Choosing an air compressor is not black art but often you can get lost in the features when making a choice. We will try to cover some of the important choices that you have and give you a better understanding of what an air compressor really does.
The most important thing when deciding which compressor is right for you is finding out if it will meet the minimum requirements of the tools that you want to run with it.
The Air that comes out of a compressor is rated in two ways.
PSI or pounds per square inch is the pressure level
CFM is Cubic Feet per Minute and is the volume of air that comes out of the compressor.
Each of these ratings is important on its own but they are also important when matched together.
For instance a small compressor that can inflate your tires may be rated at 145psi but it may only serve that presure at a very small volume maybe .5 CFM or half a cubic foot per minute.
A medium sized compressor may be rated at 4 cfm @ 90 psi
and a large compressor may be rated at 12 cfm @ 60 psi
Now one interesting thing has happened in the rating systems lately especially with Sears Craftsman Compressors. When you go into the store and look at the rating it will say rated to 90psi or 125psi and it is very difficult to find what volume CFM that compressor can push out at say 90 PSI. Another thing manufacturers are doing is saying their compressor is a 1 hp or 5hp compressor. The Horse Power rating of the compressor is important when you look at the strength and the ability of the compressor to maintain a higher volume at a higher pressure but it says nothing alone about what tool the compressor can run.
So when choosing a compressor the first thing you need to do is find the tool you want to run and see if you can match that to the compressor specs.
Lets look at a few tools to see what they need to run and then talk about the compressor that would best fit that tool.