Air compressor ratings can often be confusing and we have seen many customers get confused into just looking for the largest tank size (gallon) compressor or the highest PSI compressor within their budget. But in the real world the spec that matters the most for you is the SCFM of your compressor. SCFM stands for Standard Cubic Feet of air per Minute, and its true definition is the amount of free flow air going into the intake filter of the compressor. This can get confusing as it is NOT the amount of air flowing from the discharge of the compressor (AKA what you see out of the hose). Where it gets difficult is that some vendors bend the rules or blur the lines of how they measure SCFM and often are just measuring the CFM out of the discharge. We suggest diving deeper into how a manufacturer measured their supposed SCFM and see if it is a true SCFM reading so you can compare it with other compressors correctly.
You will then need to determine what the requirements of you pneumatic tools are. What CFM do they require and at what PSI? From there you can look at the output of your potential compressor. A quick generic rule of thumb is that for every horsepower of a compressor will equal 2-4CFM. If you’re just a casual air compressor user and not regularly blasting, painting, or running multiple tools at once, you may be safe calculating quickly that way.
We also suggest reading the compressor manual or operating guide to find the high and low CFM and pressure ratings. Many manufacturers will use a cold CFM or pressure rating because ratings go down as the compressor is used and gets hot. In the fine print you will find a low and high spec and if you’re already almost maxing out the high number, you know once you starting working the compressor for extended periods of times, you won’t have the CFM you need to run your tool. A little extra digging and reading goes a long way!
For our full line of air compressors visit our site here: https://www.eastwood.com/shop-equipment/air-compressors.html