Indoor bioaerosol dynamics

Nazaroff, William W

Among the major categories that can contribute to indoor bioaerosols is air exchange-induced supply from outdoor air. From equations (1) and (2), the rate of supply of bioaerosol material from outdoors is represented either by the term (Q N + pQ L )C o (for the residential schematic, Figure 6a ) or by the term [(1Àg M ) Q M + pQ L ]C o (for the commercial building schematic, Figure 6b ). We have discussed the various air exchange flow rates and-to an extent-the outdoor bioaerosol concentration, C o . The new terms to address here are the fractional penetration of bioaerosols along with infiltration flow, p, and the efficiency of bioaerosol particle removal in the mechanical ventilation supply flow, g M . An important point is that both of these efficiency terms are expected to exhibit significant particle-size dependence. Consequently, the relationship between outdoor bioaerosol concentrations and the source of indoor bioaerosols can vary with particle size.