A Computational Study of Hospital Isolation Room Environment to Assess the Spread of Airborne Contaminants

The safety of healthcare workers and patients in hospitals is a matter of paramount importance. Therefore, the significance of adequate ventilation in hospital rooms towards controlling airborne infections cannot be ignored. Although several reports discuss natural and mechanical ventilation in hospital isolation rooms, conflicting opinions recommend one ventilation method. There is also a paucity of information that relates engineering evaluation of hospital room ventilation to the design standards laid down by established public health agencies in the United States. This research aims to study hospital isolation room ventilation performance using natural and mechanical ventilation methods and assess certain guidelines on hospital room ventilation. Computational Fluid Dynamics is used to evaluate the concentration of contaminated air following a coughing event within a hospital isolation room using natural and mechanical ventilation. A novel technique employing a mechanical exhaust tube is proposed that may substantially reduce contaminant concentration. Within the same hospital isolation room, the normalized maximum concentration of contaminated air is much lower with two different mechanical ventilation methods (0.2% and 0.25%) than with the natural ventilation method (0.6%), suggesting that mechanical ventilation methods are more effective in reducing the concentration of contaminated air. In addition to established design parameters such as Air Change per Hour (ACH) and ventilation volume per patient, closer proximity to the vent from the contaminant source may also play a critical role in reducing contaminant concentration.