Here are some photos of my window installation of a 5,000 btu/hr AC unit. As you can see, it only takes up about 1/3 of the window, so you can still see out and let natural light in. It is located in the middle bedroom/closet area of the Tradewind. Therefore, if you close off the front area and the rear bathroom, I don't care how hot it gets, the ac will cool this small 40 sq ft section, in the event a small child needs to take a nap in the middle of the day. Part of the key to the design is that the ac unit is mounted on the window frame at the cg (center of gravity) of the ac unit. Therefore no external support is needed.
90% of the time we don't need AC and the unit rides in the bottom of a cabinet.
If you want more information, tap on Touringdan, tap on statistics to find the threads I have started. Then tap on the 5,000 btu/hr AC powered by a 1,000 watt Genny thread.