Window air conditioners provide an easy and convenient way to cool off any space, whether it's a small bedroom, a large living room, or an open concept area. Setup is usually straightforward, with options to fit single- and double-hung, slider, and casement windows, in both semi-permanent and temporary installations.
To help you find the best window air conditioner for your space, we researched models from manufacturers like Midea, GE, Frigidaire, and more, to find top performing models suitable for small, medium, and large rooms, and different types and sizes of windows.
We evaluated dozens of window air conditioners for cooling power, efficiency, features, window style compatibility, modes, and overall performance. We also looked for advanced features like enhanced air quality, quiet operation, and smart controls to find the best options for every room.
What is a BTU?
A window air conditioner’s cooling capacity is measured in BTUs. The BTU rating indicates how much energy is used to remove heat and moisture from the air, and effectively cool down a room. Square footage directly correlates to the BTU rating, and the BTU should be appropriate for your room size. You can refer to The Spruce’s window air conditioning chart to determine the amount of BTUs required to cool your space.
Our Top Picks
Best Value:
Best for Small Rooms:
Toshiba 5,000 BTU Mechanical Window Air Conditioner at Home Depot$166
Best Smart:
Best for Large Rooms:
Best Overall
Midea 10,000 BTU Window Air Conditioner
What We Like
U-shaped design allows you to open window
Smart-home enabled
Very quiet operation
What We Don’t Like
Can only be installed in hung windows
We like that the Midea Smart Inverter Window Air Conditioner sets itself apart from the competition with its exceptionally quiet operation and U-shaped design. The unique design reduces the noise coming from the compressor (it runs at maximum of just 42 decibels), which is located outside of the window. This means you can sleep, relax, or watch TV without being disturbed while the AC is in use.
With a rating of 10,000 BTU, this unit is suitable for cooling rooms up to 450 square feet. It's also extremely efficient, with a CEER (Combined Energy-Efficiency Ratio) rating of 15 and Energy Star certification. That efficiency comes from advanced DC inverter technology, which uses significantly less energy than standard air conditioners.
This air conditioner includes a remote control for easy operation, and it's also smart-home enabled for convenient, hands-off operation. We like that you can control it via the Midea Air app on your phone, or with voice controls if you have an Amazon or Google smart speaker.
We love the unique U-shaped design of this air conditioner, because it helps reduce noise and lets you open the window for a bit of fresh air. It does restrict your window options, since it needs to be installed in a window with a bottom sash that slides up, but it comes with a quick-snap bracket that simplifies installation. For added peace of mind, it also includes an anti-theft mechanism that locks the window once it’s closed.
Dimensions: 19.17 x 21.97 x 13.46 inches | Cooling Area: 450 square feet | BTU: 10,000 BTU | Weight: 59 pounds | Window Size: 22 to 36 inches wide | Energy Star Certified: Yes
What We Like
Ideal for smaller rooms
Simple, adjustable controls
Mount kit included
What We Don’t Like
No energy-saving features
No remote control
We love that the GE Mechanical Air Conditioner effectively cools smaller rooms. You’ll have to forgo some of the additional features you might find on other models, but this unit is easy to operate and install. With 5,000 BTU, this air conditioner is best suited for rooms up to 150 square feet. With two cooling modes and 10 temperature settings, you can adjust the climate exactly to your liking.
Featuring two manual dials, the design is fairly rudimentary, and it lacks the convenience of a remote control. Despite its lack of bells and whistles, this air conditioner gets the job done. An EZ mount kit and fixed chassis allow for easy installation in a double-hung window. Plus, the filter is both removable and washable, keeping maintenance to a minimum.
One potential drawback to this air conditioner is that it isn’t energy efficient, nor is it Energy Star certified. It also lacks an energy-saving mode, which you’ll find on many of our other picks, such as our best overall, the Midea 10,000 BTU Window Air Conditioner. On the whole, we think this is a reliable choice for cooling smaller rooms like bedrooms, guest rooms, and home offices.
Dimensions: 15 x 16.44 x 12.56 inches | Cooling Area: 150 square feet | BTU: 5,000 BTU | Weight: 36 pounds | Window Size: 13.38 to 21.88 inches wide | Energy Star Certified: No
What We Like
Compact and lightweight
Easy-to-use controls
Removable filter
What We Don't Like
No remote control
Noisy
If you can forgo digital controls and special features, this Toshiba window air conditioner is a great choice for a small space. With a 5,000 BTU cooling capacity, this unit is perfect for small bedrooms and home offices. It has seven temperature settings, as well as two speeds and cooling modes, which can all be adjusted using the manual dials on the front of the machine. Although the controls are fairly rudimentary, operation couldn’t be simpler. Plus, the manufacturer has a one-year warranty.
