Patent ID: 6866480

Claim:
A centrifugal fan with a single or double intake, comprising: a fan impeller of a closed type including blades attached to a rotatable disk and a covering element, wherein (i) said blades are flat and backwardly inclined with respect to a direction of rotation of said fan impeller, and (ii) said covering element includes along a direction of airflow a frustoconical surface portion, a first curved surface portion and a second curved surface portion, with a radius of curvature of said first curved surface portion being smaller than a radius of curvature of said second curved surface portion; an air inlet located upstream of said fan impeller; an air outlet located downstream said fan impeller; and a baffle at said air outlet, said baffle comprising a sheet element arranged parallel to a plane of said air outlet and having at a top portion thereof two upwardly diverging surface portions curved in the direction of airflow so as to impart to said top portion substantially a V-shape.