The aim of using air filters is to protect people’s health by maintaining a good hygiene level in the ventilation system and clean indoor air quality (IAQ). It is commonly known that air pollution is unhealthy, but it is not so well known that the smallest particles are the most dangerous. The aspects could be different depending on the outdoor air quality and the indoor activities. The urban air quality is nowadays polluted by small PM1 particles and gases coming from combustion and diesel engines (see the post The Composition of Air), which city centres are crowded with. Additionally, for hygiene reasons, bacterial and fungal spores must be removed from the air stream, which are typically in a size range between 1 and 10 μm (see Figure 1). Therefore, for the human health and indoor hygiene, it is important to clean the inlet air with sufficient air filters.
The most common air filters in comfort ventilation are ePM1, ePM2,5 and ePM10. ePM1 is recommended in buildings such as schools, hospitals, office buildings, apartments and residential facilities.
Source: Eurovent Guidebook. Air Filters for General Ventilation