Central ventilation system - Required sensors, intelligent control

Hello everyone! On video platforms, you can find promotional videos for a centrally controlled ventilation system that can be controlled individually room by room. There are modes such as Abwesend-Modus, Urlaubsmodus (almost no ventilation), Partymodus (full throttle in the living room, bathroom, and kitchen), or Kaminmodus (more supply air so the fireplace works better). But my question to experienced ventilation system operators is: 1. Does it make sense for the system to control each room individually and to have various programmable modes? 2. To what extent does "intelligent control" increase the investment costs for such a system? I’d need a cable from each sensor to the control center... Should I expect an additional 10K? 3. Which sensors in certain rooms have proven useful? That is, is a humidity, CO2, or temperature sensor recommended in every room? 4. The display: A small display in each room or just an app on the smartphone (if that exists)? These are many questions at once, but I would be happy if someone could comment on one or more of them. It doesn’t have to be all at once or today.

I consider it a gimmick without real benefit. The question is rather which actuators or servo motors are used?

If I understood correctly, actuators are control units that are directly connected to the fans and linked to the central control via (KNX? radio?) bus. They are then installed hidden somewhere, either at the fan or nearby.

Do you mean by "what kind of actuators or actuating motors" the brand/quality of the same or a specific type?

We always ran our last controlled residential ventilation in one mode: good air, not audible.

When we were away for a long time, we turned it down one level using the switch.
And when guests came and the room was full, one level up.
Neither was really necessary.

1. From a certain house size onwards, certainly, but in a typical single-family house rarely necessary. The different modes can also be handled by any standard controlled residential ventilation system without individual room control.

2. Um, nothing specific can be said here, as there are too many variables. But roughly speaking, you are looking at around €500 per room for the extra technology plus installation.

3. Individual sensors are of no use. A concept must be developed and then followed. But to answer the question: humidity, CO2, VOC sensors, and smoke detectors have proven themselves in relation to ventilation systems.

4. It depends on what you want to do with the displayed data. To satisfy pure playfulness, any visualization on any device is sufficient. Having one in every room might be over the top.

The system is supposed to operate quietly in the background without disturbing the occupants.

Mycraft, rarely do I see such clear and structured posts as yours. Thank you very much!