Exterior wall air vents

Hello, we are being offered a ventilation system or flush-mounted external wall air vents in the exhaust rooms by a construction company. Is this legally required (according to the state building code) and is it sensible?! Fresh air should flow in due to the resulting negative pressure... but what about the heat loss of the house if I have air vents everywhere?!

Hello,

...Is this legally required (according to the state building code) and is it sensible?!

According to the state building code, ventilation systems are only required in interior windowless rooms (bathrooms, toilets).

...Due to the resulting negative pressure, fresh air should flow in... but what about the heat loss of the house if I have air vents everywhere?!

If you have air vents everywhere, a central system with heat recovery would be more advisable.
It is important that the planned air volumes are taken into account in the heating load calculation. Otherwise, there can be unpleasant surprises.
Best regards

Who can advise me?

Well, everywhere might be an exaggeration. The air vents are planned in the exhaust rooms, kitchen, guest WC, bathroom, utility room. The room air is intended to be continuously renewed this way. Who does such a heating load calculation? And whom can I contact to check if the planned air-water heat pump is the right one?!?

Hello,

..Well, everywhere might be an exaggeration. The air outlets are planned in the exhaust rooms, kitchen, guest WC, bathroom, utility room.

So after all, a normal controlled residential ventilation system. Usually, the supply air is also delivered to the individual (supply air) rooms via ducts from the ventilation center. "Peppering" the building with numerous supply air openings is somewhat unusual.

..Who does such a heating load calculation? And who can I contact to check if the planned air-water heat pump is the right one?!?

Me, for example. For this, send me an email or private message.

Regards

That is not unusual, but completely normal with a decentralized controlled residential ventilation system.

Hello,

Das ist nicht sonderlich, sondern ganz normal bei einer dezentralen Kontrollierte-Wohnraumlüftung.

Correct, that is exactly the problem!

Kind regards