Welcome to the world of LED lighting where match and harmony do not matter ;)

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Electric-Light

Senior Member
Generally, more than one fixtures are used side by side.

Welcome to the world of LEDs where zero mercury, higher lm/W than CFL and hour ratings with lots of zeroes behind it dominate the show.

Here, we don't care about harmonious appearance. Like CFLs, the base contains circuit boards and it's a common point of failure.

The unspoken rule of the LED world: When a lamp or decorative light emitting devices fail, corrective measures shall be limited to close enough ism.
"our liability shall be limited to refund of purchase price or replacement with similar specifications at our discretion, whichever is less expensive to us"

Replacement that satisfies requirements without satisfying application needs:

If the x'd out devices fail, there are other specification wise equivalent products. I mean, who cares they look different, right?
X1b0yya.jpg


The x'd out products are only a few years old, far younger than the life they tout, but they're already discontinued, so if you have a matching set, :happyno: :happyno: :happyno:
Again,thanks for trying out Decorative products that Emit Light

So, before you get sold on light emitting ceiling cosmetic accessories, ADD A LINE TO SPECIFICATION that creates warranty obligations for harmonious match that you would expect from an auto body repair :)
Imagine how cheap would collision repair be if the industry repair standards were to simply pre-paint the parts with same color code paint and bolt it on and not require aesthetic match. I think I just spoke the standards that apply to LED install warranties :ashamed1:
 
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GoldDigger

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I think your analogy fails. The proper analogy would be if they prepaint the fender with their choice of colors in use during the *current* model year.
 

Electric-Light

Senior Member
I think your analogy fails. The proper analogy would be if they prepaint the fender with their choice of colors in use during the *current* model year.

Either way, it is matching the rest of the system aesthetically that presents a challenge. Paint fades with age and exposure to elements. If you're painting a wall and you have several jugs of paint, it's a common practice to mix them all instead of using them back-to-back, because if you start with can 1 and go to can 2 half way through a wall, its quite likely that you can see where the change was.

Low pressure mercury discharge fluorescent technology has variation, the variation from lot-to-lot and aging have much less effect than Light Emissive Decorations.
LEDs shift like metal halide. (but in Sam's Club or Costco ceiling, aesthetics of high bay lamps are not a big deal...) and you can see where the system has been spot relamped.

If there are more than one switched circuits in an area and they accumulate substantially different number of hours, LEDs are FAR more likely to develop different aging. So, when they're brand new, you can't tell which ones are switched separately. After 2-3 years, you could have a zebra pattern and warranty would not consider it a defect as long as it has not fallen below expected lumen values. This is very much LED specific problem. :happysad:

Even if they're the over priced expensive microprocessor tuned type only meant to be bought with tax payer funded grants, you could experience a difficulty in making sure units that failed 12,000 hours into use to aesthetically match the rest and ensure the replacement ages uniformly with the system.

If it requires skilled matching like auto body paint, that's substantial labor expense.
 

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Electric-Light

Senior Member
Performance standards of LEDs still immature.
http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/led_luminaire-lifetime-guide.pdf


The theme of LED push is extension of lifetime. The initial measurements only tell you how it works at the very beginning. So, if winter tire ad blasts good performance and long life, you could still get very stellar review even if they last only a third of what they claim and how long they last depends on how they define end of life.

Fluorescent lamps are fairly clear cut. It's the time for half of them to fail in a large sample and it follows a statistical curve once this value is established. LEDs are based on time it takes to DEGRADE to UNACCEPTABLY POOR performance of 70% of initial output. (fluorescent lamps with median failure life as much as 70-80,000 hours are available... with output maintenance of about ninety-three percent. No LED product I know of gets a L90 (time until 10% decay) that high)

I believe there are very expensive CFL troffers that tout 120 lm/W with something like 50-100K hour life, but that's 84 lm/W at end of life. It would be irresponsible to specify solid state junk without using the output after half the advertised life has been consumed.

The best fluorescent system pushes about 100 lm/W and good optics can provide about 92% efficiency and lamps hold 92-95% output at end of life... so you only need to over-specify the initial lumen output by about 10% to hold design illumination level. LE Decoras require 42% over-spec to allow for depreciation down to 70%. So, dimming is touted as a feature, but it's a requisite... to tune down in the early portions of life and ramp up to compensate for decay :lol::lol::lol::lol::lol:
 

James L

Senior Member
Location
Kansas Cty, Mo, USA
Occupation
Electrician
Product lines change all the time. Big deal.

