[ceaz40]

I really like the idea of LED lighting in the Bay colours...wasn't there an issue many years ago about the lighting of the top where people complained that it created a very eerie glow on streetlevel for those walking at night in the area?

 

[Marko]

Actually, knowing LED technology as well as I do - I am certain that the crown could be illuminated by solar energy - assuming there is enough open rooftop. Even animated/color changing if need be - though less tacky than the effects chosen for the CN Tower.

So it could be completely off the grid - but battery change outs every 3~5 years would cost about the same as actually being on the grid (at today's rates), Disposal is another matter altogether - but this could be done of there is a will to try.

 

[AGTO]

If energy efficiency is the goal, fluorescent is still more efficient then LEDs.

 

[Marko]

If energy efficiency is the goal, fluorescent is still more efficient then LEDs.

Not entirely true.

There are a lot of LED products out there that meet or exceed the efficiency of fluorescents - especially when discussing specification grade products. You won't see it at Home Depot any time soon, but this type of project certainly be using a quality LED product as opposed to some offshore stuff with exaggerated claims.

That said - it really comes down to what they want the lights to do. You may need to utilize more of one product or the other, depending on spacing, effect, etc... and what the desired brightness really is. With LEDs, a larger number of lower power products can be spaced to produce the right consistency, which is harder to achieve with bright lines that fluorescents produce, not to mention that you're very limited with types of lamps. If you want the Bay colors or any sort of changing capability, then LEDs are the way to go... and fluorescents don't like the cold.

Further - a properly made LED system will last 3~5 as long as fluorescents (and still having +50% of their original light). That's 3~5 sets of fluorescent lamps that don't need to be replaced, saving cost, maintenance and disposal (mercury after all).

/LED sales pitch

 

[AGTO]

There are a lot of LED products out there that meet or exceed the efficiency of fluorescents

Only in single colours, not white. That's not taking into account the reduction in luminous efficiency over the life of the LED.
I too know a lot about LEDs.

which is harder to achieve with bright lines that fluorescents produce

They've been making fluorescent backlighting for a number of years...in fact the backlighting on an LCD monitor is fluorescent....no hot spots unless it's a very poor design.

If you want the Bay colors or any sort of changing capability, then LEDs are the way to go...

Or you could use filtered fluorescent

That's 3~5 sets of fluorescent lamps that don't need to be replaced, saving cost, maintenance and disposal (mercury after all).

As long as you completely ignore the manufacturing proces used to make LEDs, and the toxic waste produced.

Don't get me wrong, I love LEDs...it's just the constant claims of them being the ideal light source is not (yet) true.

 

[Marko]

No - there are White LED that easily exceed the efficacy of fluorescents - they just aren't used in your day-to-day LED products yet.

Of course LEDs depreciate - all light sources do. Fluorescents and neon drop 25% in the first few months alone. In winter, it's common for florescents to have less than 50% of their original output and the more winters they live through, the faster they depreciate.

Also, and LCD monitor is most certainly not "backlit" with fluorescent - it is edgelit with CCFL lamps that wrap around the perimeter of the screen. They're both gas tubes that rely on mercury and high voltages to work - so they're very similar - but the costs to seam together enough edgelit panels to wrap a building would be astronomical, not to mention the lower life expectancy.

I never said LEDs were the ideal light source for everything, but considering the parameters that this particular install might require, I would say they're a better choice than anything else available.

 

[AGTO]

No - there are White LED that easily exceed the efficacy of fluorescents

No, not yet. I'm sure you're aware that "white" LEDs are actually Blue LEDs with a yellow phosphor....limiting their efficiency.

Also, and LCD monitor is most certainly not "backlit" with fluorescent - it is edgelit with CCFL lamps that wrap around the perimeter of the screen.

They most certainly are. CCFL = Cold Cathode Fluorescent Light.
Due to the small tube diameter, and a high voltage starting pulse, the cathode heaters, found in normal Fluorescent lights, are not needed.
Most large screen LCD's have multiple backlight tubes, not edge lighting.

I would say they're a better choice than anything else available.

...probably because you're not familiar with other high efficiency lighting sources.

 

[Marko]

No, not yet. I'm sure you're aware that "white" LEDs are actually Blue LEDs with a yellow phosphor....limiting their efficiency.

Of course I am aware that White LEDs are made with a phosphor over a Blue chip. All light sources have limitations, but the blue>phosphor down conversion does not make White LEDs inherently "limited". Limited compared to what?

I have LEDs in our shop exceeding 100 lumen/W. 80 lumens/W is more typical, so when you factor in system efficiency, power supply efficiency - we're in the neighborhood of 60 lumens per watt system or luminaire efficiency. That is above T12, the same as T8, but below T5HO... though all fluorescents drop significantly after burn in.

Most large screen LCD's have multiple backlight tubes, not edge lighting.

You didn't say large screen LCDs - you said LCD monitors - but rather than argue semantics, I'll concede that yes, large screen LCDs do use rows of CCFL tubes... for now. Samsung, LG and others are all re-engineering for LED.

...probably because you're not familiar with other high efficiency lighting sources.

