With a single hose portable unit, the nice cold air that you feel coming out the front is also being used to cool the hot condenser down in the back of the unit (the heat that you feel going through that single hose). Now this is where it makes the unit useless! The unit is taking the same cold air from inside the room, and then shooting that inside air through that one hose outside. This balances out to zero! If it’s 100 degrees inside, it will make no difference if you have a single hose unit. It will still be100 degrees inside! Only a fool would buy this!  What a waste of money!