Jimy3435 schrieb:
The window has two seals. One can still be seen from the outside when the window is closed, and one is located in the middle of the frame. The outer seal appears to be somewhat thicker and more robust than the one in the frame. Only the outer seal has the cut parallel to the frame, about 7cm (3 inches) long.My guess is that the window has a third seal as well, located on the sash on the interior side.profil65 schrieb:
My crystal ball says that the window also has a third seal, located in the sash on the room side.The crystal ball is correct. But what is it exactly? Is it pressure equalization or (unwanted) forced ventilation?Jimy3435 schrieb:
The crystal ball is correct. But what is it exactly? Pressure equalization or (unwanted) forced ventilation? If there are no gaps, holes, interruptions, or trickle vents (?), that could break through the central seal and the inner stop seal, it can only be pressure equalization, which has nothing to do with ventilation.
Notes:
Quite a few laypersons and "experts" do not recognize trickle vents... this is especially true for the new models from one manufacturer.
Unfortunately, trickle vents are also often installed incorrectly (i.e., not according to the manufacturer’s instructions)... for example, there may be too many or too large gasket cut-outs, or the opposite...