Apparatus and methods for providing a desired volumetric conditioned airflow rate and for reducing noise level, airflow recirculation and airflow separation are disclosed. An example apparatus includes a nozzle housing having a pair of opposing sidewalls and a front and back wall that define an airflow passage. The airflow passage has a centerline extending between the inlet and the outlet and hasa plurality of cross-sections taken perpendicular to the centerline that collectively define a smooth contour along a length of the airflow passage. The cross-sections each have a thickness between the front and back wall that is greater at side edges than at the centerline. The thickness of the cross-sections decreases along a length of at least a first portion of the nozzle housing. A width ofeach of the cross-sections between the sidewalls increases along the length of at least the first portion of the nozzle housing.