MPL and Z-line filters: how to choose the right one?
The material of MPL filters is very densely pleated, which results in a very large filter surface. Therefore, even with extremely dense materials, the filter has a high air throughput. Quality MPL filters are sealed by gluing the material to the frame to ensure the required filtration level. Filters are typically available in grades ePM10 (M5), ePM2.5 (M6, F7), ePM1 (F7, F8, F9).
Z-line filters have a corrugated material and a significantly smaller surface area than MPL filters. Higher-density materials have significantly higher resistance, and such filters are usually only available in Coarse (G4) or maximum ePM10 (M5) grades. Some manufacturers do not glue the material to the frame in Z-line filters because the filters are not required to clean the air of the finest particles (although gluing does of course increase the filtration efficiency).
Both Z-line and MPL filters are used in air handling units (AHU). The Z-line filter is well suited for exhaust air purification, as a pre-filter (pre-filter) function and often used as a supply air filter in clean areas.
MPL-type filters are used to improve the quality of the supply air, and are therefore usually placed on the supply air duct. In some cases, the manufacturer of the AHU also adds this filter for exhaust air cleaning, but this is not cost-effective.
The combination of an MPL (class M5 or F7) supply air filter with a Z-line (class G4) filter for exhaust air treatment (e.g. SALDA, Dantherm, etc.) and, in less frequent cases, an additional Z-line filter used as a primary air filter is common in AHU.
The main mistakes used by manufacturers of AHU or air filters are:
M5 and higher efficiency filter in media in Z-line filter. Due to its small surface area, such a filter has a low permeability, resulting in increased pressure losses in the system. This results in louder operation, significantly shorter lifetime, reduced airflow and higher energy consumption.
The use of an unsealed MPL M5 and higher class filter. In such a filter, some of the particles bypass the filter material and do not provide the required air cleaning.
In these cases, the seller of analog filters simply wants to make more money by offering a cheaper product, as the cost of these filters is significantly lower than that of higher-quality analogs.
As an example of this is the non-genuine F7 (ePM1) class Z-line filter often used for Komfovent air handling units. Usually, some sound marketing description is used as „Light“ or „Eco“. But in general, such filter provides high resistance, reduces initial airflow rate, and serves much shorter.
