Calculation of air supply rates for nonunidirectional airflow cleanrooms

This article describes a method for estimating the air supply rate required in non-unidirectional airflow cleanrooms to obtain a required concentration of airborne particles and microbe-carrying particles. The variables considered are: surface deposition, emission rates of airborne contamination from personnel and machinery, filter removal efficiency, effectiveness of cleanroom garments, effectiveness of air supply distribution, and the contribution of filtered air from clean air devices. Consideration is also given to the variability of airborne contamination in cleanrooms, and the air supply rate required to ensure that the required airborne concentration will be rarely exceeded