What should I need to know before I buy an air compressor?

I understand that one advantage of air compressors is the number of tools that you can adapt to them. I would like to know the difference between an oil free air compressor and another. What size air compressor is perfect for home shop use? Thank you in advance for all your help.

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vince 094 years ago
If you are planning to use it heavily I would go with an oiled one if you have the money. In my experience they last much longer and they are quieter, this is my experiences. I have had two oil free ones and the oiled one that we have at work has out lasted them both.
rimar20004 years ago
Maybe some dollars...
blkhawk (author)  rimar20004 years ago
It seems that the oil air compressors are more expensive than the oil free ones, and better for industrial work. And you are absolutely right, money is always an issue for us makers! :-)
Burf4 years ago
My personal preference for a shop compressor is a 220v. stationary unit with at minimum, a 10 gallon tank.
But whether you want a portable or stationary, some of the things that are a must for either type:
A cast iron, oil type compressor
Capable of a constant 90 psi @ 4cfm
Dual outputs
Easily replaceable air filter
Repair/replacement parts are easily obtainable
Conveniently placed moisture drain plug
Industry standardized connections, fittings and gauges.
iceng4 years ago
I have an air compressor from Harbor Freight for 9 years now and it still works great. 

The only difficulty is the pressure release leaks just before the 100psi cut-off due to vibration.

"perfect" depends on your intended use. The VOLUME of gas that that you get from the compressor is a key variable. What kind of tools do you want to use ?

Oil free compressors tend to be clean, but very low capacity.
blkhawk (author)  steveastrouk4 years ago
I'm planning to use woodworking tools mostly, nailer, sander, planer, etc.
Air powered sander and planer ?
blkhawk (author)  steveastrouk4 years ago
Harbor Freight sells those.