In general yes, all portable ACs need to be vented in some form or the other. Since these ACs suck in any warm air from the room thereafter cooling it and releasing it back into the room. During this process, any moisture along with the warm air needs to be vented out. And the most popular way to do this is through a window. But besides the window, you can get a vent kit for a sliding glass door, casement windows as well as a dropped ceiling as per your choice. When you are purchasing this portable AC most of the brands offer a basic vent kit for a window. Which has everything you will need to set up the venting system; all you need to do is follow the instruction manual on how to do it correctly.