Chemical Filters and AMC Molecular Contamination Control

Target gas selection | Adsorption and reaction medium configuration | MAU, FFU and equipment matching

Aili industrial chemical filters are used to reduce the concentration of specified gaseous pollutants in the air and provide gas-phase filtration products for clean rooms, air treatment systems and local areas of equipment.


For different pollutants, physical adsorption, chemical adsorption or reaction medium configuration can be used. The selection is based on the target gas, inlet concentration, outlet requirements and operating conditions, and also confirms the treatment air volume, resistance, installation space and maintenance methods.


Aili Industry covers air filter manufacturing, fan and motor matching, control system development, sheet metal processing and complete machine assembly. It can jointly confirm the structure and operating conditions of chemical filters and air treatment equipment.


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Control objectSpecified gaseous and molecular pollutantsmedia directionAdsorption type, impregnation type and reactive type
Product structureBox type, V type, flat typeSupporting locationMAU, AHU, FFU and device side
critical operating conditionsConcentration, air volume, temperature, humidityPerformance requirementsRemoval efficiency, capacity and export limits
Interface configurationDimensions, sealing, fixing and replacement structuresCustom supportMedia combinations, non-standard sizes and equipment matching

What is a chemical filter?


Chemical filters, also called gas phase filters or molecular filters, mainly deal with gases, vapors and molecular pollutants in the air.
As air passes through the filter media, target contaminants are trapped through adsorption or chemical reaction, reducing downstream concentrations. Different media have different effects on different gases, so chemical filters need to be selected for pollutants.
In clean manufacturing environments, AMC refers to molecular contamination in the air. Even if the particle cleanliness requirements are met, the impact of molecular contaminants on the product, equipment or materials still needs to be evaluated based on the process.

What is the difference between chemical filters and HEPA and ULPA?

Chemical filters and particle filters perform different tasks and cannot replace each other.

Compare itemschemical filterHEPA/ULPA filter
main objectDesignated gas, vapor and molecular pollutantsparticulate matter in air
Main mechanismAdsorption, chemical adsorption or reactionInterception, inertial collision, diffusion, etc.
Performance confirmationEfficiency, capacity and breakthrough performance of specified gasesParticle filtration performance under corresponding detection conditions
Replace judgmentDownstream concentration, breakthrough trend and medium statusPressure difference, air volume, leakage and maintenance requirements
System cooperationControl gas phase pollutionControl particulate pollution
When the project requires both particle and molecular pollution control, the corresponding filter section should be configured based on the pollution source, air flow path and material requirements.
If you need to configure particle filtering products at the same time, you can learn about Aili IndustryHEPA/ULPA air filter . \


Aili industrial chemical filter products

Equipment side and non-standard customized chemical filters


The equipment-side configuration is oriented to the designated process area, and the filter structure and media plan can be confirmed based on the equipment interface, local air supply range, pollutant types and material requirements.

For projects that cannot directly meet the standard specifications, the overall dimensions, installation sealing, media combination and maintenance methods can be evaluated based on the drawings.

Learn about customized EFU equipment packages → Consult non-standard chemical filters →

What contaminants do chemical filters control?


The following are common selection directions. The specific medium should be confirmed based on the actual gas and working conditions.

Pollutant directionExamples of typical objectsKey points in selection
acid gasHydrogen chloride, hydrogen fluoride, sulfur dioxide, etc.Immersion or reaction media suitable for the target gas
alkaline gasAmmonia and some aminesMedia selection for alkaline molecular contaminants
VOC and organic vaporToluene and other designated organic substancesMolecular properties, concentration, humidity and adsorption capacity
organic acidAcetic acid, formic acid, etc.Suitability and performance data for specific species
oxidizing gasOzone, etc.Dedicated media configuration and response suitability
corrosive contaminantsHydrogen sulfide, etc.Export requirements, media capacity and monitoring plan
Process specific AMCCondensables or other process sensitive moleculesConfiguration after clarifying specific species and limits
Sealing methodSealing form between filter and mounting structureCheck gasket compression or tank and knife edge conditions
Conditions of useAllowable temperature, humidity and other environmental conditionsConfirm filter media, frames, adhesives and seals
Test dataCorresponding product performance and testing informationMatch the model, serial number and testing conditions to confirm

Molecular filter media needs to be configured for pollutants, and the same media may not be suitable for all gases.

How to choose chemical filter media?


