Need help on estimating shop lighting requirements

grsthegreat · Jan 15, 2014

actually have a lighting software program on my comp0uter provided from Lithonia. The only problem is that it gives output in lumens. its something i use in commercial jobs where they specify the amount of lumens they require as a minimum.

depending on how much light you need, i would personally installl 4 four) T8 fixtures, 8 foot long with 4 - 32 watt lamps per fixture.

I have scanned 3 pages as the program picked for your building. The fixture spacing is shown, and its explaned on page 3 (lumens method study)
Hope this helps

View attachment Visual - Lumen Method Summary.pdf

cmyoung2 · Jan 16, 2014

I have a 25x40 metal building, concrete floor. Use a total of 10 4'x2bulb T8 shop fixtures ie cheap. Just wasn't enough so I added two low bay metal halide. Really helped, but I still use trouble lights a lot. The cheap T8 fixtures -ballast don't last long, been replacing the ballast as they fail, so far seem to be outlasting the originals, but probably not cost effective. Just really frustrating when fluorescents don't seem to last as long as incandescents.

Cat_Driver · Jan 16, 2014

Look at LED lighting. You can run the entire shop on a 20 amp circuit. I added some 60 watt LED area lights that throw as much light as the old 500 watt halogen HOT lights. The price of running the lights is cut by more than a fifth of what I had.

adventure bob · Jan 16, 2014

Lighting requirements should be calculated from a foot candle illumination perspective. OSHA and many others recommend levels of light per square foot for certain functions. Those are attenuated by age. An auto shop for example is recommended to have 60-80ft/cdls per square foot. A body shop is 80-120. Age factors in that per 5 years beyond 50 the ft/cdls go up by 10. You can then back into how many fixtures of what type to get the output your looking for.

jeepcj7 · Jan 16, 2014

Thank you!

Willie B · Jan 23, 2014

The most cost effective way to wire is EMT use 10' lengths to separate lampholders, use 165 Raco or equivalent. Arlington 800 and 370. Get ground screws. place the boxes in an E pattern, I would run down the front wall above the door where doors won't hit it and lights won't burn the ceiling. I'm guessing a two bay, 3 boxes each side of overhead doors. Bend Emt to fit to ceiling, run with 10' or shorten to gain one more light in each bay, With 9 or 12 boxes. Use Leviton 29816 C2 porcelain sockets with pull chains. #14 solid THHN three conductors (black white green). Ideal 341 wire nut, use a solid tail #14 12" long to connect each color together Use ground screws (special for the purpose) to ground each green to the box. Strip 5/8" on each, don't be lazy, twist until you see two full spirals of each conductor outside the wire nut. After mounting fixtures on boxes, staple one end of a 8" piece of light chain to the ceiling about 14" away from box. Run pull string through other end before connecting to fixture. Home Depot sells a (compact fluorescent) 68 watts (replacement for 300 watt incandescent)
Power all of this through a switch on the wall. Use the pull strings to turn off unneeded bulbs.

ETpilot · Jan 24, 2014

I just replaced my very old fluorescent fixture that put out 27,000 lumens. I installed a high output T5 4 bulb fixture. This fixture is rated at 20,000 lumen. It is just a bit less bright than what I had but it is still bright for my needs. I plan to add a second fixture on a separate switch. This will give me 40,000 lumen in the center of my 30x40x12 shop. I also have 2 T12 HO fixtures, one on each end of the shop. I use these periodically but the center is my working area. Should be very bright at 40,000 lumens.

Willie B · Jan 24, 2014

ETpilot said:
I just replaced my very old fluorescent fixture that put out 27,000 lumens. I installed a high output T5 4 bulb fixture. This fixture is rated at 20,000 lumen. It is just a bit less bright than what I had but it is still bright for my needs. I plan to add a second fixture on a separate switch. This will give me 40,000 lumen in the center of my 30x40x12 shop. I also have 2 T12 HO fixtures, one on each end of the shop. I use these periodically but the center is my working area. Should be very bright at 40,000 lumens.

I've used them on commercial jobs. They are efficient, very good lighting, but the down side is you really need a lot of ceiling height to get even light distribution, I haven't seen long ballast life, and they are staggeringly expensive.

Wyobuckaroo · Jan 24, 2014

Bwahahahaa..... "At 55 you need more light than you did at 25"....... That's me.... And so true....

My experience with adding onto a machine shop is that the pros can figure the light minimum easily... I got them to go 150% the minimum for lights...
I also insisted on the ceiling being painted white.... Caught lots of crap that paint wasn't necessary....
When the shop was expanded again, they didn't paint the ceiling and there was a world of difference between the two area...
My 2 cents of experience....
Good luck...

texasjohn · Jan 24, 2014

some time ago I had the same problem...how to determine shop lighting.

I summarized all I learned in an old thread...I've looked it up...here it is

http://www.tractorbynet.com/forums/projects/91587-shop-light-decision-thanks.html#post1030584

I spent a lot of time learning...it's all there...including formula for calculating lumens at work bench height, number and placement of lights, etc...hope you find it and it's helpful.