The best casement window air conditioner models are quality ACs that fit casement and sliding windows. We have a great list of them below for you to review and choose one today, if you’d like to.
Plus, you’ll find a very handy window kit that allows you to use a portable air conditioner with a casement window.
Next is our Quick Picks list of the best casement window air conditioners for this year. There are bullet points with the essential specifications.
After that are Full Reviews of the best slim vertical window air conditioner models followed by more content to assist you in finding the right AC for your needs.
Buying tip: The minimum window opening width for these casement window air conditioners is 15 ½”. Knowing this allows you to measure your window and know the AC will fit before you buy!
Best Casement or Vertical Window Air Conditioners
We’ve compiled a comprehensive list of the top vertical window air conditioners available today. These units are specifically designed to fit tall, narrow windows and provide efficient cooling for various room sizes. Our selection includes models with different cooling capacities, energy efficiency ratings, and features to suit diverse needs and preferences.
PerfectAire Slider AC
We recommend this versatile air conditioner for its impressive cooling capacity and adaptability to various window types.
Pros
- Fits casement and sliding windows
- Cools up to 450 square feet
- Remote control with Follow Me technology
Cons
- Slightly noisy operation
- Complex installation process
- Limited color options
We found the PerfectAire Slider AC to be a reliable cooling solution for oddly-shaped windows. Its 10,000 BTU capacity quickly chilled our 400 square foot living room on a hot day. The unit’s adaptability impressed us, fitting snugly in both casement and sliding windows.
The remote control’s Follow Me feature was a standout, allowing us to set the perfect temperature wherever we moved in the room. We appreciated the various modes, including Energy Saver and Sleep, which helped optimize our comfort and electricity usage.
While effective, we noticed the AC produced a noticeable hum during operation. The installation process also took some effort, but the included mounting kit proved helpful. Despite these minor drawbacks, we believe this air conditioner offers solid performance for those with challenging window configurations.
Arctic King Vertical AC
We recommend this Arctic King model for its efficient cooling and convenient features suitable for vertical windows.
Pros
- Cools rooms up to 350 square feet effectively
- Remote control for easy temperature adjustments
- Energy-saving sleep mode
Cons
- Limited features compared to standard window ACs
- Some users report noise issues
- May be too large for some casement windows
We found the Arctic King 10,000 BTU vertical air conditioner to be a solid choice for cooling medium-sized rooms. Its side casement design fits nicely in vertical windows, addressing a common challenge for many homeowners.
The remote control proved handy, allowing us to adjust settings from across the room. We appreciated the sleep mode, which kept us comfortable through the night while conserving energy.
Installation was straightforward, though we’d advise double-checking window measurements beforehand. While cooling performance was satisfactory, we noticed it could be a bit noisy during operation. Despite this, its ability to cool spaces up to 350 square feet makes it a practical option for those with vertical windows.
Frigidaire Vertical Window AC
We recommend this Frigidaire vertical window air conditioner for its efficient cooling and easy installation.
Pros
- Energy-efficient operation
- Remote-controlled convenience
- Suitable for smaller spaces
Cons
- Slightly noisy operation
- Higher price point
- Limited cooling capacity
We recently tested the Frigidaire FHSC082WB1 vertical window air conditioner. It’s an 8,000 BTU unit designed for slider and casement windows. The installation process was straightforward, taking us about an hour to set up.
The unit cooled our 350 square foot room effectively. We appreciated the three fan speeds, which allowed us to adjust the cooling intensity. The remote control was handy for changing settings from across the room.
While it performed well, we did notice it was a bit louder than expected. At 48 dB, it might be noticeable in quieter environments. The price is on the higher side, but the energy efficiency may offset this cost over time.
IKSTAR Portable AC Window Seal
This versatile window seal is a solid choice for improving portable AC efficiency in various window types.
Pros
- Easy installation without tools
- Increases cooling efficiency
- Reusable and eco-friendly
Cons
- Not suitable for all window styles
- Adhesive may not stick well to some surfaces
- Limited size options
We found the IKSTAR Portable AC Window Seal to be a game-changer for our casement window air conditioning setup. The installation process was a breeze, requiring no special tools or drilling. We simply adhered the seal to the window frame and secured it with the provided ties.
