The ARC-14S performs relatively well in expert tests, and user feedback is better than for many other portable ACs. It's decently featured too, with self-evaporation so there's no need to empty moisture unless humidity is high; a remote; 24 hour timer and more. A single-hose portable air condition exhausts hot air to the outside, but draws air to be cooled from the room itself. However, as experts at TheSweethome.com, YourBestDigs.com and elsewhere point out, this produces a negative pressure that actually draws warm air into the room through doors, around windows, etc., reducing efficiency.