EC direct-drive centrifugal fan with backward blade is a high-efficiency ventilation device that is directly driven by an electronically commutated (EC) permanent magnet synchronous motor with a backward centrifugal impeller.
It is high energy efficient, low noisy, easy to maintenance, and intelligent controllability, making it suitable for medium to high-pressure and long-distance air delivery application.
1. EC Motor (Electronically Commutated Motor): Essentially a permanent magnet brushless DC motor, it replaces mechanical brushes with electronic commutation and incorporates a built-in driver to achieve stepless speed regulation, soft start, and intelligent control. With an efficiency 30% higher than general AC motors, it also has excellent low-speed performance and low energy consumption.
2. Backward curved centrifugal impeller: The blade curved direction is opposite to the rotation direction, making it a high-pressure, high-efficiency impeller. It has high peak efficiency, stable operation, and noise levels 10-15dB (A) lower than forward-curved impellers. Suitable for medium to high static pressure (e.g., 1000-2200Pa) and long air delivery task.
3. Direct Drive: The rotor is directly mounted on the motor shaft, eliminating intermediate transmission components such as belts and couplings. This reduces transmission losses (typically 3%-8%), lowers maintenance costs, and enhances system reliability and lifespan (up to 40,000 hours).
Main Particulars
| item | General Parameter | Advantage |
| Motor type | Outer Rotor Power: 55-3700W | Compact structure, rotor surrounding stator, low wind resistance, good heat dissipation |
| Speed regulation | 0-10V/PWM/RS485（Modbus） | constant speed/constant air volume/constant static pressure control, suitable for building automation (BA) |
| Protection Class | IP67 | Dustproof and waterproof, suitable for multiple scenarios such as industrial/clean rooms |
| Impeller Type | Diameter 120-710mm，Capacity: 25000m³/h | Can meet wide requirements from cabinet heat dissipation to large AHUs |
| Efficiency | IE4+ | Significant energy savings and low operating costs |
Working principle
1. Electronic commutation and driving: AC power is rectified into DC by a built-in driver, and the controller detects the rotor position in real time through sensors or algorithms, accurately controls the stator winding current, generates a rotating magnetic field, and interacts with the permanent magnet rotor to achieve efficient operation.
2. Airflow pressurization process: Air enters the center of the impeller along the axial direction, and the high-speed rotating backward blades radially eject the airflow through centrifugal force. After being expanded by the volute (or static pressure box), it is discharged. The direct drive design ensures that the impeller and motor speed are synchronized without slip or loss.
3. Intelligent control logic: Receive external signals (such as temperature/pressure sensors), dynamically adjust the speed to match the load, achieve “on-demand air supply”, and have multiple protections such as overcurrent, overheating, and stalling.
Typical application scenarios
1. HVAC and Air Handling Unit (AHU): Suitable for medium to long pipelines and high static pressure requirements, such as ventilation systems in commercial complexes and hospital operating rooms.
2. Precision air conditioning for data centers: high static pressure, low noise, meeting the requirements of cabinet heat dissipation and constant temperature and humidity.
3. Industrial ventilation and clean rooms: such as smoke exhaust in welding workshops and air supply in clean areas of pharmaceutical factories, suitable for harsh environments and BA systems.
4. Other: such as commercial kitchen exhaust, fresh air system, electrical cabinet heat dissipation, etc.
