How a Refrigerated Air Dryer Works | CompressedAirUSA.com 

Thanks for the question, for your application being mobile we would recommend a free-standing pneumatic controlled tower style air dryer that utilizes desiccant rather than a refrigeration cycle.

Install the dryer where it is most convenient in your system, as the distance does not matter much if at all in your application

Thanks for your question, for getting air out of your air lines you would need to pull a vacuum on the distribution system, although I don't think that is what you mean. If there are air bubbles entrained in your gel coat, it could be due to incorrect pressure, unless the bubbles are from moisture in which you would need better air treatment.

No I was just making a statement. I use my air dryer to get the moisture out so I can spray gelcoat. I'm not sure if it's working though because there is never water in the bottom in the pan but that may be due to it being colder outside lately here in north Florida. I bought a used one its an arrow brand one with only 1 gauge that says refrigerant vacuum (I think that's what it says but I'm not at the shop) and it goes to 30 when I turn on the unit and the unit all turns on, I'm just not sure of it's cooling. I need to wait for a hotter day. I have it going from my gas compressor outside, running in a 1/2"od line to my auxiliary tank inside then from auxiliary tank through filter then through refridgerated air dryer then into desiccant dryer to line for spray gun. Any tips on determining if air dryer is not working? I bought it used so I'm not sure how to tell. Have not had to paint with it since buying it.