Electric light, your exactly right. I can't easily disprove light output claims here. I haven't even dug into UL compliance issues, lumen maintenance, CRI, realistic life expectancy and more. I am not a fan of LED replacement tech and discredit it whenever possible.
LED replacement
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Electric-Light
Senior Member
I usually find creative presentation in LED equivalencies like coming up with worst possible scenario for fluorescent technology to compare against the LED setup (setup, not "upgrade") to make LEDs look better.
If currently installed fixtures provide some uplight by design and you replace the lamps with LED with only 160deg beam spread, its possible to match the foot candle reading below the fixture by circumventing the uplight feature of the fixture. That kind of fixtures provide some space above them to send uplight towards the ceiling.
Same number doctoring can be accomplished by using a different fluorescent fixture with narrow beam, less lamps, zero uplight and high coff. of util.
Another example, old fixtures with 10 years worth of dust, seriously decayed lens and decayed F34T12 lamps against shiny new LED fixtures.
For sales case study, they'll look for job sites that make LED systems look better like the examples above. They're not going to do side-by-side against a brand new 8-lamp T8 system in a gym.
There are fluorescent fixtures that provide as much as 95% utilization of output produced by lamps. LED sales people can't utilize them as they can't exploit the poor CU or dust accumulation of existing fixtures to make LEDs look good.
http://www.cooperindustries.com/con...rary/literature/Metalux/ACF092055_IndFluo.pdf
In applications where these industrial fixtures are appropriate total luminaire average efficacy[using average lumens of lamps, not brand new specs] of 90 lm/W can be achieved factoring in for lamp depreciation and reflector losses. 60-80 lm/W if you play conservative and include luminaire depreciation factor to account for accumulation on fixture optics.
Good luck getting anything close to that with LEDs.
Since many LED tubes with clear tube and limited output angle do not utilize the fixtures for its optics, its only fair to compare them against the best possible fluorescent setup.
If you have a 60% CU troffer, simply replacing the housing with 95% fixture and utilizing the existing lamps/ballasts provide 58% gain in total efficacy. Suppose an LED lamp existed that performs exactly like the old lamps, but installed with the new fixture. I suspect LED sales people would credit the 58% gain to "LED technology", when in reality is the optics.
To play fair, we can only use real lumens, not scotopic junk. To compare sources, fixture performance can't be exploited to optimize the presentation of LEDs.
http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/t8_replacement-lamps.pdf
See implied performance.
Those familiar with the art of lighting components know that 130+ lm/W is not realistic with the exception of low pressure sodium, a type of lighting that provides amber light with absoluely no color discrimination ability. It is used in roadway lighting, but its totally unacceptable for general lighting.
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mtfallsmikey
Senior Member
Wish me luck...just ordered a bunch of RAB WPLED26's to replace the Ruud HID lights on the exterior canopies of both of my buildings, the existing M139E bulbs are $$$.
crazedengineer
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I will throw in my 2Cents for what it is worth
I will throw in my 2Cents for what it is worth
This post is much longer than I initial intention. But I hope I can help. If not I apologize for wasting your time.
I have ran the "Engineering Economics" several times for a comparison for both Federal and private projects. I have had both results that say it is a good and bad. Since the studies are paid for by my client can't release the studies, but I can tell you how I have ran them.
I usually use Present Worth/Cost Analysis. There isn't a set formula you can use for all cases. It is all going to depend on your application. In the last application a one for one replacement of a CFL downlight and a equivalent LED downlight.
So for CFL's I found the cost of the life of the fixture (Present Worth/Cost, PC) was, assuming 3% inflation everyear, lamp change for the CFL every 3.8 years. , and a 20 year life cycle.
PC = IC + (Cost of Lamp + Labor)[(P/F,3%,3.8)+(P/F,3%,7.6)+
(P/F,3%,11.4)+(P/F,3%,15.2)+(P/F,3%,19)] + Energy Cost Per Year(P/A, 3%, 20)
Pretty much it takes the cost of each lamp change at future year X from now, and converts it to what it will cost you today if you to put the money aside right now.
*****(P/F, 3%, 11.4) are all formulas you can google "Engineering Economics formulas" for Present Cost of a Future Cost in 11.4 years, inflated @ 3%. I wrote a program on my TI-89 in college that calculates the values. I am sure you can find one online.
And I did a similar formula for LED downlight, but at the usage I was using the LED didn't need to be changed over the 20 year life of the project.
Doing this, I found a 1 for 1 replacement of 266 downlights would save the client 26 thousand dollars over the project life.
