Roof fire exhaust fan product structure and application characteristics. Roof fire exhaust fan with molded axial flow impeller, built-in high-temperature motor (arranged special motor cooling systems), rain hood, base flashings. High temperature performance, high efficiency, small size, easy installation, and other advantages. Optional two-speed motors can be achieved in one machine (ie, usually at high temperature exhaust smoke and fire), arranged after the electrical control box can be remotely controlled automatically. Press GA211-1999 Fire fan high temperature test methods, can run at 400 ℃ high temperature continuous 100 minutes or more, the medium temperature at 100 ℃ continuous operation 20 hours / times without damage, has been the provinces, municipalities and fire departments for approval Rooftop fire smoke ventilation applications. WJGF fire exhaust fan roof unique product structure: the transmission of gas is not in direct contact with the motor and arranged a special motor cooling system. Can be used as temperature, humidity, corrosion-type roof fans, used in electric power, petroleum, chemical, metallurgy and other high-temperature, high humidity industrial applications roof exhaust, ventilation.