Central air is the ideal way to cool your home. However, not all of us can foot the high initial costs, especially if your home lacks a ventilation system. Window air conditioners are the next best thing since they only require a double-hung window and a little bit of clearance.
If you are concerned that a window AC might fall out of your window, you don’t need to worry. If you follow the installation instructions closely and use all of the safeguards at your disposal, your unit will stay firmly in place. Plus, with window security brackets that are commonly included, potential burglars will have trouble accessing your home from what had previously been considered a weak point in home security.
From our research and professional consultation, there are four things to look for: room size, outlet type, window size, and extra features. Air conditioners are rated by BTU (British Thermal Units), ranging from 5,000 to 24,000 BTU. The Department of Energy provides a helpful guide for determining the BTU that is right for your room size. If you get a unit that is too big for your room, it will cool too quickly without removing the moisture, which will create a cold, clammy environment. And, an AC that is too small will be overworked, which boosts your energy costs.
Along with testing window air conditioners (details on how we tested air conditioners can be found at the end of this guide), we looked at the ratings and reviews of the top models from experts and owners. Our guide features units that performed well in our tests, have useful features that justify their price, and are energy-efficient. We also discuss what other models we looked at but didn’t make our cut.
If you are searching for a portable model, check out our guide on the best portable air conditioners.
Here are the best window air conditioners:
- Best overall:LG Dual Inverter Smart Window Air Conditioner
- Best for small rooms:Frigidaire 6,000 BTU Air Conditioner
- Best for medium-sized rooms:GE 8,000 BTU Smart Window Air Conditioner
- Best for bedrooms:Haier Serenity Series Quiet 6,000 BTU Window Air Conditioner
- Best for efficiency: Midea U Inverter Window Air Conditioner
Prices and links are current as of 9/2/20. We added the Midea U after testing as the best window air conditioner for efficiency.
The best overall
The LG Dual Inverter Smart Window Air Conditioner provides an impressive combination of quiet operation, outstanding performance, and energy efficiency.
LG is currently ahead of the competition with its dual-inverter technology. With most window ACs, the compressor runs until it hits the target temperature, then it turns off until the temperature increases again, which starts the process again. Dual-inverter compressors, however, have variable-speed motors that adjust to maintain the desired temperature. For instance, at first, it might run at full speed, but when the ambient temperature reaches the target temp, the motor will slow to maintain the target temperature.
LG claims this makes their dual-inverter ACs 25-percent more efficient than what is needed for Energy Star certification.
We tested the 14,000 BTU model (LW1517IVSM), but LG also offers it in 9,500, 18,000, and 22,000 BTU. The 9,500 BTU model should suit most people, but pick the recommended BTU that best fits the size of your room — see our chart below.
The LG performed the best in our cooling tests, dropping the temperature in a 650-square-foot room by 3.3 degrees in one hour. It was also the quietest, registering just 53 decibels when on high — it did not inhibit normal conversation. Plus, it has the highest energy efficiency ratio (EER) of 14.7. When it comes to performance, noise, and efficiency, it’s the best.
The unit quickly sends a jet of cool air into the room once you turn it on. I found that it does a good job of staying at the set-point you choose and maintaining the comfort level. Since the compressor is operating at a lowered capacity once it hits the set-point, it gets even quieter when it’s in temp maintenance mode — I often forgot it was on. Fortunately, you can set a timer to turn the unit off.
Installation was difficult, however. It took me two hours and included steps like removing and reinstalling the cabinet from the unit and installing the face. This could be an issue for people who need to remove an AC from a window during colder months of the year.
Another issue is that the window has to be 27-inches wide in order to accommodate the AC. Because our testing room’s windows were 24.5-inches wide, we had to set-up the LG in another room for testing. I also wished LG had provided a longer warranty than one year, which, admittedly, is standard for many appliances.
The LG can be integrated into a smart-home setup — it can connect to a Wi-Fi network and supports Alexa and Google Assistant. You can use LG’s SmartThinQ app to schedule the unit and perform other remote operations.
Pros: Top performer in our cooling tests, quiet operation, energy-efficient dual-inverter technology, Wi-Fi connectivity with support for Alexa and Google Home, remote control with smartphone app
Cons: Pain to install, underwhelming one-year warranty, only works in windows at least 27-inches wide
The best for small rooms
For rooms of up to 250 square feet, the Frigidaire 6,000 BTU Air Conditioner hits all of the right notes with low energy usage, low noise levels, and easy installation in a variety of window sizes.
At 6,000 BTU, the Frigidaire 6,000 BTU Air Conditioner (Model FHWW063WBE) is designed for use in small rooms, and it carries out that job quietly and efficiently. According to the manufacturer, this AC operates at just 51 decibels.
The Frigidaire FHWW063WBE is Energy Star-certified and has an EER of 12.2 so you can count on reasonable electric bills. The user manual comes with additional energy-saving ideas, including making full use of the six-way air directional louvers to send the cool air precisely where you need it most.
