Electric_Light

As to why you feel customers should get LEDs for general service lighting applications for new install or retrofit instead of the newest discharge technology available.

BBQ

Hmmm, I have only once 'pushed' for LED. That particular application was for security call stations located in a parking lot.

They wanted these to run 24/7.

Something like this ...




That said I install tons of LED because the customers come to us wanting it done and we are in the business of installing electric equipment.

In most cases the utility incentives are the reason the customers want these.

chicken steve

because led's are in vouge

validity be d*mned....

~CS~

Dnkldorf

Led's have ONLY one advantage, as far as I am concerned, over gas technology.

LED's emit no UV light, meaning no bugs. Bugs, like flys, moths, beetles, bees...ect are attracted to UV light. This makes LED's ideal for applications like food areas, pharma applications, and anywhere else you don't like bugs flying around.

LED's can be made to emit UV light, but these are special made UV LED's, and aren't cheap.........as if regular LED was......

IMO

Electric_Light

Even that seems to be challenged.
http://www.energycircle.com/blog/201...o-attract-bugs

If you use amber LEDs, then its possible

Big John

I've looked at LED wall-packs in the supply house and was really shocked by how short the life was. These things were advertised at about 60k hours. I don't know if the lamp assembly is replaceable or what it costs when it needs it, but that definitely cut down on the perceived value for me.

-John

Dnkldorf

From that link:

" We placed the two bulbs in fixtures on either side of an exterior door. Lo and behold, both, sadly, did attract bugs."


Well duh...........what kind of control variable is that? The bugs will be attracted to the incandescent, and flow over to the LED, not 4' away.

A better test would of been, If he shut off all the lights in the house, and measured how many bugs were attracted to his lights one night, and then changed them to LED, leaving the same variables in place, he would of gotten a better sampling of whether they are more, or less, attracting bugs.

Agree?

BBQ

No, this is another 'slam LED thread' so please don't try to be fair.

MarkyMark

The only LED's I push are the Cree recess can CR6's and LR6's.

They are cheaper than compact fluorescent recess cans, and easier to install, with a higher quality and better dispersed light IMO.

They look way better than an incandescent can, and use much less energy. Also a higher quality and better dispersed light.

I do mostly commercial fit-ups. I've installed 100's of these in the last year and a half. They are an easy sell.

mbednarik

less maintenance. GE lamp prices just had a rate hike. more to come i'm sure. Makes long term cost go up. What lumen to watt ratio's are your gas discharge lamps?

captkirk

I bought a couple of small r20 screw in type for my house and i can get past the poor light color.... not to mention the poor beam spread angle... They all seem to put out a tight beam and you can see a spot on the floor.. I dont get that when i use standard incandesant bulbs...

Although i am really impressed with the six inch cree retro rit style in my kitchen... Nice color and great beam spread...

__________________
Full time Bovine Scatologist.

wendon

I'm still not sold on LED's. Maybe when the cost comes down to where you can justify them over fluorescent. The life expectancy isn't that much more than some of the fluorescent bulbs. The only advantage I can see is less watts per lumen which is important if your restricted by the energy code as to how many watts you're allowed per square foot.

__________________
Ive seen burnt up outlets, chard neutrals, and shorted wires.
Uncfesta

Electric_Light

I don't know what you mean by "your" lamps, but the top line GSFL with NEMA Premium ballast gets 92-105 lm/W (not including optical losses in fixture, but that is true with every type of fixture) and maintains 90-95% of new specs until they burn out.

After they're integrated into high efficiency fixture with 85-90% efficiency, the initial lumens per watt is fairly comparable with the latest CREE LED troffer, but the specs on CREE troffer allow 30% depreciation in output over life.

Though each manufacturer tries to differentiate their product with extended warranty for paring their ballasts with their lamps and push sell sheets that emphasize about insignificant details (i.e. 50 lumens on 3,000 lumen lamp), the performance differences are small.

