Actual cubic feet per minute (ACFM) is a unit of volumetric flow. It is commonly used by manufacturers of blowers and compressors. This is the actual gas delivery with reference to inlet conditions, whereas cubic foot per minute (CFM) is an unqualified term and should only be used in general and never accepted as a specific definition without explanation. Since the volumetric capacity refers to the volume of air or other gas at the inlet to the unit, it is often referred to as "inlet cubic feet per minute" (ICFM).