Cell and self-consistent models for a diffusion deposition of aerosol parti
cles at small Peclet numbers were considered. Formulas for collection effic
iency were derived depending on gas velocity the diffusion coefficient, and
a radius of aerosol particles, as well as on the fiber diameter, the packi
ng density, and the filter thickness. The theory developed agrees with the
experimental data obtained for the cases of the deposition of particles on
the model and real filters.