Venturi effects / microbial wind tunnel

Venturi Effects describe the acceleration of airflow as it is squeezed through constrictions in a building's geometry — gaps between blocks, passageways, gable channels — creating a 'microbial wind tunnel' that concentrates and drives spores and particulates onto and through specific zones. As a component of architectural aerodynamics, it explains why certain corridors and funnelled elevations carry disproportionate contaminant load and colonisation, and it sharpens the deposition-velocity map of where a property is most at risk.