Is a central ventilation system absolutely necessary?

What now? Clean the filters at the exhaust vents once a week? All of them? Seriously?
Then I would just be running around all the time? Why is that?

Dust and more dust. It was better in winter, but now people ventilate at night or the patio door is open.
Main road, agricultural traffic, everything dry and dusty, construction site in my own garden, construction site opposite,
construction site behind the house.
Ask how my windows look. I've never had windows this dirty and I've never cleaned so many windows.
It's not because of the ventilation, but simply because of the surroundings.

Cleaning the filters doesn't cost much work or time. I get through them all in 10 minutes.
The supply air filter in the ventilation system is relatively normally soiled, but it hardly runs at the moment, at most at night and very early in the morning.

Oh, well then that's no wonder. I was just wondering where all the dirt was coming from when the fresh air intake is filtered^^ So if you use the system as intended (i.e. not leaving the windows open, etc.) you don't have the problem as badly. Good, because otherwise it would be like that here (allergy sufferers, house cats, warmer outside than inside, etc.).

Thank you!

We are already using the system as intended.
A ventilation system does not mean you have to seal yourself in to use it "correctly." It switches on and off automatically with the summer program.
With children, the balcony door is never fully closed, and I also leave the door open sometimes when I have to go out "quickly."
Whether you need to ventilate at night or not is debatable. My daughter and I prefer cool temperatures, and mechanical ventilation cools faster and more at night.
Especially the terrace door at the back of the house, where a vegetated north-facing slope rises, it still brings in cool air now at 11 PM, while the system still draws in warm stuff.

For you as an allergy sufferer
Pollen in the spring was surprisingly low in the house. Ignoring the supply air filter this time.

Mottenhausen

How high is the residual heat that remains?
With us, cold air comes out with about 90 or 95% (I don’t remember exactly) heat recovery.
It is also the question whether it is permitted. Not that somewhere a regulation states that exhaust air is not allowed in enclosed spaces.

So if you use the system as intended (i.e., not leaving the windows open, etc.) you don't have the problem so intensely. Good, because it would be like that here (allergic, house cats, warmer outside than inside, etc.). Thanks!

Even with summer bypass, such a system does not have a huge air exchange. If you want it colder, it helps a lot more to just open the windows. The argument from controlled residential ventilation opponents that you’re not allowed to open windows is just nonsense; you can open them anytime, but you just don’t have to when it’s cold outside. We also don’t do the weekly filter cleaning; I vacuum it every 2-3 weeks when I’m vacuuming anyway, and every 3-4 months they are replaced.

Sorry, that might have come across wrong. We meant the same thing, it was not supposed to be a reproach. For us, it will basically be that the place stays closed and the air conditioning comes on when heat is needed. That way, my cats don’t run away, the flying bugs stay outside, and the humid pollen-laden air stays out too. If the filters also stay fresh longer because you only have the dust you bring in yourself, it’s a win-win for me and I need a device like that! Regarding cleaning: I found an Austrian study that really breaks down the topic in detail. It recommends round spiral-joint ducts ≥125mm and sufficient inspection openings. Is that still current? I would feel better if you could inspect and clean it yourself, since I am also a mild asthmatic and you never know if there might be a floor change at some point (floor change -> worsening) But is it even practical to get such thick ducts under with cleaning openings?