I guess Sylvania now make T8s rated at 52,000 hrs on 12/hr day cycle now.

mbednarik

do they still have the same lm/watt ratio with a dimming ballast and same life with more frequent starts, lets say 2hr/start.

Electric_Light

Programmed start setup can achieve over 90lm/W and offer something like 100,000 starts. I don't have the specific data, but frequent starting reduces life regardless of starting method. Not that much with programmed start. Quite dramatically with instant start.


Newer programmed start ballasts apply power to lamp cathodes but they're turned off thereafter. When they're dimmed, the heaters are turned back on at some point since the cathodes can't remain hot enough on their own at reduced power. I think the power consumption drops linearly down to about 50%, then the output falls faster than the power consumption.

Dimming ballasts should provide about 90 lm/W on maximum setting. They're used where dimming is needed for visual or aesthetic reasons. Dimming setup is costly and payback period is long to never just like LED system.

In applications where cycle time is 2 hrs/cycle, the burn time is probably not that long. Say it was reduced from 42,000 hrs to 8,000 hrs, but you're only using a total of 4 hrs a day, 260 days a year(5 days a week) and you're still looking at about 7.7 yrs of life. Such a dramatic reduction is likely with instant start, but not so with programmed start. Either way, you can see that at that pace, LEDs will not recoup the incremental cost in any foreseeable time frame.

General area lighting LEDs are still great for reefer trucks though. The cargo area lights don't get left on that long, and instant-on full brightness is expected. Instant full output at frigid temperature is one thing LEDs excel at and in this application cents/kWh is not a relevant factor.

captkirk

wow 52000 hrs is almost the death blow for led.... If the color is right i would go with that ..

__________________
Full time Bovine Scatologist.

wendon

......and the lumen maintenance. I was at a meeting with a lighting rep. He thinks LED's are the up and coming thing then proceeds to tell us how the lumen output drops on an LED as it nears the end of it's life....not good!

__________________
Ive seen burnt up outlets, chard neutrals, and shorted wires.
Uncfesta

Theriot

ESL will be the next big than in lighting

Electric_Light

Found it. They cite 52,000 on IS and 62,000 on PRS at 12hrs/cycle.
http://assets.sylvania.com/assets/do...1c57ffc768.pdf

They're only available in 48" T8, the defacto size for commercial fluorescent lighting today. They're available in 32W(normal) and Energy Saver type in 25 and 28W. 3,000; 3,500 and 4,100 are available in every model and the 32W version offers 5,000 and 6,500K.

Those five pretty much covers 99.9% of commercially available general service fluorescent lamps.

Electric_Light

They're held to some unreasonably low expectations. LEDs life span is based on a metric called L70, which is the expected life before the output falls to 70% of original. This is a freaking joke. Even F40/CW in my 1970s IESNA Lighting Handbook have better maintenance over life than this.

Fluorescent lamp life indicates when 50% of lamps will fail within a large sample, if they're used as prescribed, it is forecasted that 50% will fail by that time. Obviously, you can't allow half the lamps to fail and get an acceptable result, so if the site follows group relamp they need to be replaced at ~75% of rated life to keep burned out bulbs to minimal. At 75%, you'll have something like 15% failure. The relationship is not linear and it has a mortality curve that looks like the letter "Z" stretched out sideways

When bulbs fail, the output drops (no chit)... but unlike LED decay, when lamps burn out, power consumption drops correspondingly.
So, fluorescent lose output by some of lamps failing. LEDs degrade by continuing to consume the same power while dropping to 70% of new output which effectively reduces efficacy to 70% of original lumens per watt.

Instant start ballasts and the newest programmed start are better at giving longer re-lamp interval. Older rapid start was daisy chained like Christmas lights, usually two lamps in series, so if one goes out, it takes out two. There are some 3 or 4 lamp series configs, but as you know, the more you have in series, the higher the probability that one of them will fail.