Air Filters for AHU – Pre, Fine, HEPA and Carbon Filters for Air Handling Units

Air Filters for AHU are filtration products installed inside Air Handling Units (AHUs) to remove airborne contaminants from outdoor, return and recirculated air before conditioned air is supplied to occupied or controlled spaces.

Depending on the application, an AHU filtration system may include several stages such as Pre Air Filters, Panel Filters, Pleated Filters, Bag Filters, Pocket Filters, Fine Air Filters, Compact Filters, V-Bank Filters, Activated Carbon Filters and HEPA Filters.

Proper AHU filtration helps protect cooling coils, heating coils, fans and ductwork while reducing airborne particulate contamination and supporting indoor air quality. In cleanrooms and critical environments, upstream AHU filters also help protect expensive final HEPA or ULPA filters.

VIETPHAT supplies Air Filters for AHU systems used in commercial buildings, factories, hospitals, hotels, data centers, pharmaceutical plants, electronics factories, semiconductor facilities, food processing plants and cleanrooms.

What Are Air Filters for AHU?

Air Filters for AHU, also known as AHU Air Filters or Air Handling Unit Filters, are filters installed in the filtration sections of an Air Handling Unit.

Their primary function is to remove contaminants from air passing through the AHU before the air reaches downstream HVAC components or occupied spaces.

Depending on filter type and efficiency, AHU filters may help remove:

• Coarse dust.
• Fine dust.
• Fibers and lint.
• Pollen.
• PM10.
• PM2.5.
• PM1.
• Fine airborne particles.
• Odors.
• Selected VOCs and gaseous contaminants.

No single filter is designed to remove every type of contaminant. For this reason, AHUs commonly use multi-stage filtration.

What Is an AHU?

AHU stands for Air Handling Unit. It is a central component of many HVAC systems used to condition and distribute air throughout a building or industrial facility.

Depending on system design, an AHU may contain:

• Outdoor air intake.
• Return air section.
• Mixing chamber.
• Pre-filter section.
• Fine-filter section.
• Cooling coil.
• Heating coil.
• Humidification or dehumidification components.
• Fan section.
• Sound attenuator.
• Carbon or molecular filtration section.
• HEPA filtration section where required.

Because large quantities of air continuously pass through the AHU, filtration is critical to both air quality and equipment protection.

Why Are Air Filters Important in AHUs?

Outdoor and return air can contain substantial quantities of airborne contaminants. Without suitable filtration, these particles can enter the AHU and accumulate on internal components.

AHU filters can help:

• Reduce airborne dust.
• Reduce fine particulate matter.
• Protect cooling and heating coils.
• Keep fan sections cleaner.
• Reduce contamination of ductwork.
• Protect downstream filters.
• Support indoor air quality.
• Reduce particulate contamination in controlled environments.
• Support stable HVAC operation.

Main Types of Air Filters for AHU

1. AHU Pre Air Filters

AHU Pre Filters are normally installed at the first filtration stage.

Their main purpose is to capture larger airborne particles before they reach cooling coils, Fine Filters, Compact Filters or HEPA Filters.

Common constructions include:

• Flat Panel Filters.
• Pleated Panel Filters.
• Synthetic Media Filters.
• Washable Filters.
• Metal Mesh Filters for selected applications.

Effective pre-filtration can help extend the service life of downstream filters.

2. AHU Panel Air Filters

Panel Air Filters for AHU are commonly used as primary or pre-filtration stages.

They can be manufactured using:

• Synthetic filtration media.
• Polyester media.
• Glass fiber media for selected designs.
• Pleated nonwoven media.

Frames may be manufactured from galvanized steel, aluminum, plastic or other materials according to installation requirements.

3. AHU Pleated Air Filters

Pleated Air Filters for AHU use folded filter media to increase effective filtration area within a relatively shallow frame.

Advantages may include:

• Increased filtration surface area.
• Improved dust-holding capacity.
• Compact installation.
• Suitable airflow characteristics.
• Longer service life than some flat-media designs.

4. AHU Bag Air Filters

Bag Air Filters for AHU use multiple flexible pockets to create a large effective filtration area.

They are widely used as medium- and fine-filtration stages in commercial and industrial Air Handling Units.

