View Full Version : DIY/dirt cheap shop compressor intercooler

10-25-2005, 05:19 AM
Being that my shop is small (REALLY small) I didnt have room for a refridgerant style air dryer and due to obsticals like cabinates and shelves I couldnt plumb my shop with the correct metal piping with traps/drops. So that means with extended compressor use (like porting heads) I get a shower of nasty condensate flung at me out of the exhaust on the air tool. The norm was to wrap a shop rag around the air tool so it covered the exhaust which would at least keep me from getting soaked.

Skip ahead to a couple of weeks ago when my compressor broke a connecting rod which required a complete rebuild and while waiting on the replacement parts to arrive I did some googling for possible ideas to help with my condensate problem. I ran across a fellow who had the same problem and he plumbed a transmission cooler into the line in series between the compressor head and the tank. His condensate issues were solved but he still had to constantly drain the water which my forgetfull self would only occassionaly remember to do and his set up was one of those small ~10 gallon portable set ups where as my compressor is quite a bit bigger than that so I was concerned that just a trans cooler by itself wouldnt help in my situation.

I started scrounging around the garage/brain storming and came up with the below monstrosity (dont laugh it works way better than it looks).

I used a Setrab oil cooler I bought used from a winston cup team as my condensor (I used an oil cooler due to the PSI involved since most trans coolers arent rated high enough). The cooling fan is a 110VAC unit from an old large window AC unit and some misc fittings and tubing to replumb everything.

I decided to get a little high tech on my set up since I cant ever remember to drain the condensate from the tank. Being an industrial electronics tech by trade I whipped up a simple 555 timer circuit to drive a relay which actuates a 110VAC selonoid valve in each one of the condensate traps (four of those total). Its set up so that the selonoids blow down the condensate for 2 seconds every 20 minutes. I powered the 555 timer circuit using an old 12VDC power supply I had laying around from a printer thats long been dead (yeah, Im a pack rat). The power supply/selonoids are hooked up to the supply side of the incoming power to the compressor so that even when the compressor is off the condensate traps are still blown down every 20 minutes. To shut everything down I just pull the disconnect on the wall so I dont have to hear the PSSSSSST of the selonoids every 20 minutes in the middle of the night since the garage is on the other side of the wall from the bed room.

The cooling fan is powered through an adjustable time delay off relay (TDR-off) in such a way that the cooling fan turns on as soon as the compressor motor kicks on but when the motor turns off after the air pressure has built up the fan continues to run for 4 minutes to completely cool the condensor/oil cooler. This was done to keep the relatively small cooler from becoming heat soaked due to no air flow during off times.

In the below pic you'll note I installed the first of four traps/selonoids on the output side of the air line where it comes out of the cooler and before it goes into the tank. I used gravity to help direct any condensate into the trap so that little if any moisture even makes it into the tank from what Ive seen so far.

The other three selonoids/traps are located in the following places... One is plumbed into the bottom of the tank where the drain pet c0ck used to be. One is plumbed into the pipe drop/trap thats mounted on the wall beside the compressor and the last one is in the bottom of the filter/seperator (the blue cylinder) where the drain c0ck for it was originally located.

After 7-8hrs of steady die grinder work while doing some minor bowl work on a set of SBC heads I have noted that the only place Im getting condensation when the selonoids blow down is the very first one thats right after the cooler. Not a single drop of water has made it to the tank let alone the other selonoid valves.

The best part (besides no more nasty condensate baths) is that Ive got ~80 bucks in the whole mess and it works WAY better than I could have hoped for so if you have condensate issues when using your compressor but dont have the space/cash for a store bought dryer I promise you that one can be made for minimal cash with parts most of us on this forum prolly have laying around the garage.

David Pozzi
01-08-2006, 10:28 PM
Good idea.
I added a couple of loops of copper tube positioned in front of the compressor pulley since it has fan blades cast into it's center.
I also found that if I plugged into my shop piping as far away from the compressor, the air was cooler and contained less water.

01-09-2006, 11:12 AM
That's a great system. I always have condensation problems, especially during our humid summers. It really makes using my Harbor Freight sand blaster a pain. I will have to look into this.


01-09-2006, 11:50 AM
You know Boss Hog and Sheriff Coaltrain are gona haul you in fer moonshinin! LOL

I love it when modifications like that work.

Dan :Alchy:

01-10-2006, 04:08 PM
You know Boss Hog and Sheriff Coaltrain are gona haul you in fer moonshinin! LOL

I love it when modifications like that work.

Dan :Alchy:

LOL! there sure are some humerous people on this site.:lol:

01-11-2006, 07:02 AM
You know Boss Hog and Sheriff Coaltrain are gona haul you in fer moonshinin! LOL

I love it when modifications like that work.

Dan :Alchy:

My gear head buds have officially named it "Sputnik II" and want to be present when its launched :lmao: . Im just happy it keeps the condensate out of the air lines no matter what it looks like.