The structure of duct fan mainly includes the following parts:
Fan: Duct fan usually adopts centrifugal multi-blade fan or cross-flow fan. The impeller diameter of the fan is generally not more than 150mm, and the static pressure is maintained below 100Pa. In order to ensure fire prevention and thermal deformation safety, metal impellers are currently mostly used, made of galvanized steel plate, aluminum plate or ABS engineering plastic.
Fan motor: The motor usually adopts capacitor motor, and its speed regulation function can be achieved by changing the input voltage. With the increase of energy-saving demand, DC brushless motor has gradually become the mainstream in recent years. This type of motor has the characteristics of small size, light weight, low temperature rise and high energy efficiency.
Coil: The coil is composed of copper tube and corrugated or windowed aluminum sheet. The outer diameter of the copper tube is 10mm, the wall thickness is 5mm, and the thickness and sheet spacing of the aluminum sheet are 152mm and 23mm respectively. Through the expansion process, the copper tube is ensured to be in close contact with the aluminum sheet to optimize the thermal conductivity. The number of rows of coils is usually two.
Air filter: The filter is made of coarse-pored foam plastic, fiber fabric or nylon braid, which is used to filter and purify the air entering the system.
Regulator: The general model adjusts the air volume through a three-speed variable speed switch (high, medium and low), while the model equipped with a brushless DC motor achieves continuous speed regulation through an AC-DC converter.