Position controlled residential ventilation in the underground basement?

OK. Thanks for the explanation. Since we are currently only at the point of "whether the floor plan suits us and the windows are OK," the calculation will still come.

I don't understand that currently. It still has to draw in/blow out air from outside, right?

Come on, a little imagination please

You put the controlled residential ventilation system in the basement, drill through the exterior wall (underground), and then connect a geothermal heat exchanger right away. Sure, the pipes have to go to the surface later to draw in air. But this way, you have the system in the basement and no shaft going up to the utility room to drill outwards there.

Where the heat exchanger then gets its air from can definitely be explained in more detail by someone who is an experienced user here. It was just a thought since you want to put the controlled residential ventilation system in the basement.

OK. At first it sounded like he would then "draw the air from the earth," and I lacked the imagination for that.

@Euro: Today we received an energy saving certificate with 21 pages full of numbers, tables, and diagrams.

Is that what you meant?

..Is that what you meant?

No, this is merely the proof of the admissibility of the construction project according to the Energy Saving Ordinance or to achieve a specific efficiency level of the KfW for obtaining funding. The results from the proofs cannot be used to size a heating system, nor to derive a reliable assessment of the expected consumption. This is neither intended by the legislator nor even permissible (scope of DIN 4701-10!).

Regards