10 lamp T-5 high bays

[sparky 134]

I have an industrial customer who is looking to replace his 1000w MH high bays with 10 lamp T-5's. Does anyone know of a manufacturer who makes a 10 lamp T-5 ?

 

[ptrip]

The most I've seen are 6-lamp T5HO ... but they provide quite a punch.

What kind of facility? Do they really need that much light?

The 6-lamp fixtures, mounted at 20'-0" above the floor and spaced 15'-0" on center provided an average of 87 footcandles in a school gymnasium I just ran calculations on.

 

[ItsHot]

4 lamps?

4 lamps?

You would be suprised at the job that a 4 lamp/T-5 fixture can do. I did a job in a large warehouse that had baylamps. Changed them out with a 4 lamp/ T-5 fixture, plenty of light!!:smile:

 

[steve66]

I've also seen a very bad example of replacing MH with T5 high bay. They basically had to go back and double the number of T5 lights.

So I'm kind of skeptical about a 1 to 1 replacement for a 1000W fixture. I doubt the T-5 will have the coverage the high bays did.

I would suggest carefully running the calcs with a simulation software and making sure you aren't getting really dark areas even if you do find a 10 lamp fixture.

Otherwise, maybe they are thinking of a 8' long tandem fixture??

 

[ptrip]

I've also seen a very bad example of replacing MH with T5 high bay. They basically had to go back and double the number of T5 lights.

So I'm kind of skeptical about a 1 to 1 replacement for a 1000W fixture. I doubt the T-5 will have the coverage the high bays did.

I would suggest carefully running the calcs with a simulation software and making sure you aren't getting really dark areas even if you do find a 10 lamp fixture.

I second the suggestion to utilize simulation software. The fluorescent high bays that I use as a 'basis of design' have six different distribution patterns. Some are meant for aisles, some are meant for open warehouses, others are better at different mounting heights.

It would be really easy to choose the wrong distribution and have hot spots!

 

[JoshL]

Paragon Lighting is one of probably several manufacturers that have a 10 lamp T-5.
http://www.paragonlighting.com/

They should also be able to provide basic lighting simulations for you to check that the new lighting would be adequate. But from what I have heard, a 10 lamp T-5 is generally a 1 for 1 replacement for the 1000W MH.

 

[ptrip]

Paragon Lighting is one of probably several manufacturers that have a 10 lamp T-5.
http://www.paragonlighting.com/

They should also be able to provide basic lighting simulations for you to check that the new lighting would be adequate. But from what I have heard, a 10 lamp T-5 is generally a 1 for 1 replacement for the 1000W MH.

Thank you for your input Josh ... I learn something new everyday!

 

[Nickarus]

So I'm kind of skeptical about a 1 to 1 replacement for a 1000W fixture. I doubt the T-5 will have the coverage the high bays did.

Will the raw lumen outputs be equal? No.
Is that an overly simplistic view? Potentially...

Here's some figures from a single major lamp manufacturer's lamp catalog that support your inclinations:

1000W E25 MH - 127000 initial, 115000 mean lumens
51W T5HO lamps - 5000 initial, 4600 mean lumens.... x10 would be 46,000 mean

...so ten of those t5's would output roughly half of the MH in raw lumens if we're talking about a uniform distribution without regard to where light does/doesn't need to be and what illumination levels are actually required/desirable, and with the assumption that the MH and fluorescent fixtures have identical efficiencies...

I'd suggest you figure out how many fixtures you should have by either picking up and learning to use photometric software, or asking a fixture rep to do a layout for you addressing the above issues - you may well be able to get by with fewer than 1-to-1 while addressing your owner's needs.

 

[sparky 134]

The most I've seen are 6-lamp T5HO ... but they provide quite a punch.

What kind of facility? Do they really need that much light?

The 6-lamp fixtures, mounted at 20'-0" above the floor and spaced 15'-0" on center provided an average of 87 footcandles in a school gymnasium I just ran calculations on.

This is a food manufacturing facility. The current 1000W MH fixtures are spaced ~48' o.c.

 

[ptrip]

This is a food manufacturing facility. The current 1000W MH fixtures are spaced ~48' o.c.

Oh wow ... you will definitely have to have the calculations run then!

Are there health department regulations on footcandle levels you have meet?

Do the fixtures have to be lensed?

Let me know which fixture you find that works (possibly that 10 lamp Paragon mentioned earlier?) It's always good to have that information on hand!

 

[augie47]

I am by no means well versed on the T-5 vs MH, but, from a lowly inspectors perspective based on a number of the retrofit jobs I've seen, it appears that 20-25 ft AFF is often a "make or break ".
When the fixture height is above 25 ft on a 1 to `1 ratio, I have met a lot of unhappy campers.

 

[LarryFine]

This is a food manufacturing facility. The current 1000W MH fixtures are spaced ~48' o.c.

That's a lot of light! How high is the ceiling?