at my work we also have about 2' piece of tubing drop straight down below a Tee fitting for the quick connects coming out of the walls, at the bottom of this we have a ball valve, and a rubber hose vented outside the building.this way as the heated air cools and condenses it collects in the tube below where your air hose fitting is. periodically you open the ball valve and drain the collected moisture right outside.
i plan on doing this in my shop. i will be sweat fitting a copper pipe manifold and have a flexible line from compressor to the air manifold long enough to move my compressor outside when i am using it. i have a 22V 60 gallon upright i mounted on a 1/2" aluminum plate , and it has some craftsman tool box wheels under the plate to easily move it.
