EN 779 Particulate Air Filters for General Ventilation - Determination of Filtration Performance

The European standard, “EN 779 Particulate air filters for general ventilation – Determination of filtration performance”, covers particulate air filters for general ventilation. These filters are classified according to their performance, as measured in this test procedure. This standard includes the requirements that particulate air filters must meet. It also describes the test methods and equipment for measuring filter performance.

To obtain results for comparison and classification purposes, particulate air filters are tested against two synthetic aerosols: a fine aerosol to measure filtration efficiency depending on particle size in the particle size range of 0,2 µm to 3,0 µm, and a coarse aerosol to obtain information about filtration efficiency relative to coarse loading dust (retention) in coarse filters.

This standard applies to air filters with an initial efficiency of less than 98% for 0,4 µm particles. Filters should be tested at an airflow rate between 0,24 m³/s and 1,5 m³/s. Performance results obtained in accordance with this standard cannot be applied alone to quantitatively estimate service performance in terms of efficiency and service life. Other factors affecting performance and to be considered are described in the annexes to this standard (Annex A and Annex B).

The filter must be designed or marked in a way that prevents incorrect installation. When properly installed in the ventilation duct, the filter must be designed so that no leakage occurs at the sealing edge.

The entire filter (filter and frame) must be made of suitable material to withstand normal use and the temperatures, humidity, and corrosive environments it is likely to encounter.

The entire filter must be designed to withstand the mechanical constraints likely to be encountered during normal use. Dust or fibers released from the filter media by the airflow passing through the filter must not pose a hazard or cause discomfort to persons (or devices) exposed to the filtered air.

Filters are classified according to their efficiency (retention) under the following test conditions:

• If the manufacturer has not specified a nominal airflow rate, the airflow should be 0,944 m3/s.
• Maximum final pressure drop of 250 Pa for coarse (G) filters.
• Maximum final pressure drop of 450 Pa for fine (F) filters.
• Filters are classified according to the table if they are tested at 0,944 m3/s and maximum final pressure drops.

In the world of indoor air quality and ventilation systems, choosing the right air filter is crucial for maintaining healthy environments in buildings ranging from offices and hospitals to residential areas. One of the fundamental criteria for this selection is the EN 779 standard, a guideline classifying particulate air filters used in general ventilation. This standard provides a framework for testing and classifying filters based on their efficiency in capturing dust and particles. However, this standard was later superseded by the more comprehensive ISO 16890 standard. Nevertheless, many older systems and standards still refer to this standard.

EN 779 tests are performed under controlled laboratory conditions to ensure consistency. Filters are evaluated in a standard rectangular duct (610 mm x 610 mm) with airflow velocities between 0,24 m3/s and 1,5 m3/s. Since performance varies depending on operating conditions, results are specific to the flow rate tested.

The basic measurements are as follows:

• Retention efficiency: For Class G (coarse) filters, this is important – the percentage of synthetic coarse dust captured.
• Filtration efficiency for fine particles: Measured at 0,4 μm using sodium chloride aerosols, which is critical for Class F (fine) filters.

The EN 779 standard is designed for the classification and testing of particulate air filters used in general ventilation systems. This standard is critically important for air quality, health, and energy efficiency. The main reasons why this standard is considered important are as follows:

• Ensuring and maintaining indoor air quality: This standard defines how effectively filters capture dust, pollen, bacteria, and other particles. This reduces indoor air pollution, especially in hospitals, schools, offices, and residential settings. Fine particles (e.g., PM2.5 or PM10) can lead to respiratory illnesses, allergies, and heart problems. This standard minimizes these risks by defining filter classes (G1 to F9) and minimum efficiency levels. For example, F7-F9 filters capture 80-95% of fine particles, making them indispensable in sensitive environments (laboratories, clean rooms).
• Health and environmental benefits: According to the World Health Organization (WHO), air pollution causes millions of premature deaths annually. The EN 779 standard protects users by ensuring filters are tested under conditions close to real-world conditions (with synthetic dust and aerosols). During pandemics, these standard-compliant filters reduce the risk of transmission by filtering out virus-carrying aerosols. EU indoor air quality regulations refer to this standard, guiding building designers.
• Energy efficiency and sustainability: This standard optimizes the energy consumption of HVAC systems by measuring the performance of filters under pressure drop and dust load. The EN 779 standard reduces the carbon footprint by promoting low-energy consuming filters.
• Standardization and comparability: It provides consistent test methods (e.g., 0.4 μm particle efficiency) among manufacturers, allowing buyers (engineers, plant managers) to easily compare filters. At the same time, this standard forms the basis for global trade.

Choosing the right filter from an economic perspective reduces maintenance costs and prevents production losses.

In conclusion, the EN 779 standard has played a significant role in raising air filtration standards worldwide, providing safer and more efficient ventilation.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the "EN 779 Particulate air filters for general ventilation - Determination of filtration performance" standard.