New construction: Floor structure / ceiling thicknesses for controlled residential ventilation piping

Good evening,

we are building a house (are in the preliminary design phase) and I am currently stuck clarifying between the architect (who has never installed a controlled residential ventilation system - but is otherwise great) and the heating engineer and have a comprehension problem regarding the floor construction with controlled residential ventilation:

As I understood the heating engineer there are 3 options:

Option 1 is: With a 20cm concrete ceiling, the 63mm pipe disappears completely in the concrete ceiling. On top of that comes a 15cm build-up as planned by the architect. Impact sound insulation, underfloor heating, etc.

Option 2 is concrete ceiling (20cm) and then in the 20cm above (instead of the planned 15cm build-up) 63mm pipes, plus underfloor heating, etc.

Option 3: too expensive because flat ducts = not doing that.

Or are option 1 and 2 the same and I definitely need 20cm concrete ceiling + 20cm build-up...

Additional question/note: At the end of the day, it is advisable in the ground floor with the large rooms anyway to increase the floor-to-floor height (top of floor to top of floor) to 275 and be on the safe side...

Thank you very much

Variant 1 is probably the most commonly done. Just make sure there is enough coverage here and, if necessary, add a little more reinforcement.

Variant 2 is also possible; here you depend on sufficient ceiling height.

Variant 3 is IMHO the most elegant but yes, more expensive.

There would also be Variant 4 where the ceiling is suspended and Variant 5 where everything is distributed over the attic (here, however, insulated).

Do you have 2 reinforced concrete ceilings or just one? Possibly you also have to combine variants, for example V1 for ventilation ground floor and V3 for upper floor. Better 75 pipes than 63 pipes. The flexible pipes are also available flat, so V3 is hardly more expensive than the 2 with appropriate proper planning.

With proper planning, flat ducts (sheet metal) can sometimes even be cheaper, because many things are omitted, such as large air distributors, etc.

With proper planning, flat ducts (sheet metal) can sometimes even be cheaper, because many things are omitted, such as the large air distributors, etc.

Sorry, don’t want to hijack but I have to ask briefly here, maybe it will also help the OP. To be honest, I have dealt least with our ventilation system technically, because I have the feeling that we are in good hands with our provider.

We didn’t install flat ducts but round ducts in the concrete ceiling. However, I keep reading here about air distributors that need to be placed in the ceilings, etc. There was also a thread where it was installed in a very unusual way in the floor structure. I am 99% sure that there are no air distributors in our ceiling? Now I’m just unsure because it sounds like from you that you could only do without them by using flat ducts!?

For the round flexible pipes, the distributors are usually located under the ceiling or on the wall – exactly where the pipes come out.