Typical applications include:

• Commercial buildings.
• Factories.
• Hospitals.
• Hotels.
• Pharmaceutical plants.
• Electronics manufacturing.

5. AHU Pocket Air Filters

Pocket Air Filters and Bag Air Filters are closely related terms. These filters provide extended media area through multiple pockets and are commonly installed downstream of the pre-filter stage.

Depending on tested performance, modern products may be classified according to ISO 16890 as ePM10, ePM2.5 or ePM1.

6. AHU Fine Air Filters

Fine Air Filters for AHU are designed to capture smaller airborne particles than typical coarse pre-filters.

Fine filtration is important where improved control of:

• PM10.
• PM2.5.
• PM1.
• Fine dust.
• Outdoor particulate pollution.

is required.

7. AHU Compact Air Filters

Compact Air Filters for AHU use extended pleated or mini-pleat media inside a rigid housing.

They provide a large filtration area in a compact design and can be suitable for higher-efficiency filtration in industrial and commercial AHUs.

8. AHU V-Bank Air Filters

V-Bank Air Filters contain multiple filter packs arranged in a V-shaped configuration.

This design provides a large effective media area and can support high airflow while maintaining a compact installation footprint.

V-Bank filters are particularly suitable for:

• High-airflow AHUs.
• Data centers.
• Large commercial HVAC systems.
• Industrial facilities.
• Continuous-operation HVAC systems.

9. AHU Activated Carbon Air Filters

Activated Carbon Air Filters for AHU are designed primarily for gas-phase filtration rather than particulate filtration.

Depending on the carbon media and target contaminant, they may help reduce:

• Unpleasant odors.
• Selected VOCs.
• Organic vapors.
• Selected gaseous contaminants.

Carbon filtration is normally used together with particulate filtration rather than as a replacement for Pre or Fine Air Filters.

10. AHU HEPA Air Filters

HEPA Air Filters for AHU are used where high-efficiency particulate filtration is required.

Applications may include:

• Hospitals.
• Pharmaceutical facilities.
• Cleanrooms.
• Electronics manufacturing.
• Semiconductor facilities.
• Laboratories.
• Medical manufacturing.

HEPA filters should be selected and tested according to the applicable high-efficiency filter standard and project requirements.

AHU Air Filter Types at a Glance

AHU Filter Type	Main Function	Typical Position	Typical Application
Panel Filter	Coarse dust removal	First stage	General HVAC
Pleated Filter	Pre / medium filtration	First or intermediate stage	Commercial AHU
Bag / Pocket Filter	Medium / fine filtration	Intermediate stage	Commercial and industrial AHU
Compact Filter	Higher-efficiency filtration	Intermediate / final HVAC stage	Industrial HVAC
V-Bank Filter	High-airflow fine filtration	Intermediate / final HVAC stage	Data centers, large AHUs
Carbon Filter	Odor / gas control	Dedicated gas-phase stage	Commercial and industrial HVAC
HEPA Filter	High-efficiency particle filtration	Final filtration	Cleanrooms and critical areas

Typical AHU Multi-Stage Filtration System

Many Air Handling Units use more than one filter stage because different filters perform different functions.

Two-Stage AHU Filtration

• Stage 1: Pre Air Filter.
• Stage 2: Fine Air Filter.

This configuration is common in general commercial and industrial HVAC systems.

Three-Stage AHU Filtration

• Stage 1: Pre Air Filter.
• Stage 2: Medium / Fine Air Filter.
• Stage 3: High Efficiency or HEPA Filter.

This arrangement may be used where greater particulate control is required.

AHU Filtration with Odor Control

• Stage 1: Pre Filter.
• Stage 2: Fine Filter.
• Stage 3: Activated Carbon or Molecular Filter.
• Stage 4: Final high-efficiency filtration where required.

The actual sequence must be engineered according to contaminant type, system configuration and project requirements.

Air Filters for AHU and ISO 16890

ISO 16890 is widely used for classification of general ventilation air filters.

The main filter groups include:

• ISO Coarse.
• ePM10.
• ePM2.5.
• ePM1.

This classification system helps engineers select AHU filters based on their tested performance against relevant particulate matter size fractions.

ISO Coarse Filters for AHU

ISO Coarse filters are primarily intended to capture larger particles.

