Simulations are performed using both single zone and multizone models of building and ventilation systems as necessary. The multizone modeling software program CONTAMW is used for building evaluation and results may be contingent on the degree of detail provided by the client. The following release scenarios, which may be interpreted as either naturally occurring or intentional (i.e. bioterrorist) releases are used as a design basis for sizing systems:

Outside air intake release
Internal building release
Release in the air handling unit
Release in the ventilation system
Outside air release
Releases on specific floors or building areas

Systems are sized to provide maximum protection to building occupants under all release scenarios including the above and any additional scenarios identified during the preliminary review. The objective of the simulations is to determine the appropriate size of air cleaning components that will minimize infections or casualties.