This air conditioner is that is compact and lightweight, which is important for easy installation. For added convenience, it also includes an installation kit. Maintenance is easy too, thanks to a removable and washable filter that you can pop out to keep this air conditioner running at peak performance.
One caveat to this AC is that it operates at 56 decibels, which is slightly louder than the average window unit. Depending on your sensitivity to noise, it might not be the best choice for a bedroom or living space–especially if it’s in close proximity.
Dimensions: 12 x 16 x 15.4 inches | Cooling Area: 150 square feet | BTU: 5,000 BTU | Weight: 43.7 pounds | Window Size: 23 to 36 inches wide | Energy Star Certified: No
Best Smart
Windmill Air Conditioner
What We Like
Sleek, modern design with cosmetic side panels
Voice control
Dual filters
What We Don't Like
App isn't intuitive
The Windmill Air Conditioner offers smart capabilities for ultra-convenient operation. Not only can it be programmed through your smartphone, but there are also voice control features available with Google Assistant or Amazon Alexa. Unlike bulkier units, the Windmill’s sleek design and cosmetic side panels create a seamless aesthetic that we love.
When we used this AC in a real-life home environment, we were impressed with how well it cools an apartment and how quietly it runs. We also like how convenient it was to control the unit remotely using the app.The app is a little unintuitive, but you can always fall back on the physical remote if you need to.
This air conditioner offers three cooling speeds and three fan speeds. With an 8,300 BTU rating, this unit is ideal for cooling rooms up to 350 square feet. To ensure clean airflow, the air is filtered twice through an antimicrobial mesh filter and activated carbon insert. This AC also features an auto-dimming LED display that won’t be a distraction in a dark bedroom.
This air conditioner comes with a pre-assembled installation kit, resulting in a simple setup process. Eco-conscious consumers, and anyone looking to save money on their electricity bill, should also note that it's Energy Star certified.
Dimensions: 15.63 x 18 x 12 inches | Cooling Area: 350 square feet | BTU: 8,300 BTU | Weight: 71.3 pounds | Window Size: 23 to 36 inches wide | Energy Star Certified: Yes
What We Like
Saddle shape is easy to install and doesn’t block window
Extremely quiet
Temperature-sensing remote control
What We Don't Like
Doesn’t fit all windows
May need to be drained manually
The Soleus Saddle Window Air Conditioner has a unique design that makes it incredibly easy to install. No tools are required; all you need to do is slide this saddle-shaped air conditioner over your windowsill. Just note that the maximum sill clearance is 11 inches, so be sure measure carefully before purchasing.
Unlike traditional window units, this air conditioner barely blocks your view, and you can open and close the window whenever you want a bit of fresh air. Because the compressor is located outside (and below the level of your window) the Soleus operates between 38 and 49 decibels, which is significantly quieter than standard window air conditioners. It comes in two sizes—6,000 or 8,000 BTU—and it’s available with or without Wi-Fi connectivity.
This air conditioner has three operating modes: auto, sleep, and dry. In dry mode, it functions as a dehumidifier, removing up to a whopping 30 pints of moisture per day. The temperature-sensing remote is another major selling point. This feature allows the AC to adjust its settings based on where you are located in the room. Just remember to keep the remote near you. However, if you live in a particularly humid area, you may need to drain this unit manually.
Dimensions: 15 x 29 x 18 inches | Cooling Area: 275 square feet | BTU: 6,000 BTU | Weight: 80 pounds | Window Size: 24 to 48 inches wide | Energy Star Certified: Yes
What We Like
Also compatible with casement windows
Versatile cooling options and dehumidify mode
Full-function remote control
What We Don’t Like
Doesn’t fit standard windows
Not Energy Star certified
It can be a challenge to find an air conditioner to fit horizontal sliding windows, but the Frigidaire FFRS1022R1 fits the bill. With its tall and narrow profile, this unit is specifically designed for sliding and casement windows. Its 10,000 BTU rating allows it to cool rooms up to 450 square feet in size, so it's a good choice for large master bedrooms and smaller living rooms. Three fan speeds allow for adjustable cooling performance, and auto, energy saver, and sleep modes provide optimal comfort at any time. Plus, its adjustable louvers let you focus the air in the direction you want it.
A full-function remote allows you to control the AC from across the room, and a 24-hour timer provides even more flexibility. One potential downside to this air conditioner is that it is not Energy Star certified, so it’s not one of the most efficient options. It can perform double duty as a dehumidifier though, removing up to 3 pints of moisture per hour in dry mode, which uses less power than the cooling modes. The washable filter tilts out for easy maintenance, and a check filter alert will appear when it needs to be cleaned.
