Advanced ventilation chair for source control of respiratory infectious diseases

¹ Department of Building Environment and Energy, College of Civil Engineering, Hunan University, Changsha, Hunan, China
² National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha, Hunan, China

^* Corresponding author: zhengtaoai@hnu.edu.cn

Abstract

Since the outbreak of the new crown, a large number of people at home and abroad have been infected, causing great damage to human lives, the economy, and the whole society, which has led to a great deal of concern about respiratory infections. Hospitals are at high risk for the spread of respiratory infections, and hospital outpatient rooms are a focal point for the prevention and control of nosocomial infections due to the small space and frequent visit of many people, where effective measures can greatly reduce the risk of the spread of respiratory infections. Airborne transmission is generally controlled by strengthening ventilation and dilution. However, full space dilution ventilation is less effective in removing exhaled droplet nuclei and is limited by the capacity of the ventilation system and other conditions. Therefore, airborne transmission is a weak section in hospital infection prevention and control, and there is an urgent need to develop advanced technical means aiming for source control. In this paper, computational fluid dynamics (CFD) simulation was used to study the interaction between exhaled airflow, thermal plume, and ventilation airflow when patients stayed in the outpatient consulting room for a short period (from a few minutes to more than ten minutes). After comparing the two styles of wearing mask, it was determined that only the top exhaust was the best distribution form. When patient wear face masks, the top exhaust with ventilation volume rate of 20 m³/h can achieve 90% collection efficiency in 30 s. After the patient left, it takes only 15 s to collect most exhaled particles. The air volume and vent dimension is important to the design of ventilation plate, when the design is not reasonable, it can cause up to 50% impact. This paper propose a personalized ventilated chair for airborne transmission which could contribute new solutions and technologies to achieve the goal of significantly reducing hospital infection rates.