The pleated construction of REQNET filters (known as accordion style) provides a very large filtration area, resulting in high dust capacity. In practice, this means significantly extended filter service life and much lower airflow resistance, enabling the use of filters with high filtration classes.

Flat filters made of so-called “meter fiber” are only seemingly a cheaper solution. Their small dust capacity means that they need to be replaced multiple times more frequently, which is also inconvenient in terms of operating the ventilation system. The small surface area allows only coarse filtration materials from G1 to G3 to be used, which only capture basic pollutants and also lead to faster soiling of the heat exchanger and internal components of the ventilation unit.