Compact enough to fit in my sliding window. They rate the unit a 10,000 BTU's, but I would say it operates around 8,000 BTU's. My room is 230 sq. ft., and at 93 degrees outside temp., it keep the room at only 80 degrees till it cooled down outside. I would have gave it 4 stars if it would have at least held the temp to 78 degrees. But all in all, not a bad little unit for the money.......