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A Tool to Model the Fate and Transport of Indoor Microbiological Aerosols (FaTIMA)



William S. Dols, Brian J. Polidoro, Dustin G. Poppendieck, Steven J. Emmerich


The web-based tool Fate and Transport of Indoor Microbiological Aerosols (FaTIMA) allows for the determination of the indoor fate of microbiological aerosols associated with ventilation, filtration, deposition and inactivation mechanisms. FaTIMA provides a representation of a single, well-mixed zone that is served by a mechanical ventilation system and incorporates particle source and removal mechanisms. The simple mechanical ventilation system model allows specification of supply, return and fraction of outdoor air intake rate to include either a positive, negative or balanced ventilation system. Particle sources are provided to enable any combination of continuous, e.g., breathing related emissions, or intermittent, e.g., coughing- related, emissions. Particle removal mechanisms include filters within the ventilation system and deposition onto floors, walls and ceilings. Simulations can be run for a 24-h period, with the results including the time history of the airborne concentration and surface loading as well as integrated exposure that an occupant might experience.
Technical Note (NIST TN) - 2095
Report Number


exposure, indoor air quality, modeling, pathogens, viruses


Dols, W. , Polidoro, B. , Poppendieck, D. and Emmerich, S. (2020), A Tool to Model the Fate and Transport of Indoor Microbiological Aerosols (FaTIMA), Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed May 20, 2024)


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Created June 1, 2020