I was doing a job yesterday. On the outer glass, it is obviously tinted. The windows are big and older. I noticed some white over spray on them. Obviously I know not to scrape them. This was the first time I cleaned them and is going to be an every two week account for me.
Is this factory tinted glass, or is there film applied to the exterior window? Film applied to the exterior of buildings is rare, but not unheard of. Exterior film is most often thicker and applied for security reasons more so than solar protection.
You should be able to look around the edges of each pane and see a very small gap if its exterior film. (If it was installed correctly). If not, than maybe its factory tint and you should be able to scape.