A blower assembly for a heating, ventilation, and/or air conditioning (HVAC) system includes a centrifugal fan having a fan wheel. A plurality of blades are coupled to the fan wheel at an inner blade boundary and extend radially to an outer blade boundary. The blower assembly includes a first housing panel and a second housing panel disposed on opposite sides of the centrifugal fan and extending transverse to the centrifugal fan. The blower assembly includes a wall extending between the first housing panel and the second housing panel and a flange extending from the wall at a vertex. The flange extends outwardly from the wall. A first radial distance from the vertex to the outer blade boundary is between 4 percent and 20 percent of a second radial distance from a rotational axis of the centrifugal fan to the outer blade boundary.