I'm actually very familiar. We're discussing possibilities here and I've done nothing but lay out information, so there's no need for ad-hominem insults.

 

[AGTO]

You didn't say large screen LCDs - you said LCD monitors - but rather than argue semantics

You're ignoring the fact that you insisted that fluorescent tubes weren't used as backlights. Screen size has nothing to do with it anyway.

We're discussing possibilities here and I've done nothing but lay out information,

Yes, it is a discussion, and when you claim to be an expert and then make statements not based in any reality, you will get called on it. No need to get upset.

 

[Marko]

You're ignoring the fact that you insisted that fluorescent tubes weren't used as backlights. Screen size has nothing to do with it anyway.

I never made a statement about fluorescent as backlights at all. Having done many signs over the years, I know that in fact they are very frequently used as backlights.

You were the one that asserted fluorescents were used to backlight LCD monitors, which isn't exactly true - this is what I was trying to clarify.

Yes, it is a discussion, and when you claim to be an expert and then make statements not based in any reality, you will get called on it. No need to get upset.

Every statement I made is in fact based on reality. You called me out, but haven't actually disproven anything I said.

 

[AGTO]

Also, and LCD monitor is most certainly not "backlit" with fluorescent - it is edgelit with CCFL lamps

I never made a statement about fluorescent as backlights at all.

Ok, sure.

You were the one that asserted fluorescents were used to backlight LCD monitors, which isn't exactly true - this is what I was trying to clarify.

But it is true, and you haven't clarified anything, other then to reveal that you didn't know CCFL was fluorescent.

Every statement I made is in fact based on reality. You called me out, but haven't actually disproven anything I said.

Likewise

 

[Marko]

Ok, sure.

You're taking things out of sequence and out of context.

Read my post #34 in this thread, which is where we start this whole LED vs flourescent debate in reply to your post #33.

Re: efficiency.
I mention that LEDs meet or exceed fluorecent efficiency.
> You reply that is true for single colors only, but not white, which is wrong. First off - how many colors do you think standard fluorescents come in? Gels are usually used for colors. You then comment about reduction in efficacy of LEDs... but fluorescents experience an even greater reduction.

I reply that there are in fact LEDs with efficiency at or better than fluorescent.
> Your reply then changes topic and talks about conversion from Blue to White using phosphors, but this doesn't disprove my claim in any way. It also ignores the fact that fluorescent lamps also use phosphors to convert blue light to white. So now that we know both technologies use phosphors to convert Blue light to White, can you explain to me how this inherently limits LED efficiency to less than fluorescent? That's what you're claiming, right?

Re: backlighting
Again - go back and read post #34. I discuss how one technology may or may not work better than the other, depending on what is required to illuminate a specific project, or in this case the crown.
> You reply that they've been making fluorescent backlighting for a number of years. So what? Can you show me where I mentioned backlighting at all? You then say that fluorescents are used to backlight LCD monitors.

I reply that A) flourescents are not used for LCD monitors. An edgelit CCFL and a fluorescent backlight are not the same thing, and B) to use such a method would not be wise for this application.
> You then claim that they are in fact used for large screen LCDs (a whole different thing), and then you actually explain how CCFLs and fluorescents are in fact 2 different things! (I'm still wondering why the hell we're talking about backlights to begin with?).

I reply that you moved the target with the monitor vs large screen, but concede that at this point we're talking semantics.
> You reply that I'm ignoring that I insisted fluorescents were never used as backlits - when I never said such a thing. You are the one who brought up backlighting specifically for LCD monitors, which I refuted and still do - but this still has nothing to do with the discussion about the crown lighting of the building which is not backlit to begin with!

I'm scratching my head as to why you brought up backlighting at all?

But it is true, and you haven't clarified anything, other then to reveal that you didn't know CCFL was fluorescent.

Actually, I explained how they are very similar - you actually explained how they are different. Talk to anyone in the lighting industry and no one will say that a CCFL "is" a fluorescent. You and I both know that they are used differently and for different things, but if you wanna hang onto this little overlap in definitions as proof that you have somehow proven me wrong, feel free.

In every other part of this discussion, you have either avoided a direct answer on LED efficiency, or somehow come back to the backlighting thing, which was never part of the conversation to begin with.

 

[AGTO]

Actually, I explained how they are very similar

Actually, you didn't....you made it clear that you didn't know they were the same, and now you're backpeddling.

You're pedantic and then cry foul when you got confused with symantics.

you've also avoided my questions to you, and parroted marketing literature instead.

 

[Marko]

Actually, you didn't....you made it clear that you didn't know they were the same, and now you're backpeddling.

They aren't the same.

You're pedantic and then cry foul when you got confused with semantics.

Right. Force someone to explain the error of your logic to you, then call them pedantic for trying to be clear and concise to avoid further confusion.

you've also avoided my questions to you, and parroted marketing literature instead.

I just went back over all your replies on this page and did not see one single question mark, or even sentences that could have been questions... so this accusation is plain wrong. Now you claim that I am parroting marketing literature (when I did no such thing), as if this accusation magically made your comments on LED efficiency right (which they weren't)?

 

[adma]

Tech talk. Wow.