An air compressor paired with pneumatic tools can be a great addition to any DIYer's arsenal, whether you're a professional mechanic, or just do a lot of spray painting and nailing. Here's what to look for when selecting an air compressor that suits your needs.
First, look at the type of pneumatic tool you will need for the majority of your projects, then select an air compressor that will fit that need plus a bit more.
Every air tool will have a different PSI (pounds per square inch) rating, from 50 PSI for a spray gun to 90 PSI for a nailer. A single-stage compressor is usually rated at 135 PSI which is good enough for most home workshops.
The most important factor when selecting a compressor is its CFM (cubic feet per minute) rating. CFM is going to determine how many tools you can run, and how much power you're going to have. Every air tool has an operational CFM requirement -- select a compressor with enough CFM to support the most demanding tools in your workshop. Continuous-use air tools, like grinders and sanders, will have higher CFM requirements than intermittent use tools, like a stapler or wrench. (Remember CFI is power, PSI is storage.)
Compressor tank size is also important, but secondary to CFM rating for a home air tool system.
No matter what type of compressor you buy, always remember to drain the water from the tank after each use. Air under pressure creates condensation and this must be removed to prevent rust in the tank.
How to Choose and Use an Air Compressor [This Old House (YouTube)]