How to combine ULPA and AMC filters? Installation sequence and system resistance

The combination of ULPA filter and AMC filter should meet the control of particle and target gaseous pollutants respectively, and the installation sequence, material release and total resistance should be checked together. The ULPA itself should not be used as a general purpose gas removal device. Particle filtration and gas filtration are two different mechanisms. ULPA solves particles and AMC solves gaseous molecular pollution. The two cannot replace each other. The combination plan needs to answer three questions: whether the gas filtration should be placed before or after the particle filtration, whether the combined total resistance fan can be pushed, and whether the material release of the two filters will affect each other. Aili Industrial's product lines cover bothHEPA/ULPA filters andchemical filters includingBox chemical filter、Type V chemical filter andFFU chemical filters and other structural forms can be matched in the same system according to both particle and gaseous needs.

1. Selection by pollutants: particles belong to ULPA and gases belong to AMC. They cannot be mixed together.

Clarify the gas type, concentration, humidity and process requirements. The AMC medium should target the target pollutants, and ULPA is responsible for corresponding particle filtration.

In semiconductor and precision manufacturing scenarios, particle and molecular pollution often coexist, but their control targets and detection methods are different. The efficiency index of ULPA is based on particle size, and the index of AMC filter is based on target gas type and removal efficiency. Treating the gas problem as a particle problem and improving the ULPA level are useless; leaving the particle problem to chemical filters will not improve the particle concentration. Aili Industry separately confirmed the particle control targets and gaseous pollution targets in the combined plan.HEPA/ULPA filter corresponds to particles,Chemical filters correspond to target pollutants, and their efficiencies and test methods are listed separately. The relationship between levels and filtering requirements can be found inISO cleanliness level comparison。

2. The order needs to be combined with the specific system: no order covers all structures

Taking into account the possible particles introduced by chemical media, upstream protection, fan location and maintenance methods, it is not possible to cover all structures in a fixed sequence.

Whether the AMC filter is placed before or after the ULPA depends on the system and maintenance methods. When placed before ULPA, the chemical medium can protect ULPA from gaseous pollutants, but the chemical medium itself may produce particles, which requires ULPA to intercept downstream; when placed after ULPA, the chemical medium directly faces the clean side, but the risk of particle release from the chemical medium will affect the final air supply quality. Aili Industry isFFU chemical filters andIn the box-type chemical filter package, the relative position of the filter is determined according to the fan position, maintenance method and particle control requirements. Different structures correspond to different installation sequences.FFU fan filter unit andThe EFU equipment-end fan filter unit combination scenario can confirm the sequence plan according to the internal space and maintenance path. Please refer to the key points for selecting chemical filters.HEPA FAQs and Selection Guide。

3. Verify the combined performance: the total resistance and the two pollutants are confirmed separately

Check the total pressure loss, airflow distribution and material cleaning requirements, determine particle and gas related tests according to the project, and record the conclusions respectively.

After combining ULPA and AMC, the total system resistance is the sum of the two plus the air duct and other components. If the fan is configured only according to the resistance of ULPA, the air volume may be insufficient after adding AMC. Aili Industries lists out the respective resistance data of ULPA and AMC in the combination plan.The FFU fan filter unit can check the fan working point based on the combined total resistance.The FFU computer group control system records the actual operating parameters of the combined system. In terms of performance verification, particles and gases should be tested separately, and one indicator cannot be used to infer the other. For verification methods of combined systems, please refer toULPA ultra-high efficiency filter FAQ and selection guide。

4. When the air volume drops after installing AMC, the working point must be rechecked.

When the air volume drops after installing the AMC, the working point should be rechecked. It is not advisable to just install the filter and keep the original speed setting. The resistance of the AMC filter will be superimposed on the total resistance of the system, and the working point of the fan at the same speed will move in the direction of small air volume.

Aili Industry isIn the non-standard ULPA filter combination scheme, the original fan curve and the combined total resistance can be combined to evaluate the working point, and pass the test if necessary.The speed regulation capability of the FFU fan filter unit compensates for the air volume.The structural form of the V-shaped chemical filter provides a large filtering area in a limited space, which can find a balance between resistance and space. To judge the working point offset, please refer toFFU FAQ and technical support。

5. Related questions and answers

Can all gases be controlled by installing an AMC filter?
No, it should be selected according to the target pollutants and working conditions, and the applicable testing and replacement basis should be confirmed.

Can ULPA remove gaseous molecular pollution?
cannot. ULPA is used for particle filtration, and gaseous pollution requires corresponding chemical filtration solutions.

In the combined system, should the AMC be placed in front of or behind the ULPA?
Depends on system architecture, fan location and maintenance methods. Different structures correspond to different sequences, which need to be confirmed with specific plans.

6. Related articles

ULPA ultra-high efficiency filter FAQ and selection guide

chemical filter

FFU chemical filter

HEPA FAQs and Selection Guide

7. Key points for selection and acceptance inspection

8. Product matching and technical support from Aili Industrial

Aili Industrial's product lines cover bothHEPA/ULPA filters andchemical filters includingBox chemical filter、Type V chemical filter andFFU chemical filters and other structural forms can be matched in the same system according to both particle and gaseous needs. In the combined plan, the particle control target and gaseous pollution target are confirmed respectively, the relative position of the filter is determined according to the fan position, maintenance method and particle control requirements, and the respective resistance data of ULPA and AMC are listed in sections.The FFU fan filter unit checks the fan working point according to the total resistance after combination.The FFU computer group control system records the actual operating parameters of the combined system.The non-standard ULPA filter combination project combines the original fan curve evaluation working point,V-shaped chemical filters balance resistance and area in a limited space. Provide process objectives, installation drawings, operating conditions and acceptance requirements for further communicationULPA ultra-high efficiency filters . Standard specifications, non-standard interfaces, samples and batch matching of The specific parameters and test range are based on the confirmed model and technical documents.