What is the reason for insufficient air volume in FFU? Where should I start checking?
Insufficient air volume is not necessarily a fan problem
Insufficient stroke volume is a common problem in FFU operation. It is easy to suspect that the fan is aged or damaged at the scene. However, insufficient air volume may come from many aspects. Dust accumulation on the filter, air inlet obstruction, seal leakage, changes in control settings, abnormal power supply or changes in fan status may lead to a decrease in air volume.
If you only check the fan and ignore other aspects, you may not be able to find the real cause. Therefore, the troubleshooting should be carried out in order, starting from the operating status and filter, and gradually confirming the fan, air duct and control system.
Aili Industrial has complete production capabilities in FFU complete machine and air flow design, and can cooperate with the project to conduct air volume inspections. For the basic structure of the FFU machine, please refer toAili Industrial FFU fan filter unit。
First confirm the operating status and control settings
Before troubleshooting, confirm the running status of FFU. Including: current speed or control setting; whether it is in local or remote mode; whether the group control issues normal commands; whether the power supply voltage is normal.
If the control setting is turned down or the mode is switched, the air volume may decrease. If the group control shows offline but the fan is still rotating, the actual speed may be inconsistent with the setting. For relevant judgments, please refer toFFU group control shows offline but the fans are still running。
How to check filter status
Dust accumulation on the filter is a common cause of insufficient air volume. After the filter resistance increases, the fan operating point moves toward the low air volume direction. If constant speed control is used, the air volume will decrease significantly.
The inspection contents include: filter usage time; filter pressure difference; whether the filter is damp, damaged or bypassed; whether the filter is installed in place.
If the pressure difference is significantly higher than the initial value, it means that the filter is dusty. A sudden drop in differential pressure may indicate bypass or damage. For relevant judgments, please refer toIs the drop in pressure difference on the FFU filter a good thing?。
Are the inlet and return air blocked?
Obstructed air inlet will directly reduce the air volume. The inspection contents include: whether the FFU air inlet is blocked by bridges, pipelines, lamps or structures; whether the mezzanine air supply is sufficient; whether multiple FFUs interfere with each other; whether the return air path is smooth.
If the air inlet clearance is insufficient, the air volume may decrease. For details, please refer toFind out how much air volume will be lost if the FFU air inlet is blocked by the bridge to understand the impact of the air inlet conditions.
Obstructed return air may also affect air volume. If the return air outlet is blocked by equipment or materials, system resistance increases and the air volume may decrease.
How to check seals and leaks
A leaky seal may cause some air to bypass the filter, but it won't necessarily show up as a drop in air volume. If the seal leakage is serious, it may affect the system pressure distribution. The inspection contents include: the status of the filter sealing strip; whether the pressing mechanism is uniform; whether the box joints are sealed; whether the installation frame is leaking.
For sealing inspection, please refer toWhat to do if the FFU sealing strip is not pressed evenly. Learn how to troubleshoot.
How to check fan status
If the above links are normal, you can check the status of the fan. The contents include: whether the fan speed is normal; whether the fan has abnormal noise or vibration; whether the impeller is dusty or damaged; whether the bearings are worn; whether the motor is normal.
If the fan speed is normal but the air volume is insufficient, there may be a problem with the impeller or air path. If the fan speed is low, there may be a problem with the controller or power supply.
How to measure air volume
Air flow measurement can help confirm the extent of insufficient air flow. Measurement methods include wind speed conversion method and air volume hood measurement. Measurements should be carried out under the same working conditions, and the measurement location and method should be recorded.
Regarding the caliber of air volume measurement, please refer toWhen FFU uses wind speed to calculate air volume, which air outlet area should be used to understand the area value.
What are the processing methods?
If it is confirmed that the filter is dusty, the filter can be replaced. If the air inlet is blocked, the position of the shield or FFU can be adjusted. If the seal leaks, the sealing strip can be replaced or re-tightened. If the fan is abnormal, the fan can be repaired or replaced. If the control settings change, you can adjust the settings.
After treatment, the air volume should be measured again to confirm that it is back to normal.
Issues that should be confirmed in advance during project communication
During the FFU air volume deficiency investigation stage, it is recommended to confirm the following with the FFU manufacturer: control settings and operating modes; filter usage time and pressure difference; air inlet and return air conditions; sealing status; fan status; air volume measurement methods; processing methods and replacement requirements.
If you are dealing with the problem of insufficient FFU air volume, you can visitAili Industrial FFU fan filter unit to learn about the complete machine configuration, you can also refer toFFU is equipped with ULPA ultra-high efficiency filter to learn about the filter configuration, or contact Aili Industrial for troubleshooting support.
in conclusion
Insufficient FFU air volume may come from filter dust accumulation, fan status, air inlet obstruction, seal leakage or control setting changes. The investigation should start from the operating status and filter, and gradually confirm the fan, air path and control system. Don't just check the fan. The air volume should be re-confirmed after measurement and processing.
Aili Industrial has complete production capabilities in FFU complete machine and air flow design, and can cooperate with the project to conduct air volume inspections. If you need to know more about FFU air volume issues, you can visitAili Industrial FFU fan filter unit , you are also welcome to contact Aili Industrial for project support.
