Modeling SARS-CoV-2 Infection Risk in Various Office Building HVAC Systems

The SARS-CoV-2 pandemic aroused great interest in the HVAC community regarding both the design of new systems and management and operation strategies for existing ones. Risk management plays a key role in all-air systems, which are based on air recirculation among all spaces, and also in primary air systems. Following an explanation of the analytical approach, this article assesses the infection risk in several HVAC system layouts. It takes into account the role of air renewal (ventilation) and recirculation and the lowering of infection risk due to virus removal or inactivation (through mechanical or electrostatic filtration or inactivation technologies such as UV-C irradiation and ionization), with special attention to the management of airflows depending on plant layout.