Abstract: An air blower for an air conditioning unit or system including a cross-flow fan, with stabilizer being mounted in a passage on a suction side of the cross-flow fan so as to extend from both side plates of the cross-flow fan toward a central part thereof within a range of L/D.ltoreq.2.5, where L equals the length of each of the stabilizers and D equals the outside diameter of the cylindrical bladed rotor of the cross-flow fan. By virtue of such an arrangement the back flow developing at positions of low flow velocities near both side plates when the flowing resistance of the suction passage has increased is prevented thereby preventing the occurrence of cyclic unsteady noise.