How to choose between H13 and H14 high efficiency filters?

The difference between H13 and H14 is clearly written in the standard: the filtration efficiency for 0.3 micron particles is different. But when it comes to actual selection, this numerical difference is not the decisive factor.

What really needs to be judged is whether the efficiency improvement brought by H14 is of practical significance under the specific conditions of the project, and whether the system can withstand the changes that will follow. After thinking about these two things clearly, which level you choose will be the natural result.

Confirm the standard first, then look at the grade

H13 and H14 levels come from specific testing standards, and the definitions under different standards are not exactly the same.

If it says 'H14 required' in the procurement document, it is best to indicate the applicable standards and testing methods at the same time. If only the grade is written but not the standard, the report provided by the supplier may use another system and the data may not match. This needs to be paid more attention to in multinational projects or multi-party supply projects.

After confirming the standards, look at the actual particle control requirements of the project. If the target particle size and concentration requirements themselves are not high, H13 may already meet them; if the process is sensitive to extremely small particles, the remainder of H14 is more valuable. Level selection should go back to craft requirements, rather than starting from level numbers.

The change in resistance should be calculated as the margin of the air inlet fan.

H13 and H14 of the same size do not necessarily have the same resistance. H14 usually has denser filter material or more compact structure, and its resistance under the target air volume is often higher.

When planning to upgrade the grade, the resistance of the candidate product under the design air volume must be calculated together with the fan curve, air duct resistance and final resistance conditions. The purpose of the calculation is to confirm whether the fan can still maintain the target air supply volume after replacing it with H14, and whether the margin is sufficient when the filter element reaches the later stage of dust accumulation.

If the calculation finds that the margin is insufficient, there are several processing directions: choose an H14 structure with a larger effective filtration area, adjust the fan configuration, or re-evaluate the target wind speed. Replacing the rating label without verifying the fan is a common mistake in retrofit projects. For matching FFU fan filter unit system, the filter element and fan are in the same unit, the calculation is relatively straightforward; the equipment-side application is as follows The space of the fan filter unit at the EFU equipment end is limited, and there are few options available, so more room needs to be left during calculation.

Sealing and leak detection conditions must be checked simultaneously

The higher the rating, the more sensitive it is to localized leaks.

A small bypass leak may have limited impact on H13, but may significantly affect the overall performance of H14. Therefore, when choosing H14, the reliability of the sealing structure and the rigor of on-site leak detection need to be confirmed accordingly.

The liquid tank sealing structure requires higher matching accuracy. For verification methods, please refer to the relevant instructions on knife edge size verification. The detection method, scanning path and judgment criteria must also be specified in the project document. Do not directly apply the leak detection plan of the H13 project to the H14 project.

Installation space and maintenance methods

The thickness or structure of the H14 filter element may be different from that of H13. Even if the length and width are the same, it may interfere with the box, diffuser or access opening after installation.

Changing the path also requires confirmation. If the original system was designed with an inspection space based on the thickness of H13, replacing it with the thicker H14 may affect disassembly and assembly. This is especially true in device-side applications, where the available height is often determined during the device design phase.

A practical order of judgment

It is recommended to go in this order:

First confirm the testing standards and particle control objectives adopted by the project. Then get the efficiency and resistance data of the candidate product under the target air volume. Then put the resistance data into the system and check the fan working point. Finally, check whether the sealing structure, leak detection requirements and installation space match.

If these items are passed, the plan is feasible. If you are not satisfied with any of them, you have to go back and make adjustments. Efficiency level is only one of the inputs and cannot alone determine the selection result. involving For HEPA/ULPA air filter products of different grades, the testing data and acceptance requirements should also be clearly stated in the project documents.

About Aili Industrial’s grade selection and cooperation

Aili Industry can discuss the matching relationship between efficiency level and air volume resistance based on the filter element, fan and equipment structure. filter with FFU fan filter unit、The EFU equipment-side fan filter unit is matched in the same manufacturing system, and the fan operating point and filter element resistance can be calculated together during the planning stage.

Provide target operating conditions and acceptance requirements to help determine specific product parameters. Specific performance is subject to product technical information and project confirmation documents.