cove Powercore.
From the sell sheet you linked.

What a shame of an analysis. Probably written by a sales person. It's embarrassing. They modeled it as if a fluorescent fixture is equivalent to a bare lamp painted with 85% pass neutral grey on 1/3 of the section and flat black on remaining 2/3.



The pamphlet claims are wrong or misleading.
  • Fluorescent lamps emit in all directions in 360?
  • fixtures do NOT radiate over the entire 360? as the pamphlet claims. The 15% drop is incurred in the fixture in redirecting the light to where it is desired.
  • 2800 lumen is a common "mean" lumen rating on a fluorescent lamp after 40% of hrs are used.
  • They're using brand-new out of the box output for LEDs, not the mean lumens.
 
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mirawho

Senior Member
Location
Sun Valley, CA
This could go back and forth forever. So you know, I worked in film for a while and we used fluorescents. Fluorescent's have a green spike in the light. A meter can see this. The camera sees this light and you have to add a magenta (minus green) gel to the lights to cut the green hue. They now make Bi-Ax lights that are corrected but unfortunately, the magenta added into the phosphorus coating is very prominent for a while. For you to try to go tit for tat with the blue against green, really???

Also, since you know so much about LED's, I am not sure how you did not know that you do not need color wheels or gels for them. Where you are mistaken with me is I am not saying LED over fluorescent, as I use fluorescent lights that I am having manufactured on shows. But, in your case, you appear to be implying that LED's are a novelty.

You can feel like you are vindicated now since I refuse to reply to this thread anymore. But, walls just don't give. They don't bend. You will try your hardest to convince others how bad LED's are. Maybe you a vested interest in fluorescents, who knows. Me, I just have studied all of this technology as when we purchase lights, we are doing it to the tune of $1/4m +. So, we know as we have studied, we have the best engineers come over from all of the manufacturers. And these manufacturers also fabricate very expensive intelligent lights that use HMI's so it would be in their best interest to have your point of view, that LED's are the evil empire of lighting. In fact, they see the future. They are not salespeople, but engineers.

I guess you missed the part where I said Philips made that catalog. Ever hear of Philips??? They make lamps, all types. And they make a lot of money from lamp sales. Anyway, if you respond I wont see it as this is more or less a joke to me at this point. I will leave you alone to your mission here in this thread.


A little picture for you

why-cats-hate-their-owners.jpg

I am not putting you down or trying to make you look stupid or inferior, just letting you know what I think of your thread at this point.

Cheers and have a good Holiday!
 

Electric-Light

Senior Member
Fluorescent's have a green spike in the light. A meter can see this. The camera sees this light and you have to add a magenta (minus green) gel to the lights to cut the green hue. They now make Bi-Ax lights that are corrected but unfortunately, the magenta added into the phosphorus coating is very prominent for a while. For you to try to go tit for tat with the blue against green, really???

Fluorescent lamps have a green spike that comes from mercury emission spectrum. Sensitivity curve of our eyes and photographic film are different and the higher sensitivity of film to the mercury line is why pictures turn green even though the light doesn't look green to your eyes.

Our eyes, film emulsion, CCD, CMOS and photo tubes all have different response curves. In film making, how it looks to the photographic equipment is more important than how it is seen by the eyes. I honestly don't know how ordinary 3,000K lighting LED vs 3,000K halogen vs 3,000K fluorescent on a "tungsten" gets rendered. I haven't use a film camera for a long time. I suspect both the LED and fluorescent will cause a strange tint in the image. I remember the magenta FLD filter from the film camera days.

Most white LEDs for lighting are solid state fluorescent lamps which is a yellow glowing phosphor pumped by a shortwave blue LED. The blue from LED and yellow from phosphor coating blend to form white light. The output has a strange double hump spectral distribution. LED lighting that use R,G and B LEDs are rarely used in general lighting.

Also, since you know so much about LED's, I am not sure how you did not know that you do not need color wheels or gels for them.
What I meant to say is that getting vibrant saturated color from a white light costs you a ton of output even if it is a white LED behind it.

There's no doubt that LEDs do very well when you want saturated colored light. These lights use an array of R,G,B LEDs to produce colored light.


Where you are mistaken with me is I am not saying LED over fluorescent, as I use fluorescent lights that I am having manufactured on shows. But, in your case, you appear to be implying that LED's are a novelty.
Where you're mistaken is the performance of T8 fluorescent and general purpose lighting LEDs such as your belief that RE80 fluorescent lamps only exist in 5,000K or higher CCT.

