Direct answer: When EFU configures the U15 filter, four aspects need to be focused on: First, resistance matching. U15 belongs to the ULPA level, and the initial resistance and final resistance are higher than conventional HEPA. The fan needs to confirm the working point according to the final resistance working condition; second, the air volume design should be based on the target surface wind. Quickly push back the air volume, and evaluate the air volume attenuation after the filter resistance rises; the third is the sealing structure, U15 has higher sealing requirements for the filter and the box, the box and the mounting surface; the fourth is leak detection verification, after the whole machine is assembled, scan and detect leaks according to the agreed method to confirm that there is no leakage.

The role of the U15 filter in the EFU is to provide filtration capabilities for finer particles, but it also brings higher system resistance requirements. The following is an explanation from the four key points of resistance, air volume, sealing and leak detection.

1. Resistance: The impact of U15 filter on EFU system

U15 is a ULPA grade filter. According to EN1822 standard, its MPPS efficiency is ≥99.9995%. Compared with H13/H14 HEPA filters, U15 filters will bring the following resistance changes in the EFU:

1. High initial resistance : The initial resistance of U15 is usually higher than that of H14 filter of the same size. The specific value is related to the filter material, separation method and surface wind speed;

2. The final resistance increases with the dust capacity : as the running time increases, the filter resistance gradually increases, and the final resistance may reach 2 times or higher than the initial resistance;

3. Sensitive to face wind speed : ULPA filters are usually designed to operate at a face wind speed of about 0.45 m/s. Wind speed deviations from the design value will significantly affect the resistance;

4. Impact of structural differences : Different filter materials and separation methods will bring different resistance curves.

In the equipment-side EFU, if the internal diffusion space is limited, the resistance problem of the U15 filter needs to be evaluated in advance.

2. Air volume: reverse the wind speed at the target surface and check according to the final resistance.

The air volume design of U15 filter EFU is recommended to be promoted in the following order:

Step 1: Determine the target surface wind speed.
Confirm the target wind speed on the filter outlet surface according to the requirements of the clean area. The common reference value is 0.45 m/s. The allowable deviation is agreed upon by the project.

Step 2: Calculate the required air volume.
Air volume = target surface wind speed × effective air supply area. The effective air supply area should be calculated based on the actual air outlet area of ​​the filter, not the outer dimensions of the box.

Step 3: Evaluate the total system resistance.
The total system resistance includes the final resistance of the U15 filter, the local resistance of the air inlet, the internal resistance of the box and the resistance of the air outlet. The filter resistance should be evaluated according to the final resistance state after dust collection.

Step 4: Confirm the fan operating point
. Use the total system resistance as the static pressure requirement for fan selection, and confirm that the fan can still output the target air volume under this static pressure. The nominal air volume usually corresponds to low static pressure conditions and is not suitable for direct use.

Step 5: Evaluate air volume attenuation.
After the filter resistance increases, if the fan speed remains unchanged, the air volume will decrease. For equipment that requires long-term stable air supply, consider configuring an adjustable-speed fan to increase the speed appropriately when resistance increases.

3. Sealing: Key points of sealing of U15 filter EFU

U15 filters have higher sealing requirements than conventional HEPA applications because small leaks will directly affect the filtration effect. Seal areas that require attention include:

The sealing design should be confirmed in conjunction with the filter replacement method. For equipment that requires frequent filter replacement, please refer toThe snap-on EFU filter fixing and disassembly structure also confirms whether the sealing surface can remain stable after repeated disassembly and assembly.

4. Leak detection: Verification points of U15 filter EFU

Leak detection of the U15 filter should be carried out after the assembly of the whole machine is completed. The verification points are as follows:

1. Timing of leak detection : after the whole machine is assembled and the filter is installed in place, instead of just testing the filter for leaks;

2. Leak detection method : Scan and detect leaks according to EN1822 or related standards to confirm that there is no leakage on the sealing surface of the filter and box;

3. Scanning speed and distance : Perform according to the agreed method to avoid deviation in results due to different scanning methods;

4. Key parts : filter frame, sealing strip, box weld and interface position;

5. Recording and judgment : Clarify the judgment standards and recording methods to facilitate subsequent traceability.

If the project has further requirements for cleanliness, the face air velocity uniformity and filter resistance can be confirmed at the same time during acceptance.

5. Information required for U15 EFU selection

It is recommended to provide: when communicating with the project:

1. Target cleanliness level and particle size requirements;

2. Target surface wind speed or volume;

3. Available filter sizes and mounting options;

4. Available space inside the device, including length, width and height;

5. The system estimates resistance or wind channel information;

6. Power supply, control methods and communication requirements;

7. Whether it needs to be linked with the device master control;

8. Equipment operating conditions and expected replacement cycles;

9. Acceptance measurement methods and leak detection requirements.

6. Aili Industrial U15 EFU supporting capabilities

Aili Industrial has the following supporting conditions for configuring ULPA U15 filters in EFU:

• Self-produced filters : HEPA/ULPA filter production capacity, U15/U16 grade can be configured;

• Fan matching : self-produced EC/DC/AC motors and fans, which can match the static pressure parameters according to the resistance characteristics of the U15 filter;

• Sealing structure : The sealing scheme can be designed according to the filter structure and replacement method;

• Whole machine verification : conduct air volume, wind speed, resistance and operation tests before leaving the factory;

• Customization ability : The cabinet, air inlet and outlet methods and interfaces can be customized according to the equipment space.

For ultra-thin or space-constrained devices, please refer toThe structural solution of the 70mm ultra-thin EFU confirms the installability of the U15 filter. For more EFU product systems, please refer toEquipment-side fan filter unit (EFU)、Custom EFU andDC EFU。

FAQ

What is the difference between U15 filter and H14 filter?

U15 belongs to the ULPA level, and its filtration efficiency for MPPS is ≥99.9995%, which is higher than H14's 99.995%. The initial resistance of U15 is usually higher than that of H14, which requires higher static pressure of the fan.

EFU is equipped with U15 filter. Should the air volume be designed based on initial resistance or final resistance?

It is recommended to design the fan working point according to the final resistance working condition and confirm that the target air volume can still be maintained after the filter resistance increases.

What is the final resistance of U15 filter?

Different products and structures vary greatly, and the specific values ​​need to be confirmed based on the filter specifications and operating conditions.

Does the U15 filter need to be tested for leaks?

It is recommended to proceed. U15 is a ULPA grade filter and should be scanned and tested for leaks according to the agreed method after the entire machine is assembled.

What should we pay attention to when sealing U15 EFU?

It is necessary to pay attention to the sealing between the filter and the box, the box and the mounting surface, the filter frame and the inspection port, and confirm whether the sealing performance is stable after repeated disassembly and assembly.

Can the ultra-thin structure of U15 EFU be customized?

The filter thickness and internal diffusion space need to be evaluated, and the installability and resistance impact of the U15 filter in the ultra-thin structure need to be confirmed through prototype testing.

What items should be tested for U15 EFU acceptance?

It is recommended to measure the surface wind speed, filter resistance, fan operating point, including air volume, static pressure and power, and confirm the filter leak detection results.