Fan shroud structure reinforcement to reduce or eliminate warping and distortion

A fan shroud structure is constructed and arranged to carry a fan and motor. The fan shroud structure includes a base and an annular rim extending from the base. The rim defines a generally central opening sized to accommodate blades of a fan. Motor mounting structure is coupled with the rim and is disposed generally adjacent to the central opening. The motor mounting structure is constructed and arranged to support a motor for driving a fan. The fan shroud structure includes a first pair of opposing sides and a second pair of opposing sides coupled to the base to form a box-like configuration defining a perimeter of the fan shroud structure raised with respect to the base such that the sides are discontinuous with respect to the base to shift resonance of the shroud structure.