Need help on estimating shop lighting requirements

jeepcj7 · Jan 15, 2014

Whats the best way to estimate shop light requirements? A few years ago I built a 24 x 26 garage with a 10' ceiling. The interior walls and the ceiling are finished with standard unpainted OSB and the concrete floor is painted white (you would be amazed how much that helps lighten up the inside of the building). I finally got around to running 100 amp service to the building and I will be using conduit and boxes to run all the wiring. I am tryng to determine what type of light fixtures would work best in this appliation and how many fixtures I will need. I prefer a brightly lit building interior over a dimly lit building interior. Would appreciate some opinions. Thanks.

KennyG · Jan 15, 2014

In my pole barn (12 foot ceiling Osb walls bare concrete floor) I have T8 fixtures 1/2 watt per square foot with 1 watt per square foot over the work bench. I find it quite good for my old eyes.

s219 · Jan 15, 2014

I have three T8 fixtures, two 48" tubes each, in my 17x24 workshop and that is a nice amount of light. It's what the electrician recommended for that size, and I think he was pretty much on the money. Walls and ceiling are finished drywall painted off-white, floor is concrete. Prior to final trim-out, we had ceramic bulb holders in the same room for temporary lights, and the lighting was hideous.

newbury · Jan 15, 2014

Slide on over to Sawmillcreek forums they've got a good sticky on workshop lighting in their workshop forum..

T8 sounds like it will meet your needs.

Murfster3 · Jan 15, 2014

I have white metal ceiling with white osb on walls, It took me a while to figure out what I was going to use for lights maybe cause I have been an electrician for 20 yrs. With the price of t-8 lamps just keep going up I took a chance and put the old porcelain fixture up (plastic now) I put them every 6' And with a 23watt compact fluorescent 6000k . The price of under $10.00 for box,fixture and bulb I haven't had a problem with needing extra light.

Industrial Toys · Jan 15, 2014

I have about 24 T8 tubes in something a little bigger then a two car garage. That and a couple of 500 Watt Mogual base Eddison bulbs that I rarely use. They are original lighting.

The fixtures were cheap, two tube units on sale at TSC. Not sure I would use them again, but they have not failed me yet. They are failing, one by one where I put them in at a friends welding shop. They are used everyday for long days! Or is it the welder spikes killing them?

I have just built a 28 X 72 Foot drive shed and am not sure what I will use. It actually has been two years and I just have not needed to do anything in the dark in there. There IS temporary lighting. Six more of those cheap TSC T8 fixtures.

Recently I have been using the vapour tight fixtures. I used some in a new wood shed. The bugs don't get into them and you can clean the lenses quite easily. They are kind of pricy, but I would like to use them in my drive shed. I would want lots and lots of them! I like LIGHT but this will be a very costly project.

I installed them at a friends place. Another welding shop, and I upgraded all the ballasts, in these brand new fixtures. He likes to listen to the radio, and many cheap ballasts give off piles of RF interfereence! Bit of a PITA, but they didn't stock the vapour tight fixtures with the better ballasts.

Another (you guessed it) welding shop buddy just replaced his eight foot fixtures with large reflectors from warehouse style commercial lighting to which he added sockets and very large spiral CFLs. One each per reflector. Didn't work out too bad for light.

Teikas Dad · Jan 15, 2014

newbury said:
Slide on over to Sawmillcreek forums they've got a good sticky on workshop lighting in their workshop forum..

T8 sounds like it will meet your needs.

:thumbsup: This - Sawmillcreek has a lot of good info!

thirdroc17 · Jan 15, 2014

Three times as much when you're 55 as you needed when you were 25.

Just saying..... :shocked:

kuboter · Jan 15, 2014

I have the same size garage with OSB and I have 16 8ft T8 fixtures with 2 bulbs each. I wired them in 2 banks so I can turn every other one on or all of them on. Spreading them out evenly is just as important as having enough so that you don't get shadows. I almost always turn all of them on.

Industrial Toys · Jan 15, 2014

I rigged my lights up with low voltage relays so I can operate them from different locations or only have certain ones on. You simply run power to all lights and then through a relay to each light or set of lights. Going to do this in my drive shed as well.

Worst thing (so far) about getting old. Can't see worth a darn without light.

Just thinking. By the time I do the driveshed lighting, maybe LED stuff will be better and affordable!

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.