400W MH highbay retrofit options T5HO, T8 vs LED

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Electric-Light

Senior Member
If you currently have 400W MH 455W input, you could save energy use by using another technology. Your HID would be one of these two types.

A: Pulse Start
B: Probe Start

Pulse start has a better lumen maintenance and if it was already designed to take advantage of this, you likely need to match with 24,000 to 25,000 lumens. 5 T5HO/8 T8

Probe start lamps have a poorer lumen maintenance and then can generally be substitute by 18,000 to 20,000 lumens. This is made possible due to higher lumen maintenance and better fixture efficiency of alternative technologies. You'd beed 4 T5HO or F32T8 x 6 (high BF)

To use LED or traditional fluorescent?
Available control options: all lamps on or partially off, step dimming or full range dimming. Dimming is not exclusive to LEDs.

6 lamp T8:
This example is 91.1% efficient, cost is <$150 with lamps.
http://www.visual-3d.com/tools/photometricviewer/default.aspx?id=30954

Life hours comparable with LEDs is possible with special long life 28W lamps when usage under 60F is not needed. Doing the math, your expected performance is around 187W with 17,100 Lm output
https://www.platt.com/CutSheets/Philips/P-6049-E 2XL EA T8 28W bulletin_v1_web.pdf

214W with 20,000 lm delivery using F32T8/HL 32W Super T8 lamps. Require re-lamp at 20-25K hours of use. (rated life to 50% failure is 30-36K)

4 lamp T5HO: about $150 with lamps
The Best 54T5HO performs comparably with Best T8. Howard HFB FE454 with 51W/5,000 lm Super T5 lamps provide 210W input with 18,900 LM delivery

LED: 200W/19,000 lm ($450-500 ea)
http://www.acuitybrandslighting.com/library/ll/documents/specsheets/ibh.pdf
Lumen maintenance prediction: L90:25,000, L80: 60,000
Output sharplyplummets above 95F. At the mounting height high bays are used, the air temperature at the fixture will probably be above that in the warm season unless it's a fully conditioned space. Under those conditions, I would use Philips Extreme Temperature T5 in those.

The price difference between 4 and 6 lamp T5HO fixtures is not significant. When you need 24,000 or 30,000 lumen class output, the price difference between LED and fluorescent will widen, because LEDs become more expensive with increasing lumen output. Modern T5 fixtures are parallel wired as are T8 fixtures, so one lamp failure will only black out one lamp which maintains enough light output until scheduled maintenance.

LEDs and fluorescent can both suffer a ballast failure, so LEDs do not get any advantage here.

The actual maintenance savings of LEDs compared to T5HO or T8 is not yet proven. It's good to be aware that as of now, the performance difference between higher end LED and high performance fluorescent is negligible.

Both fluorescent and LED allows immediate power cycling, a switch to LED from fluorescent do not add any advantage i this regard. Many 4 or more lamp T5 systems have dual circuit ballast so they may have two hots and support step-dimming you maybe able to task it for your next scheduled re-lamp.

The power and demand savings from 455W/ea to about 220W/ea is significant. But when you pay substantially more to lower the power to 180W, you're probably not getting as good of value. Commission structure tied to selling price motivate sales people to sell the higher priced LEDs, but it might not save YOU money as efficiently. Not all fixtures are the same. Select the correct type. (narrow, wide or medium? ) (lots of uplight or no?)
 

delaware74b

Member
Location
Delaware, USA
"Modern T5 fixtures are parallel wired as are T8 fixtures, so one lamp failure will only black out one lamp which maintains enough light output until scheduled maintenance."

All of the T5HO low bay fixtures I have installed or maintained are series/parallel operation. 4-lamp fixture as a single 4-lamp ballast, driving 2 pairs of lamps in series. 1 lamp fails, the ballast shuts that pair off. 6-lamp fixtures have 2 ballasts, 1 4-lamp and 1 2-lamp. A ballast failure on a 6-lamp doesn't take out the the entire fixture although it is more noticed when the 4-lamp fails.
 

