Quest for Dry Air, On the Cheap Options

[jmill]

I'll be painting sometime soon and recently there has been several timely paint related threads. In the Midwest we're plagued by humid weather and lots of water in our compressed air. I figured I'd share my project to rid myself of water so my paint job isn't ruined.

There are several high dollar units out there to separate water from the air but I'm cheap. I decided to design some piping meant to drop the water out of suspension. All you need is 25' or more of piping, some valves, fittings and good old gravity. I wanted to use copper but it would have cost me over $150 in materials. Going with PVC cost me $40.

I still need to finish the drain and inlet/outlet piping but you'll get the idea.

[TC 914-8]

Besides the argument PVC vs copper or steel, the theory of dehumidifying the air is simple. A compressed gas gains heat thru compression. A condenser, fin and tubes, or mechanical, cools the compressed gas condenses the moisture back to a liquid, provided the dew point of the H2o is achieved. Some air driers require a refrigerated condenser to hit that dew point. Then separate the two with a trap. Simple as that....
The PVC is a safety concern but mostly a poor heat exchanger. look for an old AC condenser at the local junk yard, size the piping to avoid a pressure drop. run some sort of fan in front of it to cool the hot gas, a water trap on the outlet and viola, you should be good to go. It is best to install this on the compressor discharge line before entering the tank. Then a second trap exiting the tank. Graingers should have H2O traps fairly cheap.
32 years in the refrigeration industry I condense gas, and exchange heat several times a day (IMG:style_emoticons/default/poke.gif)

[Prospectfarms]

Besides the argument PVC vs copper or steel, the theory of dehumidifying the air is simple. A compressed gas gains heat thru compression. A condenser, fin and tubes, or mechanical, cools the compressed gas condenses the moisture back to a liquid, provided the dew point of the H2o is achieved. ...

Sort of begs the question: Do vertical runs:

meant to drop the water out of suspension.

work? Better than nothing? Not at all?

I've sprayed with a $100 "separator" with mixed results. Don't know exactly what moisture does to paint but on hot/humid days I've had blush and had to re-do a few times.