Xin Feng Classroom | Ventilator Series: Direction and Angle of Ventilators

01 

Classification of Ventilators

       Ventilators can be categorized in various ways—by airflow pattern, pressure level, or application. We'll first introduce classification by flow pattern. Here, "flow pattern" refers to how air moves within the fan when entering and being processed by the impeller, not how it enters or exits the unit. This essentially describes the fan's operating principle.      Among our company's products, both axial flow fans and mixed flow fans feature straight-in, straight-out airflow without angled configurations. The key is to distinguish between the inlet and outlet ports.

For the same axial air intake, the impeller can rotate in two directions, which requires specifying the rotation direction of the centrifugal fan. For radial air discharge, different discharge angles can be selected, which necessitates describing the angular characteristics of the centrifugal blower.

02 

Fan Direction and Angle

        For descriptions of fan direction and angle, the reference point is uniformly the drive end of the volute and impeller. For Type A units, this is the motor end; for Type C and Type E units, it is the end connected to the driven pulley.

Airflow rotating clockwise is clockwise rotation; airflow rotating counterclockwise is counterclockwise rotation.

 For top-mounted air outlets, the angle is 90º; for bottom-mounted air outlets, it is 270º; for horizontal side outlets positioned lower, it is 0º; for horizontal side outlets positioned higher, it is 180º. Additionally, commonly used angles include 45º, 135º, 225º, and 315º. It is important to note that not every fan model can be manufactured to accommodate all eight angles. Typically, standard products only offer 0°, 90°, and 180° as selectable options. Once a centrifugal fan is manufactured, its direction and angle are fixed and cannot be altered arbitrarily.

03 

Fan Direction Adaptability

       Since the direction and angle of centrifugal fans are typically fixed and cannot be arbitrarily altered, it is essential to specify their direction and angle to ensure the adaptability of centrifugal ventilation systems. This point requires particular attention.

For certain air conditioning fan blades or accessory products without a drive end or where the drive end cannot be clearly identified, it is not always necessary to specify direction or angle. For example: The XFS, XFM, XFDT, and CHA series centrifugal fans are installed inside the housing. Their orientation can only be described based on the relationship between the housing's inlet and outlet openings and the eight sides of the housing. These fans use 12 designations, numbered (1) to (12), for identification.     XFS, XFM, XFDT sets, and DZ, XFD single-inlet sets can be installed with 90º rotation. Standard products feature symmetrical dual shaft extensions (either side can serve as the drive end), eliminating the need to specify direction or angle. However, for asymmetrical dual shaft extensions or single shaft extensions, direction must be described.     DZ impellers, being accessories, require direction description solely due to their nature.