Comparative study on ventilation and air conditioning system schemes based on virus pollution control in hospital infusion room

COVID-19 is transmitted through droplets or aerosols containing the virus, the very small particles exhaled by infected people or exposure to items infected with the virus. These droplets, aerosols and particles may be inhaled by others, or fall into their eyes, mouth and nose. In some cases, they may contaminate the contact surface. It is most likely to be infected if they are less than 1 m away from the infected person. To evaluate the effects of different air conditioning systems on the spread of human exhaled pollutants, computational fluid dynamics (CFD) was used to study the movement and diffusion of exhaled air from two rows of 12 sitting adults in a hospital's closed transfusion room. In this paper, a closed transfusion room with 12 human models was established firstly, and the mathematical model verified by experimental test results was used to study the propagation of viral aerosol particles in the enclosed space under different air conditioning systems. The result showed that when the transverse strong air flow is generated in the room, the concentration distribution of virus particles will show a roll like distribution and the personnel inside the roll will cause new infection. The air flow generated by the air conditioning system will affect the dispersion of droplets in the air. Evaluating and guiding the air flow to avoid blowing air from one person to another may reduce the risk.