Electric-Light

Senior Member
"Modern T5 fixtures are parallel wired as are T8 fixtures, so one lamp failure will only black out one lamp which maintains enough light output until scheduled maintenance."

All of the T5HO low bay fixtures I have installed or maintained are series/parallel operation. 4-lamp fixture as a single 4-lamp ballast, driving 2 pairs of lamps in series. 1 lamp fails, the ballast shuts that pair off. 6-lamp fixtures have 2 ballasts, 1 4-lamp and 1 2-lamp. A ballast failure on a 6-lamp doesn't take out the the entire fixture although it is more noticed when the 4-lamp fails.

http://www.gelighting.com/LightingWeb/na/images/72757_UltraStart_T5_PS_Ballasts.pdf
http://www.lighting.philips.com/us_en/connect/tools_literature/downloads/EL-2157-C.pdf
http://unvlt.com/pdf/specsheets/B454PUNVPLHBE.pdf
 

MHElectric

Member
Location
NC
I told you this over at ET but I'll say it here as well.

You obviously know your stuff, you've got nothing but statics and charts to back up all of your money-to-lumens threads. And I don't doubt your experience level or knowledge one bit.

But I think your absolutely crazy for thinking that LED is going to cause the earth to sink and mankind to fade away. It may not be a 100% problem free product, but it certainly is moving in the right direction. It's the future dude, accept it. This product will continue to get better and better, cheaper and cheaper, and more defect free until eventually it WILL BE the most commonly used lighting source.

And then eventually, something else will take it's place.
 

Electric-Light

Senior Member
You obviously know your stuff, you've got nothing but statics and charts to back up all of your money-to-lumens threads. And I don't doubt your experience level or knowledge one bit.

But I think your absolutely crazy for thinking that LED is going to cause the earth to sink and mankind to fade away.

Those are the key figures affecting the buying decision!

This is from Lithonia ( Acuity Brands ) LED Sales. It's pretty typical of LED sales stuff.
m1utOtH.jpg


Acuity Brands LED sales shows 400W MH as 442W, T5 as 374W and their LED as 241W to make it look like LEDs save a lot and T5s don't save much. They use 6 lamp T5HO probably to pad up the "lamp and disposal cost" for the T5.

With those values and the padded up maintenance cost, the LED looks favorable.

What else is wrong with the sell sheet? Somehow, 12hrs/day 6 hrs/week accumulates expenses the same as 24/7 operation every calendar year. They're full of errors and omissions. Everything else is confusing as heck. You need a good justification to choose the option that uses fixtures costing three times. LED sales people don't exhibit the key figures the same way I do, because it will blow their cover away that performance difference is marginal for something that costs three times more.

What they want to sell is the over priced 241W 24,000 lm LED

What they claim to be the equivalent fluorescent is a 30,000 lm class 6-lamp F54T5HO and cooked up maintenance cost that use older ballasts and 54W lamps that use 374W

What they left out is the 25,000 lumen class 5-lamp 49W F54T5HO used with latest ballasts in a 94% downward delivery fixture delivering 23,500 lm for 260W which cuts down the LED advantage to less than 8% Not what LED sales department wants you to hear. It is heck of a lot cheaper than LEDs.

They assigned $211 for non-energy operating cost per fixture for T5, but only $106 for the LED.

Failed to account for increased lifespan of T5HO lamps at 24/7 operation.

Failed to account for increased percentage of lamp life available between maintenance with the use of currently available parallel wired ballast.

Failed to disclose the life of T5 lamps.

Used 6 lamp T5 instead of 4 or 5 lamp to raise the disposal and lamp cost.

Added T5HO "ballast cost" for some reason, but failed to add driver failure cost for LEDs


Sell sheets are intended to entice the manager type to make the buy decision. Omitting details make it easier to blow things out of proportion and make non-sense talk.

http://www.grainger.com/ec/pdf/IBL-Sell-Sheet.pdf2013 version.

http://www.acuitybrandslighting.com/library/ll/documents/otherdocuments/i-beam_led_brochure.pdf 2015 version.

More realistic figures on page 4 of this literature:
http://www.usa.lighting.philips.com/connect/tools_literature/downloads/EL-2600.pdf
 
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