Understand ISO 16890 ePM1, ePM2.5, ePM10 and ISO Coarse, why F7 and G4 cannot be converted exactly, and how to choose MVHR filters.
ISO 16890 is the international system used to classify general-ventilation air filters according to their performance against particulate matter. Instead of relying only on the older EN 779 labels such as G4, M5 and F7, it reports performance relevant to PM1, PM2.5 and PM10. When choosing a replacement filter for an MVHR or HRV unit, however, the filter’s fit and pressure drop are just as important as its efficiency class.
In brief: ISO ePM1, ePM2.5 and ePM10 refer to particulate-matter efficiency; ISO Coarse describes filters for coarser dust. There is no universal exact conversion between EN 779 classes and ISO 16890. Always check the manufacturer’s requirements and the tested specification of the actual replacement product.
ISO 16890 has four parts. Part 1 sets out the classification system, Part 2 covers fractional efficiency and airflow resistance measurements, Part 3 addresses gravimetric efficiency and dust-loading resistance, and Part 4 describes conditioning to reduce electrostatic charge before certain measurements. The standard concerns filter elements for general ventilation, not a promise that any filter medium will perform identically at any airflow or in every residential ventilation unit.
The ePMx indicators estimate a filter’s mass-based efficiency for particle-size fractions up to the respective nominal diameters. For example, a filter classified ISO ePM1 60% is rated at the indicated efficiency for the PM1 fraction under the test standard’s specified conditions. It does not guarantee that precisely 60% of all real-life pollutants in a particular home will disappear.
These are particle-filtration classifications, not measurements of gas or odour removal. For official methodology, consult ISO and relevant Eurovent guidance.
Not accurately in every case. The old EN 779 system and ISO 16890 use different measurements and classification criteria. Comparison tables can give an approximate orientation, but they are not proof that two particular products have identical performance. Look for the actual ISO rating on the replacement filter’s technical documentation.
Fine filters can have different pressure drops even within one efficiency class. Filter design, effective surface area, airflow rate and accumulated dust influence resistance. There is no universal replacement interval inferred solely from the class name.
Record the equipment nameplate, filter reference, length, width and depth in millimetres, airflow arrow and any seals or tabs. Do not swap the outside-air and extract-air positions. Our guide to choosing compatible MVHR filters explains the checks in more detail.
The following examples are model-specific replacement products with filtration details in their listings. Their exact suitability must be confirmed for your unit. ZenAero compatible filters are not original parts made by the ventilation unit manufacturer.
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Price range: 27.95 € through 94.95 €
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Price range: 21.95 € through 72.95 €
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Price range: 24.95 € through 84.95 €Explore ZenAero replacement filters and verify the complete model and stated performance before purchase.
No. It is a classification based on the relevant PM1 particle-mass fraction under standardised testing. Actual indoor exposure depends on many factors, including airflow, filtration bypass and indoor sources.
No. An old F7 designation alone cannot establish a precise ISO ePM1 percentage.
Not without checking the filter’s position and the unit manufacturer’s permitted specification, fitting requirements and airflow resistance.
Third-party trademarks identify compatible ventilation units only; they do not indicate manufacturer endorsement.
