We bought this air conditioner about a month ago. We've suffered trhough a lot of heat waves thinking we could never get an air conditioner for our vertical sliding windows. But this one works great and was pretty easy to install. The bedroom is on the second floor so we were a bit concerned about the installation but it turned out to be pretty simple. the unit isn't that heavy so two people can easily lift it into place. it cools 350 square feet very quickly and effectively. I'd give this unit two thumbs up!