The SCFM (Standard Cubic Feet per Minute) rating given to an air compressor will signify the flow under standardized conditions: 68 F, 0% relative humidity, and atmospheric pressure of 14.5. By standardizing the means of rating output, compressors can be better rated and compared, apples to apples.
However, as these atmospheric conditions change, the actual output of the compressor changes. The difference between SCFM and the ACFM can often vary by 5-25%, which is exactly why determining ACFM (Actual Cubic Feet per Minute) is vital in understanding what your compressor’s actual output will be given it’s present atmospheric conditions.
To determine the ACFM of your compressor, you will want to know (1) the SCFM rating, (2) actual atmospheric pressure, (3) the relative humidity, and (4) the ambient temperature.
If you want the long equation for calculating ACFM, shoot us an email. Otherwise, use our ACFM Calculator above to automatically calculate the ideal pipe size.