Underground Air Line?

[muk]

I would like to run an air line to the new garage I just had built, the proposed area is the redline in the photo attached and the compressor is directly behind the wall where the red line is. I was thinking of using the 3/4" maxline from RapidAir or 3/4" Pex, I just was not sure how to protect/insulate the line where it transitions out of the old garage. I thought about the 1/2" MaxAir line as I probably have enough of it and it is flexible enough to go through conduit, but I was worried about volume of air in the new garage if I did have to use an impact or something that draws more air. The pic is a few years old and the window is now a garage door with a ramp to it and to the left of the red line is the propane tank for the garage heater.

Does anyone have any ideas? or other suggestions? I do not want to move the compressor out of the old garage to save the space in the newer/smaller garage.

 

[mike93lx]

Regular old pvc electrical conduit. Works for power, will do just fine for air

 

[vwpieces]

Be aware the Rapid air 3/4in is smaller than PEX, not measured the same.
Years ago I bought a RA 1/2in kit for a few runs in another shop and wasn't happy.
Also not sure I would want the push connect under ground.

3/4in PEX double loop or 8 plumed in ceiling of my current shop with all drops in 1/2in with drip legs. Used Stainless crimps and very happy with the install.
1/2in PEX is going to be closer to the 3/4in RA ID. But use 3/4in PEX for the run and SS crimps.

 

[dcg9381]

Here, where the soil is rocky and ******, my choice would be 3/4 PEX sleeved with PVC. I don't know how far the run is, but you could always add a tank in the garage as a buffer to help with flow if you use high CFM devices.

 

[yatg]

One of the problems with underground compressed air is that you're going to get environmental condensation in the pipe on top of the regular compressed air condensation. The pipe will be the low point in the system. If it fills up with water, how are you going to drain it? And since you're in Ohio, are you going to bury it below the frost line? At the very least, you'll need a water separator system at the new garage.

By the time you do everything, you might be better served by getting a separate smaller compressor just for the new garage. Sounds like it would mostly be for airing up tires and blowing things off. You can pick up used compressors on fb/cl pretty cheap. And an electric or battery powered impact.

 

[muk]

I was just trying to save space in the new garage, I have a 80 gallon in the old garage and figured it was enough to supply air to the new garage.

I was planning on going below the frost line and would put dryers in front and after the line. I am trenching for the electric this weekend and figured I could trench another spot for the air line while I had the equipment. the dealer I worked at ran underground line to the body shop and the ford dealer I just didn't pay attention at the time to see how they did it and what they used. even with the dryer in front would there be that much concern for condensation in the line?

I agree another compressor would be easier and I even still have an old 6hp 60 gallon in my car trailer. I am just tight for space in the new garage and did not want something taking up floor space. I may have to get a small compressor and just mount it up high i was just hoping there was a way to accomplish the underground line feasibly.

 

[zmotorsports]

I did this at my last house. When I built the detached shop in the back yard and running gas and electric out to it, I also used some 1" black pipe and wrapped it similar to a gas line for corrosion protection. I put my air compressor in the detached shop but wanted the ability to be able to air up tires or anything else in the house garage. I put a second water separator in the house garage to combat the condensation issue and it worked well for the 25+ years we were in that house. I also put a ball valve in the shop to kill the air going to the house garage if the need arose but I don't remember ever using it to turn the air off.

It was very nice when I had the motorhome or trailer blocking access to the detached shop in the back yard to be able to check tires and when I was hauling my large race trailer around I was airing up and down my rear tires on my truck quite frequently so this was a great feature. When we were selling the house I showed this feature as was surprised at the interest it drew.

At our new house I contemplated doing the same thing but decided against it as I now have plenty of access to the shop and will never be land locked creating a time when the shop is land locked.

 

[sjvicker]

I ran mine from my shed to the garage in PVC conduit and used a conduit body "LB" to go up and punch through the wall. 2' deep and I used 1/2" rubber air line. It's been good for everything I've needed it for and I've never noticed visual condensation in the air.

The key here is that it works for everything I do. I occasionally run a plasma cutter, fill tires, run an impact (lug nuts) and blow off dust. It's all light usage stuff. If I was blasting or using air grinders I'd have built a better system but I'm not so this works for me.

 

[Bretny]

No need to go below frost line. The wonderful thing about compressed air is it dosnt need gravity to drain. Put a T at the lowest point and put an automatic drain valve on it.

 

[larry4406]

I ran the 1” Rapid Air between house and detached barn. It’s listed for direct burial. Will be moving the compressor to the barn. It’s currently not hooked up as compressor is still in the attached garage.

 

[gorilla]

My air compressor is in my house garage I ran about 25' to my shop, under ground, with 3/4" gas pipe. It comes coated for underground use and is not expensive. I did install a blow off valve and occasionly blow out the line to remove condensation. It's been in place for about 12 years without any problems.

 

[rburke65]

The idea of putting a T at the low point to drain water is the ‘low point’ is in the ground! Run a PVC condu8t and pull a pex line. One would think that you co7ld blow the condensation out if you buy a compressor….oh ..wait….you already have a compressor…..

 

[FredWanaker]

run a conduit large enough to pull an air line thru it when it goes bad. Keep in mind that sometimes things can stick inside conduit like a rubber hose, and pulling simply tears it apart. Have a plan to get the remnants out if that happens in 7 - 10 years. More than once in my life I have tried to remove something like a wrapped cable in conduit and have had the cable housing unwind and break into pieces. If it is a straight run you can pound a rod thru it but if it is curved etc., you may be oops.

 

[Bretny]

The idea of putting a T at the low point to drain water is the ‘low point’ is in the ground! Run a PVC condu8t and pull a pex line. One would think that you co7ld blow the condensation out if you buy a compressor….oh ..wait….you already have a compressor…..

Exactly. The T would be underground and a short piece of the same pipe to a drain valve.

 

[jrsavoie]

I got a deal on 4" 20 ft pvc. I ran that between the sheds. - about 100 feet. I pulled 1" 160 lb black plastic through. Along with 2 lengths of direct burial 2/0 copper for welding leads. I have to walk to the other shed to adjust my temp, but I've never had a problem, in spite of being told it wouldn't work. Been using it about 15 years.

I went 4 foot deep. With sweep 90's and ran into large electrical boxes on each end.

I have a 1/2" line run 50 ft to the house in 2" pvc that I only hook up when needed. It has come in handy many times.

 

[LXCam]

I did like zmotorsports did but with my compressor about 150ft from my shop. Been like that for 11yrs without issue or noise. That noise thing is glorious I tell ya.

 

[rburke65]

I have a good quality Champion air compressor and its really quite.

 

[kingchevy]

I ran 5/8' truck air brake tubing inside 1 1/4" conduit about 60' total. Have had no issues with condensation.

 

[CraigStu]

I say go for it w/ the grey PVC conduit. White PVC would work but I like the gentle bend pieces that you can get for the grey. Now you just have to chose your actual air line. Add in some water separators and see how it works. Worst case you abandon it and buy an extra compressor but experiences above indicate it will work for a long time.