Existence of a Nonzero Worst-Case ACH for Short-Term Exposure in Ventilated Indoor Spaces

Figure 1

Schematic of two sample trajectories (solid and dashed lines) of airborne nuclei traveling from one possible combination of a sick to a susceptible individual. For short-time exposure, the green-colored portion corresponds to the trajectory followed at a low value of ACH. The continued red-colored portions correspond to trajectories for worst-case ACH. The continued blue-colored portions correspond to even higher ACH. (a) Theoretical prediction of the product plotted as a function of scaled distance . (b) Normalized quanta inhaled (obtained from LES) plotted against ACH for two sick-susceptible combinations of and . In the former scenario, there is a clear worst-case ACH, whereas no such worst-case ACH exists for the latter.