2. The fan and the duct are connected by hose, the length is not less than 200mm, and the pipe diameter is the same as the fan inlet and outlet size. 　　3. In order to ensure that the hose will not be twisted and deformed during the operation of the system, the elastic should be properly installed. The canvas hose installed on the suction end of the fan can be installed slightly tighter to prevent the fan from being sucked in during operation and reduce its cross-sectional size.

3. The steel bracket of the fan must be fixed to the concrete foundation, and a rubber vibration damping pad must be added between the steel bracket and the foundation of the fan. All fan and motor components are mounted on the entire steel bracket, which is mounted on a vibration damping pad on top of the foundation. Use porous rubber sheets as much as possible for vibration damping pads.

4. The diameter of the fan outlet can only become larger, not smaller, and the outlet should be installed with insect-proof nets, and the hood should be added when the wind is biased upwards.