Duct type fans are fans in which air flows parallel to the fan shaft and is exhausted. These fans are divided into two groups as propeller guiding blade and shell type. These two types of fans are called duct type fans because they are arranged in a tubular shape. In these types of fans, they are the fans that provide direct connection to the fan placed directly inside or operate with the motor mechanism placed in the pipe sheath in the outer area. Due to this pipe arrangement, it is called duct type fan. The fan is manufactured using galvanized sheet metal in square or rectangular shape. In this type of fans, the air movement created by creating a pressure difference occurs in the axial direction.