This is the HTF fire rated axial flow exhaust fan produced by Quanda. The specific motor cooling system of the fan is equipped for continuous operation of more than 30 minutes at 280 ℃ high temperature. By the multi-speed drive, the fan can exhaust smoke at high temperature and ventilation. At present, the fan is used widely in high rise buildings, underground buildings, tunnels and baking rooms as an ideal and essential firefighting tool.