They are commonly used as AHU pre-filters to reduce dust loading on downstream filtration stages and internal HVAC components.

ePM10 Filters for AHU

ePM10 Air Filters provide tested filtration performance related to particulate matter in the PM10 size range.

They can be used as intermediate filtration stages depending on the indoor air quality target and system design.

ePM2.5 Filters for AHU

ePM2.5 Filters are used where greater control of fine particulate pollution is required.

They may be suitable for commercial buildings and industrial facilities in areas affected by traffic, combustion or other fine-particle sources.

ePM1 Filters for AHU

ePM1 Air Filters are commonly selected for higher-grade general ventilation systems requiring improved removal of very fine particulate matter.

Typical applications include:

• Premium commercial buildings.
• Hospitals.
• Data centers.
• Electronics facilities.
• Pharmaceutical facilities.
• Pre-HEPA filtration.

G4, M5, M6, F7, F8 and F9 AHU Filters

Existing AHU specifications may still use former EN 779 filter classes such as:

• G4.
• M5.
• M6.
• F7.
• F8.
• F9.

These designations remain common in replacement-filter inquiries. However, for new general ventilation specifications, performance according to ISO 16890 should be considered where applicable.

When replacing an older G4, M5, M6, F7, F8 or F9 filter, the selection should not be based on terminology alone. Actual dimensions, airflow, pressure drop and available test data should also be reviewed.

HEPA Filters for AHU

Where significantly higher particulate filtration is required, AHUs may incorporate HEPA Filters.

Common HEPA classes encountered in HVAC and cleanroom applications include:

• H13 HEPA Filters.
• H14 HEPA Filters.

HEPA filters should not be selected only by nominal dimensions. Important considerations include airflow, pressure drop, filter class, sealing method, housing design and integrity requirements.

Air Filters for AHU in Commercial Buildings

Commercial Air Handling Units require reliable filtration to reduce outdoor and recirculated particulate contamination.

Typical applications include:

• Office buildings.
• Shopping centers.
• Hotels.
• Airports.
• Schools.
• Convention centers.
• Public buildings.

A common configuration consists of a coarse pre-filter followed by a higher-efficiency Fine Air Filter.

Air Filters for AHU in Factories

Factories can have higher particulate loading than conventional commercial buildings because of production activities, material handling and surrounding industrial environments.

AHU filter selection should consider:

• Dust concentration.
• Particle size.
• Required indoor cleanliness.
• Production process.
• Operating hours.
• Outdoor air quality.
• Available fan static pressure.

High-dust environments may require effective pre-filtration and filters with higher dust-holding capacity.

Air Filters for AHU in Hospitals

Healthcare facilities use different filtration configurations according to the area served and applicable HVAC requirements.

Depending on the system, filtration may include:

• Pre Filters.
• Fine Filters.
• High Efficiency Filters.
• HEPA Filters.

Critical areas require filtration systems designed according to the specific healthcare application rather than a generic filter configuration.

Air Filters for Pharmaceutical AHUs

Pharmaceutical facilities use AHU filtration to support controlled manufacturing environments and cleanrooms.

A multi-stage system may include:

• Coarse pre-filtration.
• Fine filtration.
• HEPA filtration.

The required filtration level depends on cleanroom classification, process requirements and HVAC design.

Air Filters for Electronics Factory AHUs

Electronics manufacturing facilities can be sensitive to airborne particulate contamination.

AHU filtration can help control dust before air reaches:

• PCB production areas.
• Electronic assembly lines.
• Display manufacturing.
• Battery manufacturing.
• Precision component production.
• Clean production areas.

Air Filters for Semiconductor AHUs

Semiconductor facilities typically require advanced multi-stage air filtration.

General AHUs may use Pre and Fine Filters, while cleanroom supply systems may use HEPA or ULPA final filtration according to process and cleanliness requirements.

Effective upstream AHU filtration is important because it can reduce particle loading on expensive final filters.

Air Filters for Cleanroom AHUs

Cleanroom AHUs require carefully designed filtration stages to support controlled airborne particle concentrations.

A typical arrangement may include:

• Pre Filter.
• Medium Efficiency Filter.
• Fine Filter.
• HEPA Filter.
• ULPA Filter where required.

