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Discussion Starter · #1 ·
Just put a new airconditioner in the house. Got all the old stuff left over. What to do with it? Well, the condenser is a steel unit and has a large fan. Why couldn't i plumb this into my airline as a water condenser/trap? From the compressor to the condenser to the coalescing filter to the dessicant filter. Probably put a cycling drain in on the low side of the condenser. What say ye? :)
 

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I have seen this done with auto units and it works. I would recommend positioning the unit so that the coils are horizontal and the air will not have to loop up and down, that is there should be no loops where water can collect and sit in the line. If the air has to flow down into loops and then back up then water will collect in these low spots until it reaches a point that it will be picked up by the air flow and expelled in spurts. Should be no problem just watch for low spots and go for it, should work just fine.
 

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The one I saw done with a Ranger AC part worked really good, surprisingly good in fact. This was on a 6 1/2 HP :rolleyes: (3 HP actually) CH compressor that had to work pretty hard to keep up with just about anything this guy did. When he tried sandblasting he ran into some major water problems and we discussed cooling the air before the separator at which point he remembered having the Ranger AC parts. He brought the thing over and we pressure tested it to well above what his line was regulated to for safety and then he built a crude box/frame to which he attached a small fan to the back and ran his air line through this set-up. With only about 10' of line from the tank to his separator water problems were almost a certainty but after attaching this outfit there was a MAJOR improvement. He was kind of sloppy in the building of this thing and wound up with a crudely built outfit but it was very effective.
 

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Discussion Starter · #5 ·
AC guy told me this unit is good for 350 psi. 3/4" in and will be 3/4 out after mods. Recently picked up a 37 cfm @175psi @ 800 rpm compressor and a 12 hp ohv Briggs. Will require a 3.7-1 reduction at wot to get the 800 at the pump. That gives me about 40 HP to play with. Haven't made a decision about the tank, but feel that a 20 gal in line for pulse will probably be all I need. Going to be a fun project and I will have less than 800 in the setup less filters. :)
 

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You are building a gas powered compressor? You are aware of the fact that you MUST have a governor coupled to a throttle kick-down device and unloader valve? This is necessary because the load will change drastically on the engine as pressure builds and then load will be suddenly dropped when max pressure is reached, a constant throttle setting will not work. The unloader valve is a MUST because the pump has to stop compressing air when shut off pressure is reached even though it will continue to spin at reduced RPM because the engine must continue to run. This all must be arranged to occur at the proper times and pressures and although it can be done it will be a nightmare getting it set properly unless you can locate properly engineered parts, even factory set-ups can be a major PITA to get reset right when they get out of whack.
 

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Discussion Starter · #7 ·
Ya build what ya got. The Briggs is governed at 3000 rpm Wot won't exceed that regardless of load and will maintain that as long as It doesn't run out of power. without a large tank it will run almost continuously so I won't be incorporating a throttledown. Projected comp life is 20,000 hrs, I should live so long. System unloader is adjustable from 90- 175 psi. will set at 125psi as that is all that is needed and will give a slight increase in cfm. This is a piston valve compressor (unloader holds valves open) and has a pulse tank drain so it doesn't start against a head of air thus no shock load. There is a oneway downstream from the pulse tank to prevent backup.
Actually, its just a larger version of one I already built. The existing one (20cfm)uses an electric clutch and governor as an unloader but also has the pulsetank drain to prevent shock loads. A second governor runs the throttle down. Set to throttle up at 5psi before loading psi and down at same psi as unloader.
Its all fun and games till somebody puts a





marketable idea out then its everybody for themselves
 

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Ok, you obviously are familiar with this and should have no problem building it. I mentioned it because I have seen this attempted so many times unsuccessfully because of the problems I mentioned and I have gotten many calls from DIYers who were trying to sort out the governor problem. You would be amazed at how many people would call or bring their project over to the shop for help and would not even know what an unloader is or why it is necessary. Also I have spent a heck of a lot of time trying to sort out factory governor/unloader controls that owners had "adjusted" in an attempt to get more performance out of the compressor. It is fairly easy to get the settings close but getting it back to factory specs sometimes is not so easy and if out of range even a small amount it can cause a loss of performance and get quite costly in wasted fuel.

Just a note on the throttle kick down, if you decide you need one Surplus center had a really good set up dirt cheap a while back and I think it is still available. If you are not familiar with these guys you might want to check them out as they have a huge amount of goodies priced right for guys who like to build things like compressors, welders, tractors or just about anything else.

www.surpluscenter.com
 

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Discussion Starter · #9 ·
I'm kinda partial to williams stuff but am defintly going to take a look at this site. Understand about trying to sort out others fixes. Been doing that for years. Thanks for your input.You have been lot of help. Will posts some pics for sure. :)
 

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Discussion Starter · #10 ·
My how time flies. Well, the condenser idea did work very well except for one small problem. The condenser was one long tube instead of several tubes as I had thought. It restricted the flow to the point that the overpressure valve on the pulse tank would start popping when the tank pressure reached about 90psi. If I cut the compressor speed down to 600 rpm instead of the rated 800 It worked very good but lost a lot of cfm. I had it set up to push the water to the bottom (outlet) end of the condenser and into a centrifugal seperator with a cyclic drain. At no time did it ever accumulate any water in the wet tank so the dry tank was just an extra reservoir.The dessicant filter and the coalescer between the two tanks apparently are just an added precaution. Had to add in a manual unloader to facilitate starting. Incidently, the outlet air temp usually runs just a few degrees above ambient temperature. Am now trying to find a similar condenser to add in parallel to increase the flow capacity.
Les bon tempes roule
 
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