In the course of increasing production in the workings of German hard coal mining，the part of ventilation techniques as a factor of production has also increasing importance.In view of still increasing production the cooling of the air is critical for the attainable production on the one hand.On the other hand，the increasing gas emissions have to be controlled as well. This is achieved by fans of high capacity as well as by cross-sections in the underground workings，which are as big as possible，especially in the gateways.Furthermore，increasing cooling power is installed.The air volumes cannot be enlarged unlimited，yet，and rapidly reach their limit due to national statutory regulations concerning the maximal allowed air velocities.Besides that，a methane concentration of 1 Vol.％ in the maximum must be maintained in general，which is allowed to be exceeded only with the agreement of the mining authority in defined parts of workings up to a limit of 1.5 V0..％.Due to a dense sequence of coal seams in the German hard coal deposits,the firedamp is released during the exploitation not only from the worked seam，but essentially from the seams in the roof and in the floor behind the passage of the longwall.A gas drainage on the base of an efficient technique is necessary，firstly in order to fulfil the safety regulations and secondly to achieve a maximal production in the working.An investigation，recently finished and executed concerning the improvament of the gas drainage indicated that，by means of rock mechanical calculations and interpretations，an increase in the efficiency of gas drainage boreholes is still possible.