Ventilation system filter mat experiences

One more question about the ventilation system, I haven't found anything on this topic in the forum yet.

Depending on whom you ask, the air filters should be replaced every 3-12 months. Some say every 12 months and vacuum in between every four weeks, others recommend replacing every 3 months.

Original filters from the manufacturer of the ventilation system are outrageously overpriced, the only advantage seems to be the pre-cut size.

Filter mats in the corresponding grade are available in many places online. These are much cheaper, you just have to cut the mats yourself.

For our Wolf ventilation system (Wolf CWL-300 with bypass), for example, we need a size of 500mm x 237mm x 17mm.

Online it costs around €20 as an original part (item number 1668494), two pieces are included. That results in a price per square meter of about €84. Quite a sum...

If you google a bit, you can easily find prices at a fraction of that, prices of €8 to €15 per square meter are a completely different magnitude.

This note in a shop sounds interesting:

[...]
The mat has a progressive
depth structure. That is, the fiber density changes across the cross-section:
Mount the
denser filter side towards the clean pipe side, the somewhat coarser
side towards the air source. The depth structure has the advantage that coarser particles
are caught on the outside and the mat does not clog as quickly. The service life
is correspondingly extended.
Technical data: shatterproof polyester fibers silicon-free flame-retardant according to DIN 53438 F1 tested according to DIN 24185 or DIN EN 779 Filter quality class according to
prEN779 - G4 (EU4) Weight - 220 g/m² Color white
[...]

Does anyone know about this? Is this actually better?

Best regards
Baltic Sea

I am bringing up the topic again, who uses which filters.

Currently, the g4 for 2x1m is available for 15 euros at Ama..

Has anyone already had warranty issues because they did not buy the mats from the manufacturer?

Where do you buy yours and which ones do you use.

So far, we have cleaned our filters monthly. However, I also have to start looking around gradually.

When I moved in, I bought 2sqm of filter mat G4 if I’m not mistaken... I estimate it will last another year... most systems notify you when they want a new mat...