A portable air conditioners should be connected to an "exhaust hose" or "vent hose" to remove the the hot air they eject. Most portable air conditioners extract hot from the room in which it is located, that hot air is then discharged out the of the a/c unit. An exhaust hose can be connected to the portable ac unit to lead the warm air out of the window.
The most efficient way to remove hot air from a room is when you connect a flexible exhaust hose to the back of your portable ac unit and connect the other end of the hose to a window venting kit. Most new portable air conditioning units nowadays come with a venting kit included. If your Air conditioning does not have a window kit you can just slip the vent hose through a partially opened window and seal it off with a towel, but remember that portable air conditioners work best in a closed environment so try to keep all other windows and doors closed as much as possible.
Try to keep the exhaust hoses as straight and as short as possible when using portable a/c systems to achieve maximum efficiency.
Single Exhaust Hose or Dual Hose Portable A/C Units
Most portable ac units have only a single hose some have two hose connections, one for air intake and the other for the exhaust. With a single hose system air is cooled and then returned back into the room with only a small portion of the air getting directed through the exhaust hose. With a dual hose system the portable A/C takes the air in from the room or even another room though one hose, cools that air and exhausts it through the second hose.
Connecting the Exhaust Hose to a Portable A/C Unit
To connect an exhaust hose to the air conditioning unit, you will first need to slip the exhaust connector over the discharge opening at the backside of the portable a/c unit and then connect the exhaust hose to the exhaust connector and slide the other end of the exhaust hose out the window.
When your a/c unit comes with a window kit then fit the venting kit into the opened window by adjusting the size of the window kit. When the window kit has the right length you can connect the window kit adapter to the window kit and place it into the window opening. You can the connect the other end of the hose to your window vent kit.