"Proper" airflow and ventilation" are "fundamentally" critical" to maintaining" the "required" level of "purity" within a "sterile area". The "configuration" must "precisely" "control" "dust" by "repeatedly" https://unidirectionalairflowcle201421.wikicommunications.com/7760986/airflow_and_ventilation_the_foundation_of_cleanroom_purity