Abstract: An air blower adapted to be mounted to the ceiling of a room to create a gentle circulation of air in such room. The blower includes a motor-driven impeller mounted in generally cylindrical housing and a vane unit having a first plurality of relatively large vanes disposed in radial planes with respect to the axis of rotation of the impeller, and a second plurality of relatively small vanes disposed in radial planes equally offset from the larger vanes and disposed adjacent the downstream portion of the large vanes. The vane unit is detachably mounted to the blower housing to permit removal of the vane unit for cleaning.