Assessment of Air Curtain Control Efficacy in Preventing Contaminant Transmission in Cleanrooms

Abstract

Maintaining high air cleanliness in cleanrooms is crucial in manufacturing processes and scientific research. However, personnel movement can breach the sealed environment, allowing contaminant to enter cleanrooms due to disturbance created. Air curtains are a traditional solution to limit air exchange, but their control efficacy in preventing contaminant transmission into cleanrooms requires careful evaluation. In this study, factors influencing the air curtain control efficacy such as the air curtain’s supply area, personnel movement speed, and temperature difference were evaluated using computational fluid dynamics with dynamic grid technology. The results indicated that increasing the air curtain’s supply area reduced contaminant concentration in cleanrooms; however, the effectiveness in blocking contaminant transport did not improve beyond a certain supply area (0.4 m²). High personnel movement increased contaminant influx, and maintaining a low speed (0.25 m/s) significantly reduced the overall influx. As the personnel movement speed increased from 0.25 to 1.50 m/s, the total amount of contaminant increased from 2.5 × 10⁻⁸ to 7 × 10⁻⁷ kg/s. When the temperature difference decreased from 7°C to 1°C, the average dimensionless concentration of contaminant in cleanrooms after personnel movement decreased from 8.5 × 10⁻³ to 1 × 10⁻⁴. Generally, air curtains perform well but require precise design. On the basis of these findings, future research can further complement overlooked factors and enable more detailed design and control, thereby improving the efficiency and sustainability of cleanroom design and control strategies.