I had a customer with 3 pendant lights over her kitchen island. When her son broke one of the globes, she couldnt find a match. And her fixtures were only two years old.

My son has a 10" Samsung tablet that's only two years old. When he lost the charger, we couldn't find one. Too bad. Buy a new tablet.


So something doesn't match exactly, is it the end of the world? Maybe, maybe not. Should a service plumber throw his copper pipe outside in the mud for six weeks, so that when he repairs a 15 year old pipe it will match?

Should every fuorescent lamp in an office be changed at one time? Possibly. But how many times have you noticed an obvious color difference from one troffer to another. Doesnt seem to bother people too much


Ok, what about light output diminishing over time? Have you ever compared the initial lumens of an HID to the maintained lumens? Evry type of lamp diminishes over time. Change just one of 6 lamps, and you can see the difference.
 

Electric-Light

Senior Member
Should every fuorescent lamp in an office be changed at one time? Possibly. But how many times have you noticed an obvious color difference from one troffer to another. Doesnt seem to bother people too much
This is often due to mismatching lamps like 3500 and 4100 interchanged.

Ok, what about light output diminishing over time? Have you ever compared the initial lumens of an HID to the maintained lumens? Evry type of lamp diminishes over time. Change just one of 6 lamps, and you can see the difference.

HIDs and LEDs have severe degradation over lifetime. Probe start MH can lose 40-50% output.
LEDs 30%. T8 8-10%.
 

James L

Senior Member
Location
Kansas Cty, Mo, USA
Occupation
Electrician
This is often due to mismatching lamps like 3500 and 4100 interchanged.

For sure. My point is that most people don't care that much.

It irks me to see device plate screws that aren't all turned with the screwdriver slot vertical. But most people don't notice something like that.


HIDs and LEDs have severe degradation over lifetime. Probe start MH can lose 40-50% output.
LEDs 30%. T8 8-10%.

Yes. And how long have HIDs been around?
 

James L

Senior Member
Location
Kansas Cty, Mo, USA
Occupation
Electrician
Before you make a final judgment about alternatives to incandescents, it helps to get into the technical side a little. I used to be afraid of LEDs because of cost, constant changing of product, and other factors. Basically, it was a fear of the unknown.

Then I started comparing technical data, and the science behind light sources, and my perspective balanced out. Then I started talking to LED manufacturer reps in China, and discovered some of the failure problems with higher wattage applications, and I became biased against them again.

But LED technology is improving fast. They're gonna get there, and the more people buy them, the faster it will be.


Every kind of light has its pros and cons. Lumens per watt, life expectancy, product cost, light accuracy, aesthetics, etc.


Here's a very good technical article from popular mechanics a few years ago, comparing incans, led and cfl:
http://www.popularmechanics.com/tec...scent-vs-led-ultimate-light-bulb-test#slide-1


Here's another short one looking at color temp and spectral range:
http://www.soundandvision.com/content/led-vs-cfl-bulbs-color-temp-light-spectrum-and-more


Here's another one highlighting problems with LED lumens per watt issues as wattage increases:
http://spectrum.ieee.org/semiconductors/optoelectronics/the-leds-dark-secret
 

Electric-Light

Senior Member
The first link is biased or uninformed to say the least. Screw-in line voltage LEDs and CFLs both face problems with electronics failures as they both require a driver.

A lot of LED sales people parroting the very narrow knowledge about fluorescent lamps hey were taught by their trainers.

"LEDs don't generate heat"
"LEDs don't have ballasts to fail"
"LEDs are not fluorescent"

LEDs are currently not an appropriate candidate to replace something such as 1500W MH used in sports arena lighting, short arc xenon used in search lights and questionable as far as replacing large area commercial lighting.

I also find xenon arc lamps equally unsuitable for AA battery powered flashlights.

The REAL advantage in LEDs are in their ability to get lumens per watt that is competitive with high power HID and fluorescent well into fractions of watts and they're less breakable in portable use.

So, I think LEDs will push out regular bulbs like transistors pushed away vacuum tubes in flashlights and smaller portable lighting tools. I haven't used a flashlight that's not LED in a long time.

LEDs produce an output that is much more intense on the surface than fluorescent lamps so they require more diffusers. LEDs also lack the ability to produce thousands of lumens in a tiny dot which makes them unfit for high intensity use like projection and search light.

They are exceptionally good for flashlights.
 
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