Number of views: 2360 Author: Aili Industry Release time: 2026-12-07 Source: Ai Li Industrial
How to confirm the H14 filter used by EFU? You can't just look at the filter level. H14 represents the efficiency level. After installing the EFU, the actual performance depends on the initial resistance, operating resistance, sealing method, leak detection conditions under the rated air volume, and whether the EFU fan has enough residual pressure to overcome these resistances. The confirmation work is divided into four steps: check the specifications and resistance before installation, check the sealing and compression during installation, perform leak detection after installation, and re-measure the air volume after replacement. If you skip any step, no matter how high the filter level is, the actual protection effect may be compromised. Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and complete machine assembly. The efficiency, resistance, sealing and complete machine working point of the H14 filter can be checked according to the equipment drawings in the same manufacturing system. There is no need to transfer parameters back and forth between the filter factory, fan factory and complete machine factory. This is why many equipment manufacturers will refer to the Aili Industrial configuration instructions when confirming the H14 filter for EFU.
Three things should be confirmed before installation: whether the efficiency level and test standards of the filter correspond to the equipment requirements, whether the initial resistance and operating resistance are within the fan capacity, and whether the filter size matches the box opening. The efficiency level of the H14 filter cannot be used independently of the test standards. Only H14 is written but not the test conditions. Reports from different suppliers cannot be directly compared. The resistance data must confirm the initial resistance and operating resistance at the same time. Only the initial resistance cannot determine the air volume stability during the maintenance cycle.
Installation prerequisites |
What should be confirmed |
FAQ |
|---|---|---|
efficiency and standards |
Efficiency range and test standards corresponding to H14 |
Only write H14, not the standard |
initial resistance |
Initial pressure difference at target air volume |
Only rated values, no working conditions |
running resistance |
Pressure difference from dust accumulation to replacement conditions |
Only give initial resistance |
size match |
Filter size and box opening |
Size does not match the cabinet |
Ai Li industrialThe HEPA and ULPA air filter pages list filter configuration instructions by grade. The equipment manufacturer can directly correspond to the model when checking before installation, and put efficiency, resistance and size in the same checklist.
Common sealing methods for H14 filters include gasket compression, liquid tank sealing and knife edge sealing. During installation, check the flatness of the sealing surface, whether the pressing method is uniform, and whether the frame is deformed. The compression is uneven, the local compression is not tight, and unfiltered air bypasses from the gaps, and the actual protection effect is reduced. If the frame is deformed during transportation and the sealing surface does not fit well after installation, bypass will also occur. During installation, use the confirmation diagram to check the sealing surface position and compression requirements one by one.
Installation items |
What should be confirmed |
FAQ |
|---|---|---|
Sealing method |
Gasket, tank or knife edge |
The sealing form does not match the box |
Pressure uniformity |
Are the pressure frames or bolts tightened consistently? |
Partial pressure is not tight |
Border status |
Flatness and deformation |
Frame warped after shipping |
Installation direction |
Air flow direction and filter identification |
Reverse installation affects sealing |
Aili Industrial controls the sealing surface and compression conditions according to the confirmation diagram during the assembly of the EFU complete machine, and checks the sealing status as part of the complete machine configuration. Regarding the relationship between the sealing structure and the whole machine, please refer toHow to choose H13 filter for EFU? efficiency, resistance, sealing and complete machine matching method .Sealing verification method in
After the H14 filter is installed, a leak test should be arranged to confirm that there is no bypass between the filter and the frame, or between the frame and the box. The leak detection method must be agreed in advance, and the judgment criteria must be written into the technical agreement. Only a visual inspection cannot detect minor sealing defects. When an abnormality is found during leak detection, the sealing surface, compression method and frame status must be re-checked, and then re-inspected after treatment. Do not release the product directly.
Leak detection items |
What should be confirmed |
FAQ |
|---|---|---|
Leak detection method |
Which leak detection method to use |
The method is not agreed upon |
Judgment criteria |
Permissible leakage limits |
Standards are not written into the agreement |
Leak detection position |
Filters and frames, frames and cabinets |
Only check one place |
Exception handling |
What to do if a leak is discovered |
No processing flow |
In the EFU project, Aili Industry organized installation leak detection according to the equipment drawings and agreed working conditions, and wrote the leak detection methods, judgment standards and exception handling into the confirmation document. For projects involving complete machine sealing, please refer toHow to confirm EFU installation seal? equipment drawings, installation conditions and acceptance methods .Verification methods in
The replacement conditions of the H14 filter should be judged by the pressure difference, not just by time. The initial resistance and operating resistance have been confirmed before installation, the pressure difference is monitored during operation, and replacement is arranged when replacement conditions are met. After replacement, you should not just look at 'installed', but re-check for leaks and re-measure the target air volume or wind speed to confirm that the resistance of the new filter does not cause the fan operating point to deviate too much. Replacement records should retain filter model, batch, installation date, leak detection results and retest data.
replacement item |
What should be confirmed |
Recording requirements |
|---|---|---|
Replacement conditions |
Pressure difference or time? |
Change criterion record |
Replacement operation |
Disassembly and assembly directions and seal recovery |
Replace operation record |
Leak detection after replacement |
Is the seal restored? |
Leak detection results |
Retest after replacement |
Whether the air volume or wind speed returns to the target |
Retest data |
Regarding the relationship between filter operating resistance and replacement judgment, please refer toWhat should I do if the operating resistance of the EFU filter increases? pressure difference, air volume and replacement judgment . The troubleshooting ideas in For methods involving air volume retesting, please refer toHow to calculate EFU surface wind speed? how to determine effective filtration area and average wind speed .Measurement methods in
The acceptance of H14 filters must match efficiency, sealing and air volume. Efficiency depends on whether the filter test report is consistent with the overall machine configuration, sealing depends on the leak detection results, and air volume depends on whether the retest data reaches the target. If the three items do not correspond, the acceptance conclusion will be incomplete. If only the efficiency is checked but not the seal, the risk of bypass is not eliminated; if only the seal is checked but not the air volume, the fan operating point may have shifted.