Now I have done this for much smaller scale projects. That only have the anticipated usage of less than 8 hours, and have had the exact opposite result. It is all dependent on the use. Trying to replace 2x4 and 2x2's I have yet to get the numbers to work out in favor of the LEDs.
So in my experience the place where LED are going to pay back is when the anticipated operational hours are high. Especially when replacing HIDs.
Here is a link that I received published by phillips using simple paybacks for replacing Parking garage fixtures. But again this a using the right fixture for the right use. LEDs are point sources, but can be aimed to create very even and efficient lighting. Like in the example i used above, it was a 1500 Lumen LED with a 26watt CFL. IN that case the LED has less lumens, but the lumens are almost all delievered where in the CFL the lamp itself blocks a good deal of its own output and loses efficiency because it directs light in all directions and it has to use reflectors to redirect the light.
http://www.widelite.com/sites/default/files/LRMC Garage Energy Analysis.pdf
Just as a note, the government projects do allow the use of LED fixtures. There was a Engineering Technical Letter issued by the airforce, that on AF projects, you have to have a payback of less than 5 years if you are going to use LEDs.
So overall , LEDs can payback when used correctly, but it is by far not a perfect technology yet. The initial cost of LEDs are extremely high when compared to CFL, or HIDs. Also, someone mentioned earlier that if you do have a premature failure of a fixture, you are looking at almost the replacement cost of the entire fixture. So if you are specifying it, you better make sure you have a kick ass warranty.
I will throw in my 2Cents for what it is worth
This post is much longer than I initial intention. But I hope I can help. If not I apologize for wasting your time.
I have ran the "Engineering Economics" several times for a comparison for both Federal and private projects. I have had both results that say it is a good and bad. Since the studies are paid for by my client can't release the studies, but I can tell you how I have ran them.
I usually use Present Worth/Cost Analysis. There isn't a set formula you can use for all cases. It is all going to depend on your application. In the last application a one for one replacement of a CFL downlight and a equivalent LED downlight.
So for CFL's I found the cost of the life of the fixture (Present Worth/Cost, PC) was, assuming 3% inflation everyear, lamp change for the CFL every 3.8 years. , and a 20 year life cycle.
PC = IC + (Cost of Lamp + Labor)[(P/F,3%,3.8)+(P/F,3%,7.6)+
(P/F,3%,11.4)+(P/F,3%,15.2)+(P/F,3%,19)] + Energy Cost Per Year(P/A, 3%, 20)
Pretty much it takes the cost of each lamp change at future year X from now, and converts it to what it will cost you today if you to put the money aside right now.
*****(P/F, 3%, 11.4) are all formulas you can google "Engineering Economics formulas" for Present Cost of a Future Cost in 11.4 years, inflated @ 3%. I wrote a program on my TI-89 in college that calculates the values. I am sure you can find one online.
And I did a similar formula for LED downlight, but at the usage I was using the LED didn't need to be changed over the 20 year life of the project.
Doing this, I found a 1 for 1 replacement of 266 downlights would save the client 26 thousand dollars over the project life.
Now I have done this for much smaller scale projects. That only have the anticipated usage of less than 8 hours, and have had the exact opposite result. It is all dependent on the use. Trying to replace 2x4 and 2x2's I have yet to get the numbers to work out in favor of the LEDs.
So in my experience the place where LED are going to pay back is when the anticipated operational hours are high. Especially when replacing HIDs.
Here is a link that I received published by phillips using simple paybacks for replacing Parking garage fixtures. But again this a using the right fixture for the right use. LEDs are point sources, but can be aimed to create very even and efficient lighting. Like in the example i used above, it was a 1500 Lumen LED with a 26watt CFL. IN that case the LED has less lumens, but the lumens are almost all delievered where in the CFL the lamp itself blocks a good deal of its own output and loses efficiency because it directs light in all directions and it has to use reflectors to redirect the light.
http://www.widelite.com/sites/default/files/LRMC Garage Energy Analysis.pdf
Just as a note, the government projects do allow the use of LED fixtures. There was a Engineering Technical Letter issued by the airforce, that on AF projects, you have to have a payback of less than 5 years if you are going to use LEDs.
So overall , LEDs can payback when used correctly, but it is by far not a perfect technology yet. The initial cost of LEDs are extremely high when compared to CFL, or HIDs. Also, someone mentioned earlier that if you do have a premature failure of a fixture, you are looking at almost the replacement cost of the entire fixture. So if you are specifying it, you better make sure you have a kick ass warranty.
Electric-Light
Senior Member
crazed,
Good start, but a few things come to my mind.