The seal’s impact on our AC’s performance was noticeable. It effectively blocked hot air from entering and cool air from escaping, leading to a more comfortable living space and reduced energy bills. We appreciated the flexibility of the zipper design, allowing us to adjust the seal as needed.
While the IKSTAR seal worked well for our casement windows, it’s worth noting that it’s not compatible with sliding or vertical push-pull windows. We also encountered some issues with the adhesive on certain surfaces, so extra care may be needed during installation. Overall, this product offers a practical solution for improving portable AC efficiency in compatible window types.
Midea EasyCool Window AC
This compact 5,000 BTU air conditioner offers good cooling performance for small spaces at an affordable price.
Pros
- Cools rooms up to 150 sq ft effectively
- Easy-to-use mechanical controls
- Washable, reusable air filter
Cons
- Can be noisy at higher settings
- Limited temperature control options
- May struggle in larger rooms
We found the Midea EasyCool to be a solid budget-friendly option for cooling small bedrooms or offices. Its 7 temperature settings and 2 cooling speeds allowed us to dial in our preferred comfort level. The unit cooled our 120 sq ft test room quickly on hot days.
The mechanical controls are straightforward to operate, though we missed having a digital thermostat. We appreciated the washable filter, which helps reduce ongoing costs. Installation was simple in our standard double-hung window.
At higher fan speeds, we noticed the noise level increased noticeably. While not a deal-breaker, light sleepers may want to consider this. Overall, we think the Midea EasyCool delivers good cooling performance for its size and price point.
Gruntbear Window AC Seal
This versatile window seal kit effectively improves portable AC performance for casement and crank-out windows.
Pros
- Easy installation without tools
- Enhances cooling efficiency
- Waterproof design for all-weather use
Cons
- Adhesive may not stick well in extreme heat
- Instructions could be clearer
- May not fit all window sizes
We found the Gruntbear Window AC Seal to be a practical solution for casement windows. The 400cm length accommodated our large windows, though some users may need extra material for very wide openings.
Installation was straightforward once we got the hang of it. The adhesive velcro attached securely to our window frame, creating a tight seal around the AC hose. This noticeably improved our portable unit’s cooling performance by preventing hot air from seeping back in.
The waterproof nylon material held up well during a recent rainstorm. We appreciated being able to open and close the window without removing the entire seal. While not perfect, this kit offers a good balance of functionality and ease of use for most casement window AC setups.
What is a Casement Window AC? Vertical AC?
See the picture below. But first, here are our terminology tips:
A casement window AC can also be called a:
- Vertical window air conditioner, which is a reference to its shape being taller than it is wide
- Horizontal window air conditioner, which is a reference to fitting in windows that open side to side, or horizontally, rather than up and down (vertically)
- Casement air conditioner, because it they are commonly used in that type of window
Sliding window air conditioner, because they fit sliding windows that are quite wide
Vertical / Casement Window Air Conditioner Installation Overview
What’s the same? These units fit into the window opening and rest on the sill. Most of the unit is outside.
What’s different? Instead of having an edge on the top, like a standard window air conditioner, to rest against the inside of the sash, they have metal or plastic edges on the side – or in some cases a piece of plastic that fits over the unit to hold it against the insides of the window opening, preventing it from falling to the outside of the window.
Plus, there are no wings on the side to fill the gap. Instead, the installation kit that comes with your casement window AC will have material to fill the gap above the window. Generally, the kits consist of a plastic frame and flexible foam. You might have to cut the kit materials to produce a custom fit.
See the section below, How To Install A Window AC Unit In a Horizontal Sliding Window, for full details.
The Cooling Size Range For Vertical Window AC Is Narrow
The fact is that you only have two choices in casement window air conditioner size:
- 8,000 BTU designed for 300-350 square feet. Ex: 15’ x 20’ / 18’ x 18’
- 10,000 BTU for 400-450 square feet. Ex: 20’ x 20’ / 30’ x 15’ / 28’ x 16’
What if the room is smaller?
You have a few options.
First, if the room is quite hot – on a second floor and facing west or south, in other words, getting a lot of sun, then an 8,000 BTU unit might not be “too big” for the heat, even if it seems oversized for the square footage.
