CFM stands for Cubic feet per Minute and is essentially the amount of working power that a compressor provides to the equipment it is powering. The other factor a compressor provides is PSI or pounds per square inch. Typically PSI is the same with all compressors but CFM varies greatly. That is why it is critical to understand the CFM you will need for your equipment, if you do not have a large enough compressor you will experience a variety of issues. The most common issues you will encounter are sputtering of your spray gun, poor material break up, and a change in your spray pattern during painting. While in the ideal world you will always have more compressor than you need, in the real world you often will have multiple tools using your compressor or you may not be able to invest in a large compressor. So how do you determine how many CFM you will need? The best answer is to evaluate the spray equipment you will be operating. Different spray equipment will have different air requirements and even within the same type of spray equipment different set ups will require varying amounts of air. What I mean by different setups is that spray guns come with a variety of air caps all designed for different purposes. Each air cap requires different CFM (typically the higher the CFM an air cap uses the better it is able to break up heavy bodied material or to sustain high production needs). That is why if you are on a compressor budget you should mention this when considering a spray gun purchase, depending on the manufacturer the spray gun may come with a low CFM air cap designed to use minimal air. As for a general reference see the chart below to see the CFM use of various spray equipment.
Back to Pittsburgh Spray Equipment Company