Dimensions: 23.5 x 14.5 x 20.25 inches | Cooling Area: 450 square feet | BTU: 10,000 BTU | Weight: 72 pounds | Window Size: 21.5 to 40 inches tall, and at least 15.5 inches wide | Energy Star Certified: No
What We Like
Good circulation for large spaces
Automatic eco mode
Alexa and Google Assistant voice controls
What We Don't Like
Can't disable auto-dim
No dry mode
This Frigidaire air conditioner provides plenty of cooling power for a large living room or open concept area, with a multi-direction airflow system that's perfect for big multi-use spaces. We like the way the vent design sends air in six directions to promote circulation around furniture and other obstructions to really cool off the entire space.
While this is a powerful air conditioner that's suited to large rooms, it's also energy efficient. It's Energy Star certified, and it also includes an automatic eco mode that helps save energy and money. When the desired temperature is achieved, the air conditioner turns off, then cycles the fan every 10 minutes to determine if further cooling is required.
Since this air conditioner is designed for large rooms, you won't always want to walk all the way over to the unit to make adjustments. To that end, it includes a remote control and Wi-Fi connectivity. If you have an Amazon Echo or a Google Home smart speaker in the room, you can use that to operate the air conditioner with voice commands. If you don't, and the remote isn't nearby, you can use an app on your phone.
Other useful features include a sleep mode that increases the temperature slightly at night to save power, a fresh air vent to draw in clean air from outside during times of the year when it isn't too hot, an alert that lets you know when it's time to clean the filter, and a display that dims automatically. We wish the auto-dim feature was optional, and there're s no dry mode, but the feature set is fairly comprehensive aside from those few issues.
Dimensions: 21.5 x 19 x 14.5 inches | Cooling Area: 550 square feet | BTU: 12,000 BTU | Weight: 75.8 pounds | Window Size: 25 to 36 inches wide, and at least 15.5 inches tall | Energy Star Certified: Yes
Final Verdict
The Midea Smart Inverter Window Air Conditioner earns our best overall title, thanks to its quiet operation, impressive energy efficiency, and convenient smart-home features. For these reasons, it's a standout among the competition in our book. Or consider our best value pick, the GE 5,000-BTU Mechanical Window Air Conditioner. It’s suitable to cool rooms up to 150 square feet, and we love that it’s easy to install and operate.
What to Look for in a Window Air Conditioner
Window Type and Size
When you start looking for a window air conditioner, you need to take a look at your windows. Some air conditioners will fit multiple types and sizes of windows, but most are designed for a single type of window and also have specific size requirements.
Here are the common types of windows and the types of air conditioners that work with them:
- Single- and double hung: These windows have one or two sashes that slide up and down. Window air conditioners are installed by raising the bottom sash, inserting the air conditioner, then closing the sash. The Frigidaire Smart Window Air Conditioner (our best for large rooms pick) includes two adjustable filler panels, so it works well with these windows.
- Slider: These windows slide open horizontally, so air conditioners designed for them are often taller than they are wide. The Frigidaire Slider / Casement Air Conditioner (our best for sliding windows pick) comes with a trimmable plastic panel and all the hardware required to perform a weathertight installation in a sliding window.
- Casement: These hinged windows open outward to the left or right, so it’s important to select an air conditioner that’s the right size to not interfere with the window, and you’ll typically need to apply weather stripping. The same Frigidaire model we recommend for sliding windows also works in casement windows.
- Awning: These are like casement windows, but they open out and up, so they don’t work well with window air conditioners without modifications or removing the sash. Instead of a window air conditioner, you may want to consider a portable air conditioner and use the window as a vent.
Within those constraints, there are also a few unique types of window air conditioners—like saddle and u-shaped units—that provide unique benefits if you have the right windows.
- U-shaped air conditioners: These air conditioners are designed for use in single- and double-hung windows, with a U shape to accommodate the lower window sash. The benefit of this design is that you can raise and lower the window sash to get fresh air. The Midea U Smart Inverter AC (our best overall pick) uses this design.
- Saddle-shaped air conditioners: This design is like the reverse of a u-shaped air conditioner, with a deep pocket that fits over the window sill. The benefit is that they don’t block the window, which allows more natural light into the room and doesn’t interrupt your view. The Soleus Air 6,000 BTU Over-the-Sill Air Conditioner (our pick for best design) is a saddle-shaped model.
Unit Size
Before you buy an air conditioner, make sure to measure the height and width of your window opening and select an air conditioner with a required window size that matches those measurements. It isn't enough to just look at the physical dimensions of an air conditioner, because an air conditioner will often need a little extra room to comfortably slide into place.
For example, the Frigidaire Slider / Casement Air Conditioner (our best for sliding windows pick) is 14.5 inches wide and 20.25 inches tall, but it requires a window opening that's at least 15.5 inches wide and 21.5 inches tall.
Most air conditioners will have a required window width or height that provides a minimum and a maximum measurement, which reflects whether the air conditioner is designed for windows that slide open vertically or horizontally.
