The Best Air-Conditioning Solution for Crank-Out Casement Windows

Whitney Houston

Some portable air conditioners come with a fitting for casement windows, making them the easiest units to install into crank-out windows. Though the actual unit doesn’t fit into the window, a portable air conditioner still needs a way to blow dirty air out of the room to the outside. While a window unit air conditioner is meant to be installed in a window and possibly left there through all seasons, a portable unit features handles, is more compact and can be carried from location to location, if desired. Once the installation of the air conditioner's exhaust hose is complete, the portable unit functions as a standard air conditioner does.

Casement Component

Casement windows open sideways, like doors, instead of the panes sliding up and down.

A portable air-conditioner casement component is an exhaust hose with a thin, wide mouth. The round end attaches to the back of the portable air conditioner, which sits on the floor, while the flat end fits between the two casement windows, leaving as small an opening between the two windows as possible. When the unit is activated, dirty and hot air is removed from the air within the room and evacuated out of the window through the exhaust hose. The portable air conditioner sucks in air through the intake grille on the actual unit, cools it and blows it through the unit's front vents.


Once the component is installed in the window, the two windows can be secured with a rubber band or rope tied around both window latches. If only one window features a window latch, you can use the suction cup that comes with the casement window installation kit. The suction cup holds tightly against a clean, dry window surface. A rope or rubber band can be laced through the hole in the suction cup and the opposite window latch to prevent the windows from opening.


An air conditioner that fits into a standard double-hung window drains outside of the home through the back of the unit. A portable air conditioner drains into an internal water tank, because the unit sits inside of the room. When the drainage tank is full, the unit’s cooling element shuts off, until the tank can be emptied. The internal tank can be removed and drained or the whole unit can be unplugged and taken to a drainage area for draining. Once emptied, the unit’s cooling element is able to function again.


Once the exhaust hose is installed in the window, there will be some small openings where the hose fits between the two windows. You can use weather seal to fill the holes, until there are no leaks within the window. Weather seal backing can be peeled off to reveal a sticky side. The sticky side can be pressed against the insides of the windows and at the tops and bottoms of the windows to fill the gaps.