This model weighs 42 pounds and only requires a Philips screwdriver for installation so it’s easy to set-up during the warm months and remove when the weather turns cold. And, Frigidaire offers an impressive warranty: In addition to the basic one-year limited warranty on general parts and labor, there’s a five-year limited warranty on the sealed system, including the compressor, condenser, evaporator, and tubing.
The unit as also WiFi capable and compatible with Alexa and Google Assistant, allowing you to control the unit via the Frigidaire app or using voice commands.
Pros: Quiet operation, easy setup, fits a wide range of windows, energy-efficient (Energy Star certified), limited five-year warranty on sealed system, Alexa and Google Assistant compatible
Cons: Not suitable for cooling larger rooms efficiently
The best for medium-sized rooms
The GE 8,000 BTU Smart Window Air Conditioner is the best for rooms between 300 and 350 square feet in size, with its low-decibel output, outstanding cooling, and easy installation.
In regions where the temperatures dip below zero for weeks at a time, you want to be able to take your AC unit out for storage in the winter and reinstall it when the mercury starts to climb again. The GE 8,000 BTU Smart Window Air Conditioner (Model AHY08LZ) is ideally suited for this with its relatively light weight of 54 pounds and simple installation. I had it up and running within 20 minutes of opening the box, and it fit my slender 24-inch-wide windows.
But, more importantly, it’s a workhorse. In our test room of 650 square feet — twice what the unit is rated for — the GE was able to drop the temperature by more than 3 degrees Fahrenheit in an hour. It did this while remaining fairly quiet, registering only 55 decibels. And, there were no obnoxious jarring sounds as we switched between cooling speeds, which makes it suitable for bedrooms and offices.
This model features a brushed steel control panel presenting the temperature in large, easy-to-read digital numerals, which automatically dim to keep light pollution to a minimum. The face also features adjustable louvers that allow you to send the cool air precisely where you want it most.
The GE has Wi-Fi connectivity and can be operated remotely, but the biggest negative I found with the unit was that I could not get it to connect with GE’s Comfort app. At times, the app would recognize the existence of the appliance, but it would not connect. After several other tries, I still couldn’t use any of the smart features. Based on the 2.5-star rating in the Google Play store, I’m not alone. Several reviewers point out that an update in April 2020 led to the app’s downfall.
I reached out to GE about the app issues, and they responded quickly. It’s a known issue for some users, and they did not have a timeline for when it would be fixed. However, even without the smart features, this is an outstanding unit.
GE offers this AC in other BTUs, as well — all the way up to 24,000.
Pros: Energy Star-certified, performed well in cooling tests, easy to install, quiet operation
Cons: Unable to access smart features, unimpressive EER rating, minimal warranty
The best for bedrooms
The Haier Serenity Series Quiet 6,000 BTU Window Air Conditioner is ideal for bedrooms thanks to its ultra-quiet design.
With a manufacturer-reported 43-decibel operation, the Haier Serenity Series Quiet 6,000 BTU Window Air Conditioner (Model ESAQ406T) is one of the quietest models in our guide, which makes it ideal for bedrooms of 150 to 250 square feet.
The unit also comes with everything you need for a thorough installation, including a foam seal, weather seals, a window lock bracket, and side curtains with an additional foam insulation layer. You just need a screwdriver and a drill.
The Haier ESAQ406T has a respectable EER of 12.1, and the four-way adjustable air directions give you control of where the cool air goes.
The biggest negative is that this model requires a window that is at least 26 inches wide, which is more than most units with its BTU output. So, make sure you measure before choosing this.
Popular Mechanics recommends the Haier ESAQ406 because it’s one of the most energy-efficient and quietest window ACs available. The reviewer found the internal compressor blanket dampened the noise so well that it operated at an impressive 43 decibels.
Pros: The quietest model in our guide, Energy Star-certified, high EER, easy to install, multi-directional vent control
Cons: Stingy warranty, requires window width of at least 26 inches
The best for energy efficiency
The Midea U Inverter Window Air Conditioner features a unique U-shape design that allows you to open the window when it’s installed, and it’s one of two ACs to earn Energy Star Most Efficient Certification.
The Midea U Inverter Window Air Conditioner has a unique U-shaped design that offers a more secure installation when combined with the included support bracket — hardware rarely included with AC units — and allows you to open and close the window to let in fresh air. The design also reduces the need for side curtains and requires minimal insulation.
The other important feature is efficiency. It’s the first window AC to receive the Energy Star Most Efficient Certification, and it remains one of only two models to receive that designation — the other is our top pick. Like the LG Dual Inverter AC, the Midea U uses inverter technology for efficient operation. Per Energy Star, the CEER is an impressive 15.
Installation of the Midea U is a breeze, though the instructions could be clearer. Everything you need for a secure, well-insulated install is included in the box. Since my install was short-term for testing purposes, I skipped several of the insulation steps and had the unit up and running within 25 minutes of opening the box. You’ll likely need a little more time to properly install and insulate your model. I like that this model fits in a broad range of windows ranging from 22 to 36 inches wide.
