Patent ID: 8550066

Claim:
An air handler comprising: an enclosure having an interior volume and a distribution air outlet opening on the enclosure that is adapted for communication with an air distribution system; a fan wheel in the enclosure interior volume, the fan wheel having an outer diameter dimension and a circumference dimension, the fan wheel having a center axis of rotation that defines mutually perpendicular axial and radial directions and the fan wheel being rotatable about the center axis of rotation in a rotation direction; a blower housing in the enclosure interior volume, the blower housing containing the fan wheel and having an air outlet opening, the air outlet opening having a minimum radial dimension, a ratio of the minimum radial dimension and the fan wheel outer diameter dimension being at least 0.73, the blower housing having an outer wall with a volute-shaped portion that extends from a first end of the volute-shaped portion around the fan wheel in the rotation direction to the second end of the volute-shaped portion, and the volute-shaped portion of the blower housing outer wall having first and second sections as the volute-shaped portion extends in the rotation direction around the fan wheel, where an expansion angle of the second section of the volute-shaped portion increases at an exponential rate of 1.5 to 2.1.