Lighting a 40x75 shop

[Bigredford]

The shop side of my build is 40x75 with 17 foot eaves. I've got a bunch of second hand Lithonia IBZT5 6l high bays or very close to that model. 6 bulb t5 high bays. I actually have three up in the shop right now temporary.

Going to do a lot of machine shop work. How many of these high bays should I put in?

 

[Dagny]

36to40

 

[toyotadriver]

More. The answer is always more

 

[theoldwizard1]

For machine work, you will need lights on the machine.

 

[13mo]

The shop side of my build is 40x75 with 17 foot eaves. I've got a bunch of second hand Lithonia IBZT5 6l high bays or very close to that model. 6 bulb t5 high bays. I actually have three up in the shop right now temporary.

Going to do a lot of machine shop work. How many of these high bays should I put in?

It depends on how well lit you want the shop. Fortunately, if you know how well lit the shop needs to be, Acuity has a free tool (https://www.visual-3d.com/tools/interior/) where you can select their products such as the IBZ and determine this.

If we assume the typically recommended 93 foot candles, a typical open rafter, open pole/stud/beam building, the fixtures hung 18" below the bottom chord, and that the T5HO 6-lamp IBZ is the standard distribution IBZ 654 (there are actually several different variations), you will need 15 fixtures spaced 15' by 13' 4' apart to give 92 fc. The 6-lamp T5HO fixture you would need the most of would be the IBZ 654 WDU ACL, you would need 18 as these have a lot of uplight.

36-40 of these would be overwhelmingly bright, that number of fixtures would be more appropriate to a light with much less output such as a 4 lamp T8 fixture such as the IBZ 432.

 

[Bigredford]

That points me in a good direction. After I got the roof on my building I temporarily hung three high bays in the shop. I'm not exactly sure on the model number but I got more then enough high bays to hang. This style with the plexiglass lenses and more I beam open type.

 

[13mo]

If you already have a large number of these fixtures, you can always delamp (not put in all of the bulbs it can fit.) These fixtures will have 2 ballasts, and generally they are a four-bulb and a two-bulb or two 3-bulb ballasts. If you only connect power to one ballast and only connect the bulbs to the ballast with power, you end up with a fixture with lower output that you can use more of. For example, if you only install four of the six lamps (if you have one four-bulb and one two-bulb ballast and don't hook up the two-bulb ballast), you would use 21 fixtures instead of 15 to hit 93 fc, and you would use 30 if you only install three bulbs (if you have the two 3-bulb ballasts and only connect one.)

 

[dcg9381]

I'd consider round UFO-type lights. I think you'll get away with a lot fewer lights and they just work great with 16-17' ceilings.