Fire-fighting smoke exhaust axial fans are generally used for fire protection, to exhaust smoke in the early stage of a fire, with high-temperature resistance, and are typically designed to operate normally for 30 minutes at a temperature of 280 degrees. Fire-fighting axial fans include smoke exhaust axial fans and air supply axial fans (which have symmetrical construction), one for exhaust and the other for supply. The air supply axial fan is also known as a fire protection exhaust fan in the industry. Appendix: Working Principle of Axial Fans - Axial fans have a very wide range of applications; they are characterized by airflow that moves in the same direction as the shaft of the fan blades, such as in electric fans and outdoor fans of air conditioners, which are fans operating in an axial manner. They are called "axial flow" because the gas flows parallel to the fan's axis.