A system, method, and process of for packaging liquid product into cartons using an automated packaging system and more specifically methods of enclosing the packaging system and routing conditioned air over the cartons is presented. More specifically, a carton magazine assembly for collecting plastic coated paper carton blanks prior to sanitization, assembly, filling, and sealing includes a magazine cover that can be opened to insert additional carton blanks into the packaging system as necessary. The magazine cover has an integrated air manifold that directs pressurized conditioned air over the carton blanks towards suction ports. The suction ports collect the air with potential contaminants and the filters the air prior to ejecting it away from the vicinity of the packaging system.