More on the Saga to inform you no doubt:
In Germany, windows do not have screens. They tilt in or they act kinda like doors when you twist the handle, but they do not have screens.
To compensate for no screens the window coverings are usually sheer lace curtains to keep the flies out. D@** Flies, Auf Deutsch"Fleigers."
In the Summer, if one is smart, one uses the rolladens, a form of armour for windows, to darken the room and also to provide some airflow with the window fully open. There is a fabric strap on the side of the window, one the wall, kinda like a tie-down strap feel to it, that one pulls up or down. This raises or lowers the rolladens.
In Germany there is no air conditioning. Usually air conditioning is not needed.
But sometimes it is. Especially if one is peri-menopausal and ready to become a screaming "biotch" cause there isn't a ceiling fan in sight and a personal Summer hits.