It will cool one large room well. I’m not sure about the word “portable” because you MUST have a window for the exhaust tube (The window fit is reminiscent of regular window air-conditioning units, except this unit sits on the floor with a clothes-dryer-type hose that hangs out of the window. It comes with plastic spacers that block out the rest of the open window space.) I envisioned taking it from room to room — wherever I currently needed it. I suppose I could, but I’d have to go through that entire window set up, and that seems like too much (especially when I’m hot, sweaty, and cranky). It works very well!