Airflow patterns through single hinged and sliding doors in hospital isolation rooms – Effect of ventilation, flow differential and passage

Abstract

a b s t r a c tNegative pressure isolation rooms are used to house patients with highly contagious diseases (e.g. with airborne diseases) and to contain emitted pathogens to reduce the risk for cross-infection in hospitals. Airflows induced by door opening motion and healthcare worker passage can, however, transport the potentially pathogen laden air across the doorway. In this study airflow patterns across the isolation room doorway induced by the operation of single hinged and sliding doors with simulated human passage were examined. Smoke visualizations demonstrated that the hinged door opening generated a greater flow across the doorway than the sliding door. Tracer gas measurements showed that the examined ventilation rates (6 and 12 air changes per hour) had only a small effect on the air volume exchange across the doorway with the hinged door. The results were more variable with the sliding door. Supply-exhaust flow rate differential reduced the door motion-induced air transfer significantly with both door types. The experiments showed that the passage induced substantial air volume transport through the doorway with both door types. However, overall, the sliding door performed better in all tested scenarios, because the door-opening motion itself generated relatively smaller air volume exchange across the doorway, and hence should be the preferred choice in the design of isolation rooms.

Experimental assessment of different mixing air ventilation systems on ventilation performance and exposure to exhaled contaminants in hospital rooms

“…These recommendations are based on the belief that high renewal rates could reduce cross infection risk in such spaces by diluting and removing pathogens. Nevertheless, recent research focuses attention on providing a good air distribution rather than on maintaining high renewal rates as being the most important factor in reducing cross infection risk [15,23,24]. Thus, if this requirement is met, strategies to reduce energy usage in ventilation systems by lowering airflow rates can be achieved [25].…”

Experimental evaluation of thermal comfort, ventilation performance indices and exposure to airborne contaminant in an airborne infection isolation room equipped with a displacement air distribution system

“…These recommendations are based on the belief that high renovation rates could reduce cross infection risk between patients and health workers in such spaces by diluting and removing pathogens. Nevertheless, recent research focusses the attention in provide a good air distribution rather in maintain high renovation rates as the most important factor in reducing cross infection risk [22][23][24]. Thus, current strategies to reduce energy usage [25] in ventilation systems typically involve lowering airflow rates and/or heating/cooling capacity.…”

Implementing a negative-pressure isolation ward for a surge in airborne infectious patients

“…[25][26][27] Inducing a pressure difference, however, across a door can decrease the air volume exchange across the door. 25,28 For this demonstration, it would have been optimal to construct an ante-room at each hallway entrance to the temporary isolation ward (we only constructed one to minimize project complexity). With 2 hallway anterooms, one would be used as a clean anteroom for ingress and PPE donning, and the other would be a potentially contaminated anteroom for egress and PPE doffing.…”