Controlled residential ventilation: How to lay pipes?

Hello everyone.

We have just finished the shell (still without floor construction). Somehow our architect messed up embedding the pipes for the controlled residential ventilation in the concrete ceiling, as we had actually wanted.
Now our construction company has suggested suspending the ceiling and installing the pipes below the ceiling. That way, it would probably also be accessible if a pipe breaks. However, we’re not so keen on suspending the ceiling.
As an alternative, the ventilation pipes could also be installed in the floor construction, directly together with the underfloor heating, but this still needs to be discussed with the heating engineer.
What do you think would be the better option? How important is it to have access to the pipes?

Thanks in advance

How much floor construction height do you have, do the controlled residential ventilation pipes or flat ducts still fit in there at all? I would probably also lower the ceiling, but if possible try to lower it as little as possible, maybe it is possible to realize the distribution with wall valves over the hallway.

Planned were 15cm, if it doesn't fit, you can go up to 20cm. We only have a classic hallway in the attic (1.5-story building), on the ground floor we only have an entrance hall. But how is, for example, the middle of the living room to be reached from the hall? It must be done either from the floor or from the ceiling anyway. Another question: Is it better for the air to enter the living space from above or rather from below?

Be grateful to the architect first of all that he "messed it up." Such things should not be embedded. Actually, not even in the floor structure, but it may now be easiest to accommodate it there without major additional costs. Who else is going to bear the costs for the suspended ceiling and the possibly resulting lower room height due to the suspension construction... with everything that goes with it? Plan flat ducts and the crossing points well. With all the trades that will be working around there... So electrician, sanitary solderer, and ventilation builder at one table. And get started on the screed standard so you can immediately put a stop to them not adequately covering crossing points with impact sound insulation at specific points...

Unfortunately, due to various circumstances, I have to cover all further costs myself. So it is important to keep the installation cost-effective. Nevertheless, my primary concern is "practicality." How are the ventilation ducts and ventilation outlets usually installed? In the ceiling or in the floor?

Hello!

In our house, the supply air ducts are installed in the floor.
The system is called "proKlima" and the supply air flows around the underfloor heating to a certain extent. This way, the air is preheated when it flows into the room in front of the windows.
The exhaust air is classically extracted from the ceiling.

I have seen a similar system at our neighbor's. There, too, the supply air comes from the floor.

Is the system good?
Please ask me in spring 2014 - then I can give you a first assessment

Best regards
Micha