To come up with this list of the best window air conditioners, we thoroughly researched various models and evaluated them on cooling power, energy efficiency, noise level, and extra features. For expert tips and recommendations, we consulted Gary McCoy, store manager at Lowe’s, and Matthew Brown, merchant of ACs and fans, air quality, and floorcare at The Home Depot. “Window AC units are an easy-to-install, affordable option to cool a single room by essentially reducing the temperature and humidity of a room’s air and then recirculating the cool air with a fan,” says McCoy. Our top pick is the Midea U Smart Inverter Window Air Conditioner, which features a unique U-shaped design that allows you to open and close your window without uninstalling the unit. Read on to learn more about our recommendations for the best window air conditioners, and keep scrolling to find out how to find the right one for your space, according to experts. This U-shaped window air conditioner from Midea checks all of our boxes. Out of all the units on our list, it has the highest combined energy efficiency ratio (CEER) at 15 and the lowest noise level at 42 decibels. We tested this air conditioner for over two months, and we can confirm that it is impressively quiet—on the lowest setting, you can barely hear it unless your home is otherwise silent. On higher settings, there is some additional noise from air blowing through the fan, but not enough to bother most people. It’s also Energy Star certified, which means it meets strict energy efficiency criteria from the U.S. Environmental Protection Agency. This window AC takes it a step further by using nearly 38 percent less energy than the federal standard. Our tester was impressed at how little running this AC unit raised their energy bill, even though it was running for at least eight hours a day for over 6 weeks. But what really makes it stand out is its innovative design: The U-shaped notch lets you open and close your window without uninstalling the air conditioner. Not only does this give you the freedom to let in fresh air whenever you please, but it also means the compressor (the loud part of an air conditioner) sits outside, with the window acting as a noise barrier. The Midea U Smart model is available in three different sizes—8,000, 10,000, and 12,000 BTUs—that can cool rooms ranging from 350 to 550 square feet, depending on which you buy. The inverter technology helps control the output of your unit by consistently running it at a lower setting, which makes it more energy efficient. In terms of maintenance, this air conditioner comes with a washable, removable filter and has an indicator light that reminds you to clean it. Testing has confirmed that it’s incredibly easy to clean the filter and replace it to get your unit back to work quickly. One downside is that the installation process can be a little more involved than many other window units because you have to install the included mounting bracket. In addition to the instruction manual, you can refer to the brand’s helpful video tutorial to make the process easier. But we think this window air conditioner is well worth the effort because of its unique design, low noise level, and energy efficiency. Product Details:
Room Size: 350-550 square feetBTUs: 8,000-12,000Window Width: 22-36 inchesMinimum Window Opening Height: 13.75 inchesEnergy Star Certified: YesCEER: 15Control Type: ElectronicRemote Control: Yes
If you’re looking for an affordable yet reliable air conditioning unit, this window-mounted model is one of Frigidaire’s most popular for its straightforward design and ease of use. It’s available in six BTU options, but because each BTU model comes with slightly different features, we’ll focus on the 5,000 BTU model, which is the most affordable. It has four modes and seven pre-set temperature settings, so although you can’t set it to a specific temperature, you still have plenty of control. Two of these modes are Fan modes, which act the same as window fans—they won’t change the temperature of your room, but will get air moving and help cool down your space. With a noise level of 51.3 decibels on the low setting, this window AC is still quiet enough for people who can tolerate a little white noise while they sleep. The unit is also pretty easy to install because it comes with adjustable side panels so you can fit it to the width of your window. Its low cost and easy installation make it an ideal choice for a first apartment or temporary living space. Product Details:
Room Size: 150 square feetBTUs: 5,000Window Width: 23 inchesMinimum Window Opening Height: 13 inchesEnergy Star Certified: NoCEER: 12Control Type: ManualRemote Control: No
This LG window air conditioner comes in four sizes, but we’re focusing on the 18,000- and 22,000-BTU models here. They can cool up to 1,000 and 1,300 square feet respectively, so they’re ideal for large rooms and open floor plans that require plenty of cooling power. Just like our best overall pick, this window air conditioner uses inverter technology that continuously makes small adjustments to the temperature, as opposed to turning the compressor on or off to regulate the temperature (like most other models). But even with all that power, this window AC is still pretty quiet while operating—just 44 decibels while in sleep mode. We appreciate that this LG window air conditioner will automatically restart at the set temperature in case there’s a power outage. That means you won’t wake up in (or come back to) a super hot room as long as the power turns back on. There’s also a check filter light to remind you when it’s time to wash the reusable filter, which is important to keep your air conditioner working properly. Other notable features include a 24-hour programmable timer, LCD remote, and an adjustable vent that lets you move the airflow to where you want it. The window air conditioner also connects to Wi-Fi, so you can control the temperature and change settings with a voice-control device or the LG ThinQ app on your smartphone. Just keep in mind that the 18,000- and 22,000-BTU window air conditioners can’t be used on standard wall outlets because they require 230-volt outlets. Product Details:
