Unless you have 0.0% humidity you will have condensation. I've run an elaborate cooling system with a automatic drain and a dessicant filter for years with nary a drop of moisture getting to the tools. But, recently the dessicant filter died and I've been running w/o it - and got a slug of moisture to the impact. Next stop is a refrigerated drier.

 

I'm late seeing this but wanted to add some thoughts. Some have already been said, but here goes.

I used to install & maintain compressed air systems. We almost always used galvanized pipe that we would cut and thread per whatever situation/space we were in. PVC also works good and will hold pressure but watch the specs as all PVC is not equal. We never used copper or (?) the other pipe mentioned earlier.

All of our compressors were 2 stage and either Ingersoll-Rand or Quincy. Quincy was a much better product IMO.

Refrigerated dryers are the best for moisture, but there are some other things you can do and should do regardless.

> Use electric drain(s) at the compressor storage tank(s) and along the line somewhere depending of it's size/length. You can adjust the on/off times, but a couple of seconds every hour or so would be a good start. Set them up to be on when the compressor is powered, or they will blow the whole system flat when you go out there the next day. You can use one electric drain and plumb multiple lines to it depending on what your setup is/how big.

> Run the main header up top, and take off the legs by going up first, then down to the drop station.

> Ball valves at the bottom of each leg to drain. Put a smaller line leading somewhere for it to blow to, or could line it to a common electric drain like mentioned above.

> On the drops, use a tee to put your actual QD perpendicular from the main drop line. If you add a regulator, put a QD in front and behind it so you have both main line pressure and regulated pressure access at the same point.

> We had the most problems from systems that don't run that much. When the compressor ran more and remained hot it was much better. Systems that rarely ran almost always had milky oil and lots of moisture in the system regardless of dryers and electric drains. This was sometimes due to a much bigger compressor than needed for that application.

I know you're using a compressor you got cheap used. That should be good for most things, esp if you're using that extra tank. Also consider the lines themselves act as air storage as well. It may take it a while to pump back up on a bigger system, so bear that in mind. It should be no problem unless you're doing something high demand like sandblasting or air cutoff or grinder. Keep good oil in the compressor and change periodically. It's OK that the compressor runs for a while to pump things back up, but if it's running all the time then let it catch up sometimes.

All that said, I've been getting by with a little 4 gallon HF special compressor. Most of my pwer tools are electric, altho I do run a pneumatic socket driver sometimes. I would like more capacity to have a little sandblast cabinet, but haven't done that yet.

 

Copper and aluminum are ductile and don't have problems with rust or zinc flaking off inside the lines.

PVC (at least common rigid PVC) is shrapnel waiting to happen.
A shop environment is the perfect place for it to be contaminated with petroleum products, get nicked or scratched (creating a stress riser) or actually smashed by something heavy and metallic.
Google PVC air lines. The images should REALLY make you think.

 

Amen! I did that research before I built my shop and galvanized was poor due to flaking. Black pipe will rust. PVC is a no-no because it will explode - it is just a matter of when. Copper is very good, and that's what I have. But the best is the new PEX line as it won't rust, won't flake, and won't explode.

 

By all means, go with what's best to the situation and you are comfortable with. I'm just putting out what we used. We never had problems with flaking or rust with galvanized pipe that I recall. Pipe is a pain to run if you don't have a pipe cutter and threader, and in any case you need to know how to use that measuring stick.

There is some very good PVC, but yes understand there are better products to use. If you don't like it, don't use it, no problem.

There are ways to protect the lines in the way it's run, and I personally would do that as much as possible regardless of what was used.

 

I think Bruno has his plumbing all sorted out.


I used sweated copper lines because it was easy to mount, easy to hold tight to inside corners, and easy to tee up to a drop ear ell for all the couplers I had placed around the shop.

I didn't run it at the ceiling and plumb 'over the top', I ran it at 44" off the floor to pass beneath wall switches and plumbed up to the wall mounted couplers. (so, not 'best' practices...)

But I did pitch the lines and included drip legs with ball valves for drains at the end of each run.

 

I do like what fljab saidup to the PVC pipe but he did say to each their own.
I would use copper if the $$let you. In my new to me garage I went with RapidAir kit made just forcompressed air systems, see following pictures.


Most of the refrigerated air dryers I worked with were low CFM units used in HVAC and not cheap so I can think what the high flow CFM units would be that most of us would need for our garages!
http://cars.grantskingdom.com/index....mpressor-Drier


The first 7 pictures are of the copper fin tube dryer I made to cool the air so the water would condense. I used box fans to blow air across the fins and it worked great, hose came off the side of it.


The other pictures are of my new larger garage using the same fin tube before a regulator and to a loop around the upper side of my garage of Rapid Air kit. You can also see I did drip legs at each QD that I have 5 of around the garage. The compressor is a 2 stage think 25 CFM @ 90 PSI, 175 PSI MAX a lot more than I need …right now.

Bruno how does your system work we are waiting!
Dave ----

 

Copper isn't nearly as expensive as you make it out to be, Dave.

Fittings add up, but the same holds true for iron.

Lighter weight, being able to fit it all up without any threading and soldering everything in place (at once) made it much easier for me.

 

And me. As for refrigerated air dryers, the one I'm looking at is #40211 from Harbor Freight and handles 21.6 CFM and costs $430. I have almost that much in the desiccant dryer, having bought it and re-bought it piece by piece, and it is down again.

 

I am scotch and cheap and yes that has come back to bite me.


I have a hard time laying out a lot of money at one time like $450 for a dryer when the $100 I spent for the used fin tube & new fittings to make my dryer will work for me.


I should pick up a desiccant dryer to use when I paint the body of my truck & the car I am working on. I would use QD on either side so I could hook it up for painting and un-hook it for doing everything else. This way I can also move it to any air outlet in my garage I may need it at.
I know others that do it like that also and works well for them.
Dave ----

 

You do know that you have to dry the desiccant pellets frequently, which takes heating at 300 degrees for 3 hours? And if you let water form in the drier you'll have to replace the pellets and probably the container due to rust?

Mine is similar to this one from Eastwood (EW Desiccant Dryer 2 Quart 1/2" NPT) and cost ~$250 new. Since then I've replaced the pellets once, the container once, and the filter at the bottom several times. So I surely have about as much in it as the big refrigerated drier from Home Depot.

 

Yes I know of the "baking" to dry them out.
You have no other way of drying the air before it gets to the desiccant filter?
If not may want to try putting a coil of hose in a bucket of ice water then into water collecting filter, drip leg type unit maybe, before the desiccant filter for a final "water filter".


I have not used my system much in my new garage but what little I have only the compressor tank has had water and I drain it every time I use it. I also check the dryer drip legs and the 1 outlet I use for water each time also.
Dave ----

 

I think I will just run barbed t-s and a old rubber compressor hose for my system be cheap and easu. Some people might even call it sleezy.

 

As they say what ever makes your boat float
I have work in some places that is what they had. No did not float my boat.


My first garage was a small 1 car, I ran the hose off the compressor tank till I was getting more water out of my air sander than air.
I then built the fin tube cooler. Working at the door end and compressor & cooler at the other I was also getting more water than air out the sander.
When I walked to the back of the garage I could not believe how hot it was.


That is when I set up 2 box fans to move air around & across the fin tube cooler. Once all the water passed thru the rubber hose I had no more water issues in the air..

 

Here is the compressor in place.





Here is the condenser and box fan set up.<br/>





The reservoir tank.