[Me, I just have studied all of this technology as when we purchase lights, we are doing it to the tune of $1/4m +. So, we know as we have studied, we have the best engineers come over from all of the manufacturers.
Theatrical and production lighting are speciaty applications with needs that are very different from general lighting. Your office light do not need the ability to produce colorful lights or intelligent DMX control capability. The example applications you've given are all specialty lighting. No doubt theatre and venue lights are very expensive and you don't buy them for the percent of lumens that remain after 40,000 hours of burn time or the lumens per watt.


I am not putting you down or trying to make you look stupid or inferior, just letting you know what I think of your thread at this point.
You're only making yourself look silly with ignorant claims like RE80 fluorescent lamps only exist for CCT 5,000K or higher.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
FYI the Academy of Motion Picture Arts and Sciences has published an extensive study comparing color output of various standard film and digital imaging techniques when used with tungsten light and with a variety of fluorescent and LED types. One notable result was that although standard CRI measurements gave some useful information, the combination of film sensitivity curves and emitter curves (especially with spikes) defied simple analysis.
The bottom line is that for filming rather than live shows a lot more work needs to be done.
There is a thread back a few months that includes links to the full report.
 

iwire

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White LEDs have a tremendous level of potentially retina damaging blue.

Source?

That's an urban legend. The truth is watts in = heat out. Given the same input wattage, LEDs produce the most conducted heat that must be dissipated by the heat sink. Total BTUs is the same if the input wattage is the same regardless of lighting technology. Law of Physics.

That response is a fail, it is what a snake oil salesman would say.

While essentially accurate it does not address the issue of a customer saving money.

Very simply no one is replacing 34 watt T8s with 34 watt LEDs. Typically I see 2/3s of the wattage dropped.

Less watt in = less heat out. Law of Physics

LEDs maybe considered hazardous waste depending.

Maybe? Depending?

The fact is currently I can toss LEDs in trash while I have to pay to dispose of fluorescent lamps.

The manufacturing process of LEDs may not be environmentally friendly either.

Which is much more controllable than sending hazardous waste out to consumers.

Which means fabric brighteners or anything that rely on UV content to contribute to appearance won't work.

UV fades colors, I would call it a wash. :D





Electric-Light said:
mirawho said:
If you drop or break a fluorescent lamp that is ceiling mounted, you are going to have shards of glass everywhere that are hard to find.

That's why there are coated lamps for those applications requiring shatter resistance.

Come on, another disingenuous answer?

You don't really believe he is talking about a lamp in a rough location do you?

He is talking about handling lamps while installing, replacing, transporting them.

I am sure you are aware of the recommendations for broken lamps right?

Here is a Google search so you can pick your own source https://www.google.com/search?q=disingenuous&ie=utf-8&oe=utf-8#q=fluorescent+lamp+clean+up&spell=1

Now as a contractor working in a building if I drop a lamp I could be looking at a real issue.


To me your posts have proved one thing to me and that is you will say anything at all to discourage the use of LEDs which to me is just as bad as the LED makers that make outrageous claims.

Well off to install some light emitting decorations. :D
 
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mivey

Senior Member
Anyway, if you respond I wont see it as this is more or less a joke to me at this point. I will leave you alone to your mission here in this thread.
I find your need for hostility interesting. You seemed to be more sensitive than necessary. Why not just present the facts as you have them and forget the drama?

Drama aside, I certainly appreciated the input you gave about your lighting application as it was very interesting.

I am not putting you down or trying to make you look stupid or inferior, just letting you know what I think of your thread at this point.
I find his posts interesting to read. They are a good balance considering the over-hype we get for LEDs. Many of the LED pitches mis-state the comps and I find Electric-light often reveals those things thus I like his posts.

Much like you, I have found some places where LEDs work well, places some places where fluorescents work well, and some places where MH work well.
 

mivey

Senior Member
While essentially accurate it does not address the issue of a customer saving money.

Very simply no one is replacing 34 watt T8s with 34 watt LEDs. Typically I see 2/3s of the wattage dropped.
But it was a response to un-fair comps which I'm sure you see from sales pitches as well as I do.

To me your posts have proved one thing to me and that is you will say anything at all to discourage the use of LEDs which to me is just as bad as the LED makers that make outrageous claims.
Yes, he does tend to be anti-LED but it is refreshingly balancing. I get sick of the LED over-hype. I like vendors that are straight with the facts. I do find them to be revealing but I always make my own checks for lighting design. I do appreciate the information he gives that is not so easy to find.