Filter parameters should be read in conjunction with the test conditions. Especially the air volume and resistance need to be compared in pairs and cannot be judged separately from the corresponding air volume.

media directionSelection ideasCheck conditions
activated carbon adsorption mediaAdsorption of suitable gas molecules through pores and surfacesSpecify species, concentration and temperature and humidity
impregnated activated carbon mediaEnhanced control of specific gasesCompatibility of impregnation system and target gas
reactive mediaCapture pollutants through designated reaction processesReaction objects, capacity and usage conditions
Composite or layered mediaCompatible with different contaminants and treatment stagesMedium combination, sequence and total resistance

Activated carbon is not a one-size-fits-all solution for all gases. The adsorption performance of different VOCs may also be different, and it is not appropriate to directly use the data of a certain test gas for all organic matter.

Submit the target gas and consult the medium configuration →

What is the difference between removal efficiency, capacity and breakthrough?


indexmeaningPay attention when purchasing
removal efficiencyThe reduction ratio of inlet and outlet concentrations under specified conditionsGas, concentration, air volume and measurement time
dynamic capacityCumulative amount of pollutants removed under specified test and termination conditionsWorking conditions, measurement methods and termination conditions
breakout curveChanges in downstream concentration or penetration ratio with time and loadBreakthrough criteria and performance change trends
initial pressure dropResistance of new filter at specified air volumeTest air volume and system allowable resistance
Service lifeRunning time to reach replacement conditions under actual working conditionsPollution loads, environment and export requirements

Under the same units and comparable measurement conditions:

Removal efficiency = (inlet concentration - outlet concentration) ÷ inlet concentration × 100%

High initial efficiency does not mean that the media capacity must be large. The service life is affected by factors such as air volume, pollutant type and concentration, temperature and humidity, and media quality.

Chemical filter installation location


Installation locationMain tasksConfiguration focus
MAU fresh air sectionControl of specified gaseous contaminants entering the systemChanges in inlet concentration, treatment air volume and capacity
AHU filter sectionCooperate with air treatment system for gas phase filtrationFilter section space, resistance and maintenance conditions
FFU supporting locationControlling Molecular Pollutants in Circulating AirFan margin, space and replacement structure
Device local areaProtect designated process locationsProcess limits, materials and installation interfaces
Circulation filter boxHandle corresponding circulating airPollution sources, circulating air volume and sealing

The sequence of pre-particle filtration, chemical filtration and downstream particle filtration should be jointly designed based on media protection, powder loss control and process requirements.

Equipment local air supply project can learn more about Aili IndustryEFU equipment fan filter unit。

Materials and secondary pollution control

Chemical filters need to control target gases while meeting the installation area requirements for the product's own materials.

projectConfirm content
media dustPowder loss control, fixation methods and downstream protection requirements
material releaseDielectric, Adhesive, Gasket, and Encapsulating Material Requirements
Interface sealAvoid air bypass without media treatment
environment adaptationTemperature, humidity, condensation and detergent contact conditions
Packaging and transportationMoisture, pollution and mechanical protection
Installation operationAvoid media damage, spillage or interface contamination

When low-release or special process material requirements are involved, testing items and acceptance conditions should be clearly defined.

Chemical filter selection steps


Target gas → Concentration and outlet requirements → Air volume and working conditions → Medium and structure → Interface and resistance → Verification and maintenance

01 Clarify the pollutants: Provide the specific gas name and whether it is a mixed pollutant. Do not just write 'odor' or 'VOC'.

02 Confirm the concentration and target: Provide the inlet concentration range, peak situation and allowed outlet concentration, and indicate the unit.

03 Confirm operating conditions: Provide air volume, temperature, humidity, operating time, and condensation or other special conditions.

04 Select media and structure: Confirm the media and box, V-shaped or flat plate configuration based on gas suitability, capacity requirements and space.

05 Check the interface and resistance: confirm the size, sealing, fixing and maintenance space, and check the fan capacity of the equipment.

06 Clarify verification requirements: Agree on test gas, concentration, working conditions, efficiency, capacity or breakthrough criteria.

07 Develop maintenance methods: confirm monitoring locations, inspection cycles, sampling methods and replacement conditions.

Submit chemical filter selection parameters→

How to read the performance data of chemical filters?


Data itemsneed clear information
test subjectMedia sample, or complete filter?
test gasSpecific species and single or mixed gases
challenge concentrationConcentration values ​​and units
airflow conditionsAir volume, wind speed and corresponding test structure
environmental conditionsTemperature and relative humidity
Performance resultsEfficiency, capacity, breakthrough curve and termination conditions
Sample correspondenceModel, media configuration and sample information

ISO 10121-1 is used for performance testing of gas phase filtration media, and ISO 10121-2 is used for performance testing of complete gas phase filtration devices. Media sample data cannot be directly regarded as the performance of the entire filter, nor can high-concentration challenge tests directly convert field life.

