Two-compartment modeling of a hospital isolation room informed by CFD

Computational fluid dynamics (CFD) will be used to inform a lower order modeling approach, namely the well-known box or compartment models of indoor air quality, to obtain rapid and accurate prediction of aerosol concentrations in isolation rooms. Compartment modeling of pollutants (including infectious aerosols) in ventilated spaces has a rich history in the occupational hygiene community and, to the knowledge of the authors, this marks the first time it will be informed through CFD. The isolation room will be represented by two compartments, an inner and an outer compartment, with each compartment assumed to be perfectly mixed, but with different aerosol concentrations. In this model, the patient (or source of aerosols) occupies the inner or sub-compartment located within the parent compartment, the latter corresponding to the isolation room. Compartment model equations consist of initial value, coupled linear ordinary differential equations describing aerosol mass balance for each compartment. Parameters in the model equations associated with short-circuiting intensity (between the inner compartment and the air exhaust vent in the outer compartment) and flow exchange between the two compartments will be calibrated via the CFD.