LED lumens vs metal halide lumens?

Number21

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I have a big shop with 400 watt metal halide light fixtures. There are currently 4 of them but I need 8-10 total. Of course, the problem with that is I would be burning 3200+ watts. :duh2:

I've been looking into LED replacements, or converting some older fixtures to LED. All the conversions I can find claim a 100-120 watt LED with less than 12,000 lumens is a replacement for a 400 watt metal halide with 36,000 lumens.

Is that just because more of the light is lost in the reflector with the big MH bulb? Would they actually put the same amount of lumens on the floor? Here is an example:
http://www.myledlightingguide.com/120W_LED_Retro_Unit___12000_Lumens-details.aspx

I know they won't be cheap but if I could do the same with 120 watts as 400 watts I would save about $0.25 per hour in electricity!
 

brickbat

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5 year warranty from a no-name company? No thanks.

Unless your MH fixtures are insanely inefficient, their 12000 lumen replacement will be dimmer. How long since you re-lamped? New MH lamps might be your best value. LEDs will displace MH lamps soon, but I'd be leery now...

If you have the itch to install new fixtures now, T5HO fixtures might be a better value than those LEDs...
 

Number21

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That is only an example. I just want to know how many watts of LED is actually equivalent to metal halide? On paper they are both right around 90lm/w, but that doesn't tell the whole story...
 

AnAppleSnail

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It depends on your assumptions. An LED drops to 70% output in a few years. T5 florescent drops to 90% in about a year. Metal halide is somewhere in between.

Does the LED distribute light better or worse? Does the relamp savings matter? Lumens are lumens, but LED gives you more options (CRI, CCT, beam pattern) at a higher cost. Right now it looks like, unless someone gives you a hefty discount on the fixtures, LEDs aren't it for high bay lighting. Maybe in three years, outside special cases.

It's just power intensive to light a work floor. Some shop owners can skimp general lighting to focus on task lighting. What measurement says you need another 4-6 units? Where do you need what levels of brightness?
 

idleprocess

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On a simplistic mitigating level, LED component spec sheet lumens should be limited to those that are thrown forward as opposed to the near-omnidirectional radiation from a HID lamp. On an aggravating level, LED spec sheet lumens are typically a wee bit optimistic (quoted at low temperatures never seen during normal operation) and the fixture manufacturer may simply be using these rather than measuring the light that escapes their product.

In a perfect world, a LED fixture should run maintenance-free for 25,000 - 50,000 hours and produce superior quality light relative to a HID fixture. In reality, their track record seems to be a bit sketchier and maintenance of what's often designed to be a sealed assembly can prove trickier than re-lamping or re-ballasting a HID fixture. In theory, as more companies adopt Zhaga standards LED fixtures should become more maintainable and longer-lasting.

I would look to reputable companies such as Philips or Cree (as in the fixture is manufactured by Cree) if I wanted to know what was possible with LED lighting replacing HID fixtures.
 

Number21

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What measurement says you need another 4-6 units? Where do you need what levels of brightness?
The area to light is 30x80. The lights are roughly 20 feet off the floor. The ceiling above it does not reflect light, because it is 45' to top. The walls don't reflect light either, there are 10x80 unlit storage areas on both sides. (spill from the main area lights this) The 4 fixtures I have are not close to enough.

I won't be buying any fixtures. To buy (2) 100w LEDs, for example, and install them myself would be very cheap. If it provides a comparable amount of light. If I needed 400w for the same light, then it wouldn't be worth the trouble to gain a few lumens/watt in efficiency.

Being able to save whole kilowatts here is a big big deal.
 
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slebans

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It depends on your assumptions. An LED drops to 70% output in a few years. T5 florescent drops to 90% in about a year. Metal halide is somewhere in between.

I have been closely monitoring the LED Low/Med/High Bay marketplace over the past 2 years. I am not seeing the lumen depreciation values you have posted. I realize that manufacturer specs sometimes are based on ambient temps that are not realistic but for the most part the larger players supply the required information to calculate a lumen depreciation curve for a specific situation.

I just did a quick check of Cree, Philips and Lithonia Med/High Bay LED fixtures. The L70 values for the fixtures exceed 100K hours. The average warranty period is 10 years.

T5 Fluorescents, at 40% of rated life(8K hours), have a rated output of between 92-95% and the curve stays at this level until end of life(20K hours).