Final HEPA or ULPA filters may be installed in the AHU, terminal housings, Fan Filter Units or other cleanroom supply-air configurations depending on system design.

Air Filters for Data Center AHUs

Data centers require reliable filtration with particular attention to airflow and energy consumption because cooling systems may operate continuously.

Compact and V-Bank Filters can be suitable for high-airflow applications because they provide large media areas within relatively compact housings.

Important considerations include:

• Particle-removal efficiency.
• Initial pressure drop.
• Average operating pressure drop.
• Dust-holding capacity.
• Rated airflow.
• Filter service life.

Air Filters for Food Processing AHUs

Food processing facilities may use multiple filtration stages in AHUs serving production, packaging, processing and storage areas.

The required filter configuration depends on hygiene requirements, production conditions and required air cleanliness.

Air Filters for Hotel AHUs

Hotel AHUs typically require particulate filtration for outdoor and recirculated air. Where odors or gaseous pollutants are also a concern, Activated Carbon Air Filters may be added as a dedicated gas-phase filtration stage.

Air Filters for Paint Facility AHUs

Paint and coating facilities may require specialized filtration depending on whether the AHU supplies general ventilation air or process air.

Supply-air systems may use:

• Pre Filters.
• Fine Filters.
• Ceiling Filters for selected paint booth applications.

Paint overspray exhaust filtration is a separate function and may require fiberglass arrestors, paper filters or other dedicated paint filtration products.

AHU Air Filters for PM10 Control

PM10 includes larger inhalable particulate matter. Depending on tested efficiency, suitable AHU filters can help reduce PM10 entering through outdoor-air ventilation.

AHU Air Filters for PM2.5 Control

PM2.5 is an important consideration for buildings located in areas affected by traffic, industrial emissions and combustion sources.

Filters with suitable tested ePM2.5 or ePM1 performance can be selected to improve fine-particle removal.

AHU Air Filters for PM1 Control

PM1 represents very fine particulate matter. For applications requiring improved removal in this range, filters with suitable ePM1 performance should be considered.

AHU Air Filters for Odor Control

Conventional particulate filters do not effectively remove most gaseous odors.

Where odor control is required, AHUs may use:

• Activated Carbon Filters.
• Carbon Pleated Filters.
• Carbon Panels.
• Carbon Cartridges.
• Impregnated Carbon Filters.
• Molecular Air Filters.

The correct media should be selected according to the target odor, VOC or gaseous contaminant.

AHU Air Filters vs FCU Air Filters

Criteria	AHU Air Filters	FCU Air Filters
System	Air Handling Unit	Fan Coil Unit
Typical Airflow	Medium to very high	Generally lower
Filtration Stages	Single or multiple	Usually simpler
Filter Types	Panel, bag, compact, V-bank, carbon, HEPA	Mesh, synthetic, panel, shallow pleated
Typical Application	Central HVAC	Local room conditioning

AHU Air Filters vs HEPA Filters

AHU Air Filter describes where the filter is installed, while HEPA Filter describes a high-efficiency particulate filtration category.

An AHU may contain a HEPA Filter, but many AHU filters are Pre, Medium or Fine Filters rather than HEPA filters.

AHU Air Filters vs Carbon Filters

Criteria	Particulate AHU Filter	Carbon AHU Filter
Main Target	Airborne particles	Gases and odors
Contaminants	Dust, PM10, PM2.5, PM1	Odors, VOCs, selected gases
Mechanism	Particle filtration	Adsorption / chemisorption
Typical Media	Synthetic or glass fiber	Activated carbon / molecular media

AHU Air Filter Efficiency

Filter efficiency should be selected according to the actual air-quality objective rather than choosing the highest possible efficiency without considering the system.

Important factors include:

• Outdoor air quality.
• Indoor air-quality target.
• Process requirements.
• Particle size of concern.
• Downstream filtration.
• Available fan static pressure.
• Energy consumption.

AHU Air Filter Pressure Drop

Pressure Drop is one of the most important parameters when selecting Air Filters for AHU systems.

Each filter creates resistance to airflow. The AHU fan must provide enough static pressure to overcome the combined resistance of filters, coils, ducts and other system components.

