The ventilation needed to control thermal plume and particle dispersion from manikins in a unidirectional ventilated protective isolation room

Infection is a major cause of death for the immunocompromised patients whose immune mechanisms are deficient. The most effective way of protecting these patients is the total environment protection such as protective isolation room (PIR). Unidirectional airflow ventilation is usually used in PIR. The supply air velocity in PIR can affect not only the cleanliness level of the room and total environment protection effects to the patients, but also the energy consumption and initial equipment investment of the room. Computational fluid dynamics (CFD) program is used to simulate the airflow field and the concentration distribution of the particles from human body and breathing. Three scenarios when the manikin is standing, sitting and lying are investigated in this study. The intensities of supply airflow with different velocities and the upward airflow induced by thermal plume with different postures are compared. The qualitative and quantitative analysis of the simulation results show that the required supply air velocity to control the thermal plume and particle dispersion from human body and breathing is at least 0.25 m/s when the manikin is standing or sitting, and 0.2 m/s when the manikin is lying.