The exploitation of the deposit necessitates continuous optimisation of the ventilation network, as well as the need to change fans. One way of optimising the network and increasing the efficiency of ventilation may be to make interlevel connections in the form of large-diameter openings. In this study, simulation calculations were carried out by assuming the drilling of large-diameter holes and the selection of parameters for the main ventilation fans. An evaluation of the ventilation network was carried out by checking the validity of the simulation data with the actual data. The ventilation calculations showed that it is possible to increase the ventilation efficiency through the aforementioned method. The results of the calculations are presented with tabular data and simplified ventilation diagrams. The creation of at least one large-diameter opening and the upgrading of the main ventilation fans will ensure a minimum of proper functioning of the ventilation system. The drilling of a further opening will ensure that there is sufficient air in each ventilation area - an increase of 50% in the mine's air volume will be achieved.