The lumen depreciation curve of Metal Halide is the poorest of the three technologies. At 40% of rated life(8K hours) I find values between 60-80%.

LED:
http://www.acuitybrandslighting.com/library/ll/documents/specsheets/ibl.pdf

http://www.lightingproducts.philips.com/Documents/webdb2/DayBrite/pdf/HB-20010.pdf

http://www.cree.com/~/media/Files/C...rial_EdgeHOHighBay_Hook andCord_SpecSheet.pdf

HID and Fluorescent:
http://www.lithonia.com/micro_webs/electronicballast/source.pdf

http://www.lrc.rpi.edu/programs/NLPIP/lightingAnswers/LAT5/pc9.asp

http://www.lrc.rpi.edu/programs/nlpip/publicationdetails.asp?id=882&type=2

Finally, in an Industrial setting, dirt/dust accumulating on/in the fixture is going to be the largest contributors to lumen depreciation.
 

slebans

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That is only an example. I just want to know how many watts of LED is actually equivalent to metal halide? On paper they are both right around 90lm/w, but that doesn't tell the whole story...

Most of the larger brand name suppliers of LED fixtures have a calculator on their sites to determine how many watts of LED are required to replace a specified amount of HID watts. If you are not familiar with these brands have a look at my post further down within this thread.

Finally, for some background info comparing LED to HID, have a look at this document:
http://www.betaled.com/us-en/LEDEducation/LEDFAQ.aspx
 

degarb

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Hmm. Someone mentioned they replaced their 400 watt MH with an ALL start/ceramic/shrouded open fixture rating/universal burn 320 or 330 watt MH. Same output, better color rendering, less wattage--pulse start that works in a probe ballast. I believe it was a Philips, please correct me if I remember wrong on any of these points.

http://advancedtechlighting.com/cdmallstart.htm ? Could have, should have bought it last year when it was fresh in my mind.

http://www.usa.lighting.philips.com/pwc_li/us_en/connect/tools_literature/downloads/232595.pdf


http://advancedtechlighting.com/mhc150recal1.html Interestingly, these cdm bulbs' cri, under perfect conditions, would improve to 100 cri for short periods of time. This was frighterning to some, so they were recalled.

I am wondering if the other guy got "all start" meaning wrong, and these don't work in probe ballasts. I don't see anything to this effect.
 
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AnAppleSnail

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I have been closely monitoring the LED Low/Med/High Bay marketplace over the past 2 years. I am not seeing the lumen depreciation values you have posted. I realize that manufacturer specs sometimes are based on ambient temps that are not realistic..n.

Hello,
Thank you for setting me in my place. I've been looking at the wrong end of the market at work. By the way, can you PM me the name of a company selling the Cree units? Thank you,
 

Number21

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Looking at how incredibly cheap the chinese LEDs can be I think I'm just going to buy a few in different wattages and see how they perform. Would it be very efficient to simply mount the LEDs flat with no optics/reflectors for flood lighting?
 

slebans

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If your shop is not being lit 12 hours a day 5+ days a week, I would consider high efficiency T8 with specular reflectors. They have low install cost and with 40,000 hour bulbs, they will last forever if only used infrequently. Because they maintain 90%+ of their output over life, you don't need to start with as many lumens.

Semiman

When I first encountered these, I was amazed at the specs for the Osram High Efficacy - Long Life T8 Bulbs.
96 lumens per watt
96% lumen maintenance
80K+ Hours

To reach these specs, the ambient temperature must remain above 60 degrees with a minimum 3 hours per start.

https://assets.sylvania.com/assets/Documents/FL083R5.00f41d36-53cd-4480-a4f4-c309fdc0e382.pdf
 

Goodkid

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I've been looking into LED replacements, or converting some older fixtures to LED. All the conversions I can find claim a 100-120 watt LED with less than 12,000 lumens is a replacement for a 400 watt metal halide with 36,000 lumens.