How are the lamps changed in MH system? Lamps that go out follow a normal distribution and rated life is based on when 50% of sample will go out. There are several approaches.
1.) ignore outages, then replace at n% of rated life.
2.) replace outages as they occur.
3.) replace outages to address complaints/as needed, but still replace at n% of rated life
The n value depends on service level you expect. If you choose option #1, it clearly can't be 100%, because having 1/2 the lamps out is not acceptable.
With metal halide, I like #3 as you ensure lighting is maintained, but cost is controlled. The replacement lamp cost and per fixture lamp labor is quite different depending on how its done. The small number can be done by in-house maintenance using spare parts while the routine change-out can be bid-out to a commercial company for lower cost.
Ballasts and fixtures are not considered wear item, but a certain number will be lost due to premature failure, vandalism and mishaps and even theft for LED fixtures just as in the case of PV panels.
I don't know the failure rate, but I suspect out of warranty and damage replacement cost quite a bit more than HID fixtures.
Consider Prius. You may actually finally break-even at ten years, but around the same time the battery may need replacement and the cost may backpedal a significant amount.
If the plan is to replace the battery, you could try allocating 1/10 the anticipated replacement cost for each year. If the plan is to get rid of the car at the end, you could try allocating 1/10 of salvage value onto saving.
Good start, but a few things come to my mind.
How are the lamps changed in MH system? Lamps that go out follow a normal distribution and rated life is based on when 50% of sample will go out. There are several approaches.
1.) ignore outages, then replace at n% of rated life.
2.) replace outages as they occur.
3.) replace outages to address complaints/as needed, but still replace at n% of rated life
The n value depends on service level you expect. If you choose option #1, it clearly can't be 100%, because having 1/2 the lamps out is not acceptable.
With metal halide, I like #3 as you ensure lighting is maintained, but cost is controlled. The replacement lamp cost and per fixture lamp labor is quite different depending on how its done. The small number can be done by in-house maintenance using spare parts while the routine change-out can be bid-out to a commercial company for lower cost.
Ballasts and fixtures are not considered wear item, but a certain number will be lost due to premature failure, vandalism and mishaps and even theft for LED fixtures just as in the case of PV panels.
I don't know the failure rate, but I suspect out of warranty and damage replacement cost quite a bit more than HID fixtures.
Consider Prius. You may actually finally break-even at ten years, but around the same time the battery may need replacement and the cost may backpedal a significant amount.
If the plan is to replace the battery, you could try allocating 1/10 the anticipated replacement cost for each year. If the plan is to get rid of the car at the end, you could try allocating 1/10 of salvage value onto saving.
crazedengineer
Member
- Location
- Florida
all good points
all good points
All good points.
I personally like to try and stay on the cutting edge of technology, but a good piece of advice a mentor once gave me that has served me well so far is " let other people be the ginny pigs and jump on once it is proven safe."
all good points
All good points.
I personally like to try and stay on the cutting edge of technology, but a good piece of advice a mentor once gave me that has served me well so far is " let other people be the ginny pigs and jump on once it is proven safe."
Electric-Light
Senior Member
Duration of ownership plays a major role too. Something I just remembered is the Visteon lifetime air filter which is designed to last 150,000 miles.
If you just look at what they say, it lasts five times longer than 30,000 mile common filter saving you four filter changes at what, $8/filter and 10minutes labor. At 140,000 miles, it would look like you saved $32 material and 40min labor (at whatever rate they use). It's debatable if the labor saving is even realizable depending on billing (whether adding 10min on other repair would change billable cost)
The cost to replace that filter at 150,000 mile is something like $350. Requires OEM parts since nobody others to make generic and requires 1-1.5 hrs labor. Now if you were to allocate that to four changes, it comes out to $87.5 per skipped maintenance. Hardly a bargain over traditional filters. If the negative influence on salvage value exceeds maintenance cost skipped, you're still going in the red. Just the filter isn't a biggie, but if it's clear that the vehicles are getting dumped in anticipation of a long list of very costly repairs/maintenance, it will take a toll on salvage value.
So, if you were to wash your hands right before 150,000 miles you might have saved on maintenance, but if there are many other things like that on the car that requires maintenance for the first time and it is well known, it might just get shaved off of salvage value which won't necessarily turn out in your favor. Cars are depreciated very differently from industrial capital asset, but the idea here is that you can defer the maintenance outside of your duration of planned ownership and hope to make it someone else's problem.
Energy saving asset with PBP past your intended occupancy or the PBP and useful lifetime are almost the same, it will never work out. You don't start saving any money period until you cross PBP.
It just seems to me that, when you add in these so called "nit picky" yet real variables that add up, LEDs just don't make sense.