I was most impressed with how quietly the AC runs. The sound meter registered 48 decibels when the Midea U was operating on its highest setting. I also tested to see how much energy the unit used when I blasted the air for 24 hours. According to my smart plug, it consumed 9.6 kWh, which is the lowest power consumption reading I’ve recorded of the ACs I’ve tested.
In my cooling test, the Midea U didn’t do as well as the LG, but I tested the 14,000 BTU LG and 8,000 BTU Midea. Such a drastic difference in BTUs will correlate to a difference in cooling ability. The Midea U decreased the temperature of our 650-square-foot room 1.7 degrees in the first hour. This is comparable to the GE Smart Window AC.
Lastly, I was impressed with how well the smart feature worked. Connecting was a snap and I could seamlessly control the Midea U with my voice using Alexa.
Pros: Unique U-shaped design, Energy Star Most Efficient Certification, easy to install in a wide array of windows, comes with a support bracket, quiet 48-decibel operation, smart connectivity that works well
Cons: Can only change airflow direction horizontally
What else we considered
We looked at several window air conditioner models and brands while researching this guide. The following missed the cut, but are worth looking into.
If you’re on a tight budget and only need to cool a small room (about 150 to 250 square feet), this Amana model may be your best bet. It fits various window sizes and is easy to install. Plus, it only weighs 44 pounds. But, it tends to run loudly, and in Consumer Reports surveys, owner satisfaction was only “fair.”
LG is one of the top names in air conditioning. But, we think that if you’re going to go with the brand, the dual-inverter models are worth the extra initial cost since you will recoup your money in energy savings. This model doesn’t have inverter technology, but it’s still impressive with an EER of 12.1 and Wi-Fi control through the LG SmartThinQ app. But, as with the LG unit we tested, it’s a pain to install.
This model is similar to the LW1017ERSM. The main differences are this model is not Wi-Fi-enabled and has more cooling power at 12,000 BTU (versus 10,000) so it can cool rooms of between 450 and 550 square feet in size. Many reviewers recommend this unit. However, we don’t due to the difficult install, it only fits larger windows, it lacks an inverter compressor, and the one-year warranty is unimpressive.
This model was in previous versions of our guide because it’s available in a broad range of BTU ratings — from 5,200 to 24,000. We also appreciate that it’s Energy Star-certified, comes with a remote control, and has a 24-hour timer. Additionally, it has good air direction control and a five-year warranty on the sealed system. We decided not to include it this time around because we believe there are better options at this price, and it runs relatively loudly.
This Frigidaire is very stylish, which may be important for some since a window AC is noticeable in a room. We like the clean look, Wi-Fi connectivity, and easy installation. However, reviewers ding the unit for its loudness and there are owner complaints about difficulty connecting to the AC with their phones. We hope to test this unit soon to give it a second look.
How we test window air conditioners
There are numerous tests I put each unit through, and for any highly rated models I have not fully tested, I extrapolated the key performance indicators based on testing results from other trustworthy product-review websites. The most important AC factors to consider are performance, noise, and efficiency.
Here are the main attributes we look for and how we test them:
Cooling: What good is an air conditioner if it can’t cool a room? This is our most important test. I set the unit up in the test room, which is approximately 650 square feet. I place a thermometer on the opposite end of the room. Then, I have the air conditioner run on high. I measure the temperature and humidity before I turn the unit on and compare it to the readings after it’s been running for an hour.
Loudness: You don’t want an AC unit to keep you from sleeping, working, or watching TV so it needs to run quietly. To test this, I used a sound meter positioned six feet away from the air conditioner as it ran on high. I also adjust the fan speeds and set point to see if these changes caused off-putting sounds that could startle people nearby.
Extras: At a minimum, an air conditioner should come with a window installation kit, remote control, dehumidifier and fan modes, and delayed on and off. I also look for additional conveniences, like including foam to seal and insulate the openings around the AC. WiFi-enabled smart capabilities are also a major plus, but I found there’s a lot of room for improvement in this area.
Energy-Efficiency: I look at whether the unit is Energy Star-certified as well as the energy efficiency ratio (EER). The EER is the BTU divided by the Watts. The combined energy efficiency ratio (CEER) is also commonly used. It takes into consideration the energy consumption while a unit is in standby mode. To receive Energy Star certification, most units need a CEER of at least 12 (in addition to other requirements). Every unit in our guide is Energy Star-certified. This is crucial for keeping down long-term utility costs.
Installation: Though installation will likely only be a small part of your relationship with your AC, it’s an important part. Windows between 27 and 36 inches wide will accommodate most window units, but if you have a 25-inch-wide window, it gets dicey. We look at what windows different models fit. We also look at how long it takes to install the ACs, if you need special tools, and how difficult uninstalling and reinstalling it will be if you live in a climate where winterizing is a must.
Additionally, we examined how much control you get over airflow direction and warranty information. The units tested in this guide were supplied free of charge by the manufacturers for us to review.
The model numbers of nearly identical units may vary by one or two digits. This is done to denote different BTU ratings and colors for essentially the same model. Rather than ensuring you get the precise model number you’re looking for, it’s more important that you choose the BTU rating that is right for your room.