I'm looking at getting an air compressor for my shop. It will be used to run die grinder, air wrench, possibly paint gun down the road. My dad has a small one that works perfect so that is what I'm using as a basis for my search. His has a 2hp motor and puts out 7 cfm @ 90psi. In my search I can't find anything that puts out that amount with less then a 5hp motor. I was wondering if they changed the way the compressors are rated in the past 20 years? My dad's was bought in the late 80s. Also is there a difference between cfm and scfm? I've seen compressors listed both ways and always thought they ment the same. What does the "s" stand for?
yeah, they did change the way compressors are rated. Instead of using the old, sensible "continuous duty" HP rating for the motor, the marketing guys decided the numbers would look better if they used the "maximum developed" HP numbers. That means, how much HP it produces as it starts turning, not as it's running compressing air! pretty fricken stupid if you ask me. Used to be (about 25 years ago) you'd pay $300 for a 1hp compressor....now you pay that much for a 5 hp compressor that puts out about the same CFM as the old 1 hp. So, ignore the hp numbers and go by cfm.
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