Evaluating Clean Room Performance in the Pharmaceutical Industry: A Numerical and Experimental Investigation Based on Iso 14644–3 Standards Publisher



Yarahmadi R ; Damiri Z ; Darvishi MM ; Alipoor A ; Pourbabaki R ; Moridi P ; Sharifi J ; Borhani Jebeli M
Source: Aerosol and Air Quality Research Published:2026

Abstract

Nowadays, clean rooms have become an indispensable part of various industries for the production of sensitive products. This study evaluates the operational performance of a pharmaceutical clean room using a combined experimental approach and Computational Fluid Dynamics (CFD) simulations to model airflow distribution and particle transport. The evaluated parameters included airflow velocity and volume flow rate, differential pressure between clean rooms, temperature, relative humidity (RH), airflow patterns and inter-room airflow direction, high-efficiency particulate air (HEPA) filter leakage, and airborne particle concentration in accordance with the ISO 14644–3 method. The measured environmental parameters, including airflow rate and velocity, temperature (22 ± 2 °C), RH (45% ± 15%), and differential pressure (10–15 Pa between adjacent clean rooms), were all within acceptable standard ranges. The test results for 27 HEPA filters indicated that three filters had leaks in the filter media, while the remaining 24 filters showed acceptable performance with a filtration efficiency of 99.997%. Finally, the particle counting test indicated that all three clean rooms met the desired cleanliness grade based on the ISO 14644–3 method. The airborne particle concentrations (> 0.5 μm) were within the standard limits for Grade B clean rooms. This is due to adequate airflow rates (providing sufficient air changes per hour) and high-quality HEPA-filtered air in Grade B clean rooms. © The Author(s) 2026.