Deep mines often require cooling to comply with local heat stress regulations. Attempts to mitigate heat strain via improved heat indices are well documented. However, the impact of heat-stress index on refrigeration capacity is less explored. The paper examines the refrigeration capacity necessary to develop a 1.5 km deep mineshaft as a function of wet bulb globe temperature (WBGT) and wet bulb temperature (Twb). Thermodynamic simulations in Ventsim indicated chiller capacity sized from a sigma-heat (σ) balance was insufficient to prevent elevated heat stress, at working depth, according to the WBGT. The study revealed that enhanced wet-bulb depressions, associated to an overwhelming percentage of sensible to total heat ratio, was the primary factor. Furthermore, the work investigated active engineering controls like increased airflow quantity, duct insulation, and secondary cooling to satisfy refrigeration equipment constraints, such as minimum collar Twb, and ventilation design criteria. Additional research is necessary to develop empirical methods that could facilitate the prediction of cooling requirements for mine sites that do not employ Twb as the design heat index.

As relatively hot mineral deposits are being developed to considerable depth, the issue of mitigating heat will require monumental cooling capacity in some cases. For deep deposits to be mined at increasing depths, mechanical cooling systems used to maintain an ac-ceptable underground climate will most certainly become increasingly complex and ex-pensive. In most methods, the main source of potential cooling energy comes from cold water. The cold water can come from ice (stowed or transported), in situ reservoirs or re-frigerated water chillers. This paper investigates the use of in-situ ice as the source of cooling. 
Air cooling power is available by passing intake airflow through stowed ice accumulated during favorable atmospheric conditions. Planning for sustainable cooling potential re-quires protected space to successfully maintain ice in storage until needed. Stored ice or cold water should be judiciously cared for, safely kept from the ill effects of heat, in order to remain useful for bulk air cooling. Maximizing the production of ice means that atmospheric conditions will be monitored closely during the formation phase. Storage facilities would maintain restricted airflow while minimizing possibilities for heat transfer during the storage phase. Successful installations will prioritize environmental management to favor long timespan usage of sustainable cooling systems. Sustainable cooling systems could reduce or eliminate the need for mechanical cooling if installed with favorable conditions.

With the ever-increasing drive towards decarbonization, the case for mine refrigeration using geothermal means is gaining traction. Potential mines must however be located in both favorable geo-political jurisdictions and areas with adequate geological conditions. One such area is Sudbury, Ontario, Canada where a conceptual evaluation found that geothermal additions can be cheaper and reduce CO2 emissions when compared to a conventional mine refrigeration system.