Present article is devoted to issues connected with calculating general ventilation in buildings affected by vapouring moisture. The aim is to improve the methods of determining the parameters of air and air exchange in rooms with the release of water vapor. The description of calculating techniques and analysis of research observations has been presented. In the course of research shortcomings of known graph-analytical method of calculation with use of l-d-chart were identified, to basic of which belong: low accuracy of the results, inability to use algorithms and computer methods for calculating. As a result of the research the analytical technique of determination of parameters of air and air exchange in rooms with release of water vapor was developed including the received analytical dependences which allow to make calculation of systems of general ventilation more precisely and use algorithmization calculations for further calculations with use of the computer.