Technical room in the attic, problems with soundproofing?

But that definitely does not replace the controlled residential ventilation for you, and that is - back to topic - in my experience also the loudest sound source mentioned here, especially since it runs continuously. We have a concrete ceiling and the controlled residential ventilation in the attic, mounted decoupled on a specially built KS wall for that purpose. Acoustically it's okay - especially when it runs at a low level at night - but it's not really great.

The vast majority of people I know who are somehow involved with house construction and building services find ventilation systems absolutely terrible; they want to ventilate normally by opening the windows. I even know many people who sleep with a tilted window open in winter, which is really not good from a building physics perspective, but then you might as well skip installing the [controlled residential ventilation system]. I would discuss something like that in advance with all family members.

That was the same with my partner. At first totally enthusiastic about the idea of [Kontrollierte-Wohnraumlüftung] (especially because of the allegedly possible cooling function in summer). When she then found out that it is not really sensible to leave the bedroom window open all night, it was no longer attractive (putting the price aside). Dry air in winter even less so. We are now planning without [Kontrollierte-Wohnraumlüftung].

These are hanging on a wall made of tongue-and-groove boards that I built between 2 roof beams.

Something homemade for the condensing boiler? Has your installer and network operator seen it? Especially the latter are picky about the installation situation of gas boilers. How do both comment on accessibility? Out of interest: How do we run the gas line from the house entry point to the condensing boiler in compliance with regulations? What does the insurance say about this type of installation regarding water damage? Do the buffer storage and expansion vessel have a drip tray? How is the heating make-up water handled, fixed water connection in the attic?

Initially totally enthusiastic about the idea of controlled residential ventilation (especially because of the supposedly possible cooling function in summer).

Cooling in summer is also possible with the heating system if the heat pump is operating in reverse mode. Even then, it is probably advantageous not to lie the heating pipes in the screed but in the exterior walls. Has anyone read the book by Albert Ringlstetter? He comments on this very extensively.

Uh oh, now there is some dangerous half-knowledge being argued here. Even with [Kontrollierte-Wohnraumlüftung], you can ventilate however you like. Permanent tilt ventilation doesn't make sense because it causes a lot of energy (heat) to be lost. But that has nothing to do with the ventilation system. For us, there is nothing better than [Kontrollierte-Wohnraumlüftung]. Always fresh air (which cannot be achieved in new buildings just by ventilating), especially very pleasant during pollen season. Dry air occurs in winter (or right now) with and without [Kontrollierte-Wohnraumlüftung]. Advantage of [Kontrollierte-Wohnraumlüftung]: thanks to the enthalpy exchanger, it can "recover" moisture.