How many ventilation systems?

We are considering building a house (a single-family house with two separate living units) with the parents. Living area approx. 180m².

Can we manage with one ventilation system or do I need two?

Hello,

We are considering building a house (a single-family house with two separate living units) with the parents. Living space approx. 180m². Can we manage with one ventilation system or do I need two?

How are we supposed to understand this question – what do you mean by "multiple ventilation systems"?

Kind regards

I don't exactly know what is not to understand about my question, but fine.

Do I need a ventilation system for the apartment on the ground floor and a separate one for the apartment on the upper floor, or can I run both apartments through one ventilation system?

Clearer?

Hello,

theoretically, one ventilation system is sufficient. However, since the ventilation intensity can usually be adjusted via a 3-step switch, I think it is better to have two systems. This way, the ventilation can be set separately for both apartments. Another advantage here is the possibility to operate the systems via two separate electricity meters.

Hello,

Do I need a ventilation system for the apartment on the ground floor and one of my own for the apartment upstairs, or can I run both apartments through one ventilation system?

No, the ventilation system always refers to the usage unit (NE)! One building, two apartments => two NEs => two systems!
Regulated in the ventilation concept according to DIN 1946 for residential buildings to be planned. Reason: There must be a demand adjustment per NE in order to ensure, among other things, the different ventilation levels according to 1946-6.
With only one system for two NEs, this is not ensured due to the pneumatic connection.
The ventilation concept also determines the necessary air volumes according to 1946 or 18017! These are required in the heating load calculation for sizing the heat generator.

Best regards.