Question about everyday life with a controlled residential ventilation system

The cooling is actually done through the underfloor heating. However, a very strong cooling effect should not be expected here. If it is set too cold, a condensation water problem occurs on the floor. The air flow from a [Kontrollierte-Wohnraumlüftung] is also too low to achieve significant cooling effects. So do not confuse it with a "real" air conditioning system.

Will it change because of an open window? Nothing changes at the air outlet in the bedroom, the next extraction (bathroom?) possibly pulls in wrong air through the open window. The pressure loss over the filter in the intake line acts directly on the fan, yes. But just an open window should hardly affect the pressure at the supply air outlet or exhaust valve. Am I overlooking something?

Just consider the entire house as a closed system. Then the question should be answered.

If the system gives full power for 10 minutes when pressing a button (and that several times a day), what is better about that than an open window throughout the night with the supposedly so strong impact on the very sensitive setting of the system?

Exactly! With a "full throttle button" you increase the input and output values at the system. With an open window, a disturbance factor enters the system that lasts for hours.

Do you notice the difference?

Don’t talk about given parameters – normally you can adjust EVERYTHING in the settings, since no automation monitors anything.

Exactly! You can set everything, but afterwards the automation in the system does take over monitoring the values. Because for example, as soon as you turn on the system, the filters start to get dirty. They are not suddenly full but gradually, and over this time the volume flows must be maintained according to the set parameters, otherwise the system would not bring the desired effect and every user would be dissatisfied.

What happens now because of an open window? An exhaust hood or something similar? I think you can figure that out.

Do you have CO2 and humidity sensors in every room? So that the airflow automatically increases when you bathe or 15 people visit, or stops when the house is empty?

I have CO2 sensors at strategic points and also one directly in the system. This way the system is continuously ramped up or down via the sensors.

What do you think the bearings of the system say if it is constantly driven back and forth? And yes, this is a completely serious contribution - you do not generate anything else with your sensors according to your understanding.

you guys are really making a science out of it. Just set the ventilator to the normal setting and the system to manual. Whether I open a window or not doesn't matter at all. Of course, the ventilation system is tricked by this (in an extracting room like the bathroom, it sucks some of the air from the window directly back out // in a blowing room some of the air goes back out through the window), but that's it. The other rooms still work exactly as before. Neither does the filter get dirty from this, nor does any part of the system break or anything else. As soon as I close the window again, the disturbance for the system is immediately gone and it runs as set.

Leaving the window tilted open for a long time makes no sense, because THAT is EXACTLY the reason for the ventilation system’s existence.

What do you think the bearings of the system say when it is constantly driven back and forth? And yes, this is a completely serious comment - you don't generate anything else with your sensors according to your understanding.

Unfortunately, you still haven't understood it, but it doesn't matter to me; the topic is over for me. I have explained here how the systems work, the users have to decide for themselves what they want to do.

Apparently just as little as you - but sure, let's drop it.