Renovation in hospitals: a case study of source control ventilation in work zones

ABSTRACT

Approximately half of the nosocomial aspergillosis outbreaks in hospitals have been associated with renovation activities. When disturbed, spores encapsulated in building materials can be aerosolized and transported throughout the healthcare facility causing potentially fatal complications, particularly among elderly and immunocompromised patients. Thus, a series of experiments were conducted in an actual hospital to observe containment and removal of airborne particulates with respect to ventilation arrangement and directional airflow. Computational models were then developed to further study the spread of contamination during a hospital renovation project. Results of this study suggest that although directional airflow (negative pressure) was effective in containing particulates across an open doorway between patient and contaminated spaces, turbulence caused by door motion and the location of the exhaust grilles affected the transport of particulates in the work zone. A new source-control ventilation strategy is proposed where the arrangement of supply and exhaust air ventilation is optimized to more effectively contain and remove airborne particulates within hospital work zones. Results indicate that the location of supply and exhaust air relative to the contaminant source can increase particulate removal by an additional 26%, or roughly the effect of doubling work zone air changes – without added operations and maintenance (O&M) costs.

KEYWORDS:

• Hospital renovation
• ventilation system
• negative pressure
• airflow
• CFD

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was partially funded by the United States Department of Veteran Affairs (VA), Veterans Health Administration in response to the 2009 Swine Flu Pandemic.