ᐅ Where should the ventilation duct for a mechanical ventilation system be installed?

rick is right, I definitely wanted ceiling outlets, even in the flat roof. That would have required a significantly thicker construction, which in turn would have meant a thicker intermediate ceiling and foundation slab according to structural engineering. We have an additional layer of lightweight screed on the concrete ceiling of the upper floor, where the ventilation ducts are installed. Above that, there is waterproofing, insulation, and so on.

This saved a lot of weight and therefore cost, while the pipes are still located within the insulated building envelope.

There are many ways to achieve the same result.

The downside of installing on the ceiling with core drilling: just don’t hit any electrical conduit...

rick2018 schrieb:
Depending on the pipes, the ceilings sometimes need to be even thicker. And that can cause structural issues. In some cases, installing a dropped ceiling is a more practical solution. We have several different options.

You shouldn’t always assume your own “temple” as the standard. In a typical single-family home, the approach described by @neubau2019 usually applies.

Building higher means you have to do the calculations. It also depends on the type of ceilings you want.

guckuck2 schrieb:

rick is right, I definitely wanted ceiling outlets, even in the flat roof. That would have required a significantly thicker structure, which in turn would have meant a thicker intermediate ceiling and floor slab due to the structural requirements. We added a layer of lightweight screed on the concrete ceiling on the upper floor, where the ventilation system is installed. Above that, there is waterproofing, insulation, etc.
It adds a considerable amount of weight but saved money overall, and the pipes are still within the insulated building envelope.

There are many ways to achieve the same result.

Downside of installing pipes on the ceiling with core drilling: Just make sure you don’t hit any electrical conduit...

How thick would your flat roof ceiling have needed to be? We also have a flat roof, and our top floor slab is 25 cm (10 inches) thick, with the mechanical ventilation system pipes embedded within it.

Baufie schrieb:

How thick did your ceiling have to be for the flat roof? We also have a flat roof, and in our case, the top ceiling is 25 cm (10 inches) thick, with the ducts for the mechanical ventilation system installed within it.

Yes, it needed to be more than 20 cm (8 inches). Apart from installing the mechanical ventilation ducts there, there was no other reason, so the additional costs were not justified. Every centimeter of reinforced concrete costs several hundred euros, especially since it would have affected not only the ceiling but also the building elements below.

The pipes were installed under the screed in our house. No one asked about it (and to be honest, we hadn’t really thought about it) ... The inspector didn’t mention anything either.