What can I do about this air gap when my window is open? This is a very old apartment and the windows are garbage; probably over 100 years old since it's a renovated factory.
I want to get air circulating in my apartment but I also want to keep out any tiny flying invaders.
I am currently using packing tape to seal the gap but I have to remove it every time I want to close the window.
There is probably another gap at the top that I can't reach. These windows don't seal well at all and are even dry rotting in some places.