Plumbing my garage for compressed air...

So, my lovely girlfriend bought an air compressor for me for the holidays. What a girl. :D It's just a Craftsman twenty-six-gallon, 150PSI, 3.8SCFM@90PSI, upright jobber, but it'll do what I need quite adequately for now, which will mostly be running air tools. I don't think I could paint a car using HVLP gear with it, but if I decide to do that...I'll rent/borrow a better compressor. :)

I've decided to run hard line around my garage. My garage is 20'x20' and barely fits a '67 Plymouth Valiant with all the sheetmetal on and the garage door down. :) My goal is to position the air compressor near the outside rear corner of the garage (to minimize noise inside the house) and to run air along both sides and the rear of the garage. The rear will get one drop for air and the sides will get two, one near the front and the other either in the middle or near the house door, depending on the wall we're dealing with.

Complicating things are some wire shelves that are mounted fairly high on the side walls. Not sure if I'm going to go over/through or under the shelves yet.

I'm going to use 1/2" Type L copper for the hard line throughout. Why copper?

• PVC is an accident waiting to happen. PVC is downright nasty when it explodes.
• Black pipe will corrode fairly quickly when exposed to moisture---which will happen in a compressed-air system---and requires special tools to thread the pipe.
• Galvanized pipe is just as difficult to work with as black pipe, and even though the corrosion risk with galvanized pipe is a lot less, there's still a good chance of zinc flaking off the inside of the pipe and ending up downstream.
• Copper is easier to work with; you don't need much besides a tubing cutter and a torch to work decently with copper.
• Copper and sweat/solder joints can withstand the line pressure (probably regulated down to 120PSI or so) quite easily with no worries.
• Copper is the best material for getting the compressed air's temp down as low as it can go quickly, which is key for getting water to condense out of the compressed air and drain away effectively.

The only real downside to copper is that it isn't quite as durable as steel pipe is...I can live with that.

I'm going to start with a metal isolation hose (to keep vibration from making its way into the rest of the copper) going up from the compressor into a tee, with the pipes from the tee going vertical. The downpipe will be a drain with a valve near the end and the vertical will tee at the top into the main run, which will go (mostly) horizontal, with a slope down from the main tee.

The equipment taps will be teed up from the main horizontal line, go up for six or eight inches, then into a ninety-degree elbow and another ninety-degree elbow down the wall, crossing over the main horizontal into yet another tee with a downpipe and a sidepipe for the air connection that leads into a 1/4" NPT to 1/4" industrial-type quick-connect. There will be a drain valve on the downpipe and possibly a shut-off valve above the tee. Not sure about that yet.

At both ends of the horizontal run will be the "main" drains, which will just be ninety-degree elbows going to a downpipe with a drain. valve.

I'm going to anchor all of this well to the walls; a blown-out pipe can whip around pretty badly under pressure.

For now I'm probably just going to set up one dryer/filter/regulator arrangement and move it from the couplings as necessary. Down the road I may fix some in place, but moving from spot to spot isn't a huge issue.

Thoughts? Suggestions? Anyone care to see updates as this comes together? I have about $230 in Lowe's gift cards from the holidays so this will hopefully get underway very soon. :)