Abstract: A blower is disclosed. The blower comprises an impeller and a scroll housing. The impeller is provided with a plurality of blades and rotated. The scroll housing guides and discharges air sucked by the impeller to the outside, and surrounds the impeller. The expansion angle of the curvature radius of the contour of the scroll housing is designed to be less than an expansion angle in conformity with an Archimedic curve in a suction region ranging from a cutoff start angle to 160-200° from a reference angle. Additionally, the expansion angle of the curvature radius of the contour of the scroll housing is designed to be greater than the expansion angle in conformity with the Archimedean curve in a discharge region ranging exceeding 160-200°.

Abstract: A dual-intake fan which is a so-called sirocco fan used for venting air is disclosed. The fan has a structure in which a portion of an exhaust outlet is formed to be inclined while the centers of a scroll housing and an impeller are disposed to be eccentric so that noise can be reduced while air flow can be effectively guided by the scroll housing to the maximum extent and the air flow rate can be increased. The fan includes an impeller on which a plurality of blades are installed for rotating so as to create air flow, and a scroll housing formed so that the air drawn in through an air inlet by the impeller can be guided along a gradually expanding passage of the scroll housing, and the lower portion of an exhaust outlet is composed of at least one incline formed to be inclined upward toward any one side. In addition, the rotation center of the impeller and the center of the air inlet are disposed to be eccentric.