They are cheap, disposable filtering cells at medium efficiency. The filtering media, with density growing from the air inlet side to the air outlet side, is composed of continuous filament glass fibers and it is supported front and back by two metal grids which are fastened to a cardboard frame.


The filter mats normally used make them suitable to retain coarse dust particles (PM10).
They are used for fan-coil, air treatment units, warm air generators, ventilation equipment of machines and as pre-filters to filters having higher performances (like LOM-BAG pockets filters, rigid pockets or activated carbon filters). The high dust storage capacity of fiberglass media make them suitable should high dust charge be present.


The filtration class of these filters, according to EN 779 Standards, is G3.
The table below shows the capacities and the pertaining initial resistance for the standard sizes.


Dimensions [mm] Capacity [m3/h] Pressure drop [Pa] Capacity [m3/h] Pressure drop [Pa]
sp. 23 mm sp. 48 mm sp. 23 mm sp. 48 mm
400 x 500 630 15 20 950 20 30
400 x 625 800 15 20 1200 20 30
500 x 500 800 15 20 1200 20 30
500 x 625 1010 15 20 1520 20 30
595 x 595 1140 15 20 1710 20 30
287 x 595 520 15 20 780 20 30

The limit working temperature is of 90°C approx.
The DF filtering cells can be supplied with different dimensions from the standard above ones and with synthetic media (DF SINT).


The DF filters can be installed into C-shaped guides or into holding frames at frontal access. These filters are not washable, replace the cells once having reached a resistance of 200 Pa.