Ventilation Load Calculator for BEME vs. Diesel Fleets (Excel with ASHRAE 55 & MSHA Appendix A Inputs)

This calculator addresses a critical gap in underground mine decarbonization: accurately modeling how replacing diesel mobile equipment with BEME alters ventilation loads. Unlike diesel engines—which emit substantial heat, CO, NOx, and particulate matter requiring high-volume dilution airflow—BEME generates negligible combustion emissions but introduces new thermal loads from battery charging, regenerative braking losses, and motor inefficiencies. The tool disaggregates ventilation demand into three primary drivers: (1) sensible and latent heat gains (for thermal comfort per ASHRAE 55’s PMV/PPD model and air temperature/humidity constraints), (2) contaminant removal (CO, NO₂, diesel particulate matter [DPM] for diesel; minimal gaseous emissions for BEME, though battery off-gassing under fault conditions may be modeled optionally), and (3) regulatory minimum airflow mandates (e.g., MSHA’s 30 CFM per HP for diesel equipment, or 15 CFM per person plus equipment-specific allowances). It supports scenario analysis by allowing users to input fleet composition, duty cycles, ambient conditions, equipment specifications (e.g., battery capacity, motor efficiency, charging method), and mine geometry to compute total required airflow (CFM or m³/s), peak cooling load (kW), and comparative ventilation energy savings. Outputs inform capital decisions on ventilation system upgrades, heat rejection infrastructure, and compliance pathways for both occupational health (ASHRAE 55 thermal neutrality) and regulatory enforcement (MSHA Appendix A exposure limits).