Trenching PEX for air to a shed?

[SupremePossum]

I'm FINALLY building my shed, and I'm getting the plans together for the trench for power and networking

That brings up the question of if I should run air out there from my garage over just buying another compressor? I was thinking of running 1/2 PEX

Would there be a problem of condensation in the line? The ground will be much cooler than the air that's going into it, so I could see that maybe being a problem down the line? Could there be a situation where the line becomes clogged with water, or will the compressed air blow that out?

The red line to the shed will be the new trench, all other things are already there

 

[Owen Lucas]

Oh man and I thought I had it hard running an ethernet cable under ground.

I'd just get another compressor. Probably cheaper than running a line and potential future leaks.

 

[SupremePossum]

Oh man and I thought I had it hard running an ethernet cable under ground.

I'd just get another compressor. Probably cheaper than running a line and potential future leaks.

Well, the trench will be there regardless, so that's free

100ft of 1/2 PEX is what, $30? A decent compressor is going to cost upwards of $200. I just don't want to kick myself for not doing it. It would be hopefully a completely fitting free run the majority of the way

 

[Rand]

Short Answer: Don't do it.



the fact is.. pex is bad with compressed air.
has moisture issues and temperature issues.

The air will stay hot and not cool down. so your air tools wont enjoy moist hot air.
and the pex itself can fail due to lower psi rating at higher temps.

They make specific flex tubing for compressed air. but its more $200 for 100ft

Also with a 80ft run you will have flow restriction on higher cfm tools for that distance.

 

[SupremePossum]

the fact is.. pex is bad with compressed air.
has moisture issues and temperature issues.

The air will stay hot and not cool down. so your air tools wont enjoy moist hot air.
and the pex itself can fail due to lower psi rating at higher temps.

They make specific flex tubing for compressed air. but its more like $200 for 100ft

Also with a 80ft run you will have flow restriction on higher cfm tools for that distance.

Really? The general consensus online seems to be that its great

I don't see how anything other than a metal pipe would be better temp wise, its hot AF here in Houston no matter what pipe you use

 

[#18FAN]

How much air do you need in the shed CFM and at what psi? How big is this compressor in the garage honestly this wouldn't be a big deal to do if just wanting a blow gun and such or filling tires.

 

[eljefino]

What about adding a little tank in the shed? Will give that hot air a chance to cool down.

 

[SupremePossum]

How much air do you need in the shed CFM and at what psi? How big is this compressor in the garage

26 Gallon 150 PSI Compressor in the garage. I use it with a 65ft rubber hose reel in the garage with no issues for anything I'm doing

My thinking is that if I run 1/2 or 3/4 PEX to the shed, I can at the very least use it to blow out dust and stuff, and I could also potentially get a much cheaper compressor or even just a tank, and plumb it inline for any pressure problems

No idea for CFM and PSI requirements, I use air lightly honestly, blowing stuff out, airing up tires on cars and lawn equipment, sometimes running a die grinder for sanding stuff off, a 16 gauge nailer every now and then, etc

My main concerns are the water in the line if that could become an issue

 

[SupremePossum]

What about adding a little tank in the shed? Will give that hot air a chance to cool down.

Yep very possible, then no power requirements or anything, and no noise!

I thought about just throwing a compressor in the garage, but a somewhat decent, quiet compressor is expensive!

 

[#18FAN]

Short Answer: Don't do it.



the fact is.. pex is bad with compressed air.
has moisture issues and temperature issues.

The air will stay hot and not cool down. so your air tools wont enjoy moist hot air.
and the pex itself can fail due to lower psi rating at higher temps.

They make specific flex tubing for compressed air. but its more $200 for 100ft

Also with a 80ft run you will have flow restriction on higher cfm tools for that distance.

Air tools don't enjoy moisture being hot or cold air. Number 1 rule you can not take moisture out of hot air. Tools and any other air needs it to be dry period.

 

[SupremePossum]

Air tools don't enjoy moisture being hot or cold air. Number 1 rule you can not take moisture out of hot air. Tools and any other air needs it to be dry period.

