Predictions of Relative Humidity and Temperature in an Operating Room

This paper uses airflow simulations to evaluate different ventilation systems on an operating room (OR). This study compares air distribution systems for an operating room by use of computational fluid dynamics (CFD) modeling. The air supply distribution and exhaust arrangements were modeled for a directional air flow system where air moves across the space from the high-pressure supply area to the low pressure exhaust area. Calculations were done to model a typical operating room in a steady-state condition with inclusion of object such as surgical lights, operating table, heat sources such as surgical staff and a patient, side-wall supply grille and exhaust air grilles. The discharge angle for the side-wall supply grille was varied from 0 to 45 degrees. Air return locations were also studied. One and two air exhaust outlet sites inside the surgical suite were considered. In the two-exhaust outlet configuration, one position was close to the floor and the other position was high on the wall. Simulations with combinations of 1:0, 1:0.343, 0.343:1, and 1:1 flow rates between the two return locations were performed. Predictions for the air movement, room temperature, room relative humidity, and concentration of contaminants within the operating room are shown. Analysis of these predictions is discussed. The supply and exhaust conditions of the ventilation air flow are shown to play an important role in the control of air quality. Results show good agreement with experimental data.