1. For ventilation networks with uniform aerodynamic resistances (in the absence of zones of caving), for which, in the range of air flow rates used in mine ventilation, the quadratic resistance law is valid, the air fed to the individual branches as a percentage of the total air feed to the network remains constant and does not depend on the total feed. This simplifies the calculations and reduces the number of field measurements if the percentage air feed to a branch is once known. The air distribution in the branch can be monitored from one measuring point. 2. For ventilation networks with nonuniform aerodynamic resistances (networks with zones of caving), there is no proportionality of the air distribution in the branches when the air feed varies. In this case determination of the air admission to the branches, for any change of the feed to the network, must be done afresh each time, and the air distribution must be monitored from all the measurement points. 3. The operational parameters of section blowers must be calculated with allowance for the natural drafts acting in the individual networks (branches) of each blower. 4. The air distribution in the network for joint operation of the main and auxiliary (section) blowers in networks with zones of caving must be calculated by the method of successive approximations [9] with allowance for nonuniformity of the resistances in the branches by means of formula (11) or (12), according to the type of blower characteristic given by (13)–(15).