| The primary objective of this thesis is to advance the understanding of physical and chemical processes the govern indoor air pollutant dynamics. A deterministic mathematical model is developed for predicting the concentrations and fates of chemically reactive gases and airborne particles. Using a flexible, multichamber description of a building, the model accounts for the effects of ventilation, filtration, deposition, and emission for all pollutants. A detailed kinetic mechanism is incorporated to account for the effects of homogeneous chemical reactions on gaseous species in the photochemical smog system. The chemical composition and size distribution of indoor aerosols are determined, including the effects of coagulation.; Equations are developed for predicting pollutant deposition rates onto indoor surfaces, accounting for the effects of advection, diffusion, and, for particles, gravitational settling and thermophoresis. Three air flow regimes are analyzed: natural convection, forced laminar flow, and homogeneous turbulence. The results indicate that near-surface air flow conditions and temperature gradients strongly influence pollutant deposition rates.; Model performance is tested by comparing predictions of time-dependent indoor pollutant concentrations and deposition rates against measurements in several buildings. Overall, good agreement is found.; The model is applied to the protection of museum collections from soiling due to the deposition of airborne particles containing elemental carbon (soot) or soil dust. Based on measurements and model predictions for three museums in Southern California, soot particles accumulate on vertical surfaces at a rate sufficient to yield perceptible soiling in 1-40 years.; Methods for reducing the soiling rate in museums are identified: (1) reduce the outdoor-air supply rate to the building; (2) increase particle-filtration effectiveness; (3) alter indoor air flow conditions to reduce particle deposition velocities; (4) place objects within display cases; (5) manage the building site to achieve low outdoor aerosol concentrations; and (6) eliminate indoor particle sources. Model calculations applied to an historic museum in Southern California indicate that, with careful design, control measures can be implemented to reduce the soiling rate by two orders of magnitude, thereby extending the time before noticeable soiling will occur to beyond a century. |