Air conditioners that have an upper and lower width measurement often include a extendable panels or baffles with a limited range of movement. Our best smart pick, the Windmill 8,300 BTU Window Air Conditioner, has cosmetic side panels to create a more attractive, seamless appearance in your space, but they only extend out a maximum of 36 inches
Coverage Area
When selecting an air conditioner, it's important to consider the size of the space it will need to cool. If you select an air conditioner that isn't strong enough, it will run all the time and never cool your room sufficiently. Selecting an air conditioner that's too powerful will also cause issues, as it may cool the space off too quickly without removing enough moisture.
Every air conditioner has a BTU rating, which is a measurement of cooling power that you can use to determine whether or not that unit will work well in your space. Manufacturers will often provide a recommended square footage as well, which is easier because it doesn't require you to do any math.
In general, you'll need about 20 BTUs per square feet of space that the air conditioner will need to cool. There are other important considerations, like higher ceilings require more cooling power, and you also need some additional cooling power in rooms where a lot of people congregate, and rooms with large windows that have a lot of sun exposure.
Here are some common BTU ranges and rooms they work well with:
- 5,000 to 6,000 BTU: These air conditioners work well in small bedrooms and home offices. The Toshiba Mechanical Window Air Conditioner (our best for small rooms pick) is the perfect size to keep a small bedroom comfortable at night.
- 7,000 to 9,000 BTU: Air conditioners in this range are good for larger master bedrooms, small living rooms, and kitchens. Our best smart pick, the Windmill Air Conditioner, is a good option for small and medium-sized living rooms and master bedrooms.
- 10,000 to 12,000 BTU: Models with this output are good for large living rooms, open concept areas, and multi-use spaces. The Frigidaire Smart Window Air Conditioner (our best for large rooms pick) is good for big open concept spaces.
- 13,000 to 24,000 BTU: Air conditioners in this range are good for especially large open concept areas and even entire homes, although you may be better off with several smaller units or even a mini split system unless you have very large, open areas in your house where air circulation isn't an issue.
You should clean your window air conditioner regularly to keep it in good working order. Part of routine maintenance is cleaning or replacing the filter as recommended by the manufacturer. Many air conditioning units have an indicator light to remind you when the filter needs to be cleaned.
If you intend to remove your window AC at the end of the season, you should drain any condensation before storing it. This will prevent mold and mildew from growing inside. Our best for sliding window choice, the Frigidaire FFRS1022R1 10,000 BTU Window Air Conditioner, has a washable, tilt-out filter for easy maintenance, as well as an alert to notify you when the filter needs cleaning.
Standout Features
Power Source
The convenient thing about most window air conditioners is that they typically don't have any special power requirements. Window air conditioners that provide less than 15,000 BTU of cooling power typically plug into a standard 120-volt receptacle and require a 15-amp circuit. The Frigidaire Smart Window Air Conditioner (our best for large rooms pick) is an example of a powerful window air conditioner that doesn't require a special outlet.
Some more powerful window air conditioners require a 240-volt outlet that takes a different type of plug, with a dedicated circuit. None of our recommendations have that limitation, but it's important to keep an eye out for because you're unlikely to have the required outlet.
Regardless of the power source, your window air conditioner should be the only major appliance on that circuit. Air conditioners draw a lot of current (especially when starting up), so having additional heavy loads on the same circuit may trip the circuit breaker or overload the circuit.
Energy Star Certification
Air conditioners with an Energy Star certification offer the latest technology to ensure efficient operation. With better sealing and insulation materials, these energy-saving air conditioners can lower the cost of your electricity bill. Several of our recommendations, including the Midea 10,000 BTU Window Air Conditioner (our best overall pick), and the Windmill Air Conditioner (our best smart pick) come with this certification.
You can refer to Energy Star to determine which window air conditioners provide the best energy efficiency rating. The higher the CEER rating, the more efficient the window air conditioner. As a note, window units can use up to 1,500 watts of electricity on average and last seven to ten years.
Noise Level
An air conditioner’s noise level is measured by its decibel (dB) rating. Most window air conditioners emit anywhere from 33 to 67 decibels, with 56 decibels being the average. We know noise is a subjective concept, and it will vary depending on the proximity of the air conditioner and how large the room is.
If you’re sensitive to noise, or using an AC in a bedroom, look for a unit that offers a sleep mode or a compressor that sits outside the window to reduce noise.That's why we're big fans of the Midea 10,000 BTU Window Air Conditioner (our best overall pick) which runs at a maximum of 42 decibels, so it's nice and quiet.
Why Trust The Spruce?
This article was written by Sage McHugh, a home and lifestyle writer who has been contributing to The Spruce since 2019. For this story, she considered dozens of window air conditioners, carefully evaluating their size, cooling area, features, efficiency, and overall performance.
Our Experts:
- Michelle Lau, editor for The Spruce
- Jeremy Laukkonen, updates writer for The Spruce
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