with / without central ventilation system experiences

So we, 125 sqm built in 2018 without [Kontrollierte-Wohnraumlüftung], timber frame, triple-glazed with window rebate ventilation, cannot complain either. We ventilate in the morning and evening, the bedroom is tilted open at night because we like it, no musty air, no mold, nothing. Gas consumption 550 sqm per year, everywhere 23 degrees, except bedroom, bathroom 24. We don’t need [Kontrollierte-Wohnraumlüftung].

In 2022, the question of "building with/without a ventilation system?" in my opinion no longer arises.

We have a controlled residential ventilation system in the solid construction from 2020 that we are currently selling, and one of the main reasons why we want to build again at the new place instead of buying an existing property is that we would like to have one again. I like the freedom of simply having nothing to do with ventilation and feeling good about it. I can open windows, but I don’t have to. Controlled residential ventilation takes care of everything. Even after showering/bathing if you make a point of it. I also enjoy how quickly my laundry dries in the utility room with the exhaust air there. That’s amazing. At one point I was visiting family, hand-washed some clothes there, hung them up in the boiler room, and was shocked the next day at how wet they still were. You get used to the controlled residential ventilation luxury so quickly. My husband and I are both allergy sufferers and our system has a pollen filter in it. That, combined with our laziness to ventilate manually, ensures a pleasantly pollen-free sleep. However, it always knocks us out of our socks when we go outside and get hit with the full blast of pollen – but that’s not the fault of the controlled residential ventilation. ;)

Thanks for all your experiences on this! Are there people who have installed one and regret it? :) You do get the impression that those who have a ventilation system really appreciate it. And the others either belong to the passionate window-opening faction or don't know it any other way :D I mean, if you like to ventilate a lot anyway, cross-ventilation might be okay, but I find it really annoying especially in the morning before work and also in the evening when you're getting comfortable, especially when it's cold outside (which is why we don't do it regularly anymore…). Or when you hang laundry in the room and the humidity rises so much that you have to open windows more often. Of course, it's also nice to open windows when you want to hear birds or smell the air outside, but only according to your own desire and mood.. And if the operating costs versus heating savings break even, how are the maintenance costs otherwise? Do you have to buy new filters often or is it enough to regularly clean the existing filters?

And if the operating costs vs. heater savings balance out to zero, what about the maintenance costs? Do you have to buy new filters frequently or is it enough to clean the existing filters regularly?

Cleaning the filters probably doesn’t work. I tried with compressed air, then washing them out. The success was so-so that I gave up. My controlled residential ventilation manufacturer recommends changing them every six months; for 2 filters (1x G4, 1x F7) that’s about €50. We will also install a filter mat in the outside air (against pollen and "coarse" dirt). It could be that this extends the interval.

In a completely different context, someone told me that you can probably clean filters well in a regular dishwasher. However, I have not tried it yet (and this is not a recommendation from me).