Best Window Air Conditioners for Casement Windows: What Actually Works
Last updated: 2026-09-15 · By NicheHive Editorial
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Most window air conditioners cannot be installed in a casement (crank-out) window at all. Here's why, and the real options: portable AC units with a casement window kit, plus which of our tested window units work if you also have a double-hung window elsewhere in the house.
Our Top Picks
Midea 8,000 BTU U-Shaped Smart Inverter Window Air Conditioner
Midea
- ✓8,000 BTU inverter compressor
- ✓Requires a double-hung or single-hung sash window
- ✓U-shaped frame splits around the sash
- ✓Not compatible with casement, sliding, or awning windows
Pros
- If another room in the house has a standard sash window, this is the quietest unit in our lineup for it
- Inverter compressor and U-shaped frame are genuine advantages once installed in a compatible window
Cons
- Cannot be installed in a casement, crank-out, or awning window under any circumstances without a custom-built frame
- Not a solution for the specific problem this article addresses; listed only as an alternative if you have a compatible window elsewhere
Not a casement window solution. Useful only if you're solving cooling for a different, compatible window in the same home.
LG 8,000 BTU Smart Window Air Conditioner LW8017ERSM1
LG
- ✓8,000 BTU cooling capacity
- ✓Requires a double-hung or single-hung sash window
- ✓Extendable side panels fill the remaining sash gap
- ✓Not compatible with casement windows
Pros
- Lower price than the other units in our full lineup, if you have a compatible sash window to install it in
- Straightforward installation on the correct window type
Cons
- Same fundamental incompatibility as every standard window unit: no sliding sash means no installation
- Side panels are designed to extend into a rectangular gap, which a casement crank mechanism doesn't create
Not a casement solution. A budget option only for a genuinely compatible sash window in the same home.
If the room you're trying to cool only has casement windows, the honest answer is that none of the window air conditioners in our other guides will physically install there, and no amount of searching for the "best" one changes that.
Casement windows crank outward on a hinge instead of sliding up like a double-hung sash. Standard window units are built with extendable side panels designed to fill a rectangular gap left by a raised sash, and a casement window never creates that gap.
The real fix is a portable air conditioner paired with a casement window installation kit, which replaces the flat slider panel in a standard vent kit with one cut to fit the narrower gap created by cranking the window partly open.
We've still listed two of our tested units below in case you have a compatible double-hung or single-hung window elsewhere in the same home and just need a recommendation for that room.
The Real Options for a Casement Window Room
Portable AC with a casement window kit. This is the standard, purpose-built solution. The kit adapts a portable unit's exhaust hose to seal against the narrow gap created by a partially cranked-open casement window, instead of requiring a sliding sash.
A through-the-wall unit, if you're open to a more permanent installation. These mount in a wall sleeve rather than a window and sidestep the casement problem entirely, at the cost of a larger installation project.
A ductless mini-split, for a room that's a permanent living space rather than a seasonal one. The indoor unit mounts on the wall and only a small refrigerant line penetration is needed, avoiding the window entirely. This is a bigger investment than a window or portable unit but is the most efficient long-term option.
Why Standard Window Units Don't Work
A window air conditioner's chassis is built to slide into the horizontal opening left when you push a double-hung or single-hung sash upward. Foam side panels then extend outward to seal the remaining side gaps against the window frame.
A casement window has no sash to raise. It swings outward on a hinge from one side, which means there is no horizontal sliding opening for a standard unit's chassis to sit in, and no flat surface for its side panels to seal against.
Attempting to force a standard unit into a casement window opening, or building a custom plywood insert to hold one, is possible in theory but is a significant carpentry project rather than a normal installation, and isn't something we recommend as a first option.
Check price on Amazon, Midea 8,000 BTU U-Shaped (for a compatible sash window elsewhere in your home)
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