Axial fans, very wide range, is the shaft with blade with the direction of the air flow, such as electric fans, running air conditioner outdoor unit fan is an axial flow fan. It is called "axial", parallel to the fan shaft because gas flows. Axial-flow fans are typically used in situations of low flow demands and pressure requirements. Fixed position of axial-flow fan and allows the air to move. Axial fans made up mainly of fan impeller and casing, the structure is simple but very high data requirements