The article describes a mathematical model for the heat-moisture treatment of air in the nozzle chamber. The dynamics of unsteady processes of heat and mass transfer between the working substances in the apparatus and the transfer characteristics, balance equations of exchanging media are considered. A physical and mathematical description of heat and mass transfer processes in a thicker working medium and the relationship between the heat and mass fluxes through a surface unit and the mass-average temperature and potential are presented. The expression and their dependencies are presented for determining the final parameters of air in the irrigation chamber.