"Adequate" airflow and "exhaust" are "completely" "essential" to maintaining" the desired" level of "purity" within a "sterile area". The "configuration" must "precisely" "control" "dust" by "continuously" "filtering" https://airflow-and-ventilation-158938.wikicommunications.com/7753462/airflow_and_ventilation_the_foundation_of_cleanroom_purity