Filter pressure drop is influenced by:

• Filter type.
• Filtration efficiency.
• Media area.
• Filter depth.
• Airflow.
• Face velocity.
• Dust loading.

Initial and Final Pressure Drop

Initial Pressure Drop is the resistance of a clean filter at a specified airflow.

Final Pressure Drop is a selected or recommended resistance level at which filter replacement may be considered, subject to manufacturer and system requirements.

For maintenance planning, differential pressure gauges or sensors can be installed across the filter bank.

Why Dust-Holding Capacity Matters

Dust-Holding Capacity affects how much particulate matter a filter can retain before reaching its service limit.

A filter with suitable dust-holding performance can help:

• Extend service intervals.
• Reduce filter replacement frequency.
• Protect downstream filters.
• Maintain airflow for longer periods.
• Reduce maintenance requirements.

AHU Air Filters and Energy Consumption

Air filtration affects HVAC energy consumption because the fan must overcome filter resistance throughout the operating life of the filter.

For continuously operating AHUs, life-cycle evaluation should consider:

• Initial pressure drop.
• Average operating pressure drop.
• Filtration efficiency.
• Dust-holding capacity.
• Filter service life.
• Replacement frequency.
• Fan energy consumption.

A filter with the lowest purchase price is not necessarily the most economical option over its complete service life.

Common Filter Media for AHU Air Filters

AHU filters may use:

• Synthetic fiber media.
• Polyester media.
• Glass fiber media.
• Nonwoven media.
• Mini-pleat media.
• Activated carbon media.
• Impregnated carbon media.
• Specialized molecular filtration media.

Common AHU Air Filter Frame Materials

Depending on filter construction, frame materials may include:

• Galvanized steel.
• Aluminum.
• Plastic.
• Cardboard for selected disposable panel filters.

Standard and Custom Size AHU Air Filters

Air Handling Units are manufactured in many sizes and configurations. Therefore, AHU filters may be required in either standard or custom dimensions.

When replacing an existing filter, confirm:

• Width.
• Height.
• Depth.
• Actual installation orientation.
• Number of filters per bank.
• Frame construction.
• Gasket configuration.

Correct sizing is important because gaps around the filter can create air bypass, reducing the effective performance of the filtration system.

Important Specifications for Air Filters for AHU

Parameter	Information Required
Dimensions	Width × Height × Depth
Filter Type	Panel, bag, compact, V-bank, HEPA, carbon
Efficiency	ISO Coarse, ePM10, ePM2.5, ePM1, HEPA or specified class
Rated Airflow	m³/h per filter
Initial Pressure Drop	Pa at rated airflow
Final Pressure Drop	Recommended replacement resistance
Media	Synthetic, glass fiber, carbon or specified material
Frame	Galvanized steel, aluminum, plastic or other material
Seal	Gasket, gel or application-specific configuration
Quantity	Number of filters required

How to Select Air Filters for AHU

1. Identify the Application

Determine whether the AHU serves a commercial building, factory, hospital, cleanroom, data center or other environment.

2. Determine the Required Air Quality

Define whether the objective is equipment protection, general dust filtration, PM2.5 control, PM1 filtration, cleanroom filtration or odor control.

3. Select the Filtration Stages

Determine whether the AHU requires one, two, three or more filtration stages.

4. Confirm Filter Dimensions

Measure Width × Height × Depth accurately and verify the filter-bank configuration.

5. Confirm AHU Airflow

Determine the total AHU airflow and the airflow through each individual filter.

6. Check Filtration Efficiency

Review the required ISO 16890, HEPA or other applicable filter classification.

7. Check Pressure Drop

Confirm that the AHU fan has sufficient available static pressure for the proposed filter configuration.

8. Evaluate Dust Loading

High-dust environments may require improved pre-filtration and greater dust-holding capacity.

9. Check Installation and Sealing

The filter should fit correctly in the housing to minimize bypass around the frame.

10. Evaluate Life-Cycle Cost

Compare filter purchase price together with pressure drop, service life, maintenance and energy consumption.

How to Measure an Existing AHU Air Filter

For replacement filters, provide the actual filter dimensions in the following order:

Width × Height × Depth (W × H × D)

It is also useful to provide:

• Photo of the existing filter.
• Photo of the filter label.
• Filter class.
• Brand and model if available.
• AHU airflow.
• Quantity.
• Application.

