An apparatus includes a base substrate and a plurality of spaced apart end brackets attached to the base substrate. A pivotable one of the end brackets is movable between a retracted position and an extended position with respect to the base. A plurality of spaced apart side panel assemblies are removably mounted between each end bracket when the pivotable one of the end brackets is in the extended position. A first edge of each side panel assembly is positioned adjacent to the base substrate. A shroud assembly extends between the two side panel assemblies adjacent to a second edge of each side panel assembly. The shroud assembly, the base substrate and the side panel assemblies define an air duct. A fan is mounted adjacent to at least one of the end brackets for directing air through the air duct. The part count of the apparatus is reduced such that cost and assembly time are also reduced. Furthermore, at least one of the end brackets can be pivoted to the retracted position to allow the printed circuit substrate and end brackets to be more easily installed in the chassis as an assembly and to permit cost effective servicing of the apparatus.