Do I dare drill here?

[pozz2]

I am going to install a fresh air vent and need to drill a 110mm hole. I want it above the windows, but the question is whether I dare to drill such a large hole without affecting the load-bearing capacity. Four windows with a total width of 4 meters, above which there are 30 cm, lightweight concrete walls or similar. Should I just go ahead or should I find another placement?

 

[KnockOnWood]

It sounds like you want to make 100 mm holes in the beam that supports the upper floor.
Intuitively feels a bit risky.

Can't you make slot vents in the window frames?

 

[Fotografen]

There is either a reinforced concrete beam or a steel beam above the windows. I wouldn't drill there.

 

[pozz2]

No upstairs, but I took the hole next to it instead to be on the safe side.