Meridional acceleration design with drum casing, tapered hub, and twisted blades; combines high pressure coefficient of centrifugal fans with high flow coeficient of axial fans-low noise, energy-efficient, compact, horizontal or vertical installation. Supply and exhaust ventilation for industrial and civil buildings, especially where duct installation space is constrained. Impeller balance grade ⩽G5.6; variable frequency motor

and controller available for stepless speed regulation. Roof-mounted version (add suffix "W") /External silencer box (add suffix "X").Corosion-resistant and explosion-proof versions available for corrosive, flammable, and explosive gas handling.