We have windows that open side to side (vertically) instead of the standard up and down ones (horizontal) so we needed a unit that would allow us to use our bedroom window. This unit is great because it came with a window kit that we were able to adjust to fit perfectly in our window. Not only does it fit well, but it also cools down our room (which is on the 2nd floor) really well. We thought 8000 BTU may be too much, but we have a larger bedroom and it's just right. Honestly, works just as good as a window a.c unit...couldn't tell the difference. We haven't emptied the water in the unit yet or received our first electric bill, but we are very happy with this purchase. Highly recommend it!