I bought this to put in a window that only opens 12 inches. I had to remove the bottom sash to fit the unit in. Once installed, it only takes up 4 inches in height and the bottom sash went back in no problem. Bonus, it's super quiet and we don't need to crank the TV to hear it. This is installed in a room that's about 250 sqft and keeps the room comfortable, not super cold, even when outside temps are in the 90s.