One of the windows in my new apartment has moisture between the surfaces of the lower pane. There appears to be a lot of water in there -- enough to form a film over nearly the entire pane, which is thick enough to interfere with the view outside.
I researched this and learned that the moisture is caused by a leak in the sealed space between the surfaces, which has allowed the insulating gas to escape and water vapor to enter. The only solution to this is supposed to be to replace the pane.
My research did not tell me what to do if I'm renting and the required replacement must be done by the landlord. I have spoken to the property manager about this, but she evidently has never encountered the situation before, and has no idea how serious it is. Come to that, neither do I. What is it, really: a mere nuisance, or a potentially serious failure?
I assume that any problems caused by the moisture will appear in the winter. I'm in Chicago, where temperatures are mostly below freezing for about three months, and annual minimums of about -15°F are common.