The testing basis and information of specific products shall be subject to the corresponding model and order agreement.

How often should chemical filters be replaced?


The replacement timing should be determined based on the downstream concentration, breakthrough trend and maintenance requirements of the target gas. The pressure difference is mainly used to observe the air flow resistance state.

If the pressure difference is normal, it does not mean that the medium still has sufficient gas removal capabilities.

Basis for judgmentMaintenance purpose
Downstream gas concentrationDetermine if process or project limits are approached
break trendObserve changes in removal performance
Media Sampling AssessmentAssists in determining media status when the method is applicable
Pollution load recordAnalyze concentration anomalies and usage cycle changes
Pressure difference and air volumeCheck for blockage, airflow and operating status
Installation checkCheck for moisture, damage, bypass and fixation abnormalities

The absence of odor cannot be used as a basis for low-concentration AMC compliance, and some pollutants are not suitable for judging by odor.

Consult filter replacement and replacement configuration →

Chemical filter application areas


Application areascontrol needs
Semiconductor manufacturingProcess Dependent AMC Control
Display panel manufacturingProcess Sensitive Gas Control
laboratorySpecified Vapor Phase Pollution Control
Data Center and Control Roomcorrosive gas control
Pressure difference and air volumeCheck for blockage, airflow and operating status
Installation checkCheck for moisture, damage, bypass and fixation abnormalities

High-concentration process exhaust should be evaluated separately and the treatment system should not be directly applied to clean air supply filters.

Why choose Aili Industrial Chemical Filter?

Aili Industrial has the ability to manufacture air filters and support clean air treatment equipment, and can jointly confirm the target gas, filter section structure, fan operation and maintenance conditions.

The company covers motor manufacturing, independent research and development and production of fans, control system development, sheet metal processing, air filter manufacturing and complete machine assembly. It has 30,000 square meters of modern industrial plants and provides manufacturing support for standard products and non-standard projects.

Supporting capabilitiesProject support
air filter manufacturingConfirm structure, media and product interface
Fan and motor matchingCheck the air volume and resistance after adding the filter section
Sheet metal and box processingCoordinate installation, sealing and maintenance spaces
Control system developmentCoordinate with equipment speed regulation, operation and linkage requirements
Components and whole machine synergySupports joint selection of filters and equipment
Non-standard project supportConfirm dimensions, interfaces and delivery requirements according to drawings

Aili Industrial Chemical Filters and Equipment Coordinated Support


Chemical filters need to be matched with air treatment equipment. After determining the target gas and medium configuration, it is necessary to check the processing air volume, filter section resistance, installation sealing and maintenance space before the selection plan can be implemented into the actual equipment.
Aili Industry has the capabilities of air filter manufacturing, independent research and development and production of fans, motor manufacturing, control system development, sheet metal processing and complete machine assembly. It can collaboratively confirm the following conditions around MAU, AHU, FFU and equipment-side projects:
collaborative projectsSupporting content
Filters and fansCheck the total resistance and target air volume after adding the chemical filtration section
Filter and boxMatching installation dimensions, support structure and perimeter sealing to reduce bypass air leakage
Media and Maintenance StructureConfirm the replacement direction, operating space and maintenance methods
Equipment and controlsConfirm speed regulation, start-stop and linkage conditions according to operating requirements
Prototype and series manufacturingImplement the verified dimensions, interfaces and configurations into the confirmation drawings
Aili Industrial Motor R&D and Production(1)(1)

Fan and motor matching

For FFU, EFU, BFU and other equipment, check the filter resistance, design air volume and fan static pressure conditions together.


Related: air volume, static pressure, filter resistance

Aili Industrial Intelligent Group Control System

Control system collaboration

Equipment projects can simultaneously confirm speed regulation, operation control and communication requirements, so that filters and air supply equipment can communicate according to the same working conditions.


Related: Equipment operation and control requirements

Aili Industrial FFU production sheet metal production

Sheet metal and structural processing

The box, frame and related structural parts can be confirmed according to the installation space and equipment interface, and manufacturing support is provided for standard and non-standard sizes.

Related: Dimensions, interfaces, installation structures

Aili Industrial FFU high-efficiency filter production workshop

Filter independent production system

Covering HEPA, ULPA, chemical filters and other air filtration products, the grade, filter material, size, frame and sealing method can be confirmed by project.


