* HTF-V Mixed-flow Fire-Fighting Heat Fume Extraction Fan is a novel and in termediate fan between axial-flow fan and centrifugal fan.It absoths the advantages from both fans.Its wind pressure is higher than the same machine number axuakflow fan and flow larger than the same machine number centrifugal fan.It has advantage a such as wide and effective operational zone, high efficiency etc, This fan is widely applicable for the ventillation and exhaust system in the office buiding hotel large-size high-rade civil puroose architectures etc, It can also be used for ventilation and air-exchange In the mining and Industrial enterprises such as freezing house, textile and so on in order to replae for the low-pressure centrifugal fan or high-pressure axial-flow with no need to install large amounts of the noise blanking facilities.