Plumbing for air

[Steve Sawyer]

Just bought a used air compressor, and realized it's too big to fit in the basement shop. If I place it strategically in the garage, I could run a pipe along the I-beam between my shop on one end of the house to the garage on the other. Only problem is the I-beam is all boxed in, and only exposed in the shop at one end (about 12' of it), and about 1" is sticking out under the basement stairway.

It seems that from the shop I could shove an 8-10' section of pipe up along the I-beam (with some 12-gauge Romex taped to it to provide a separate circuit for the compressor), screw or solder another section onto the first, shove that down the I-beam and repeat the process until it sticks out the far end.

My question is what kind of pipe could I do this with? Seems that 1/2" copper would be easier to handle, but I think 1/2" black iron pipe is what is usually used.

[Ken Fitzgerald]

Steve,

Copper would work fine and is probably cheaper than black iron and for the average person easier to work with.....I can solder and I don't have threading tools.

If you do a search here you can find numerous threads about running pipe for a/c's.

[Allen Bookout]

Use copper if you can. I used pipe and never have been able to make it absolutely air tight. No matter how many times I redid it there was always a small leak somewhere. I like everything about copper except the price.

[Jim Becker]

1/2" copper is what I used for my air system.

[Ken Deckelman]

Go with the copper for sure, it will be much easier to deal with.

As for the 12 gauge wire though, we will need to know what size compressor you have to answer that for sure. But I think I would run a 10 gauge instead in case you get a larger unit.

Or, if space allows, you could tape a 3/4" or 1" plastic EL conduit (grey PVC) to the copper pipe as you push it in so you will always have an easy path.

[Steve Sawyer]

Or, if space allows, you could tape a 3/4" or 1" plastic EL conduit (grey PVC) to the copper pipe as you push it in so you will always have an easy path.

Now there's a good thought!

Thanks, Ken.

And thanks to all for your recommendations. Copper does seem to be a better choice, and while I haven't compared the prices, I wouldn't be surprised if the copper is only slightly more than black iron (I always seemed to be shocked by the price whenever I've bought black iron in any quantity).

[Tom Veatch]

Definitely go with the conduit rather than romex. Be much easier to pull the proper gauge wire if and when it needs to be upsized. If the compressor is as large as you imply, I suspect it's 5+ HP and will take at least a 30amp (10ga) circuit

Either copper or iron will work. Use the one you are most confident you can join leak-free. It sounds like you'll wind up with at least one inaccessible joint that you can't leak test. You want to be as certain as you can be that it's not leaking before it becomes inaccessible.

[Steve Sawyer]

If the compressor is as large as you imply, I suspect it's 5+ HP and will take at least a 30amp (10ga) circuit

No, the implication (if any) is that I have a tiny shop. The compressor I have is only a couple horsepower at most, with a 20 gallon tank.

[Chris Padilla]

Whatever you run, think about water flow and collection points (low points) along the pipe. You'll need to drain it from time to time.

[Jozef Kaslikowski]

In their catalog, Farmtek says that their pex-al-pex is suitable for compressed air as well.

http://www.farmtek.com/farm/supplies/prod1;ft1_plumbing_accessories-ft1_tekcoil_pexalpex_radiant_coil;pg102782.html

I plumbed my house with pex and wouldn't go any other way now.

[Jim Becker]

In their catalog, Farmtek says that their pex-al-pex is suitable for compressed air as well.

http://www.farmtek.com/farm/supplies/prod1;ft1_plumbing_accessories-ft1_tekcoil_pexalpex_radiant_coil;pg102782.html

I plumbed my house with pex and wouldn't go any other way now.

The only issue is that most PEX requires isolation from UV to keep it from degrading. In the floor or in the wall, that's not an issue. Exposed in the shop, it could be. There is a PEX-like product that folks have mentioned from time to time that is specifically for compressed air applications.

[Steve Sawyer]

Exposed in the shop, it could be.

My basement shop? I hope not! :eek:

[Matt Meiser]

I used 3/4" copper with 1/2" drops. Based on our previous conversations, your compressor and air consumption needs are a lot smaller so 1/2 should be fine. I've run black pipe for gas lines and its not too bad to work with either. Two minor concerns I would personally have with the install technique if i were doing it: 1) how confident are you that you can do your connections with no leaks. With copper I have to probably re-sweat 1 in 10 connections. With black pipe, the only leak I've had is a union that I just had to crank down on harder. 2) is the pipe going to be well supported and not rattle around against the beam making enough racket that I eventually rip into the ceiling covering to fix it. One thing you could do there is to use the foam insulation on the pipe. Its cheap at the borg. Also make sure you use a short length of hose between the compressor and piping to mechanically insulate it.

One other thought--Since you are running the power from the shop, I would switch the compressor outlet with a switch conveniently located in the shop with with some kind of indicator light to remind you it is on. When that compressor leaks down enough to kick on late at night when you forgot to go out and shut it off, SWMBO is going to kill you when her heart starts beating again. I have a neon lamp from radio shack mounted in the cover of the disconnect for my compressor that I can see as I'm leaving the shop. Since doing that I think I forgot to shut it off once. The Borg sells heavy duty switches suitable for this purpose.

[Steve Sawyer]

Excellent points and suggestions, Matt - 'specially the one about the shut-off! :p

The issues of leaks (and noise) are causing me to re-think feeding the piping through the I-beam. Maybe just running alongside of it, secured with zip ties or something. I may be able to look at that alternative as I'm re-doing part of the wall that is built below the I-beam.

[Victor Stearns]

Greetings. If I may add my two cents. When running the air lines in my shop, I chose to use DOT 5/8 inch nylon brake tubing. This is the same tubing that is used on semi trucks and has a burst rating of 250 psi. I also chose to use a push-to-connect fittings that can be assembled/disassembled without tools. These all carry a DOT rating for vehcile use. I attached the lines to the walls and ceiling with a loom clamp and single screw. The advantage is that the line is very easy to work with, not too costly and can be changed any time you need to add a drop. You will however have to fabrcate a manifold were you plan on have a quick connector. I added several regulators that served the same purpose.
Keep Making Sawdust
Victor