Related: Filter production and project selection

Aili Industrial Filter Testing

Assembly and process inspection

Quality inspection covers core components, production processes and complete machine assembly, and corresponding inspections are carried out according to product type.


Associations: parts, processes, assemblies

Aili Industrial FFU strict testing

Product testing and delivery

Conduct corresponding performance and operational tests based on product type, and confirm specifications, materials, packaging and delivery arrangements based on project requirements.


Related: testing, information, packaging, delivery

For new equipment matching, the filter section and unit structure can be jointly confirmed during the design stage; for original system modification, the configuration can be evaluated based on the existing fan capacity and installation space. Gas removal performance is based on corresponding media, product testing and project conditions, and equipment collaboration is used to implement installation and operating conditions.

Project support advantages for large factories


Aili Industry has a 30,000-square-meter production base. The production area covers motors, fans, filters, control systems, sheet metal processing, complete machine assembly, product testing, and finished product management. For HEPA and ULPA filter projects, complete site and manufacturing zoning provide the organizational basis for raw material entry, filter production, structural component processing, process inspection, finished product storage and packaging delivery.


The project value of large-scale production bases is mainly reflected in multi-category collaboration, parallelization of standard and non-standard products, batch project organization, and supporting communication of filters and clean equipment.

Aili Industrial 30,000 square meters modern industrial plant
Aili Industrial FFU production sheet metal production

Sheet metal processing

Aili Industrial FFU production

Whole machine assembly

Aili Industrial FFU strict testing

Product testing

Aili Industrial FFUEFU and other purification equipment warehouse

Finished product area

Chemical Filter FAQ

From target gases and filter media to equipment matching and customization, the following are the issues that customers often pay attention to when choosing chemical filters.

Q1: Is a chemical filter an activated carbon filter?

A: Activated carbon filter is one of them, and impregnation or reaction media can also be used, which should be selected according to the target gas.

Q2: Can HEPA or ULPA replace chemical filters?

A: No. Particle filtering and designated gas control need to be configured separately. For details, seeHEPA/ULPA air filter。

Q3: Can one chemical filter handle all VOCs?

A: This cannot be directly judged. The specific species, concentration and working conditions need to be clarified.

Q4: Can chemical filters handle ammonia?

A: It is necessary to select a medium suitable for ammonia and check the air volume, temperature, humidity and outlet requirements.

Q5: What is the difference between MAU and FFU chemical filters?

A: The installation location, air volume, space and pollution load are different. Can be viewed separatelyMAU box products andFFU supporting products.

Q6: The pressure difference is normal, does it still need to be replaced?

A: Yes, the impact method is related to the medium and gas, and should be confirmed based on the actual temperature and humidity.

Q7: Will humidity affect filtration performance?

A: HEPA mainly filters particulate matter. Odor and gas pollutants require gas phase filtration products configured according to the type of pollutants.

Q8: Can the chemical filter be cleaned or regenerated by itself?

A: You should not clean or regenerate yourself if the corresponding procedures are not clearly provided.

Q9: Can the installation size be customized?

A: It can be evaluated and customized based on the medium, air volume, resistance and interface requirements.

Q10: What parameters are required for inquiry?

A: Please provide the target gas, concentration, outlet requirements, air volume, temperature and humidity, size and operating time. For more equipment selection and maintenance content, please view Aili IndustryClean Equipment FAQ and Selection Guide。

Chemical filter selection and technical consultation


Chemical filter selection requires clearing the contaminants first, and then matching the media, structure and operating conditions. Complete gas and working condition information helps reduce selection deviations and establish verifiable maintenance basis.
Aili Industrial can provide product information, structural matching and non-standard customization support for MAU, AHU, FFU and equipment-side projects.


Contact us for chemical filter information and selection support→

Consult MAU Chemical Filters → Learn about FFU Chemical Filtration Configurations →

Submit non-standard size and interface requirements→

Aili Industrial - From chemical filters to air treatment equipment, it provides product support for clean manufacturing and gas-phase pollution control projects.


Contact Aili Industrial to obtain chemical filter information and technical parameters

Customized chemical filter solutions for your special needs

Aili Industry - From air filters to clean air supply equipment, it provides product matching and technical support for clean rooms and production equipment.

Still want to know more technical issues about chemical filters?

View more chemical filter selection and technical issues to obtain more complete chemical filter knowledge and solutions.
Aili Industrial develops and manufactures FFU, EFU, HEPA/ULPA air filters, high-efficiency air supply vents, fan boxes and other clean air equipment. Relying on motors, fans, control systems, filters and complete machine supporting capabilities, we provide selection and customization support for clean room and production equipment projects.

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