Portable air conditioners are best vented through a window, and most manufacturers include a window vent kit when you purchase the air conditioner unit. The kits usually adapt to double-hung sash or a sliding sash, and installation is pretty similar in each set-up. The kits are portable if you want to be able to move the air conditioner from room to room, although you may want to also consider purchasing an additional window vent kit and installing it in a second room, making room-to-room movement especially easy.
Cut the foam seal that came in the kit to the required length, using the hobby knife. On a double-hung window, that length is along the bottom window ledge, sometimes called the stool; for a sliding sash window, the length is along the side of the window frame.
Attach the window exhaust adaptor to the window panel's inside opening; both items should be part of the vent kit. The exhaust adaptor is the tubelike part that connects the hose to the window panel. The window panel fills the gap in the partly-opened window.
Attach the kit's protective screen to the outside of the exhaust adaptor. Use the two supplied screws. Install the rain deflector to the outside of the window panel.
Attach the window panel to the window ledge (or, for a sliding window, the side of the window frame). Open the window and insert the panel, secure the panel to the ledge with two large screws.
Slide the adjustment panel to fit the window opening and add foam to the gap between the window panel and the window. Close the window and attach the locking bracket to the window where the two sashes meet.
Attach the exhaust hose between the portable air conditioner and the exhaust adaptor and lock it into place. Avoid any kinks.
If using a window is inconvenient, some manufacturers make kits to vent portable air conditioners through sliding doors and through suspended ceilings.