01.10.26

New version of DIN EN 16798-3

One of the most important standards for ventilation in non-residential buildings has undergone a comprehensive revision after nine years. With regard to air filters, the new DIN EN 16798-3:2026-10 introduces three significant changes:

1. Stricter air quality limits
2. Adaption of DIN EN ISO 16890
3. Requirement for molecular filters

Who is affected?

EN 16798-3 applies to the ventilation of all non-residential buildings in Europe that are intended for human occupancy. It applies to new systems, as well as energy assessment, retrofitting, and renovation of existing systems. EN 16798-3 aims specifically at planners, installers, manufacturers, building owners and occupants, as well as regulatory agencies.

As part of the EPB standards set, EN 16798 serves as a tool for implementing the EPBD (Energy Performance of Buildings Directive). The EPBD is linked to the overarching European Green Deal, which includes the goal to create more environmentally friendly buildings and better living conditions through a wave of renovations.

A Closer Look

1. Stricter air quality limits
Compared to the previous DIN EN 16798-3 version, slightly higher filter classes are recommended. This results from the stricter limits in the new WHO 2021 Air Quality Guidelines. These limits form the basis for classifying outdoor and supply air in the standard.

DIN EN 16798-3 divides outdoor air quality into three classes (ODA 1 – ODA 3) and supply air quality into five classes (SUP 1 – SUP 5). Table 1 shows the new limit values for air quality classification. The WHO limit values correspond to classes ODA 1 and SUP 4, respectively.

A new aspect is the additional assessment of air quality based on harmful gases, rather than exclusively on particulate matter, as was previously the case. The classes for outdoor and supply air refer either to particulate matter and are marked with a (P), or to harmful gases and are marked with a (G).

Category
Particulate Matter (P)
Gaseous Pollutants (G)
Outdoor Air

Supply Air
PM10
µg/m3
PM2,5
µg/m3
NO2
µg/m3
SO2
µg/m3
O3
µg/m3
-
SUP 1
≤ 3,75
≤ 1,25
≤ 2,50
≤ 10,00
≤ 15,00
-
SUP 2
≤ 7,50
≤ 2,50
≤ 5,00
≤ 20,00
≤ 30,00
-
SUP 3
≤ 11,25
≤ 3,75
≤ 7,50
≤ 30,00
≤ 45,00
ODA 1
SUP 4
≤ 15,00
≤ 5,00
≤ 10,00
≤ 40,00
≤ 60,00
ODA 2
SUP 5
≤ 22,50
≤ 7,50
≤ 15,00
≤ 60,00
≤ 90,00
ODA 3
-
> 22,50
> 7,50
> 15,00
> 60,00
> 90,00
Table 1: Limits for air quality classes according to DIN EN 16798-3:2026-10

2. Adaption of DIN EN ISO 16890
In 2018, DIN EN ISO 16890 has replaced DIN EN 779 as the classification standard for air filters. Standards such as VDI 6022-1, VDI 3803-4, and Eurovent 4-23 already refer to the current classification. Now DIN EN 16798-3 follows, thereby harmonizing the state of the art in Europe.

Table 2 shows the current recommendation for fine dust filters. Depending on the applicable ODA class and the desired SUP class for the system, a recommendation is made for filter efficiency.

Category
SUP 1 (P)
ePM1
SUP 2 (P)
ePM1
SUP 3 (P)
ePM2,5
SUP 4 (P)
ePM10
SUP 5 (P)
ePM10
ODA 1 (P)
70 %*
50 %*
50 %**
50 %
50 %
ODA 2 (P)
80 %*
70 %*
70 %**
80 %
50 %
ODA 3 (P)
90 %*
80 %*
80 %**
90 %
80 %
Table 2: Required average filtration efficiency based on particle outdoor air quality
* Final filter stage should be minimum ePM1 50 %.
** Final filter stage should be minimum ePM2,5 50 %.

These are cumulative efficiency values, meaning the efficiency of all filter stages is added together. For example, if an average filter efficiency of 70% is recommended, it can be achieved by using an ISO ePM1 65% filter in combination with an ISO ePM10 50% prefilter.

3. Requirement for molecular filters
The new requirement for gas filtration represents a major change. Until now, there had only been a vague recommendation to use appropriate gas filtration if pollution levels were too high. This was also due to lack of filter classes for the molecular filters, which are usually made of activated carbon.

EN ISO 10121-3 enables filter classification for molecular filters (see also „ISO 10121-3“). DIN EN 16798-3 specifically refers to these classes and their respective filtration efficiencies, expressed as percentages, in its specific filter recommendation. The process of choosing the right filtration efficiency is analogous to that for particulate filters.

However, there is one crucial difference: The Efficiency of a molecular filter differs against different gases. This results in different filter classes based on the specific gases the filter can remove. For filter design in accordance with DIN EN 16798-3, the decisive factor is which of the three pollutants NO2, SO2, or O3 exceeds the WHO (SUP 1) limit value the most. A molecular filter only has to be effective against that specific pollutant, with efficiencies as shown in the following table.

Category
SUP 1 (G)
SUP 2 (G)
SUP 3 (G)
SUP 4 (G)
SUP 5 (G)
ODA 1 (G)
70 %*
-
-
-
-
ODA 2 (G)
80 %**
70 %**
50 %*
-
-
ODA 3 (G)
90 %**
80 %**
70 %*
-
-
Table 3: Required / Recommended integrated gas filtration efficiencies for the respective gas
* Recommended
** Required

Conclusion

For fine dust filtration, DIN EN 16798-3 now aligns with current practice. Filter designations in accordance with DIN EN ISO 16890 and designs based on stricter limit values have already been implemented in comparable standards in Germany for some time. No major upheaval is expected here, though it may serve as an impetus to revise one or two outdated filter designs.

The situation is different when it comes to gas filtration. Until now, molecular filters have hardly been used to clean outdoor air for indoor applications. The new requirements will add a new dimension to system planning in the future. Nevertheless, molecular filters are necessary to provide a holistic approach in ensuring air that is beneficial to health. Especially in areas heavily polluted by traffic or industry, harmful gases have negative effects comparable to those of particulate matter on people.

The standard thus takes an important step toward to get uniform, healthy living conditions in buildings.