Not exactly sure how long the hose is if fully extended. However, you don't want too long of a hose as there needs to be a consistent rise in the hose from the a/c to the window bracket. Heat rises, so if there is any kind of a sag in the hose, efficiency will suffer. This is true for any portable a/c, not just this particular make and model. Additionally, the a/c needs to be at least 20 inches from the wall, but I wouldn't put it much more than that if you can help it. There needs to be a minimum distance for air flow (the 20 inches) but extending that distance much more will start to reduce efficiency (in my opinion). When the a/c is running and you put your hand on the hose, it is noticeably warm. The shorter the distance (observing the minimum distance, of course) the sooner the warm air will exit out the window.