Copper Pipe air dryer

[rbruno68]

I am finishing up wiring for my compressor and my next upgrade in my garage is making a copper pipe air dryer to be able to paint the cab and have drier air for my power tools. I have notice in some of the pictures people post that they have air dryers/manifolds, so I thought I would ask some advice on the design. I have a 3/4 rubber air hose already on my compressor and plan to use 3/4 inch copper pipe.

1. How much total length of the manifold do I need to cool the air?
2. Did you put a regulator BEFORE the manifold where the compressor attaches or just at points where hoses would plug in. Or both?
3. Are 1/2 inch regulators/filters large enough for enough air flow to use a paint gun. I don't plan to be a professional painter, but would like to do a decent job on the truck and other projects. Not sure if I need a 3/4 inch regulator and filters for the best flow.
4. Who makes decent regulators and filters? Again, I won't be opening a paint shop so I don't want to buy the Cadillac of filters/regulators, but I also don't want something that is going to break/fall apart with minimal use.
4. Any other design recommendations?

Thanks for any advice.
Rob

[jayoldschool]

The guys over at Garage Journal will have lots of good advice on this, worth signing up.

[theastronaut]

I used an old dorm fridge with copper tubing coiled up in a five gallon bucket. This chills the air and gets moisture out much better than a zig zagging pipe on a wall.

[raggedjim]

that's cool, do you just drain it at the external trap? How did you seal the exit of the tubing in the bucket at the bottom?

[A1971Blazer]

This is my experience, and the results may vary according to specific conditions.

A copper pipe set-up will help, but when you start dealing with large volumes of air it won't be as effective.

The only sure way to get dry air is by using a refrigerated dryer.
You have to be able to lower the dew point enough for the water vapor to condense quickly, and drop out of the air stream.

The copper may work fine until it starts heating up, then it just won't be able to remove the moisture efficiently.

A water separator will help, along with perhaps a fan on the copper to help keep it cool.

Be sure to add in some kind of drain, preferably an automatic one that can be set to activate at timed intervals. The water will build quickly especially in high humidity conditions.

I have a small machine shop with several machines that use compressed air solenoids to operate. The air must be dry!
I use a 25HP Ingersoll Rand rotary compressor with an output of about 100 SCFM and a refrigerated dryer rated for that amount.

[A1971Blazer]

Originally Posted by theastronaut

I used an old dorm fridge with copper tubing coiled up in a five gallon bucket. This chills the air and gets moisture out much better than a zig zagging pipe on a wall.

Nice set-up and that's thinking outside the box to create a refrigerated dryer!

[rbruno68]

Originally Posted by theastronaut

I used an old dorm fridge with copper tubing coiled up in a five gallon bucket. This chills the air and gets moisture out much better than a zig zagging pipe on a wall.

Same question. How do you get the water that condenses in the coil out?

[theastronaut]

Originally Posted by raggedjim

that's cool, do you just drain it at the external trap? How did you seal the exit of the tubing in the bucket at the bottom?

Yep, the trap on the outlet catches whatever condensates in the line. This is the first one I built, the second one I built has an auto drain valve. I used windshield urethane on the first one, on the second one I rant the tubing over the top instead of going through the bucket.

[theastronaut]

Originally Posted by A1971Blazer

This is my experience, and the results may vary according to specific conditions.

A copper pipe set-up will help, but when you start dealing with large volumes of air it won't be as effective.

The only sure way to get dry air is by using a refrigerated dryer.
You have to be able to lower the dew point enough for the water vapor to condense quickly, and drop out of the air stream.

The copper may work fine until it starts heating up, then it just won't be able to remove the moisture efficiently.

A water separator will help, along with perhaps a fan on the copper to help keep it cool.

Be sure to add in some kind of drain, preferably an automatic one that can be set to activate at timed intervals. The water will build quickly especially in high humidity conditions.

I have a small machine shop with several machines that use compressed air solenoids to operate. The air must be dry!
I use a 25HP Ingersoll Rand rotary compressor with an output of about 100 SCFM and a refrigerated dryer rated for that amount.

This X2. Any kind of loop no matter the material its made from or how large it is can only drop the temp down to ambient at best, no lower. Refrigerated is the way to go.

[raggedjim]

Nice work, Rg

[rbruno68]

Originally Posted by theastronaut

This X2. Any kind of loop no matter the material its made from or how large it is can only drop the temp down to ambient at best, no lower. Refrigerated is the way to go.

Sent you a PM with some questions. Hope that is ok.
Rob

[Dead Parrot]

I have this as a dryer cooler setup. Picked up a gov surplus cold side AC addon for Humvees for almost nothing. Only using half the coil. The fan is a 24V fan running on 12V. Takes the hot air out of the compressor, cools it, separates out the water, then routes it to the tank. Even after a long run on humid days, rarely get more then a few drops out of the tank drain. Power supply for the fan is tied to the compressor auto switch. Air going into the tank is near ambient. 2hp motor. Probably be good for a 5hp setup if I ran both sides of the coils in parallel.

Even if you still wanted the cold air out of a true chiller, something like this as a pre-cooler would greatly cut the amount of water to deal with later.

[rbruno68]

Thanks to John's suggestion and design, I finished building my air dryer needed to do some painting. As I was using some of my air tools, I was getting way to much moisture out of them. So, I knew I had to do something before painting. With suggestions from here, I built this out of an old dorm fridge. Hopefully this will fix the problem. Need to do some fine tuning and finishing, but I don't think I have any leaks. Next is having the inside, firewall, and bottom media blasted and epoxy painted. Hopefully that will happen this week.





https://www.youtube.com/watch?v=X-wLnP-9oRU

[raggedjim]

Originally Posted by rbruno68

Thanks to John's suggestion and design, I finished building my air dryer needed to do some painting. As I was using some of my air tools, I was getting way to much moisture out of them. So, I knew I had to do something before painting. With suggestions from here, I built this out of an old dorm fridge. Hopefully this will fix the problem. Need to do some fine tuning and finishing, but I don't think I have any leaks. Next is having the inside, firewall, and bottom media blasted and epoxy painted. Hopefully that will happen this week.
https://www.youtube.com/watch?v=X-wLnP-9oRU

Nice work, Rg