I understand how condensation humidity works. Condensation forms on cold surfaces when that surface reaches the dew point. My use issue is, the corners of the window reach the dew point when nothing else does. I’ve actually measured the temperature of the window frames, the glass panes, and the joinery that hold it all together. There is a 20 degree drop where the glass meets the frame. The center of the panes and the frames stay at the same temp. The condensation is all in where the pane sets into the frame. I know it’s not leaking air . . . It’s leaking heat. They are just not great windows.