New ISO EN 16890 standard classifies filters by their efficiencies according to different sizes of particle matters. Various particles can cause different negative effects on people’s health. But different sizes of particles may travel to different parts of respiratory system to cause damage.
Harmful particles
Even the smallest dust particles can pose a risk to human health. Airborne particles, which during normal breathing, can get in the nose or mouth.
Outdoor air quality
| Category | Description |
| ODA 1 | It would be fresh, fresh air that could only get polluted from time to time. (Mostly during the flowering period of spring plants) |
| ODA 2 | When the air is moderately polluted. |
| ODA 3 | Heavily contaminated air, usually in large urban centers or living near factories. |
Indoor air quality
| Category | Description |
| IDA 1 | High indoor air quality |
| IDA 2 | Average indoor air quality |
| IDA 3 | Harmful indoor air quality |
| IDA 4 | Poor indoor air quality |
Filter Selection
Depending on the ambient air quality and indoor air requirements, Eurovent provides its recommendation table for filter selection.
| Outdoor air quality | Indoor air quality | |||
| IDA 1 | IDA 2 | IDA 3 | IDA 4 | |
| ODA 1 | F9 | F8 | F7 | M5 |
| ODA 2 | F7+F9 | M6+F8 | M5+F7 | M5+M6 |
| ODA 3 | F7+GF*+F9 | F7+GF*+F9 | M5+F7 | M5+M6 |
| GF* – is an active carbon filter to contain gaseous pollutants. | ||||
If the system uses F7 and higher filters, it is recommended to pay close attention to the tightness of the building and premises.
Activated carbon filters are recommended in areas with outdoor air quality ODA 3. Use in outdoor conditions ODA 2 is also a good solution if gaseous pollutants are available in the area.
It is important to keep activated carbon filters away from moisture!
Although it is recommended to replace the filters twice a year, it is best to consider filter wear before replacing. If you notice a decrease in fresh air in your home or an increase in electricity costs, it is likely that your filters are clogged and need to be replaced.