How much lighting to install

[red90q]

My garage/workshop is 18'x20'x12' high. My ceiling is not yet dry walled for a good reason. How much lighting to install? Is there a specific formula to figure out how much to use? I plan on using florescent but don't want to not use enough, I'm also working on a budget so installing too many with switches to turn on only what is needed at a specific time is out of the question. Can anyone shed some 'light' on my problem?

 

[Ray-CA]

The funny answer is:

If you turn on the lights in your shop and all the other lights in the neighborhood dim, you've got enough.

But, to answer your question, yes there are calculators available to determine lighting requirements. I don't have the knowledge to help you much more, but if you do a search you'll come up with a lot of information.

As for switches, it shouldn't cost much to put your lights on two or three zones (and it's easier and cheaper to do that now as opposed to later.)

Ray

 

[thrifty bill]

+1. Switches are cheap, assuming you do the work, and will pay back quickly in electricity savings. I always zone my garage/workshop lights, either by location or intensity (level 1 could be for general use, level 2 could be for while you are doing work and need/want more light.

 

[MotoDave]

My garage is the same size. I have 3 of the 8 foot long 4 48" bulb fluorescent fixtures, basically one in the middle and one on the side of each bay. I also have a 4' fixture over my workbench, and one more over my lathe. I'm really happy with the amount of light, and its made working in the garage in the evening a lot nicer.

 

[red90q]

Thanks for all the input guys
Cheers
Ian

 

[TWX]

My old place had a roughly 20' by 20' garage with about a 9' ceiling. I had four 8' fixtures, eight total bulbs. I mounted them roughly as a square so that when the door was open only one 8' fixture would be blocked by it.

There was also a single 100W bare bulb right in the center on a separate switch, plus the two 60W bulbs on the garage door opener. When going out just to get something I'd use the single 100W (well, probably 20W, replaced with a CFL) instead of the big bulbs, which I'd generally only turn on when working.

 

[DoyleDee]

I have 1watt per square ft of space- that is what I have seen from here.
How you lay them out is a different story, you might get shadows.

 

[7echo]

If you get your fixtures from an electrical supply house they will do a lighting plan for you, at least the one I use will. You can tell them the height above work table and how many foot candles you want and they will tell you how many fixtures and where to locate them. I try to get 75 foot candles at 36" above finished floor for most of my shops.

 

[dave67fd]

Seeing as you have 12' ceilings you may consider hanging your fluorescents. If you plan to finish your ceiling it will increase the lighting. Stick with T8's 8' or 4' fixtures. Your 18 x20 shop won't take alot to illuminate. IMO i keep the majority of the lighting on one switch. This probably isin't the best choice with garages that are partitioned or bronken up into seperate areas. If all open space i prefer most of my lights on if im in their for the most part. I have one fixture on a seperate switch to basically light my way to and at my toolbox and in and out.

You can also add a ceiling outlet for drop lights.
General rule of thumb is you really cant have enough in my opinion.