Abstract: Apparatuses and associated methods for producing energy from building or mine ventilation exhausts are disclosed herein. In one embodiment, an apparatus for extracting energy from the ventilation exhaust includes a turbine rotor having a plurality of turbine blades that are at least partially airfoils (e.g., NACA or SG60XX airfoils). A flow conditioner may be positioned to direct the exhaust air to the turbine. In some embodiments, the turbine rotor may be configured to rotate at high RPM. Accordingly, a rotating shaft of the turbine can be connected with an electrical generator without an intervening gearbox. In some embodiments, electricity produced by the electrical generator can be fed directly to the electrical wiring of the building or mine to offset energy consumption of the ventilation system.