The amount of air provided by your air compressor is measured in CFM (cubic feet per minute). This measure is the most important element in choosing the right air compressor or when adding tools to your compressed air system – for two reasons.
Firstly, and most obviously, you need to know the total CFM consumption of the equipment that will be supplied by your compressed air system so you can size your compressor correctly.
Secondly, if you are buying a piston (reciprocating) compressor, manufacturers supply two sets of data for CFM. The displacement CFM is the air produced at the pump but the figure you need to rely on is FAD (free air delivered). That’s a measure of the air delivered to the outlet. When buying a piston compressor, make sure to match your consumption against the FAD figure.