There is inflation and when you look at investment with very high upfront cost, there is opportunity cost or interest carrying expense.
The money spent on pimping out factory lighting with LEDs may have been able to upgrade one of the production lines which could give higher yield than LEDs can ever save or go further towards company's long term goal.
There's no doubt LEDs can save energy usage over existing old technologies, but the disproportionately high cost over competing alternatives make them a ridiculously over priced option in many cases.
LEDs are ridiculously expensive upfront and benefits aren't proportional. There is a certain value to immediate cash (hence the reason sales people love selling LEDs).
LEDs are at a point where its not just about energy and cost. It could be that the customer has vendor sustainability rules and if eliminating mercury adds a point or two, then installing LEDs is just a means of "BS through" those requirements.
The customer may very well have the said requirement to attract tree hugging hipsters to buy there.
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Electric-Light
Senior Member
When something is tied to consumer behavior, all bets are off and logic isn't the reason here.
Tools made for construction people aim emphasize "Made in THE USA" not really have anything to do with quality, but because of perception of quality and tickling emotional good with the consumer base.
However, if the tailored market is hipsters, its about perception of environmentally and socially responsible operations like selling humanely slaughtered chicken in a store that uses rainwater for the toilets and lit up by mercury free LED lights while requiring suppliers to use renewable biodiesel to make deliveries.
So yeah people do things that simply don't make sense on paper. I sell things on eBay for fun and I know that certain item consistently averages $25 final price. Start at $0.99 and usually they sell for $25.
Start at $20 and they usually end up going unsold.
Tools made for construction people aim emphasize "Made in THE USA" not really have anything to do with quality, but because of perception of quality and tickling emotional good with the consumer base.
However, if the tailored market is hipsters, its about perception of environmentally and socially responsible operations like selling humanely slaughtered chicken in a store that uses rainwater for the toilets and lit up by mercury free LED lights while requiring suppliers to use renewable biodiesel to make deliveries.
So yeah people do things that simply don't make sense on paper. I sell things on eBay for fun and I know that certain item consistently averages $25 final price. Start at $0.99 and usually they sell for $25.
Start at $20 and they usually end up going unsold.
line voltage to a tombstone.
line voltage to a tombstone.
What is the feeling for putting line voltage to a tombstone, would you take out the 18 awg fixture wire and install 12's on a 20 amp circuit? Fusing? UL issues...
The reason I ask is a vendor came to me yesterday with a linear Tube LED I asked the questions and they have not been answered yet.
I feel the fixture should be replaced and not retrofit with tubes.
line voltage to a tombstone.
What is the feeling for putting line voltage to a tombstone, would you take out the 18 awg fixture wire and install 12's on a 20 amp circuit? Fusing? UL issues...
The reason I ask is a vendor came to me yesterday with a linear Tube LED I asked the questions and they have not been answered yet.
I feel the fixture should be replaced and not retrofit with tubes.
Be real careful with this stuff. I had a vendor come to me with cut sheets for a similar product. They listed CRI as being 90. I know the real players out there are not that high. So I looked at their lighting facts sheets and the DOE listed the same product as having a CRI in the 60s. The bulk of LED tube manufacturers are not to be trusted at all.
And, yes, you're going to have UL issues. I know leviton issued a statement that they would not recommend using their fluorescent tombstones at line voltage.
Electric-Light
Senior Member
I would be sketched by those China brand lamps, but Philips T8 form factor LED tube also utilizes the same setup. Performance is not stellar, but compliance issue is probably addressed properly.
I'm not the one to endorse LEDs, but the Philips 10W 900 lm CFL style one they just released isn't bad except for the price tag of $50.
That's the only size it's available in.
RE80 GSFLs offer CRI of 85 or so on Ra8 scale, but the missing story is that on Ra14 scale, it gets 0 on R9 color. R9 represents deep red. 8xx lamps all get 0 on R9.
There are ceramic metal halides that get pretty good R9 value, but not as good as incandescent.
Specialty fluorescent lamps like Chroma 50 offers some R9 rendition, but not that great. I don't have the exact value as the data is hard to come by.
In the 2700 to 3000K range, only lamps that offer much R9 rendition so far is filament tungsten and that LED lamp from Philips. R9 isn't critical for average lighting though.
They're in field test use in places that don't make sense, like hydro electric BC, Canada....
www.lightingprize.org/pdfs/Philips_Field_Demos.pdf
If someone gave me enough of them to do my whole house with, I'll say good things about them too. If I had to pay $50/ea for them,then I would say the opportunity cost is not worth it.
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