One of the first things I activated in my shop after running electrical to the existing structure was a few lights and my air compressor. It's a 6hp, 60gal unit in a fixed location on a dedicated 220V circuit. I've used either a 50' hose or a 100' hose dragged around my 36'x24' shop to do everything from using a pin gun to spraying finish. After the third time LOML asked me when I was going to run air lines rather than walking over the hose, I decided it was time to tackle that project.
I chose to use copper for most of the lines because I was planning to run them around the junction of the walls and ceiling. My completed system now consists of a piece of flex hose from the compressor to a tee on the back wall. Lines run each way to the side walls. One of them terminates near the area I use to spray finishes; galvanized pipe was used for this drop for protection. The other side has two tees with copper lines running down the walls in the new section of the shop; it terminates through the front wall to an outlet by the door. These lines are all copper but I plan to cover them with plywood for protection.
One of the photos below shows the drop near the spray area. I have an extension to catch any water droplets that make it that far and a valve to dump the collected water. I added a filter to trap any water vapor still in the air at that point. I removed the regulator from one of my HVLP guns and placed it at the outlet to eliminate some of the bulk at the sprayer.
The two drops in the new area of my shop, where my tablesaw and assembly tables are located, allow the use of an air hose without it being in the way too much. I uploaded one photo showing this configuration; both are the same.
In addition to the air lines, I also built a dust hood for my lathe. It doesn't do a thing for the heavy chips, of course, but should take care of the fine dust from turning and sanding. It's built from scraps of 1/4" and 1/2" birch plywood and a few pieces of solid pine. The top is clear acrylic. I haven't added a clear flap on the front yet - still thinking if it's necessary.