In mining, good ventilation of the mine shaft is indispensable. Not only to provide the miners with sufficient oxygen, but also to remove any harmful gases (mine gas and methane). Furthermore, the rock was cooled to create a tolerable working climate in the mine. Every mine therefore had a 'salle compresseurs', a room with compressors that powered the ventilation system by means of compressed air.

Preference was usually given to a system in which a suction fan drew the noxious gases out of the mine along a specially designed shaft, creating a negative pressure so that fresh air was drawn into the mine through another shaft. Sufficient compressors were always provided so that, in the event of failures, other compressors could immediately take over the task.