Thank you for tackling the puzzle with me.

The air conditioners are 9300 BTU and although the apartment is only 530 sf, these two units do very little to cool things even when I had one replaced.

They don't overhang as they are encased in interior hinged housings that are 2 feet high, 2 feet deep and four feet across.

I've found that if they run for more than four hours, that ice forms and then that eventually drips onto my floors.

The landlord won't allow ceiling fans even though the ceilings are a shade underneath ten feet tall.

Perhaps I should get a powerful fan and blast it toward the center of the room. Would a dehumidifier be practical as well?

The windows all face on way and since they basically open up into the shaft of a 20 foot by 20 foot chimney, there's nothing to look out at and no current of air to speak of.

I will definitely investigate window film kits.

The two windows are 6 feet high and 4 feet across.

There also appears to be some sort of underfloor leak as we had to replace the floorboards last summer when they rose and broke apart even though the landlord insisted that it was incidental and from a kitchen leak.

Being that the windows are single paned, I don't know what I can do to better insulate. Upon looking into the air conditioning unit housings, I don't see any daylight or sense any direct temperature input from outside, but is there perhaps a way for me to better insulate that?