The design of the roof fan will become an important direction for future development
Roof fans are mainly made of all-metal construction and fiberglass construction. The all-metal structure house has more steels for the fan, and the air tube and the base are welded by hot-rolled steel plates of 3 to 4 mm thick. The rain-proof caps are welded by 1.0-1.5 mm cold-rolled steel plates, and coated with anti-rust paint. Appearance of painted or painted paint. Applicable from the application of multiple projects: due to the poor air condition of the roof, especially during the dry season of the plum, the local corrosion of the steel structure is serious, and the corrosion resistance of the steel structure rain cap can be very unremarkable, which seriously affects the wind turbine of the house. Use life and beauty. For example, a steel-structured roof fan installed in an automobile manufacturing plant has obtained structural strength for most of the rain-proof cap after 5 years of use. The all-glass-steel structure roof fan can handle the corrosion performance well, but the air cylinder and the frame part are temporarily tempered by the temporary operation and the wind, the sun is deciduous, and the air cylinder and the motor fall form and become disordered.
Roof fan design
Many roof blowers are not installed after the shutdown to avoid the installation of air backflow, or the valve can not be closed after the fan is shut down. The heat loss of the workshop with large hot pressure is underestimated. Everyone can often see the fan and axial fan that are installed without a backstop. The wind turbine is twisted at high speed under the hot pressure. This scene shows that the wind speed formed by hot pressing is quite large, and the wind speed in the air cylinder can reach 2.0~3.0. m/s or more. The fan reversal is very irritating to the start of the electric motor and can be destroyed due to excessive starting current.
The anti-condensation function is poor, the temperature difference in the summer room is large, the condensation on the air duct is easy, and the dripping phenomenon occurs, which affects normal consumption.
The roof fan must have the basic function of reliable rainproof, anti-flying snow and sand control. However, many wind turbines in the design are only thinking about rain protection during design. Neglecting the snow and sand does not only enter the fan from the upper part, but also the outdoor wind speed. In the case of reaching a certain intensity, it is also possible to enter the fan from the lower part. Some houses that use external sports louvers for air-backed installations seem to prevent the snow from falling into the room. In fact, the snow gathers on the sports louvers, and after the indoor temperature is ablated, it will form a dripping scene, which can not prevent it. Blizzard effect.
In the typhoon and sandstorm-prone areas, the roof fan can resist poor winds, the center of gravity is high, and the three-dimensional and concave structures increase the wind resistance. The anti-strong wind function of the umbrella-shaped rain cap is extremely unimaginable.