Optimal positioning of air-exhaust openings in an operating room based on recovery test: a numerical study

This study investigates the influence of outlet location on conventional, turbulent-mixing operating-room (OR) ventilation performance. This was done by numerical simulation using computational fluid dynamics. Multiple configurations of OR outlets, both at floor and ceiling level, were examined, and the results were compared. OR ventilation-system performance in each case was examined by conducting a tracer-recovery test. Two common anesthetic gases, halothane (C2HBrClF3) and desflurane (C3H2F6O), were used to perform the test. Particle simulation was also considered to simulate bacteria-carrying particles. Based on achieved results, the floor-level exhaust outlets effectively removed anesthetic gases and other odors that might be released in the OR during surgery. Such gases are most likely found at floor level, since they are usually heavier than the air. On the other hand, air-exhaust openings at ceiling level very efficiently evacuated any airborne particles carrying microorganisms, lighter anesthetic gases, or other chemical substances. It is found that floor-ceiling mounted exhaust outlets at every corner of the OR is the optimal arrangement.