Jetstream Axial Mine Fans (AMF Series) are heavy-duty axial fans designed specifically for main mine ventilation. These robust adjustable-pitch fans have been designed to deliver up to 1 million CFM against 14 inches total pressure. Ranging in sizes from 76 1/2" to 148", this fan line delivers high efficiency and reliable service. These robust adjustable-pitch fans have been designed to deliver up to 1 million CFM against 14 inches total pressure. Ranging in sizes from 76 1/2" to 148", this fan line delivers high efficiency and reliable service.