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A sweltering home makes for a miserable summer. A window air conditioner can fix that, but shopping for one can be overwhelming, especially when it comes to figuring out what size and power you need for the room you’re cooling.
Jonathan Berkson, owner of SupeCoolNYC, which specializes in installing window conditioners for first-time buyers, says to always consider the size of your space and the power a potential unit will need to cool it properly, adding that performance is more important than operating cost. “The cost of operating window units has decreased dramatically over the past 20 years or so,” he says, “and most all units from major brands on the market are very comparable as far as electricity usage.”
To calculate a room’s AC needs in BTUs (British thermal units), first determine its square footage (length of room times width of room), then multiply that by 20; a ten-foot-by-ten-foot, or 100-square-foot, room needs an AC unit rated at 2,000 BTUs or higher. Just keep in mind that halls, open doorways, and archways can all cause the effective size of the room to grow, and you may need to adjust for extra-tall ceilings or how much sunlight the room gets (Energy Star has some useful tips for these and other considerations).
Jesse Mastro, owner of RentAnAc, a company that offers air-conditioner rentals, sales, service, and installation — and that also tries out the newest ACs that hit the market each year — looks first to legacy brands like LG and Frigidaire, which have stood the test of time. But Mastro is also a fan of several newer AC makers like Windmill, the brand behind one of the sleekest-looking window air conditioners on the market today.
To help you find the best window air conditioners for your space and budget, we spoke to several air-conditioner experts, who have years of experience in the AC business and have catered to everyone from homeowners to college students looking to cool dorm rooms. We also tried some units ourselves. Below, a breakdown of everything from compressor types to warranty length to unit size to operating options (which range from a simple dial to voice controls), so you can find the best air conditioner unit to cool things off. Every model here is available in a range of BTU ratings.
Update on July 18, 2024: Replaced best overall with the Midea U Shaped after additional testing and research; updated prices and checked stock for all other products.
What we’re looking for
Compressor
Also known as “variable speed compressor technology,” an inverter compressor is the number-one feature recommended by the Environmental Protection Agency as part of their EnergyStar guidelines for buying an efficient air conditioner. Not only are these units more efficient, they are much quieter too. Whereas regular compressors must run loudly at full tilt or not at all, an inverter compressor is able to cool a room quickly at full tilt, before settling into a lower, quieter setting in order to maintain the desired temperature. This feature used to be difficult to find on window units and was often only available at a premium price. But now there are many more options, often for the same price or less than a regular window unit.
Noise level
According to the CDC, prolonged exposure to noise levels over 70 decibels (dB) — which is equivalent to a washing machine’s operating noise — can put some people at risk for noise-induced hearing loss. And some of the louder window AC units do indeed exceed 70 dB (roughly the equivalent to the sound inside a car cruising down the highway at 60 MPH), though often improper installation or unfilled gaps around the units are to blame. Many great window AC units operate at much quieter levels, especially at lower power settings; some are able to run at below 50 dB, which is not much louder than the hum of a refrigerator.
Warranty
Even the best window AC unit ever made is of little use if it stops working properly and is of no use if it breaks down. We factored in the many years of experience our experts have with various AC brands as well as the warranties offered by the companies themselves. And FYI, heavy use is no problem for a good unit — per PickHVAC: “A window air conditioner can run 24 hours a day, seven days a week without shortening its average lifespan. Running continuously will not cause overheating, excessive wear and tear to the unit, or any other damage that will shorten its life.”
Best air conditioner overall
Compressor: Inverter / Noise level: 42 dB / Warranty: 1 Year (5 years for compressor)
This Midea model is a uniquely shaped, EnergyStar-approved unit that allows a closed window leaf to rest in between the exterior-facing compressor and the interior-facing blower. This separates the noisiest part of the machine from the inside of your home, resulting in a whisper-quiet lowest setting of only 33 decibels. Even its highest setting only produces 42 decibels, which is less than most machines’ lowest settings. The U Shaped also preserves the ability to open the window, which means you can leave it installed through the colder months if you’d rather not deal with storing it. It’s also quite reliable. We spoke with Robert (who asked his full name not be used) at Lowe’s Home Improvement in Garden City, New York, who told us that despite its popularity, fewer of the Mideas are returned or serviced compared to other models they sell. (It is also available in more powerful 10,000 BTU and 12,000 BTU versions for larger rooms.)
