Wall or roof penetrations (external/supply air): how did you install them?

Hi Bortel, here are our grids - unfortunately, I just noticed that they are in the shade. But you can see that they hardly stand out..

That's right, you really have to look closely The brick and its color also help with that. Thank you

Yes, but if you powder the white, you don’t see anything either - stainless steel usually doesn’t look great in my opinion...

Yes, they should then receive facade paint. The goal is to look as inconspicuous as possible.

Hi, my controlled residential ventilation system will definitely be installed on the ground floor. Should I then do the supply/exhaust air through the roof? Or go up to the 2nd floor and have holes drilled through the walls there? Can that even be properly sealed? (KfW55 or 40 house)