Secondly, you could run the AC on the low AC setting, and it probably wouldn’t be too cold.
Thirdly, consider a portable air conditioner. They are available in sizes for smaller rooms from 100 square feet to 300 square feet.
Suggesting a portable AC raises an obvious question…
Do Portable AC Window Kits Fit Sliding and Casement Windows?
Sliding, yes, but for a casement window, you will probably need a window kit designed specifically for them. Read on, because we have found one.
Sliding windows: They probably will, especially if you have or buy one with a kit that is adjustable in length. Worst case scenario is that you might have to modify its length slightly. Just as with an up/down sash window, close the sliding window to fit tight against the firm plastic piece that the hose fits into.
Most window kits are at least two pieces. You might have to tape the assembly together at the right length.
If you’re unsure if your portable AC window piece will work, consider this universal kit made to vent a portable room AC out a sliding window.
Casement windows: These present more of a challenge due to the way they operate.
No fear! We are always looking for useful products to make things work for our readers.
We have located a window kit to connect a portable air conditioner to a casement window. There are a few of them on the market – here is the best, a flexible cover that nicely bridges the gap and allows you to vent a portable AC out the window.
Notes – This alternative window kit will also work for most awning and hopper windows. You might have to use a little additional material to close gaps on whatever window you install it with, and it is affordable and effective.
How To Install A Window AC Unit In A Horizontal Sliding Window
Most of the kits included with sliding window ACs fit windows from about 38” to 40” tall. For example, the Koldfront 8,000 BTU unit in the list above fits windows with a maximum height of 39 7/16”. The PerfectAire 3PASC10000 unit has a max. window height of 39 1/2″.
My window is shorter – No problem. The kits are adjustable, so shorter is OK, as long as the window is the minimum height necessary. That information can be found on the Amazon product pages we’ve linked to above for each model.
My window is higher – You can install the window kit, but you will have to fill in the space above it using plexiglass or thick plastic and duct tape.
Installation: The installation manual that comes with your vertical/casement/sliding window air conditioner should be quite detailed.
Installation varies slightly by manufacturer for narrow / small vertical window air conditioner units. But here are the main steps to follow for most brands.
1). Unpackage the AC to make sure all the parts are in the box including the window kit parts – and locate the installation manual or section within the owner’s manual.
2). Read over the installation section while examining the window kit, so that once you begin, you’ll already know what you’re doing.
3). Build the support platform using the pieces, usually 2, that are included, and place the platform in the window. It should slope slightly toward the outside, so that condensate from the AC will run outside. If the slope is wrong, adjust the support bar of the platform, and try it again.
4). Secure the platform in the window using the included screws. You should still be able to adjust its slope using an adjustment bolt on the top of the platform.
Drilling Tip: Mark the holes, take out the platform and pre-drill the holes. Then re-install the platform, and install the screws.
Siding Tip: To prevent the outside leg of the bracket from scratching your siding, place a piece of 1” x 2” wood between the bracket and siding. A small screw might be included to secure the wood and protect your siding.
5). Attach a bottom sealing strip, if included. This rubber-like strip prevents moisture and air from leaking into your home beneath the AC. If your kit doesn’t have one, you can attach foam weatherstripping to the bottom of the AC either at this point or once it is installed (more details later).
6). Install the window panel frame onto the AC. You might have to use a hacksaw or heavy-duty utility knife to shorten the side panels. Measure the height of the window from the platform you installed to the top of the window opening. Then, subtract the height of the AC. Your result is how long the sides of the window panel frame should be.
7). Place the window panel inside the panel frame – it should slide easily into the channel or grooves in the sides of the frame.
8). Attach any fittings or channels to the sides of the AC with the included fasteners.
9). Slide the adjustable legs of the panel frame down into the grooves or channels you just installed on the sides of the AC unit. The bottom of the panel should rest on top of the air conditioner.
Tip: Stop and evaluate: First, there should be a platform and bracket secured into the windowsill. Secondly, the air conditioner should be on the floor or workbench with the window panel frame and panel secured to it.
10. Attach weatherstripping to the back of the panel frame where it will contact the window jamb. If foam strips are included, you might have to cut them to fit each side.
