Ventilation in new buildings (central vs. decentralized), noise disturbance

Damn, so I would have just needed to install a lot more multimedia and could have saved myself a normal heat generator

Well, a computer gaming easily consumes 350 watts and when the projector + system are running during a movie, that uses even more electricity.

is really like that, because an open window simply creates more airflow. We also fell for the misconception that the ventilation system cools the house in summer. The ventilation system is meant to reduce the need for ventilation in winter and to prevent mold-prone humidity.

I also endorse the statement. Completely correct.

Otherwise, the device would be called an air conditioning system.

But it is "only" a controlled residential ventilation system.....as enormously good and valuable as it is, it does not make things colder....it can only normally make things warmer. And even with cooling options (expensive): folks, that NEVER replaces an air conditioning system. Never. It doesn't work. If you want active cooling, you have to install an air conditioning system *in addition*.

In summer (which I mostly lost somewhere in 2016, but when there is summer, so not 2016) we turn off the controlled residential ventilation. Or only set it to exhaust. In any case, we are old enough to remember: The house has many windows, you can open them!!!
Summer bypass on controlled residential ventilation: completely pointless waste of money. As I already wrote elsewhere here. Set to exhaust / open windows. Same effect.

PS: On 08/11 (AUGUST) and 08/12 I had to turn on the heating. At night under 6 degrees. During the day barely over 10.
The days where I would need an air conditioner here: <10/year (2016: 0.00000 days/year).
The controlled residential ventilation helps 75-80%, with the weather in NRW it is almost always needed.

We have the ventilation system running at level 1 even now in summer because of the new building (1 year old). This way, every room gets fresh air repeatedly.

What you really must not forget when planning: the ventilation system does not really cool in summer. Roller shutters prevent ventilation through windows. Two people can heat a room in a newly built house through their radiant heat. Cooled down to 18°C in the evening, 22°C in the morning with tilted windows, roller shutters down, and ventilation at 2/3. And without a mosquito net, you might also get a few roommates (they like to come in at the edge of the roller shutter). Things to consider when planning. A real air conditioning system for the whole house hardly makes sense. If you absolutely want one later, 1-2 rooms will probably be enough and open interior doors. (For example, placed in the utility room, blowing cold air into the central hallway.) In the bedroom, you will definitely get sick from air conditioning.

You definitely won't get sick from that...

We have prepared the climate control in the house for four rooms - all bedrooms plus the living-dining room.

Climate control pipes, condensate drain, and electrical - all nicely concealed and waiting to be connected. It didn't cost even 500 euros...

Active cooling cannot open a window either.

However, active cooling is not possible with an open window either.

Unfortunately not, otherwise leaving the window open would be a viable business model. Especially for freezer companies or in hot regions... just kidding.

But if, for example, it is 26 degrees inside the house and the outside cools down to 19-21 degrees at night: the air flowing in from outside does "cool" somewhat.