We bought this because our central ac went kaput during one of the hottest weeks.   This portable unit when 1st installed dropped the house 6 degrees from 89 to 83 over the course of several hours.   The only drawback to this unit is in our opinion, the flimsy vent hose.  It detaches easily from the window vent and incredibly easily from the unit and has split.  Glad we bought it, just wasn't happy with the hose