Experimental assessment of the exposure to airborne exhaled contaminants using general and personalised ventilation systems in a hospital room

Ensuring good indoor air quality is critical in hospitals. An environment free from airborne particles can prevent the spread of various diseases and improve patient health. In this study, the efficiency of a personalised ventilation supply system (PSS) and personalised ventilation extraction system (PES) for diluting and removing contaminants exhaled by a patient in a hospital bed was evaluated. These systems, which were integrated into the head and foot of a hospital bed, were combined with three general ventilation strategies in the room. Fifteen ventilation strategies were analysed experimentally. Two breathing thermal manikins (BTMs) were used to simulate a patient and health worker in a hospital. The breathing of each BTM was controlled by the patient (source) generating particles that can increase the risk of infection in a healthy person (target). Experimental results show that using a PES combined with general ventilation of the room reduces the exposure of the target manikin compared to general ventilation strategies alone. However, no marked improvement was observed when the PSS was activated. The reduction in exposure to the target manikin was considerable when the PES was located at the foot of the hospital bed, which is the preferred option for integrating personalised systems in a hospital bed.