Window rebate ventilation or controlled supply and exhaust ventilation?

We also have window rebate ventilators with exhaust fans in bathrooms and the utility room. Apart from the bathroom, you cannot hear them at all, there are no problems with wind or even mold, the heating costs (with air-to-water heat pump) are so low at €50/month that heat recovery would never have been worthwhile. There are no maintenance costs; I would need to determine the electricity costs for the fans...

However, in our case, the price (self-contracting with an architect) for a central controlled residential ventilation system was also overall, across all involved trades, over €20,000. And since the architect was very precise in all his estimates, I assume that this would have been the case as well. For our decentralized ventilation, we have now paid around €2,000. Since money was tight, that was also part of the discussion.

In short: We would do it again.

Edit: I’ll add that it is mainly irony before the first ones here start hyperventilating and having cardiac arrests again.

Wrong: the second ones - that is quality! Originally brewed, where mommy usually only ...

Why irony...is the true truth...

The controlled residential ventilation is mostly comfort. I think highly of it when it is financially feasible.

Financially, controlled residential ventilation hardly pays off, but regardless of mold formation, the air in the new building quickly becomes stuffy when rooms are closed. We recently experienced this with four adults and four children in a 70m2 living room—after one hour you could cut the air with a knife, so the window had to be opened. All of this is possible, but it is a matter of comfort and must be feasible in terms of price. With another energy saving regulation, it probably won't be possible without it anymore and it will become standard, then owning a car without power steering—so it is also a question of maintaining value.

We recently had this with four adults and four children in a 70m2 living room – after an hour you could cut the air with a knife, so the window had to be opened.

Even though I like to take the side of "analog" ventilation: here the controlled residential ventilation system cannot be blamed – it would have to adjust automatically via sensors if an increase in the number of air consumers should not be noticeable. Of course, the air exchange rate must then be adjusted, gladly also through "analog ventilation".