Impact of the Speed of Airflow in a Cleanroom on the Degree of Air Pollution

Abstract

The high-energy requirements of cleanrooms are the main motivation for optimizing their operational conditions. The ventilation system consumes the most energy in order to ensure the precise air conditioning of the room (filtration, temperature, and humidity adjustment). The main function of the ventilation system is to keep particle concentration to a minimum. This work deals with the optimization of an experimental operating room via the optimization of air supply through the distribution element (laminar airflow ceiling) in the range of 0.15–0.25 m·s−1. The laminar airflow between the distribution element and the patient is influenced by the operating light and different airflow velocities. These factors affect changes in particle concentration. Ansys Fluent software was used to investigate the nature of the flow, velocity profiles, and particle trajectories. The results of our numerical simulation demonstrate that a suitable flow rate setting increases the efficiency of particle reduction in the operating table area by up to 54%, which can, in turn, reduce operating costs. The simulated air velocity profile was subsequently verified using the particle image velocimetry (PIV) method. The typical size of particles monitored for in cleanrooms is 0.5 μm according to ISO EN 7. Therefore, the results of this study should be helpful in correctly designing distribution elements for clean rooms.