Abstract: A system and apparatus for controlling airflow in large industrial forced-convection ovens that are used for cooking, smoking, drying, and processing meat and food products. The system and apparatus reduce temperature, color, and yield variation within the ovens, and also reduce cooking times and power requirements. The system and apparatus use variable-width supply-air slots and dual, side-mounted return ducts to precisely control the airflow within the oven so that the air can be directed to the slowest cooking areas in the oven.