Does FFU use H13 or H14 high efficiency filter?

When configuring filters for FFU, H13 and H14 are the two most commonly compared levels. In equipment selection meetings, this question is often simplified to 'which one is better?'

Direct answer: When choosing H13 or H14 for FFU, the starting point should be the cleanliness target and process requirements, and at the same time check whether the unit can maintain the target air volume and speed under the corresponding filter resistance. Installation of seals and on-site leak detection should also be included in the package.

A higher level does not mean a more suitable solution. If the unit has insufficient margin, a higher-grade filter element may cause the air supply volume to deviate from the design value.

Step 1: Don’t just look at the filter grade

When the same FFU is installed with different filter elements, the resistance and fan operating point may change.

When comparing candidate filter elements, parameters under the same design air volume should be used, and the increase in resistance after running for a period of time should be considered. That's right The FFU fan filter unit is particularly critical: the filter element is part of the air path of the unit. Replacing the filter element is equivalent to changing the system resistance, and the fan working point will move accordingly. To judge whether the plan is feasible, it depends on whether the wind speed on the target surface can remain stable within the expected resistance range.

Step 2: Check the box and maintenance interface

Check the filter element shape, sealing surface, pressing method, and upper or lower replacement path.

When the grade increases but the thickness of the filter element increases, the overall height of the FFU and the ceiling space need to be checked. For units with liquid tank sealing structures, please refer to The interface instructions for liquid tank seal HEPA check the blade edge and tank body; if the original plan is used For ULPA ultra-high efficiency filters , it should also be confirmed whether the unit can still meet the air volume requirements under the corresponding resistance.

Step 3: Verification of whole machine linkage

Aili Industrial can configure FFU by combining self-developed fans, motors, controls and filters. After the plan is determined, the actual measured wind speed, resistance and installation leak detection results of the entire machine should be used to determine whether it meets the project requirements.

The key here is the word 'complete machine'. Watch alone The HEPA/ULPA air filter report can only describe the performance of the filter element under specified test conditions; after it is installed in a specific unit, the wind speed distribution, noise and vibration need to be confirmed in the condition of the complete unit.

Step 4: Compare the unit and filter element under the same operating conditions

When choosing H14, you should obtain the resistance data of the new filter element under the FFU target air volume, and include the later dust accumulation margin in the evaluation.

If multiple units are running in parallel, the difference in filter element resistance may also change the air supply distribution of each unit, which needs to be measured in the actual group control gear. This point is It is also worth noting that the EFU equipment-end fan filter unit and FFU are mixed in the project: the control methods and operating gears of the two types of units are different, and they should be checked separately after the filter element is replaced.

quick checklist

Application background and judgment boundaries

FFU is an air supply unit in which the fan, control, box and filter work together. Replacing the filter element will change the system resistance, and the group control gear and single fan speed may also need to be rechecked; it is not appropriate to regard any HEPA of the same size as directly interchangeable.

The choice between H13 and H14 is essentially a system matching issue, rather than a simple level issue. The filter grade requirements and unit operation requirements should be stated in the project documents at the same time, so that they can be checked separately during acceptance.

About Aili Industrial’s FFU filter support

Aili Industrial produces HEPA filters and FFU fans, motors, control systems and complete machines, which can be selected according to the target wind speed, resistance and box interface. The specific plan is confirmed by running tests.

Since the core components are matched in the same manufacturing system, the matching relationship between the filter resistance and the fan operating point can be checked before leaving the factory, reducing air supply deviations caused by replacing the filter element on site. For clean room projects that require large-area group control, the linkage configuration of the control system and filters can also be confirmed together to facilitate subsequent debugging and maintenance.