then wind pressure is an important indicator to measure the "powerful" air volume of large fans. If air volume can be compared to the striking power of a weapon, then wind pressure is the sharpness of that weapon. Many clients who choose industrial fans consider air volume as the primary factor to consider. Wind pressure is one of the important performance indicators of large fans, and it is closely related to the shape, area, height, and speed of the fan blades. The impact of the first three is more complex, while the relationship with speed is simple and direct: the faster the speed, the larger the fan's airflow.
The wind pressure of industrial large fans changes with changes in airflow pressure. Wind pressure is caused by the obstruction of the building, which blocks the surrounding air, causing a drop in dynamic pressure and an increase in static pressure; this produces local eddies on the front and back sides. Compared with the disturbed airflow at a distance, the increase and decrease of static pressure are collectively called wind pressure. The wind pressure of a large fan is the pressure difference between the outlet and inlet of the fan. Its unit is generally mm (cm) water column, which is similar to measuring air pressure with a millimeter mercury column, but because the pressure difference is small, the water column is usually used as the unit: mmH20 / mmAq / Pa / mmHg.
To achieve normal ventilation, it is necessary to overcome the resistance within the ventilation path of the fan. The fan must generate pressure to overcome the resistance of air delivery. The change in measured pressure is called static pressure, which is the differential pressure between the maximum static pressure and atmospheric pressure. It is the pressure of gas acting parallel to the surface of an object. Static pressure is measured by a hole perpendicular to its surface. The wind pressure of an industrial fan directly affects the air delivery distance of the fan. The air volume and wind pressure described by large fans are both the maximum values under ideal conditions, that is, the air volume (maximum air volume) between the inlet and outlet of the industrial fan without pressure difference and the pressure difference (maximum static pressure) between the enclosed chamber where the fan blows air and the outside world when the air volume is zero. They are not two isolated performance indicators, but they restrict each other. The relationship between them is the typical relationship between flow velocity and pressure in fluid mechanics - as the pressure difference (specifically, the air resistance of the radiator fins) increases, the air volume decreases, and the degree to which they restrict each other depends on the design of blade shape and overall structure.
Industrial fan manufacturers consider both air volume and wind pressure in fan design. The fan blades of industrial large fans are designed with a streamlined variable cross-section design. When the fan is in operation, the blade can automatically rise by 3-8 degrees. When the fan stops, the blade can return to its original state. The fan has a diameter of 7.3 meters and rotates at 60 revolutions per minute. The design of blade shape, area, height, and fan speed can enable the industrial fan to achieve maximum air volume when in operation, reduce the central "hollow" phenomenon, and fully utilize the advantages of large air volume and wide coverage of large fans.