No power supply required, continuous airflow can be generated by hand cranking, suitable for emergency situations such as power outages, outdoor camping, temporary ventilation in warehouses, teaching demonstrations, etc. Zero energy consumption, no motor, no battery, environmentally friendly and economical. Typical application: Rapid heat and moisture removal in underground garages and distribution rooms when there is no electricity; Ventilate the tent during outdoor camping to avoid condensation water; Teaching demonstration of "Energy Conversion and Fluid Machinery" in physics classes for primary and secondary schools; Temporary warehouses storing chemicals or grains require short-term forced ventilation.