Comparison of Particle Deposition under Air Curtain, Mixing Ventilation, and Displacement Ventilation in a Negative-Pressure Two-Bed Ward

Air curtain ventilation (ACV) has been proposed in the literature as a primary ventilation strategy for infection control in multi-bed hospital wards; however, its effect on particle accumulation compared to conventional mixed ventilation (MV) and displacement ventilation (DV) has not yet been sufficiently studied. This study uses computational fluid dynamics (CFD) to compare the accumulation rates of respiratory exhaled particles in a negative-pressure two-bed ward ventilated with ACV, MV, or DV. Both patients were modeled as sources emitting particles with diameters of 1 μm. Thus, the aim was to calculate the contamination from one patient to the other, and removal efficiency, cross-contamination, and self-contamination values were obtained. The results revealed that particle accumulation rates varied considerably depending on the type of ventilation. In the MV scenario, the accumulated particles were more homogeneously distributed throughout the ward, increasing the risk of cross-contamination between beds. In the DV case, the lowest airflow efficiency was observed due to the inadequacy of thermal buoyancy in preventing particle deposition, leading to significant self-contamination among patients. In contrast, the ACV provided a more directed airflow that limited accumulation to an area closer to the source patient and reduced particle transfer to the adjacent bed. These findings demonstrate that air curtain ventilation can alter both the magnitude and location of particle accumulation, thus offering a promising alternative for reducing infection in negative pressure patient wards by limiting cross-contamination.