Room Size: 1,000-1,300 square feetBTUs: 18,000-22,000Window Width: 29-41 inchesMinimum Window Opening Height: 19 inchesEnergy Star Certified: YesCEER: 14.7Control Type: ElectronicRemote Control: Yes
If you just need to cool small rooms under 150 square feet (like a guest room or home office), this no-frills window air conditioner is a great choice. It’s also suitable for temporary living spaces, such as a trailer or RV. Plus, installation is pretty straightforward because it’s so compact and comes with a mounting kit. This window air conditioner has two cooling speeds and two fans speeds that you can change by turning the dial, and its noise level is 56 decibels on the lowest setting. This is a bit louder than some of the other models on this list, but you should still be able to hear the TV or listen to music while it’s on. Because it has a mechanical control system, this window air conditioner can’t be set to an exact temperature. Instead, you’re limited to selecting from a temperature range. This unit has six different settings to choose from, ranging from minimum to maximum cool. Despite this lack of customization, the cooling power of this window AC is pretty impressive for the size and price—but people who want to have complete control over the temperature should probably choose another model. The GE window air conditioner also lacks some of the other features that higher-priced units have, like a remote, programmable timer, sleep mode, and Wi-Fi connectivity. It’s not certified by Energy Star, either. But if you’re determined to find a simple window air conditioner for small spaces, this model will definitely get the job done. Product Details:
Room Size: 150 square feetBTUs: 5,000Window Width: 23-36 inchesMinimum Window Opening Height: 13 inchesEnergy Star Certified: NoCEER: 11Control Type: MechanicalRemote Control: No
Even if you have a heating system in your home, there might still be a room or floor that it just doesn’t reach. People often purchase a space heater to remedy this, but a window air conditioner—like this multitasking option from LG—can solve your heating and cooling problems all in one appliance. This unit can heat a room with almost the same intensity that it cools, so it provides a similar effect as a portable space heater. And for heating a single room, it’s more efficient than running central heating throughout your entire home. This LG window air conditioner is only available in 18,000 BTUs, so it’s powerful enough for large rooms up to 1,000 square feet—but it requires a 230-volt outlet. It has two cooling/heating speeds, two fan speeds, and a 24-hour programmable timer. Other features worth mentioning include automatic restart after outages, a remote, a washable filter, and a check filter alert. The air conditioner has a noise level of 61 decibels, making it one of the loudest models on our list. (For reference, this is comparable to the volume of a normal conversation or a business office.) At 126 pounds, this window AC unit is also the heaviest, so be sure to have someone else available to help you during installation. Product Details:
Room Size: 1,000 square feetBTUs: 18,000 cooling/12,000 heatingWindow Width: 29-41 inchesMinimum Window Opening Height: 18 inchesEnergy Star Certified: NoCEER: 11Control Type: ElectronicRemote Control: Yes
The Windmill air conditioner has an auto-dimming LED display that won’t bother you at night, and it shows the room’s temperature, current mode, and Wi-Fi status. This AC also has an eco mode, which regularly monitors the room temperature and switches the appliance on and off as needed to save energy. Unlike most other units, this one is designed to blow air at a 45-degree angle (rather than at waist level), which can help cool the area around your bed, couch, or desk. In terms of installation, the double-insulated accordion panels and window frame come pre-assembled, so it’s ready to go straight out of the box. It uses a washable mesh filter, but you can also use an additional activated carbon filter to purify the air and remove odors. One activated carbon filter comes included with your purchase, but you have the option to subscribe to regular refills at checkout. One thing to note is that the Windmill AC is currently only available in 8,300 BTUs, so it won’t have enough power to effectively cool spaces bigger than 350 square feet. Product Details:
Room Size: 350 square feetBTUs: 8,300Window Width: 23-37 inchesMinimum Window Opening Height: 14 inchesEnergy Star Certified: NoCEER: 12Control Type: ElectronicRemote Control: Yes
How to Shop for Window Air Conditioners Like a Pro
Room Size and BTUs
The first thing to consider when shopping for a window air conditioner unit is the square footage of the space you intend to cool. You can determine any room’s square footage by multiplying its length by its width. Once you know the square footage of your space, choose a unit with the appropriate cooling capacity. The cooling capacity of a window air conditioner is rated in British thermal units (BTU). The higher the number, the larger the space it can cool. “Choosing the right size AC unit for the room is very important to ensure it will completely cool the room and remove humidity,” says McCoy. Ceiling height, room insulation, and sun exposure can also play a role in which size window air conditioner you choose. When deciding on BTUs, Brown suggests making the following adjustments based on your room’s conditions:
For rooms with excessive sunlight: “Select room air conditioners with 10 percent more BTUs than what is required by the size of the room.“For the kitchen: “Select a unit with an additional 4,000 BTUs than what is required by the room size.“For rooms that regularly contain more than two people: “Add an additional 600 BTUs per person.”
