... procedure is the work of Norman R. Sparks, Professor and Head, Depart-ment of Mechanical Engineering, The Pennsylvania State University, and CharlesC. DiLio, Associate Professor of Mechanical Engineering, ... procedure is the work of Norman R. Sparks, Professor and Head, Depart-ment of Mechanical Engineering, The Pennsylvania State University, and CharlesC. DiLio, Associate Professor of Mechanical Engineering, ... average of 600 ft3/min (16.98 m3) of outside air to be admitted. Opening of the door by customers will cause slightly more than two air changes per hourin the building. The number of persons...