Allow me to provide some intelligent insight on the LED world as I did some extensive research. I began as a skeptic as all of us but the benefits are too numerous to list (maintenance savings, reduced energy, no more 50% performance from gas, etc.)
First off, LED is an SSL (Solid State Lighting) which provides direct light. The lumens ratings are done in a 2X 360 degree integrating sphere. LED cannot be rated the same or side by side any other lighting in the world since the light you get is direct. Some companies are placing "pyramids" on their led cells to deflect light. This drops the lumens significantly.
Engineers all over the world have been replacing 1000watt (which actually burn 1080watts) MH 115000 lumens with 70000 lumen led's for years with better results. Engineers use what is called IES (illuminating engineers society) files to compare lights. That is the only true measure to get your equivalency.
This works again because led is SSL. The difference in LED vs. MH works this way: 1000watt-115000 lumens X 75% of mean lumen and we are reduced to 86250 lumens. Factor in the lumen efficacy at 80% of that and you have 69000 lumens.
Lastly, the market is currently flooded with old technology that was built overseas years ago and is offered at ridiculously reduced prices. They are loosing money just to empty their warehouses, good luck getting warranty replacements when they fail.
What you need to look at is the lumens per watts, initial lumens and warranty. The industry standard today is roughly 100 lumens per watt and 3-5 year warranties.
If you find some with 120 or more lumens per watt (those are current technology), roughly half of your current wattage and look for 10-year warranties.
I changed my shop (16 lights) last year from 400w MH to 220w LED and the performance from these are fantastic. I couldn't be happier! I paid more than I could have but you get what you pay for. And for god sake, buy north american made products!
PM me for pictures of my shop.
 

UnpluggedOne

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How are your lamps doing after a years use? Looking at replacing 5 400 watt HIDs right now. Excellent technical summary, thanks


Allow me to provide some intelligent insight on the LED world as I did some extensive research. I began as a skeptic as all of us but the benefits are too numerous to list (maintenance savings, reduced energy, no more 50% performance from gas, etc.)
First off, LED is an SSL (Solid State Lighting) which provides direct light. The lumens ratings are done in a 2X 360 degree integrating sphere. LED cannot be rated the same or side by side any other lighting in the world since the light you get is direct. Some companies are placing "pyramids" on their led cells to deflect light. This drops the lumens significantly.
Engineers all over the world have been replacing 1000watt (which actually burn 1080watts) MH 115000 lumens with 70000 lumen led's for years with better results. Engineers use what is called IES (illuminating engineers society) files to compare lights. That is the only true measure to get your equivalency.
This works again because led is SSL. The difference in LED vs. MH works this way: 1000watt-115000 lumens X 75% of mean lumen and we are reduced to 86250 lumens. Factor in the lumen efficacy at 80% of that and you have 69000 lumens.
Lastly, the market is currently flooded with old technology that was built overseas years ago and is offered at ridiculously reduced prices. They are loosing money just to empty their warehouses, good luck getting warranty replacements when they fail.
What you need to look at is the lumens per watts, initial lumens and warranty. The industry standard today is roughly 100 lumens per watt and 3-5 year warranties.
If you find some with 120 or more lumens per watt (those are current technology), roughly half of your current wattage and look for 10-year warranties.
I changed my shop (16 lights) last year from 400w MH to 220w LED and the performance from these are fantastic. I couldn't be happier! I paid more than I could have but you get what you pay for. And for god sake, buy north american made products!
PM me for pictures of my shop.
 

Anders Hoveland

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Despite taking a long time to actually burn out, metal halide bulbs have fairly rapid lumen depreciation. I have even read some experts advise changing the bulbs out every two years, if electricity costs are an important consideration.
 

mglutz

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I have a big shop with 400 watt metal halide light fixtures. There are currently 4 of them but I need 8-10 total. Of course, the problem with that is I would be burning 3200+ watts. :duh2:

I've been looking into LED replacements, or converting some older fixtures to LED. All the conversions I can find claim a 100-120 watt LED with less than 12,000 lumens is a replacement for a 400 watt metal halide with 36,000 lumens.

Is that just because more of the light is lost in the reflector with the big MH bulb? Would they actually put the same amount of lumens on the floor? Here is an example:
http://www.myledlightingguide.com/120W_LED_Retro_Unit___12000_Lumens-details.aspx

I know they won't be cheap but if I could do the same with 120 watts as 400 watts I would save about $0.25 per hour in electricity!

First, read up on pupil lumens there are lots of information online and you will learn that lumens are meaningless. It is what the eye can see that counts. Both LED and another lighting method Magnetic Induction produce more pupil lumens per watt than any of the older Technologies. Second, use this formula (# of lights x WATTS per light x hrs. used per year divided by 1000 x cost you are paying per K/W = your yearly bill for lights). Check the LED to see what it says it can replace. Also, if you don't like the expense of LED investigate Magnetic Induction as they are less expensive and last 100,000 hours.
 
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