This information helps reduce errors when selecting replacement filters.

When Should AHU Air Filters Be Replaced?

AHU filters should not necessarily be replaced according to calendar time alone.

Replacement should be considered based on:

• Differential pressure.
• Dust loading.
• Filter condition.
• Airflow.
• Operating hours.
• Indoor air-quality requirements.
• Manufacturer recommendations.
• Facility maintenance procedures.

Signs an AHU Air Filter May Need Replacement

• High differential pressure.
• Reduced AHU airflow.
• Heavy visible dust loading.
• Damaged filter media.
• Damaged frame.
• Collapsed filter pockets.
• Air bypass around the filter.
• Unacceptable downstream cleanliness.

Can AHU Air Filters Be Washed?

Only filters specifically designed as washable should be cleaned and reused.

Most disposable:

• Pleated Filters.
• Bag Filters.
• Pocket Filters.
• Fine Filters.
• Compact Filters.
• V-Bank Filters.
• HEPA Filters.

should generally be replaced rather than washed.

Washing a disposable filter can damage media structure and alter filtration performance.

How to Extend AHU Filter Service Life

AHU filter service life can often be improved by:

• Using effective upstream pre-filtration.
• Selecting adequate filter media area.
• Operating within rated airflow.
• Preventing air bypass.
• Keeping filter housings clean.
• Monitoring differential pressure.
• Replacing damaged filters promptly.
• Maintaining outdoor-air intake areas.

AHU Air Filter Maintenance

A preventive maintenance program should include regular inspection of:

• Filter differential pressure.
• Filter media condition.
• Frame condition.
• Gaskets and seals.
• Filter-bank integrity.
• Dust accumulation.
• Coil cleanliness.
• Drain pans.
• AHU internal cleanliness.

Common Problems with AHU Air Filters

Incorrect Filter Size

Filters that are too small can create gaps and air bypass.

Excessive Air Velocity

Operating above the intended airflow can increase pressure drop and may reduce filter service life.

Insufficient Pre-Filtration

Fine and HEPA filters can become loaded quickly when coarse dust is not removed upstream.

Incorrect Filter Efficiency

Using a filter that is either insufficient or unnecessarily restrictive can reduce overall HVAC performance.

Damaged Gaskets or Seals

Even a high-efficiency filter cannot provide its intended system-level performance if contaminated air bypasses the filter.

Replacement Air Filters for Existing AHUs

VIETPHAT can support replacement filter selection for existing Air Handling Units based on the actual installed filter rather than requiring customers to replace the complete AHU filtration system.

Useful information includes:

• Existing filter dimensions.
• Filter photographs.
• Filter label.
• Current filter class.
• Required replacement efficiency.
• AHU airflow.
• Quantity.

Custom Air Filters for AHU

For AHUs using non-standard filter housings, filters may be supplied according to custom dimensions and project requirements.

Depending on product type, customization may include:

• Width.
• Height.
• Depth.
• Filter efficiency.
• Number of pockets.
• Media area.
• Frame material.
• Gasket configuration.
• Airflow capacity.

Air Filter Supplier for AHU in Vietnam – VIETPHAT

VIETPHAT supplies Air Filters for AHU systems across commercial, industrial and controlled-environment applications.

Our AHU filtration range supports applications requiring coarse dust filtration, fine particulate control, PM filtration, high-efficiency filtration and odor control.

VIETPHAT Air Filters for AHU Product Range

• AHU Pre Air Filters.
• AHU Primary Air Filters.
• AHU Panel Air Filters.
• AHU Pleated Air Filters.
• AHU Medium Efficiency Filters.
• AHU Bag Air Filters.
• AHU Pocket Air Filters.
• AHU Fine Air Filters.
• AHU Compact Air Filters.
• AHU V-Bank Air Filters.
• AHU Activated Carbon Filters.
• AHU Odor Control Filters.
• AHU HEPA Filters.
• H13 HEPA Filters.
• H14 HEPA Filters.
• Custom Size AHU Air Filters.

Why Choose VIETPHAT for AHU Air Filters?

VIETPHAT supports customers in selecting AHU filters based on actual technical requirements rather than filter dimensions alone.