Acceptance items |
What should be confirmed |
Judgment basis |
|---|---|---|
Efficiency acceptance |
The filter report corresponds to the overall machine configuration |
Test report |
Seal acceptance |
Leak detection results meet the criteria |
Leak detection record |
Air volume acceptance |
The re-measured air volume reaches the target range |
Retest data |
Document acceptance |
Complete reports, records, and random documents |
Document list |
In the EFU project, Aili Industry organizes acceptance according to the confirmation drawing and technical agreement, and maps efficiency, sealing and air volume to specific models and batches. For projects delivered in batches, please refer toWhich batch of equipment should the random spare parts of the EFU batch project be delivered with? The batch management idea in the paper corresponds to filter spare parts and equipment batches.
The resistance of the H14 filter is higher than that of the H13 filter, so the fan operating point must be rechecked when selecting the filter. Put the initial resistance and operating resistance on the fan curve to see if the working point corresponding to the target air volume falls within the effective range of the fan. After the resistance rises, the fan adjustment margin is insufficient and the air volume drops significantly. Only confirm the filter level, not the matching of the entire machine. Insufficient air volume may occur after installation. For projects involving speed-regulated operation, please refer toHow to set EFU multi-speed speed adjustment? equipment linkage, abnormal status and acceptance points .Methods for checking gears and working points in
Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and complete machine assembly. The efficiency, resistance and sealing conditions of the H14 filter can be checked according to the equipment drawings within the same manufacturing system. The filter size, box structure and complete machine working point do not need to be transferred between multiple suppliers. For the H14 filter project, Aili Industrial can organize installation leak detection, replacement retesting and batch curing according to the confirmation drawing, and put efficiency, sealing and air volume conditions into verifiable complete machine data. Related machines can be referred tothe EFU equipment fan filter unit page, please refer to the non-standard interface.For the structural description on Customize EFU page.Customization instructions in the
First complete the preliminary screening of information, and then conduct technical confirmation on the model to be purchased. Add efficiency standards, initial resistance and operating resistance, sealing methods, leak detection methods, replacement conditions and acceptance requirements to the supplementary list, and organize comparisons after the supplier responds. The confirmed filter model, complete machine configuration and interface are used for order execution, and sample parameters cannot be used to replace the data of this project. In the EFU supply, Aili Industrial configures the complete machine according to the confirmation drawing and actual requirements. The filter, fan and box correspond one by one according to the order list, which facilitates the equipment factory to confirm the H14 filter to the verifiable complete machine conditions.
It should be avoided to only write H14 but not the test standard. It should be avoided to only look at the initial resistance but not the operating resistance. It should be avoided to release it without checking for leaks after installation. It should be avoided not to measure the air volume after replacing the filter. It should be avoided to only check the efficiency without checking the seal. The core of H14 filter confirmation is not to obtain a test report, but to form a verifiable closed loop of efficiency, resistance, sealing, leak detection and complete machine matching. Aili Industrial can first form a to-be-confirmed list according to the equipment drawings, listing efficiency, resistance and leak detection conditions together.
uncertain. Increasing the level is often accompanied by changes in resistance and cost, and should be determined by process needs, fan capabilities and verification conditions.
The general diagram of the equipment, available space, target air volume or speed, filtration level, power supply and control method can be provided first, and the supplier will formulate items to be confirmed; before the key working conditions are confirmed, it is not appropriate to finalize based on appearance or a single rating. Aili Industrial can first form a to-be-confirmed list according to the equipment drawings, listing efficiency, resistance and leak detection conditions together.
Prepare current project information around filtration efficiency, resistance, sealing and leak detection. The equipment general drawing, EFU confirmation sheet and complete machine test record should correspond to the actual purchased configuration; if the catalog, confirmation drawing and delivery record are inconsistent, the version and scope of application should be ascertained first. When confirming the H14 filter for EFU, you can refer to the filter and complete machine matching instructions provided by Aili Industry according to model.
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How to confirm the initial resistance of EFU filter? Rated air volume, test conditions and fan match
Check items |
Confirm key points |
|---|---|
Before installation |
Efficiency standards, initial resistance, running resistance, dimensions |
When installing |
Sealing method, even pressing, frame condition |
Leak detection |
Methods, judgment criteria, exception handling |
replace |
Judgment by pressure difference, leak detection and retest after replacement |
acceptance |
Corresponding to three items: efficiency, sealing and air volume |
Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and complete machine assembly. The efficiency, resistance and sealing conditions of the H14 filter can be checked according to the equipment drawings within the same manufacturing system. The filter size, box structure and complete machine working point do not need to be transferred between multiple suppliers. The equipment factory completes the matching of H14 filters and complete machines in the same system, which is easier to maintain data consistency than cross-supplier coordination.
learnAili Industrial EFU products and customized configurations , filtering packages can be viewedHEPA and ULPA air filters , the overall structure can be viewedEFU equipment fan filter unit , non-standard interface can be viewedCustom EFU . Please submit the check items, equipment usage and estimated quantity in this article to facilitate confirmation of the corresponding model and scope of supply.