New construction + exhaust heat pump according to the builder, is a trench collector affordable?

Still living in a rented apartment

Where is the difference compared to owning a house? You are wasting energy.

b) despite controlled residential ventilation, I cannot imagine that the air in the bedroom is cool enough (but this is a personal assumption)

That is a personal perception. Whether with or without controlled residential ventilation, the air in a new building has a similar temperature everywhere. However, with controlled residential ventilation, you always have fresh air. You also don’t have to sleep at 10 degrees in the bedroom; 20 degrees works just as well.

Some prefer it cooler - so either the air conditioning on or the window open. Some also like the natural sounds

Hello,

what about the noises of a controlled residential ventilation system? Do you hear the ventilation all the time and how loud is it in the room where it is located?

Best regards
Sabine

Normally, you cannot hear the ventilation of a central system in the normal setting - in ABSOLUTE silence and with good hearing, you may possibly perceive a very slight noise. The device itself is audible and should be placed in a separate non-living space.

Hello,

how is it actually with the noises of a controlled residential ventilation system? Do you hear the ventilation all the time and how loud is it in the room where it is located?

Best regards
Sabine

If the house is completely silent, you can perceive a very slight air noise. However, this only works for us at night and when the dog is not snorting. Otherwise, you do not notice the controlled residential ventilation system.
It gets louder, for example, at full power when we, for instance, do raclette. But then you want a high ventilation performance anyway.

P.S. The device itself already makes noticeable noises, so it should be placed, for example, near the heating system or in the house connection room, in the basement, or in the attic.