Best approach for drying air from air compressor

[Rob Sack]

Thanks for the information. All the transmission and ac coils I have found so far have either 5/16" or 3/8" fittings which would seem to be too restrictive. I will keep looking.

[Chris Fairbanks]

Sounds like the OP has his solution but for others looking for a more permanent solution check out a great thread on garage journal about using a radiator after cooler on air compressors. I ended up buying mine from Zoro. The whole goal of the thread is to condense out as much of the moisture before the air even gets to the tank by using an aftercooler/radiator right after the air exits the compressor head and then run it through a separator before going into the tank. Most folks are seeing the air temp drop 100-200f degrees from the output of the compressor through the after cooler. I am sure there are cheaper options than the one I bought but I got it a number of years ago on a 30% off coupon so the price was not to bad.

https://www.zoro.com/akg-air-cooled-...06/?q=G2111706

If posting this link is not acceptable search for “Compressor after Cooler” on Garage Journal and you will find it.

https://www.garagejournal.com/forum/showthread.php?t=50946

[Alan Lightstone]

I have, for now a solution, but time will tell how well it will work, despite the cost involved.

I do have a question about the aftercoolers. Do they have a drain mechanism built into them (e.g. a drain valve)? If not, where does the water go?

[Harry Hall]

You might also want to consider using a large transmission oil cooler as an alternate to the refrigeration coil.

Charley

Hayden Automotive 402 Ultra-Cool Tube and Fin Transmission Cooler

this sells for $27 on the popular on line store ... I live in FL and have a 5hp 22gal compressor - you think if I copy your setup with this it might help?
Ed

[Malcolm McLeod]

I have not looked at every link provided in this thread, but the ones I have looked at do not have an auto-drain mechanism built in. You would need to install a drain in-line at the discharge of the after-cooler.

This could be as simple as a drip-leg with a manual valve. The drip-leg could be sized with a short(er) length of large(r) diameter pipe/tube, or a long(er) and small(er) diameter, to give you sufficient capacity for your typical usage (i.e. all the water produced in your typical air compressor session).

I have seen some folks use a small flow control valve here, instead of a ball valve drain. Set so there is just a hiss coming from it, it will bleed off the water, but not seriously impact the CFM of the compressor. It will also bleed off all your stored air when the system stops. I guess you could crack it open when you start the compressor, and close it when you're done .... but any way you slice it, it is still entirely a manual operation.

If you look at auto-drain options, they come in 2 general types:
1- Passive systems, typically a float opens the drain valve on high level in a filter bowl. Many FRLs use this mechanism in the filter and will be described as 'auto-drain'. One advantage is that it only operates when there's water present, so if the compressor is off, there's no water, the drain stays shut, and the system pressure will be preserved (assuming no leaks, of course). You may need to either install tubing to route the (water) flow to a suitable receptacle, or locate the filter in an area where the dripping water is not a nuisance.
2- Active systems - typically electronic 'dump' valves, that open on a timed sequence. A pair of individually settable on/off timers (i.e. 5min OFF & 0.5sec. ON) will open and close a solenoid valve to keep the water drained. This will give you positive feedback that the system is working - - you will hear it! Trust me. Downside is if you leave it powered, it will bleed off all your stored compressed air.

[Jim Becker]

Alan, if I recall accurately, I think it was Mike Hettrick who did a copper cooling/condensing system up and down his shop wall and somewhere in this very forum area should be photos.