Patent attributes
A housing cooperates with an air mover rotating about a rotation axis to move air received from an approach to an exhaust. The approach is generally oriented about a direction intersecting the housing at upstream and downstream limits. The housing presents an interior surface establishing radii between the axis and the surface. The radii have a generally constant radial value across a width in planes containing the axis in a first zone between the downstream limit and a first locus, and in a second zone between a second locus and the exhaust. The radii vary between a smallest and a largest radius across the width in planes containing the axis in a variance zone upstream of the axis. The smallest radius is less than the radial value at the first and second loci. The largest radius is larger than the radial value at one of the first and second loci.