Impact of LAF system design factors on contaminant removal and thermal comfort in the operating room HVAC system using OpenFOAM

The impact of LAF system design factors on contaminant removal and thermal comfort in the operating room is investigated. A simple operating room with staffs, patient and surgery light is modeled. LAF system is considered on the ceiling with a constant height partial wall surrounding it and air barrier supply grills around them. Fresh air is supplied to the room through LAF and air barrier systems. Then air is exhausted through the exhaust grills located on the bottom parts of the side walls. Computational fluid dynamics method is used to simulate the air pattern and contaminant distribution in the room to assess the ventilation performance. Then predicted mean vote (PMV) is calculated to assess the thermal comfort for persons in the room. Twenty seven simulations are carried out to determine the impact of three main design factors of LAF system area, supply air velocity and air barrier velocity. It is found that generally better performance for ventilation system of medium LAF systems can be obtained by adjusting the supply air velocity to an average value of 0.4 m/s alongside with the full air barrier velocity of about 2 m/s in the room. On the other hand for the same adjustments, it is recommended to use a higher supply air temperature to achieve a better thermal comfort for the patient and staffs.

Keywords:

LAF system , Operating room , Contaminant removal , Thermal comfort , Clean room