I guess the question is, will this add EXTRA moisture? I have no problems with my setup as it currently is now, so as long as it doesn't get worse, I'll be happy

My thinking is that the air on the other end will actually be more dry, no? I don't see how more moisture could get into this setup. If I go into a metal tank in the garage and then into a hose reel, it would be more dry than my existing setup, would it not?

 

[#18FAN]

Can you keep pressure on it downstream or to the shed 100% of the time yes you would want to but could you

 

[SupremePossum]

Can you keep pressure on it downstream or to the shed 100% of the time yes you would want to but could you

It would be air tight of course, and I'll just have a valve. So I guess it would be pressurized all the time. I'd probably leave the valve open all the time, as I want to be able to just go in there and use the air

Right now I leave my reel pressurized all the time, and the air compressor on so it "just works"

Not sure what everyone else is doing though

 

[#18FAN]

The pipe going underground when coming back up ideally you'd want a drip lag at that point to drain off potential water.

 

[SupremePossum]

The pipe going underground when coming back up ideally you'd want a drip lag at that point to drain of potential water.

So if its 18 inches down, have the drip leg also 18 inches down?

I wonder if I came up into a tank, would that solve all the problems? I could also have it go into some kind of sprinkler control box in the ground so I could access a low point to bleed it maybe

 

[#18FAN]

So if its 18 inches down, have the drip leg also 18 inches down?

I wonder if I came up into a tank, would that solve all the problems? I could also have it go into some kind of sprinkler control box in the ground so I could access a low point to bleed it maybe

I'm thinking if it was fed into a receiver yes it is best idea. I would make sure the air was already sent downstream from the garage as dry as possible ideally from a air dryer but a filter system would be OK with the system always charged it would minimize water .

 

[SupremePossum]

3/4 must be better than 1/2 right? I'm going to do it, if nothing else but to post the outcome here

 

[Dborch41]

What about adding a little tank in the shed? Will give that hot air a chance to cool down.

That's actually a very good idea. A 10 gallon header tank in the shed with it's own regulator and water separator would be a relatively cheap yet effective solution. I'd just be sure their was a valve in the bottom of the tank to bleed away any water that does build up.

 

[GaryMX5]

26 Gallon 150 PSI Compressor in the garage. I use it with a 65ft rubber hose reel in the garage with no issues for anything I'm doing

My thinking is that if I run 1/2 or 3/4 PEX to the shed, I can at the very least use it to blow out dust and stuff, and I could also potentially get a much cheaper compressor or even just a tank, and plumb it inline for any pressure problems

No idea for CFM and PSI requirements, I use air lightly honestly, blowing stuff out, airing up tires on cars and lawn equipment, sometimes running a die grinder for sanding stuff off, a 16 gauge nailer every now and then, etc

My main concerns are the water in the line if that could become an issue

Based on the intended use mentioned above. I'd suggest a small pancake compressor. A Ridgid from Home Depot only costs 119.00 or so and can power a surprising number of useful tools. I'd bet your line cost, fittings, extra tank and not to mention the brain damage putting it all together would cost more for a less efficient system.

 

[IndyIan]

Pex is waterproof, so its not going to add water to the air. Could some condense in the hose? Maybe, but then you have taken water out of the air, so the tool is seeing dryer air, so you're winning there. Probably adding a little water accumulator tank in your shed would capture any liquid water that gets blown along. I suspect if you do a end of the day WO blast with no tool on the hose you will get any accumulated water out into your tank, and be good to go for the next time. Just like a regular air small compressor tank, you just drain it at the end of your usage.
This is a simple calculator to give you an idea for pipe restriction. https://www.rapidairproducts.com/te...gK-L7h8QnQjSY8SNpMS_DZfAIqwR8PutQPbLa_-TVGXb4
Bends are what slows water flow down and I assume air as well. So minimize those as much as practical. A 100' hose in a 3' coil will have much more flow restriction(3-4 times IIRC) than a 100' straight hose.