Which factor affects the air temperature in mine ventilation as depth increases?

The geothermal gradient is a key factor influencing air temperature in mine ventilation as depth increases. This gradient refers to the rate at which temperature increases with depth below the earth's surface. Generally, the deeper one goes into the earth, the higher the temperature due to the heat from the Earth's core and the surrounding geological formations.

As miners descend into the mine, they encounter progressively warmer rock and air temperatures pertaining to this natural geothermal increase. This phenomenon is critical for ventilation planning, as higher temperatures can pose safety risks and impact the comfort and efficiency of miners.

Other factors, such as aerodynamic resistance, relative humidity, and pressure differential, do play roles in the conditions of the mine environment, but they do not fundamentally determine the air temperature increase with depth the way the geothermal gradient does. The geothermal gradient specifically relates to the thermal properties of earth materials and the geothermal energy within the earth, making it the primary factor affecting temperature as one goes deeper into a mine.