Analysis
Natural Resources Canada’s August announcement describes Canada–Chile mining cooperation, including an October mission addressing energy efficiency and water management. It does not report a ventilation retrofit result. The calculation here is an independent engineering illustration, not a performance claim about El Teniente, MacLean Engineering or mission participants.
For a simplified, unchanged ventilation network with approximately constant air density and efficiency, pressure loss varies with airflow squared and fan power approximately with airflow cubed. Thus P₂/P₁ ≈ (Q₂/Q₁)³. This approximation is conditional: leakage, regulator settings, static pressure, fan operating point and efficiency changes can invalidate it.
Assume a baseline fan draws 1 MW for 6,000 hours annually. Baseline energy is 6,000 MWh. At 90% of baseline airflow, estimated power is 1 × 0.9³ = 0.729 MW and annual energy 4,374 MWh. At 80% airflow, power is 0.512 MW and energy 3,072 MWh. The latter would save 2,928 MWh, or 48.8%, under these assumptions.
At an assumed USD 80/MWh energy tariff, that 80% case represents USD 234,240 gross annual energy-cost avoidance. It is not a project return: controls, drives, installation, maintenance, demand charges and lost production are excluded. The chart compares energy use, not measured savings, and assumes the same 6,000 operating hours throughout.
Airflow cannot be reduced solely to reach a cost target. Required ventilation must first be established from contaminants, heat, equipment activity, occupancy, emergency procedures and applicable mine rules, with competent engineering review and monitoring. Only then can measured fan curves and network tests support a control strategy. Missing safety or operating evidence makes the numerical scenario unsuitable for implementation.