It has been known to the air moving industry for some time that duct fittings installed close to a fan's inlet or outlet can have adverse effects on the fan's performance. The magnitude of these adverse effects is generally determined through laboratory testing, and the body of knowledge is relatively small compared to the possible combinations of fan types, duct and inlet configurations, and duct fittings. The purpose of the research described in this paper was to determine the effect of a limited number of various inlet installations and product configurations on the air performance and sound of a typical forward-curved centrifugal fan. Forward-curved fans are common in heating, ventilating, and air-conditioning systems.