Looking to upgrade to an commercial quality compressor

Fejery4491Fejery4491 Member Posts: 154 ✭✭✭
So the time has come to upgrade our air compressor. As we've started taking on larger runs of parts we've really been pushing our current compressor pretty hard and it's basically inevitable that we're going to need to upgrade soon. If we continue as we have we'll end up melting this one to the ground. We only do this part time during evenings and having to do separate processes at separate times instead of one guy painting while one guy is blasting or prepping absolutely kills productivity.

So I'm trying to upgrade to the "last compressor I'll ever buy". We all know how that goes, but that's my goal. My criteria is pretty simple....

-Single phase power. Unfortunately I have to stay 1p since someday I plan to build a shop way out in the sticks and don't figure I'll have access to 3p.

-AT LEAST 30 cfm @ 90-100 psi. That's the bare minimum I would consider. I would be alot happier closer to 40 cfm....but I will take into consideration any above 30.

-Preferably something that's somewhat manageable as far as noise. No seperate compressor room at this point and probably wont until I build the next shop.

-Price of $3000-4000 to my door.

I've made calls to a couple different companies, but the compressor that's standing out to me in the Polar Air Compressors by Eaton.


Makes high 30s for CFM, should fit my budget with freight, with their Silent Air system it supposedly runs about 65 decibels which is awesome for a piston style compressor, and the best warranty in the industry (5 years).

Just looking for any input from guys who have been in the game a while, is there another compressor I should be taking a closer look at? Any input is greatly appreciated.


  • MidOhioHydrographicsMidOhioHydrographics Member, Moderator, Business Ninja Posts: 10,305 El Moderator
    edited May 2018
    That compressor looks good. But if you keep growing? That won’t be your last compressor. LOL. I started w an Emax 10hp 120gal 2-stage right around that CFM and we outgrew it pretty quickly. Great compressor tho! Right in your price range with some room for an air drier as well. Seriously consider a refrigerated dryer if you’re going through that much air. Didn’t get mine from Home Depot, but the price is good:



    Also consider looking used. Watch auctions. Screw compressors are crazy quiet and produce more CFM for the HP, and many have integrated dryer systems. Can probably pick up a used one in your price range that will give you more air and a dryer. Good brands are Quincy, Ingersoll Rand, Atlas Copco.
  • LibertymanLibertyman Member, Business Ninja Posts: 967 ✭✭✭✭
    @Fejery4491 keep your eyes on auctions, check out this web site publicsurplus.com
    It's a public auction of schools, government agencies, colleges etc. we bought our compressor on it and came out with a heck of a deal. $895.00 it was barely used in an elementary school. It happened to be 3 phase but we just purchased a rotary phase converter and it works like a charm. The phase converter was a bit speedy, but now allows us to run other 3 phase equipment on a single phase system. Which is unfortunately what we have in our building. These auctions are all "tax payer funded stuff" so it generally goes for dirt cheap. Everything from office furniture, printers, PC's, shelving, to shop equipment and even vehicles. Every state has them so check it out. You might come across a nice compressor for peanuts. Or something else for the shop.

  • MidOhioHydrographicsMidOhioHydrographics Member, Moderator, Business Ninja Posts: 10,305 El Moderator
    A phase converter is a good idea also. I made one for my garage at home. Got a big 5hp Delta Table saw for I think $700 if I remember correctly. It’s a beast. Went cheap at an auction just because it was 3 phase and nobody there wanted it. If you’re interested, I can give you diagrams to make your own converter. You just need another 3 phase motor that is bigger than the compressor motor by at lease 50%. 10hp compressor = 15hp phase converter motor. It takes a pretty knowledgeable electrician, but it’s not difficult once you wrap your head around what is being done. Just not something I want to post up on a public forum. Although I may have a couple years back...
  • MidOhioHydrographicsMidOhioHydrographics Member, Moderator, Business Ninja Posts: 10,305 El Moderator
    There is also a way to use a VFD (variable frequency drive) as a phase converter. Some info here:
  • MidOhioHydrographicsMidOhioHydrographics Member, Moderator, Business Ninja Posts: 10,305 El Moderator
    And scroll down on this discussion. I lay out my homemade converter:
  • Fejery4491Fejery4491 Member Posts: 154 ✭✭✭
    @MidOhioHydrographics thanks for your input. Emax is just the Polar Air unit rebranded....from my understanding they're both out of the same building in Clayton Ohio. So you had the exact compressor I'm considering essentially....so I guess I'm glad you liked it.

    I've also been watching the used market pretty close. We're in a huge manufacturing area of MN. Plenty of good compressors for sale, but most are 3-phase. I would love to get a screw compressor.....but just don't know I'll find one that's in my budget.

    @Libertyman I've been considering a phase converter but aren't they pretty inefficient? My info on them is probably pretty outdated....i know that technology has grown and developed A TON in the last 10 years or so.

    I'm probably not a knowledgeable enough electrician to make my own, but basically all my friends are either journeyman or signing masters.....so I'm sure it's something they could help me put together.
  • K2ConceptsK2Concepts Administrator Posts: 14,155 El Jefe
    @Fejery4491 I have a 7.5 hp Kaiser Rotary Scroll that I only want $800...

    The former owner wired it in incorrectly and thought he blow the motor...I checked it out and I believe it only needs a couple new protection contactors...I bought 2 new main but have not put them in...so for less than what you would think? You get a damn good compressor...
  • Fejery4491Fejery4491 Member Posts: 154 ✭✭✭
    @K2Concepts I'm going to PM you. I'm interested in some more info....
  • MidOhioHydrographicsMidOhioHydrographics Member, Moderator, Business Ninja Posts: 10,305 El Moderator
    edited May 2018
    @Fejery4491 I believe you are correct. They are “inefficient” in that you basically have one motor running as a generator for the third leg of 3 phase power (one 220v circuit running the 3-phase motor, that motor then generates the 3rd leg) plus the 3-phase motor on the machine actually running. So you’re running two large motors in order to use just one piece of equipment. But the trade off is you can basically run anything 3-phase now. And often times 3phase equipment can go cheap, and is usually built better since it’s considered “industrial” power. That all being said, you’re equipment can start harder and run hotter (at least on my generic version, the store bought ones balance the legs and are probably more healthy for the equipment).
  • K2ConceptsK2Concepts Administrator Posts: 14,155 El Jefe
    @Fejery4491 What Mid Ohio is saying is true...but like he said? The advantage is you can get an awful lot of stuff that is 3 phase...really GOOD stuff...because not everyone has 3ph...you would be shocked at how many guys ask me what to look for in a new shop and the first thing I tell them is to ask “Is there 3 phase electrical?”...and then they say “I don’t know”...soon followed by “What’s that?”...
  • LibertymanLibertyman Member, Business Ninja Posts: 967 ✭✭✭✭
    The new phase converters are way more efficient. Their technology has evolved quite a bit in the last few years. Ours is wired in a way, where a signal is sent to the phase converter right before the compressor actual needs to turn on, the generater fires up to speed in an auto state creating the full three phases needed at start up so it gives a burst of full power at start up getting the15 h.p motor up and running, then it backs down in a way that is more efficient and actually is cheaper to run then direct 3 phase set up, once the compressor is done it goes into sleep mode until the compressor calls for more to start it all over again.
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