Abstract: A split scroll diffuses and directs air upwards from the circumference of a forwardly-curved centrifugal fan to a discharge plane to one side of the fan. The scroll has a first monotonically increasing curved wall that extends from a cutoff point near the circumference of the rotor, in the direction of rotation, to the discharge plane. A second monotonically increasing curved wall extends in the opposite direction from the cutoff point up to the discharge plane. The first and second curved walls are mirror images of one another taken at the plane corresponding to the air flow tangent that passes through the cutoff point. A curved cover above the fan at the exit plane blocks line of sight noise from radiating directly from the fan rotor into the work space or living space.