EN 779 Air Filter Classification Standard

Understanding EN 779 and Its Role in Air Filtration

EN 779 is a European standard that historically classified general ventilation air filters based on their performance in removing particulate matter from air.

For many years, EN 779 was widely used in HVAC systems for commercial and industrial buildings to define filter efficiency and application suitability.

Although EN 779 has been officially replaced by ISO 16890, it is still frequently referenced in existing specifications, maintenance documents, and legacy HVAC systems. Understanding EN 779 remains important for filter replacement, system upgrades, and technical comparison.

 

What Is EN 779?

EN 779 is a European testing and classification standard for particulate air filters used in general ventilation systems. It evaluates filter performance based on:

• Average arrestance (for coarse filters)

• Average efficiency (for fine filters)

• Performance under standardized laboratory test conditions

The standard focuses on the filter’s ability to capture synthetic dust particles rather than real-world particulate matter such as PM1, PM2.5, or PM10.

 

EN 779 Filter Classes

Under EN 779, air filters are divided into two main groups:
Coarse filters (G-class) and Fine filters (F-class).

Coarse Filters (G-Class)

Coarse filters are primarily used as pre-filters to capture large particles and protect downstream high-efficiency filters.

 

Fine Filters (F-Class)

 

Fine filters are designed to remove smaller particles and are commonly used in commercial buildings, healthcare facilities, and industrial HVAC systems.

 

Typical Applications of EN 779 Filters

EN 779-classified filters have traditionally been used in:

• Commercial building HVAC systems

• Industrial ventilation systems

• Hospitals and healthcare facilities

• Manufacturing plants

• Data centers and clean support areas

In many existing installations, filter specifications are still written in EN 779 terminology, especially for G4, F7, and F9 filters.

 

Limitations of the EN 779 Standard

While EN 779 played an important role in air filtration classification, it has several limitations:

• It does not directly measure PM1, PM2.5, or PM10 efficiency

• Test dust does not represent real ambient air conditions

• Efficiency values may not reflect actual in-use performance

• Limited relevance to modern indoor air quality requirements

As air quality awareness increased, a more comprehensive and realistic testing approach became necessary.

 

Transition from EN 779 to ISO 16890

To address the limitations of EN 779, the ISO 16890 standard was introduced and officially replaced EN 779.

Key Differences:

 

ISO 16890 provides a clearer understanding of how filters perform against particulate matter that impacts indoor air quality and human health.

 

EN 779 and Filter Replacement Considerations

Many HVAC systems still operate with filters specified under EN 779. When replacing these filters, it is important to:

• Identify the original EN 779 class (e.g., G4, F7)

• Understand the equivalent ISO 16890 classification

• Ensure airflow and pressure drop compatibility

• Avoid unintended system performance changes

Professional evaluation is recommended when transitioning from EN 779 to ISO 16890 filters.

Clean-Link Support for EN 779 and ISO 16890 Filters

Clean-Link manufactures air filters that support both legacy EN 779 classifications and modern ISO 16890 requirements. Our product range includes:

• G4 pre-filters

• F7 / F9 fine filters

• V-bank filters

• Pocket filters

• Synthetic and glass fiber filter media

We assist customers in selecting suitable replacement filters while maintaining system performance and compliance.

 

Related Standards and Resources

• ISO 16890 – Air filter classification by particle size

• EN 1822 – HEPA and ULPA filter testing

• ISO 14644 – Cleanroom classification

Understanding how these standards relate helps ensure proper filter selection across different applications.

 

Whether you are maintaining an existing EN 779-based system or upgrading to ISO 16890, Clean-Link provides technical support for filter selection and replacement planning.