A fan shroud structure 10 is constructed and arranged to carry a fan. The fan shroud structure includes a body 12 having a periphery, a main surface, and an annular rim 26 defining a generally central opening 28. The opening 28 is sized to accommodate blades of a fan. Fan mounting structure 30 is coupled with the body and is disposed generally adjacent to the central opening. The fan mounting structure is constructed and arranged to support a motor of a fan. The body includes a plurality of surfaces features 34 constructed and arranged to affect resonance of the shroud structure with each feature having a surface 36 that is discontinuous with respect to the main surface 38 of the body. Each feature 34 also extends from the annular rim to the periphery of the body.