A window air conditioner with significantly more BTUs than necessary will be inefficient and leave you with excessive electricity bills. But on the other hand, an underpowered AC will run constantly and still struggle to cool the room. Most window air conditioners range between 5,000 and 15,000 BTUs. To help you determine the right option for your space, here are McCoy’s guidelines: To find the energy efficiency of a unit, refer to its combined energy efficiency ratio (CEER)—the number is usually between eight and 15. The higher the CEER, the more energy-efficient the air conditioner is. You can also look for models with sleep modes that adjust the temperature throughout the night for improved comfort and efficiency. Another way to check energy efficiency is by seeing if an air conditioner is Energy Star Certified, which means it uses at least 10 percent less energy than the U.S. federal standard.
Noise Level
If you’re shopping for a window air conditioner for your bedroom or a nursery, you’ll want to pay special attention to the noise level. This is measured in decibels (you might see it abbreviated as “dB”), but the number can vary based on what cooling output your air conditioner is set to. Anything below 60 decibels is considered a quiet window air conditioner, but the quietest models can get as low as 42 decibels.
Window Size
Before purchasing a window air conditioner, always measure the dimensions inside your window frame and compare them to the minimum and maximum dimensions of the unit to make sure it’ll fit. But it’s okay if your air conditioner doesn’t extend the entire width of your window—most units come with an installation kit that includes accordion panels to seal off extra space.
Electrical Requirements
Window air conditioners are more powerful than other household appliances, which means you’ll need to make sure your outlets meet the electrical requirements of your unit. Air conditioners with a lower BTU rating (under 15,000) tend to operate on 115-volt circuits, while large units operate on 230-volt circuits.
Features
There are many different features to choose from when it comes to window air conditioners, depending on your needs and budget. Here are just a few to consider while shopping:
Mechanical vs. Electronic Controls: Lower-priced window AC units often have mechanical controls, which allow you to manually adjust the fan speed and cooling levels within a certain range. Electronic (or digital) controls allow you to set the unit to your exact desired temperature. Most window air conditioners also come with a remote so you can adjust temperature settings or switch the unit on or off from across the room. Programmable Timers: This feature allows you to set your air conditioner to turn on or off within a number of hours, which helps reduce energy consumption (and your electricity bill). For example, you can set your air conditioner to turn on an hour before you get home so it’s nice and cool when you arrive, without wasting energy while you’re away. Smart Features: Many modern AC units are Wi-Fi enabled, so you can connect them to your phone or smart device and control them remotely. “If you have pets at home, having an AC unit that is Wi-Fi enabled means that you can adjust the temperature for your pet no matter where you are,” says Brown. These smart appliances are also more accessible because consumers don’t have to actually be in the room to adjust the temperature. Filter Sensors: It’s important to regularly clean and change the filter on your air conditioner to keep it working efficiently. Consider choosing an air conditioner with a sensor or indicator light that will let you know when the filter needs to be cleaned. Additional Functions: Some air conditioners also have a dehumidifier/dry mode, which helps absorb moisture in the air without additional cooling. Others even have a heating mode that can warm the room in the winter.
Questions You Might Ask
How do window air conditioners work?
According to Brown, window air conditioners typically perform three basic functions: cooling, removing air moisture, and filtering the air. “[Window air conditioners] use an internal thermostat to monitor the temperature in the room it’s situated in,” Brown says. “When the temperature rises in the room, the thermostat triggers the unit to turn on. The air from the room is then pulled into the unit, cooled as it moves over the refrigerant coils, and blown back into the room, circulating cooler air.”
Are window air conditioners better than portable air conditioners?
It all comes down to what your needs are. Generally speaking, window air conditioners are more energy efficient than portable options and don’t take up any precious floor space. But if you’re unable to install a window unit, a portable air conditioner is a good alternative. “Both can cool a room, but advantages to a portable AC unit is that it is relatively easy to install (an exhaust hose goes through a window) and can be moved room to room,” says McCoy. “It can also supplement larger systems and help cool apartments or rentals where you’re unable to install a permanent unit.”
How do you install a window air conditioner?
Because every model is different, you’ll need to pay close attention to the manufacturer’s instructions when installing your window air conditioner. Keep in mind that window AC units are heavier than they appear, so it’s best to have a second person available to help. Start by sliding the accordion panels on either side of the air conditioner and place it inside the open window. You may need to purchase a separate support bracket if you have a particularly heavy unit. Then you’ll need to follow your unit’s specific instructions for securing it in place—just don’t forget to fill any gaps with the foam seal.
How do you care for and maintain window air conditioners and filters?
All air conditioners have a filter to trap dust and keep it from getting into the unit, so regular cleaning is a must. Some models have reusable filters that you can wash, while others have filters that need to be replaced regularly. To keep your AC unit functioning efficiently, make sure you clean or replace the filter once a month.
Take Our Word for It
This article was written by Melanie Fincher, associate commerce editor for Real Simple with nearly three years of experience writing product reviews and lifestyle content. To compile this list, she spent hours researching window air conditioners and sifting through user reviews. For expert recommendations and tips, she consulted Gary McCoy, store manager at Lowe’s, and Matthew Brown, merchant of ACs and fans, air quality, and floorcare at The Home Depot.
