Air can be as precious an origin underground as would be the one being excavated. If any existing air is overheated, this not just causes breathing difficulties with the miners but may also result in dangerous pressure changes that could inside the worst scenario result in explosions or collapses.

Today, a surface-based central cooling system is viewed as probably the most economic way of cooling air. These most often use water. Mid-air is thus dehumidified with cold water.…