This is a VERY powerful 12K BTU window unit that I installed (through the wall) in my 12X14 bedroom, as I did not want to give up the only outside window I had. Previously I ran a smaller unit (that I gave to a friend) in the window for a year,  and a 12K portable that I ran for a few years. The Commercial Cool had very high ratings no matter where I researched it. My temperature outside in the shade as I write this review is 121 deg. and the unit not only keeps my room around 80 degrees, but helps supplement my 15K unit for the rest of the house,  that does not quite get the job done in this kind of heat. I am replacing the 15K unit with a 28K 230 volt unit that requires additional work to install. While 80 degrees may sound hot to some, when it is typically 110-120 deg. outside for three to four months out of the year, it is HEAVEN.