Main negative consequences of moisture precipitation at the air intake openings of mines during the warm periods are discussed. General data on the damage inflicted by condensate brines in the openings of potash mines are presented. The work suggests a technique of air intake openings dewatering by the systems of partial air reuse. The subject of the research is heat and mass exchange processes in rock openings while applying the systems of partial air reuse. As a result, a model is designed of transformation of the mine air’s thermodynamic parameters during recirculation ventilation, taking account of heat exchange between the mine air and the massif, on the basis of a model with non-stationary heat transfer coefficient. Using the data obtained, a technique of evaluating thermal and humidity parameters of mine air in recirculation contours of ventilation network using partial air reuse was developed. With the help of l-d diagrams thermodynamic processes in the mine openings environment at recirculation contours are analysed both with and without moisture occlusion by the massif. Equations are generated to determine moisture precipitation rate in the air intake openings and distance of the initial moisture precipitation. The factors conditioning effectiveness of recirculation ventilation to dewater transport openings of potash mines are revealed. It is found that effectiveness of recirculation ventilation depends on, besides aerodynamical features, occlusive moisture exchange between mine air and the massif in all parts of recirculation contours.