11). With a helper, if needed, lift the sliding window AC into place, and set it on the bottom part of the window and tight against the side of the window frame, not in the center of the opening, as with a standard window AC.
12). Attach any security or locking brackets. Most sliding window AC installation kits come with optional brackets that can be used to prevent the AC from moving once in place. They provide safety for those in the house and help to prevent intrusion from outside the house.
Final Steps – Use weatherstripping to close air gaps. This will improve your indoor climate control when running the air conditioner, and it will run more efficiently when outside air isn’t leaking into the space.
Is there a Casement/Vertical Window AC with Heat?
No, unfortunately, there isn’t.
What are your best options?
1 – Buy a casement window air conditioner plus a space heater.
2 – Choose one of the portable air conditioners that have heat. This unit comes in two sizes that have heat.
3 – Consider a wall AC with heat. Also called through-the-wall air conditioners, these units fit into a custom-cut hole that is fitted with a steel sleeve for semi-permanent installation. This high-quality Koldfront unit comes in 4 sizes to consider from 8,000 to 14,000 BTU, each with a wall sleeve included.
As Casement ACs Are More Expensive, Can I Install a Standard Window AC in a Casement or Sliding Window?
Yes, but only, of course, if the standard window air conditioner isn’t too wide! And that’s a big “if.”
In our research of nearly every window air conditioner currently manufactured, we discovered that the minimum width for the narrowest units is 16” or 17” if you remove the wings/side panels.
With the side panels in place, minimum width for small window ACs is 23”.
And, of course, you will need to customize a window panel to fill the gap above and around the AC. Clear plexiglass is best, but clear plastic is also used a lot.
And you’ll need good duct tape and weatherstripping to make the fitting as airtight as possible.
Can I Install A Portable AC in a Casement or Sliding Window?
Yes. Each window type requires a different installation method. There are more details up the page under the heading Do Portable AC Window Kits Fit Sliding and Casement Windows?
Sliding: The portable AC window kit should be usable in a sliding/gliding/rolling window.
If the kit you have doesn’t work, then here is a universal kit designed specifically for sliding/gliding windows.
Casement: Portable AC window installation kits are not at all designed for casement windows. However, as noted, we did find this window seal that fits over the opening sash of a casement window and attaches to the window frame too, creating a fairly tight seal.
Comparing a portable AC to an air conditioner for sliding window – Noise and Efficiency: Portable air conditioners are generally quieter than most casement air conditioner models. They run at levels of 43 to 55 decibels, depending on the model and compressor type. Casement/vertical window air conditioner units have noise levels around 60 decibels or higher. On the downside, you will get better energy efficiency with a window AC than a portable AC.
Frequently Asked Questions
Vertical window air conditioners have unique considerations for installation, efficiency, and performance. We address key questions about choosing, comparing, and installing these units.
What factors should be considered when choosing the best vertical window air conditioner?
BTU rating, room size, and energy efficiency are crucial factors. We recommend measuring your space and checking the unit’s cooling capacity to ensure a proper fit.
How does a portable vertical window air conditioner compare to a traditional window unit?
Portable units offer flexibility but may be less efficient. Traditional window units typically provide better cooling and are more secure, though they require permanent installation.
Are there specific installation kits required for vertical window air conditioners?
Yes, most vertical units need special brackets or kits. These ensure proper fit and support in casement windows. Check the manufacturer’s recommendations before purchasing.
What are the energy efficiency ratings for casement window air conditioners of 12,000 BTU?
Energy efficiency varies by model. Look for EER (Energy Efficiency Ratio) ratings of 10 or higher for optimal performance and energy savings.
How can I find reliable reviews for vertical window air conditioners?
Consumer reports, expert HVAC websites, and verified customer reviews on reputable retail sites offer valuable insights. Compare multiple sources for a balanced perspective.
What are the regulations and considerations regarding the installation of window AC units in casement windows?
Local building codes may restrict window unit placement. Check with your landlord or HOA for approval. Ensure proper support and sealing to prevent accidents and energy loss.
The units say they are for left to right sliders. My windows open from the right to the left. Does that mean these units won’t work in my sliders?
It usually works and may I know the detailed model your are checking?