How to choose EFU centrifugal fan? Matching method from target air volume, static pressure to working point
Direct answer: The core selection basis of EFU centrifugal fans is the working point. The fan performance curve describes the pressure that can be provided at different air volumes, and the system resistance curve describes the obstruction of the air by the filter, box and equipment structure; the intersection of the two curves determines the actual operating air volume.
Establish target operating conditions instead of just reporting rated air volume
At least the target air volume, initial and final resistance of the filter, and additional resistance of the box and equipment are required. If the customer does not have complete resistance data for the time being, it can be gradually confirmed through prototype or equivalent tooling testing.
Choose a reasonable working area
Under normal working conditions, it is not advisable to stay on the edge of the maximum speed or performance curve for a long time. A reasonable working area can leave margin for filter dust accumulation, equipment differences and debugging, while also helping to control power and noise.
Ultra-thin cabinets require attention to entrance conditions
Fan sample curves are usually obtained in a specified test device. After being installed in an ultra-thin or small-sized cabinet, inlet clearance, bias flow and local backflow may change the actual performance, so the whole machine should be tested.
Synchronously check motor and control capabilities
Check voltage, power, speed range, temperature rise, continuous operation and speed regulation signals. Multi-gear or communication control projects should also confirm low-speed start, gear repeatability and abnormal status.
Complete final confirmation with complete machine data
It is recommended to record the air volume, static pressure, power, noise, vibration and temperature rise at each gear, and retest under the target filter conditions. Fan component testing and complete machine testing should be mutually verified.
FAQ
Can fans with the same diameter be directly replaced?
Can't. Impellers, volutes, motors, speeds and performance curves may all be different.
Does high motor power mean high static pressure?
Doesn't mean. Static pressure capacity depends on the complete fan system and operating point.
Why is filter final resistance data needed?
It is used to judge whether the air volume can still meet the requirements after the filter is used, and whether the speed adjustment margin is sufficient.
How does Aili Industry cooperate with EFU centrifugal fan selection?
The EFU centrifugal fan cannot only be selected based on the maximum air volume, but also must be combined with the filter resistance, equipment internal air duct resistance, air inlet conditions and target air supply volume to determine the actual working point. Fans have different air volumes under different static pressure conditions. Therefore, it is necessary to check the air volume, static pressure, speed, power and operating noise at the same time when selecting.
Aili Industrial can match the centrifugal fan, motor and control parameters based on the target air volume of the EFU at the equipment end, estimated system resistance, filter efficiency and installation space. Aili Industrial has the matching capabilities of fans, motors, control systems, sheet metal boxes and air filters, and can confirm the adaptation relationship between various components from the perspective of complete machine operation.
For non-standard equipment projects, it is recommended to provide target air volume, static pressure range, EFU size, filter parameters, power supply conditions and speed adjustment requirements. When conditions permit, the actual operating point can be confirmed through prototype testing to avoid judging whether the fan is suitable based on only a single rated parameter.
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Conclusion: The EFU centrifugal fan should provide the required air volume under the target system resistance, taking into account the speed adjustment margin, efficiency, noise and temperature rise. The same fan diameter or motor power does not mean the same performance of the whole machine.
