AHU Filters: The Essential Guide to Boosting Efficiency in Commercial HVAC Systems
What Are AHU Filters?
AHU filters are filtration components installed within air handling units to remove harmful particulates from the air — including dust, pollen, spores, bacteria, and PM2.5 or even PM1 fine particles. These filters are a key component of any commercial HVAC system, ensuring safe indoor air while protecting internal HVAC components from contamination.
Key Components of an AHU
An Air Handling Unit typically includes the following main components:
Air Intake: Draws in outside or recirculated air to begin the filtration and conditioning process.
AHU Filter: Captures airborne particles such as dust, pollen, bacteria, and pollutants.
Fan Section: Distributes clean, filtered air throughout the building via ductwork.
Cooling/Heating Coil: Adjusts the temperature using chilled or heated water.
Heat Recovery System: Improves energy efficiency by transferring heat between exhaust and incoming air.
Silencers: Reduce operational noise levels to ensure quiet system operation.
Plenums: Manage and direct airflow within the system.
These components work in harmony to provide clean, temperature- and humidity-controlled air for indoor environments.
Classification of AHU Filters: Primary, Medium, and High-Efficiency
Based on the ISO 16890 standard, air filters are categorized according to their particulate removal efficiency:
● Primary Filters (ISO Coarse)
Designed to capture large particles such as dust, hair, and pollen. Often used as the first line of defense in air filtration.
● Medium Efficiency Filters (ISO ePM10 & ePM2.5)
Effective against particles between 1–10 microns. Suitable for removing common pollutants in outdoor air and general indoor environments.
● High-Efficiency Filters (ISO ePM1 / HEPA)
These filters target ultra-fine particles such as bacteria, viruses, and smoke — ideal for high-precision environments like cleanrooms and medical facilities.
✅ ISO 16890 Filter Classifications:
| ISO Classification | Particle Size Efficiency |
|---|---|
| ISO Coarse | ≥ 10 µm |
| ISO ePM10 | ≥ 1 µm to <10 µm |
| ISO ePM2.5 | ≥ 0.3 µm to <2.5 µm |
| ISO ePM1 | ≥ 0.3 µm to <1 µm |
✅ Our Solutions
We offer a full range of AHU filters, including:
Primary Filters: Panel or pleated designs made from synthetic fibers or fiberglass. Strong, durable, and easy to replace.
Medium Filters: Multi-pocket or V-bank structures with high dust-holding capacity, engineered for high airflow in commercial HVAC applications.
High-Efficiency Filters (HEPA vs.ULPA filters): Available with filtration efficiency from 99.95% to 99.9995%, tailored for cleanroom and healthcare use.
How an AHU Works
The typical operation of an AHU includes the following stages:
Air Intake: Outside or recirculated air is drawn into the unit.
Filtration: The air passes through one or more stages of filters — from pre-filters to high-efficiency filters — to remove dust, pollen, microbes, and other contaminants.
Temperature and Humidity Conditioning: The filtered air is either heated or cooled through coils, and humidified or dehumidified as needed, to meet comfort or process requirements.
Air Distribution: The treated air is then pushed through ductwork and distributed into different zones of the building.
Exhaust and Energy Recovery: In double-flow AHU systems, stale indoor air is extracted and passed through heat recovery devices (such as heat exchangers) before being exhausted outdoors, minimizing energy waste.
The Role of AHU Filters in Commercial HVAC Systems
AHU filters serve several critical purposes in commercial HVAC operations:
1. Improve Indoor Air Quality (IAQ)
They capture harmful particulates, allergens, and microbes, ensuring a healthy work environment for building occupants.
2. Protect HVAC Equipment
By filtering contaminants, AHU filters help prevent the buildup of dust on heat exchangers, motors, and fans — extending system lifespan and reducing maintenance costs.
3. Enhance Energy Efficiency
High-quality filters offer low pressure drop and high efficiency, helping reduce fan energy consumption and support green building certifications.
4. Compliance with Industry Standards
Our filters comply with ISO 16890 and help customers meet requirements for LEED, ASHRAE, GMP, and more.
How to Choose the Right AHU Filter
When selecting AHU filters for your commercial HVAC system, consider these key factors:
Application Environment: Office spaces, hospital wards, cleanrooms, or production lines each require different filtration levels.
Required Filtration Grade: Based on the target pollutants (e.g., PM10, PM2.5, PM1).
Filter Media and Structure: Synthetic fiber, fiberglass, activated carbon, and more — each suited to specific use cases.
Airflow Capacity & Pressure Drop: Balance between airflow demand and energy efficiency.
Replacement Cycle & Maintenance: Choose filters that are easy to replace and offer cost-effective maintenance.
✅ We offer one-on-one technical consultation to help you select the best filters based on your system’s air volume, environment, and energy goals.
Why Regular Maintenance and Filter Replacement Matters
Even the best filter will degrade over time. Failure to replace filters regularly can lead to:
Reduced airflow and ventilation issues
Higher energy consumption
Declining filtration performance
Potential damage to AHU components
📅 Recommended replacement interval: Every 3 to 6 months, depending on load, environment, and filter type. We provide custom maintenance schedules and inventory management solutions for our clients.
Conclusion
AHU filters are not just optional components — they are critical for achieving optimal indoor air quality, HVAC efficiency, and long-term system reliability.
By choosing the right primary, medium, or high-efficiency filters, you take the first step toward creating a healthy, compliant, and energy-efficient commercial environment.
📩 Contact us today for expert guidance and custom filtration solutions tailored to your commercial HVAC system.