Ventilation system in single-family house without effect = planning error?

Sounds basically not wrong. The filter in the device is not certified, so what? Filter = resistance, the fan doesn't care whether the part is certified or not. Something else: The filters, whether in the device or on the exhaust valves – do you replace them regularly?

It's about the dust in the ducts – he said it could be (but doesn't have to be) that they are not effective enough to filter out all the dust. In combination with the airflow, dust could form/accumulate. Yes, I change them almost monthly because after one month here in the new development area they are already heavily darkened. Back then, the installer gave me a roll of fleece.

There should be no dust or only minimal dust in the ducts. Were all the openings sealed during the construction phase? When was the [Kontrollierte-Wohnraumlüftung] installed? When was it put into operation?

There should be no dust at all or only minimal in the ducts.
Were all openings sealed during the construction phase?
When was the controlled residential ventilation system installed?
When was it put into operation?

Yes, during the construction phase 2017/2018 they were sealed. The controlled residential ventilation system was installed at the end of 2018 and put into operation at the beginning of 2019, because we still had a few tasks pending that would cause dirt.

There shouldn’t be any dirt in there at all! Opened ours after 2 years: there is nothing.

There shouldn't be any dirt in there at all! I opened ours after 2 years: there's nothing.

Yes, that's how I would have expected it too - unfortunately, there are very clear dust deposits around the outlet valves.

On February 18th, we have an appointment with a Wolf field service technician, who initially could not detect any major flaws in the system from a distance. I'm curious about that.

Yesterday the Netatmo climate measuring device arrived and I have to say, I'm a bit surprised: according to the device, the air in our place at night is good to excellent (1100-900 ppm CO2 at night and in the morning, when the system is running, at 600-700 ppm). Now, when no one is in the room but the ventilation system is clearly audible (at 190 m³/h), the value is currently about 450 m³/h, which would actually be sensationally good. The device is on my nightstand, which is far away from the door. (The zero value was a brief power outage)



I wouldn't say the air is very stuffy at the moment, but I wouldn't claim that it's particularly good either. Of course, this is purely subjective...
Are we maybe expecting too much from the system!? I also think that the air is significantly worse in summer than it is now in winter. Of course, I can't really test that now.

Do you still have things in the house that might be off-gassing? New furniture, for example? Some things do emit a certain inherent odor. Have you measured the humidity in the room? In the bathrooms, for example, we still ventilate quite strongly manually after showering or bathing, otherwise the whole vapor drifts into the bedroom and lingers there noticeably. What about cooking odors?

We have a similar device (Wolf CWL 400) and are satisfied. What surely plays a role for you is that the valves on the upper floor are not placed in the corners of the rooms. That should be improved.