48 4' lamps ?

[Tscott]

Hey guys,
I am using a lighting program we have at the office. We use it for street lighting applications where the county wants a certain foot candle level. It has the ability to do interior layouts as well. However, it is saying that I will need 48 4' T8 fixtures for my new 36' x 60' steel building in order to achieve a level of 65 foot candles at a height of 3' . This sound a bit steep to me as I was planning to run 12 of these fixtures.

Does anyone have any practical experience with this? I know Rocco does this, so possibly he would be willing to chime in.

By the way the program is from Cooper and is their Luxicon lighting program if that means anything to anyone.

Thanks,
Tom

 

[sparky1562]

48 4 ft lamps I could see, but not 48 fixtures.

Used 11 6 lamp high output T8 "high bay" fixtures in my friends body shop (66 lamps) that is 80 x 40 and got 57 avg fc.

 

[Aceman]

I will need 48 4' T8 fixtures

2,3,4 lamp???

48 4 ft lamps I could see, but not 48 fixtures.

Used 11 6 lamp high output T8 "high bay" fixtures in my friends body shop (66 lamps) that is 80 x 40 and got 57 avg fc.

I've only used T5HO's, they're fairly common, never even seen a T8HO.

 

[Charles (in GA)]

How high is the building inside (peak and eaves) and how high will the lights be mounted?

Charles

 

[ArthurPE]

mounting height?
how many fixtures? lamps/fixture? 2 tubes/fixture?
65 fc is pretty high
in my experience a good level 35-40 fc equates to ~1 W/ft^2
for your application of 65 fc, you may want to use 1.25W/ft^2
example:
36 ft x 60 ft x 1 W/ft62 ~ 2160W/34W per tube ~ 64 tubes or 16 4 tube fixtures...

I would do 3 rows (12 ft centerline, 6 ft to wall) 12 + 12 + 2 x 6 = 36
6 per row (6 ft between fixtures, 3 ft to walls) 6 x 4 + 5 x 6 + 2 x 3 = 60
18 fixtures total

use 2 switched circuits, alternate & stagger fixtures

 

[Tscott]

The mounting height will be around 13' (eaves are 14' and peak is something like 13' 6"

Lamps fixtures used in the calc were 4' 2 lamp T8 HO. I have a built in library of everything Cooper makes however.


The 65 FC measurement was a number I picked up searching here. The program I have also has a library of typical applications and the FC needed for each. I chose auto assembly/ repair as the application and the program told me I needed 100 FC for that type of work environment.

Tom

 

[ArthurPE]

The mounting height will be around 13' (eaves are 14' and peak is something like 13' 6"

Lamps fixtures used in the calc were 4' 2 lamp T8 HO. I have a built in library of everything Cooper makes however.

The 65 FC measurement was a number I picked up searching here. The program I have also has a library of typical applications and the FC needed for each. I chose auto assembly/ repair as the application and the program told me I needed 100 FC for that type of work environment.

Tom

then the 48 x 4's seems appropriate...although in my opinion, overkill
so the design level was 100fc?

48 x 4 x 34 ~ 6528W/(36 x 60) ~ 3W/ft^2...that's alot of lighting!

I would suggest a lower level of ~50fc for the general areas
and put some extra fixtures over the detailed task areas...

 

[rebrewer]

The mounting height is the problem. Light falloff isn't linear, so consider suspending the fixtures at a lower height.

 

[sparky1562]

2,3,4 lamp???



I've only used T5HO's, they're fairly common, never even seen a T8HO.

The lamp is standard, the ballast over drives the lamp in the fixture we used.

Columbia LHV4-632. Does a better job than tandem 4ft 4 lamp fixtures, and is cheaper (comercial grade not home depot!).