I have found fits for both LED and HID and really could care less as to which technology it is as long as it makes sense; real sense not sales baloney.
 
Yes, he does tend to be anti-LED but it is refreshingly balancing.

I wouldn't say that, when the reporting is wrapped in the verbiage of light-emitting decorations, it's hard to consider a serious analysis.

Likewise, when I try to read the screeds, the phrase "bad science" often comes to mind. The math may be right but the basis, methodology, and conclusions may not be. A simple example of the first:
Electric-Light said:
Fluorescent lamps emit in all directions in 360?

No, they emit only axially around the long dimension of the tube; there is no light emitted through the bases. It would be valid to say "tube-style lamps emit in all directions around the axis". (While the discussion is predicated on T-8 lamps, it then veers off in to not-necessarily-valid generalizations. Stick to the exact subject.)

Also, don't mix unit systems; if you're going to talk in watts, stay in SI where heat is watts, not BTUs.

(I could go on, but don't have time at the moment. You're safe :).)
 

Electric-Light

Senior Member
FYI the Academy of Motion Picture Arts and Sciences has published an extensive study comparing color output of various standard film and digital imaging techniques when used with tungsten light and with a variety of fluorescent and LED types. One notable result was that although standard CRI measurements gave some useful information, the combination of film sensitivity curves and emitter curves (especially with spikes) defied simple analysis.
Yeah, show lighting is beyond the scope of "general service lighting".

http://smartlighting.rpi.edu/events/veitchIndustry.pdf
See page on blue light hazard.

http://ehp.niehs.nih.gov/1307294/
See conclusion

As I said, may cause.

While essentially accurate it does not address the issue of a customer saving money. Very simply no one is replacing 34 watt T8s with 34 watt LEDs. Typically I see 2/3s of the wattage dropped.
Comparing what two?

I am comparing the most typical 59W per two lamp n the beginning vs 38W per pair of input at the fixture with LEDs as shown in the lab report commissioned by Philips themselves. This comes out to about 1/3 of the wattage dropped, not 2/3 dropped. The savings claim don't come anything close to the claim.

I can reduce watts by simply substituting 32W T8 lamps with 48" 25W T8 too or removing a lamp lamp from each fixture to get a lower wattage input along with lowered output. If the original fixture design makes a very poor use of upper portion of the lamp, it makes the LED drop-ins look unduly favorable. A power reduction with a corresponding drop in output can not be attributed to "LED technology" efficiency gain.

You also need to evaluate the performance verification criteria. FC reading is often taken with the light meter at the red box. The FC readings as applicable at relevant surfaces need to be divided by LLF. If the lamp lists 40,000 hrs to L70, the FC reading with a brand new fixture needs to be correspondingly higher so that FC reading at all surfaces stay above the level needed by design throughout the entire lamp of life.

Keep in mind that FC readings at the points shown in red circles matter in real life, because it's not a museum of ordinary looking linoleum floor. A narrow beam can easily give a matching FC as measured at the point of red box, while failing to match the existing FC level on other relevant surfaces.
GpsNqJ3.jpg


I can deliver more FC with my 2 AA flashlight than the room lighting if I simply arbitrarily defined the performance as foot candles landing on the square for today's date and ignore everything outside.




You don't really believe he is talking about a lamp in a rough location do you?
He is talking about handling lamps while installing, replacing, transporting them.
Same argument applies to replacing all glassware with plastic in bars in order to prevent glass fight. They do that in England.

I am sure you are aware of the recommendations for broken lamps right?
A hysteria. I've seen in MSDS that lists ethanol as "carcinogenic, potential mutagen". If you look at the MSDS for shampoo, you'll see the same non-sense hysteria in the event of skin contact or eye exposure.


To me your posts have proved one thing to me and that is you will say anything at all to discourage the use of LEDs which to me is just as bad as the LED makers that make outrageous claims.
Well off to install some light emitting decorations. :D
Ultimately, I hope that this thread reach purchasing decision makers and give them a guidance in making a more informed decision rather than jumping on LEDs on sales people recommendations. For example, the wisdom to pop off the cover and review the ballast/lamp system specs rather than letting the sales guy use his own estimated value to calculate the payback period.

Also, don't mix unit systems; if you're going to talk in watts, stay in SI where heat is watts, not BTUs.:).)
It was intentional, because that's the convention just like 2.5 liter 175 hp rather than 130kW.
 

Cletis

Senior Member
Location
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Whoa! This is too much before coffee. Can you cliffnote this stuff? Is this Electriclight keep buying t8's v.s. Mirawho buy LED's ?
 
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