I would spend the money on a California Air Tools quiet compressor or other type of muffled compressor. When our 80 gallon 2 stage fires up at work it's deafening. When my California Air Tools compressor fires up at home you can barely hear it. I know they make sound cabinets for them too. Their 60 gallon compressor runs at 75 dB. My compressor is 55 dB IIRC.
Compressor: Best bang for the buck
- Thread starter wizbangdoodle
- Start date
Really? Even if you use an oil separator, filter and drier?
What’s the budget here or did I miss that? It’s the rpm that they run at that’s the kicker. Buy a larger two stage with at least a true 5hp motor, mine is 7.5 I believe which should be properly matched to the pump. Mine runs at ~900 rpm roughly which also helps on the wear of the pump as well as the heat and in turn less condensation in the tank as well, not to mention the noise.
I don't want to get too crazy, but the 60-80 gallon ones I see are around $800-2000. I'd like to stay below $1300.
Wrong, see below.
See above. This, I have a separate line with a drier/separator and have been using it for 20 years.
Good to know.
I realize I'll probably never need 175psi, but 60 gallons at 175psi is more cubic feet than 60 @ 135psi. I assume this would keep the compressor from running as often.
I realize I'll probably never need 175psi, but 60 gallons at 175psi is more cubic feet than 60 @ 135psi. I assume this would keep the compressor from running as often.
For your described parameters and budget I'd honestly go with something like the Quincy QT-54. We had one as backup at the old shop and it ran well. Personally I prefer a pressure lube but that's out of the budget range you prescribed.
So here's the thing, the motor should be just fine to handle whatever you want to do. I would figure out what your max cfm requirements will be (this goes for any compressor you choose) and then pulley it down to that if it isn't there from the factory IF noise is an issue and you also want to eliminate additional wear and tear, heat, etc.
For instance, the QT uses a pump rated at a minimum of 550 rpm and max of 1420. 6.4 cfm @ min & 15.2 cfm @ max. As I said earlier, I pulley swapped mine to get around 900 rpm which would be roughly 10 cfm for you (my pump is larger so ~13 for mine I believe). For most, and being you're probably not going to have multiple tools going at the same time, it might be a good compromise. Hope that makes sense.
Driers, aftercoolers, automatic drains, etc. can be added later if you need it and when the budget allows.
Maybe. Use a cheap separator and you'll see lots of fisheyes in your finished product. If your are going to paint, check out boards like the H.A.M.B. as you'll get better advice. Filter and drier are for debris and water, which are a must for painting anyway. Hand tools? As long as you maintenance them regularly (I simply put a couple of drops of air tool oil in mine for the last 20+ years), they'll be fine.
Have to remember the hotter the air the more moisture it can hold. A rotary typically only has ~<3 ppm oil carry over whereas the better two stage piston compressors are 5-7.
It’s a must to cool the air and then run it through your dryer and filter media. Having an auto tank drain is a boon in this instance. Aftercooling will get roughly 50% of the moisture. A dryer will get another 30ish% and then desiccant/filter will get most of the rest. For a diy guy that will generally be enough.
He’s right though, don’t cheap out.
It’s a must to cool the air and then run it through your dryer and filter media. Having an auto tank drain is a boon in this instance. Aftercooling will get roughly 50% of the moisture. A dryer will get another 30ish% and then desiccant/filter will get most of the rest. For a diy guy that will generally be enough.
He’s right though, don’t cheap out.
That's how my mind works too. 80 gal @150psi
So, I was really leaning toward that Quincy QT54, but then I walked into Tractor Supply and saw this:
https://www.tractorsupply.com/tsc/p...lon-5-hp-reciprocating-air-compressor-3496129
80 gallon instead of 60, 2 stage 5hp and a bit cheaper. Can anyone tell me why I shouldn't buy this?
https://www.tractorsupply.com/tsc/p...lon-5-hp-reciprocating-air-compressor-3496129
80 gallon instead of 60, 2 stage 5hp and a bit cheaper. Can anyone tell me why I shouldn't buy this?
Up to you, it would probably serve your needs well. I looked at the specs between the two, the IR provides .4cfm more (rated) at 90psi but also runs at a slightly higher speed. The compressor is less efficient and has a different motor. Between the two, the Quincy is more industrial oriented. Service life is ~3x on the Quincy, and I know the Baldor motor is a better unit than the Emerson's unless IR started using a different motor.
I'm willing to bet that 60gal would outperform the IR and be quieter while doing it. That is where your price difference comes from. I have 5 duplex IRs here at work and we haven't been super impressed, have had to replace 3 motors between them among other issues. I've got a several old Quincy, SB, and a Curtis that are 20+ years old and still perform better.
And that is exactly why I started this thread. Good info, thanks.
Yeah, read some of the reviews on that one carefully. More than a handful of motor issues that are recent. I tried to find the pump specs on the IR website for the T45 (bore, stroke, min/max pump speed and cfm) and they aren’t listed like Quincy or the higher end models though I could have missed it.
You could always look on FB marketplace or CL and see if you can find a used older compressor.
I looked at the motor tag itself on that IR unit. It's rated at 3450 rpm. Seems pretty high for a 2 stage unit.
That's a standard RPM for a electric motor unless it's VS. The speed of the compressor is determined by the pulleys.
This.
Asynchronous AC motors build torque on a curve, unlike synchronous AC or DC motors.
A single motor driving 2 stages will need more torque, so you either get that with higher speed through less pole sets or more electromotive force from larger windings. Higher speed motor will typically be smaller than one with higher hp ratings due to this.
Yes, but pulleyed down to run the compressor at ~1400 rpm. Most people have said the motor seems to be underpowered for that model which is why many have burnt up I assume. Look at the size between the Baldor and the Emerson or what we they use now on the IR. Both rated at 5hp mind you.
Yup, also the reason the larger 7.5+ motors employ a mag starter.
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