MERV vs. ISO 16890 vs. EN 779: Understanding the Global Filtration Standards

If you work in facility management or HVAC items purchasing, you likely see confusing codes on air filter boxes. You might see "MERV 13" on one quote, "F7" on another quote.

Why are there three different standards? And which one should you use?

For a long time, the filter efficiency standard are always different in different areas. North America used MERV. Europe and Asia used EN 779. But in 2018, the industry made a major shift. EN 779 was retired and replaced by the global ISO 16890 standard.

This guide will explain these three standards in a simple way, and let you no longer suffer from confusion about efficiency rating.

EN 779

For decades, EN 779 was the main standard in Europe and many parts of Asia. It classified filters into simple groups:

>>> G-Class (Coarse): G1,G2,G3, G4 (Pre-filter for large particles).

>>> M-Class (Medium): M5, M6.

>>> F-Class (Fine): F7, F8, F9.

You may ask why was it "retired"?  This is because taht the EN 779 test had a major flaw. It only tested filter efficiency on a single particle size (0.4 microns). It did not tell you how a filter performed against real-world pollution, like smog or viruses.

Although this standard is officially "dead," many engineers still use terms like "F7" out of habit. Today, if you see F7, you need to find its modern ISO equivalent.

MERV

MERV (Minimum Efficiency Reporting Value) is created by ASHRAE 52.2. It is the dominant language in the US & Canada market.

The efficiency level range from MERV1-MERV16 ( The HEPA filters are often informally rated as MERV 17–20, though ASHRAE officially stopped recognizing ratings above 16 in 2009).  It measures the minimum efficiency across three particle size ranges:

>>> E1 (0.3–1.0 microns): The smallest and hardest to catch, such as bacteria and smoke.

>>> E2 (1.0–3.0 microns): Medium-sized, like milled flour or auto emissions.

>>> E3 (3.0–10.0 microns): Larger debris like dirt and lint.

The key ratings we often use are:

MERV 8: The industry standard for pre-filters. Good for protecting HVAC coils.

MERV 13:The new "Gold Standard" for commercial buildings. It captures smaller particles like bacteria and smoke.

MERV 16:Near-HEPA performance, used in hospitals.

ISO 16890

ISO 16890 is the first truly global standard. It replaced EN 779 to harmonize filtration testing worldwide.

Why is it better? ISO 16890 focuses on human health. Instead of testing arbitrary lab dust, it tests how filters handle Particulate Matter (PM), the same metric used by the World Health Organization (WHO) to measure air pollution.

It groups filters into four clear categories:

>>> ISO Coarse: For sand, hair, and insects (Replaces G4).

>>> ISO ePM10: For pollen and stone dust (Replaces M5/M6).

>>> ISO ePM2.5: For fungal spores and bacteria.

>>> ISO ePM1: For combustion smoke and viruses (The most dangerous particles).

If a filter is rated "ePM1 60%", it means it captures 60% of PM1 particles. This is much easier for customers to understand.

The Great Comparison: Converting the Standards

There is no perfect mathematical conversion because the testing methods are different. However, the industry uses this general "Translation Table" to help you choose the right product.

At Amorair Global, we understand that drawings and specs might still use old terms. Whether you ask for a "G4 Panel," a "MERV 8 Pleat," or an "ISO Coarse" filter, our engineering team knows exactly what you need.

We manufacture filters that are rigorously tested to meet both ASHRAE 52.2 and ISO 16890 standards, ensuring you get the right protection, no matter which "language" your project speaks.

Need help translating your filter specs? Contact Amorair Global today. We make clean air simple.