This is the Size-resolved Particle Model w/ Coagulation Kernel developed for the Consumer Product Safety Commission.
This web-based tool implements a single zone, uniform concentration model with a user-defined, initially log-normal number distribution, and total particle count. The model incorporates the following transport mechanisms: a coagulation kernel, a size-resolved particle deposition model and a user-defined ventilation rate. This model provides the means to perform initial investigation of the relative effects of these various particle transport mechanisms on the fate of indoor particles. All particles are considered to be non-reactive species with the same density.
Details of the tool are provided in the following document.
https://www.nist.gov/publications/development-airborne-nanoparticle-exposure-modeling-tools