Selection can be based on:

• AHU application.
• Required filtration stage.
• Filter dimensions.
• Airflow.
• Filtration efficiency.
• Pressure drop.
• Dust-loading conditions.
• Media construction.
• Frame material.
• Installation conditions.

This approach helps customers select replacement filters that are technically appropriate for the existing HVAC system.

Information Required for an AHU Air Filter Quotation

For faster filter selection and quotation, please provide:

Information	Example
Filter Size	W × H × D in mm
Filter Type	Panel / Bag / Compact / HEPA
Filter Efficiency	ePM10 / ePM2.5 / ePM1 / H13 / H14
Airflow	m³/h
Frame Material	GI / Aluminum / Plastic
Quantity	Number of pieces
Application	Factory / Hospital / Cleanroom / Building
Existing Filter	Photo or technical datasheet if available

Frequently Asked Questions About Air Filters for AHU

What Air Filters Are Used in AHUs?

Common AHU filters include Panel Filters, Pleated Filters, Bag Filters, Pocket Filters, Fine Filters, Compact Filters, V-Bank Filters, Carbon Filters and HEPA Filters.

What Is the Best Air Filter for an AHU?

There is no single best AHU filter for every application. The correct filter depends on required air quality, particle size, airflow, pressure drop, available installation space and downstream filtration.

What Is an AHU Pre Filter?

An AHU Pre Filter is the first filtration stage used primarily to capture larger particles and protect coils and downstream filters.

Can an AHU Use a Bag Filter?

Yes. Bag or Pocket Filters are widely used as medium- and fine-filtration stages in commercial and industrial AHUs.

Can an AHU Use a HEPA Filter?

Yes. HEPA Filters can be integrated into appropriately designed AHU systems where high-efficiency particulate filtration is required.

Can an AHU Use Activated Carbon Filters?

Yes. Activated Carbon Filters can be installed in AHUs for odor, VOC and selected gas control when suitable media and system design are used.

Which AHU Filter Is Suitable for PM2.5?

A filter with suitable tested ePM2.5 or ePM1 performance should be considered. The actual efficiency percentage and pressure drop should be reviewed for the specific product.

Which AHU Filter Is Suitable for PM1?

Filters with suitable ISO 16890 ePM1 performance are commonly selected where improved control of very fine particulate matter is required.

What Is the Difference Between G4 and F7 AHU Filters?

G4 and F7 are former EN 779 classifications. G4 was generally used for coarse pre-filtration, while F7 represented a higher fine-filtration level. For current general ventilation specifications, ISO 16890 performance should be considered where applicable.

Should AHU Filters Be Installed in Multiple Stages?

Multi-stage filtration is often beneficial because coarse filters can remove larger particles before they reach more efficient and more expensive downstream filters.

How Often Should AHU Filters Be Changed?

Replacement frequency depends on dust concentration, operating hours, airflow, filter type, differential pressure and maintenance criteria. Fixed replacement intervals alone may not reflect actual filter condition.

How Do I Know When an AHU Filter Is Dirty?

Visible loading, increasing differential pressure and reduced airflow can indicate filter loading. Differential-pressure monitoring is particularly useful for AHU maintenance.

Can AHU Filters Be Washed?

Only filters specifically designed for washing should be cleaned. Most disposable Bag, Fine, Compact, V-Bank and HEPA Filters should be replaced.

Can VIETPHAT Supply Replacement Filters for Existing AHUs?

Yes. Replacement filters can be selected according to existing dimensions, filter type, efficiency, airflow and installation conditions.

Can VIETPHAT Supply Custom Size AHU Filters?

Yes. Depending on filter construction, custom sizes and configurations can be supplied to match existing filter housings and project requirements.

What Information Should I Send for a Quotation?

Please provide filter dimensions, filter type, required efficiency, airflow, quantity, frame material, application and photos or technical data for the existing filter when available.

Contact VIETPHAT for Air Filters for AHU

For technical consultation, replacement filter selection or quotation for Air Filters for AHU, please contact VIETPHAT:

• Zalo / Hotline: 0971 344 344
• Sales: 0827 077 078
• Sales: 0829 077 078
• Email: sales@vietphat.com
• Website: www.vietphat.com