Return Air Grille Position in a Cleanroom for Medicinal Packaging Using CFD Method

Abstract

A cleanroom is a highly controlled environment; therefore, air quality is of significant concern, and specific physical and microbiological requirements must meet the standard. In addition to the number of particles, another critical parameter in a cleanroom is temperature. USP (The United States Pharmacopeia) 797 recommends that the temperature of a cleanroom be around 20 °C. Air quality is achieved through several parameters and components, such as using a high-efficiency particulate air filter (HEPA), the amount of fresh air entering the room, temperature, pressure difference, and airflow direction. In this study, the cooling load of the room for the filling and sealing process was calculated, and the airflow and temperature distribution patterns between two parameters of the return air grille (RAG) position were compared using Computational Fluid Dynamics (CFD). The first parameter, RAG 1, was placed above the ceiling, while the second parameter, RAG 2, was set on the sidewall. Based on the results of the study, it was found that the heat load generated from the room was 6.99 kW with a cooling coil capacity amounting to 10.77 kW. Moreover, the supply airflow rate was 371.66 l/s. Based on the results of the simulation modelling, it was found that the RAG positioned on the sidewall was more ideal than the RAG positioned above the ceiling since the temperature was more evenly distributed in the room where the RAG was positioned on the sidewall.