The only caveat to the Midea’s design is that the heavy compressor must be supported from below. It includes a heavy-duty window bracket for this purpose (typically a $50 to $80 standalone purchase). The bracket fits a wide range of buildings, but may not accommodate brownstone-type window ledges that extend a foot or more beyond the base of the window frame. (If that describes your building, you can work around it by stacking bricks, tiles, or other durable shimming materials directly onto the ledge.) The installation process itself is simple, but differs from that of regularly-shaped window units, so be sure to read through the easy-to-follow instructions carefully. Finally, while smart features for air conditioners are more nice-to-have than necessary, the Midea app is very convenient for confirming that you remembered to turn the thermostat up before leaving the apartment.
Strategist writer Lauren Ro has three of the Midea U Shaped units in her home and said her husband found installation pretty easy. “I love the Midea because it’s quieter than all the other ones we have,” she says. “I hate loud noises, and even the Windmill [Original], which we have two of, is too loud.” Senior editor Winnie Yang has two of these air conditioners as well, and both she and Ro appreciate that this model doesn’t obscure as much of the window as more conventionally shaped ones.
Best (less expensive) air conditioner overall
Compressor: Regular / Noise level: 52 dB / Warranty: 1 Year
There are two things about this Frigidaire unit that are small: the price tag, and the size of space it can cool down (about 150 square feet). But if you are only concerned about one smaller room — a bedroom or office, perhaps — then this thing is just impossible to beat in terms of value. And I say that by factoring in price and reliability. “Frigidaire has stood the test of time as having the most well-built machines,” says Mastro of RentAnAc, and this one is backed by a year-long warranty from Frigidaire. You won’t find a much simpler air conditioner, as it features just two dials, one that controls fan speed (and turns it off) and one that controls the temperature. It couldn’t be easier to use, just as long as you make sure to rinse off the filter now and then.
Best regular-shaped air conditioner
Compressor: Inverter / Noise level: 58 dB / Warranty: 1 Year
If you want a more familiarly shaped air conditioner and are willing to put up with a bit more noise, this LG model is also EnergyStar-approved and relatively quiet, just not as quiet as the Midea U Shaped. It generates 58 dB when running on high, but when it’s in “sleep mode” it goes down to 44 — about the amount of noise you’ll hear in a quiet library. RentAnAC’s Jess Mastro says: “LG makes air conditioners with excellent efficiency and noise control.” That’s thanks to dual inverter technology that uses twin rotors to blow out compressed air instead of a single fan. You can control the unit via an app (or with your voice when it’s paired with a smart-home device). It has four fan speed settings, and the dual inverter technology also helps it waste less energy. SuperCoolNYC’s Berkson trusts LG because the brand “has invested in research and development with their units” and because “the customer service is excellent.”
Strategist writer Dominique Pariso has the LG Dual Inverter and says it cools down a large space very effectively and also handled heat waves with no problem. She doesn’t use the app but says, “It’s simple to use the manual features, and I also appreciate that it’s very easy to clean.”
Best air conditioner with regular compressor
Compressor: Regular / Noise level: 54 dB / Warranty: 1 Year
If the Midea or dual-inverter LG is sold out and you don’t mind slightly less efficiency and slightly more noise, this Frigidaire is a reliable model that’s easy to install and operate in spaces measuring up to 450 square feet. Although this unit is not EnergyStar certified, Berkson of SuperCoolNYC says that over the years, he has found “Frigidaire window units have been the most reliable.” This model measures 14.65 inches in height and is heavy but easy to install in single or double-hung windows with 18 inches of opening height and as narrow as 28 inches or as wide as 40.5 inches (no special tools needed). Control is pretty simple here too: You set the fan speed — of which there are three options — and desired temperature via remote control or on the unit itself, and there’s a timer function to use if you want the air conditioner to shut off after a given period of time. And the fan is never louder than the volume of a casual conversation, even at full power.
Best air conditioner with heater
Compressor: Regular / Noise level: 49 dB / Warranty: 1 Year
This unit not only cools your 380-square-foot space, it can warm it as well. The four-way directional air circulation spreads air or heat quickly, and at a 49-decibel operating volume, it does so quietly. This air conditioner–heater can be fit into a window opening measuring 22 inches across and just 14 inches tall, making it a great choice for apartment dwellers or for use in a bedroom or office with small windows. Do note it’s pretty heavy for a smaller unit at 66 pounds. But it’s also durable and reliable.
Best large air conditioner
Compressor: Regular / Noise level: 67 dB / Warranty: 1 Year
I used an older version of this Whirlpool air conditioner for five years when my wife and I shared our first home, and it kept most of the four-room apartment quite cool without ever experiencing a single issue. It works well for the 1,500 square feet of cooling it’s rated for, provided the area is well sealed and you keep doors open (we ended up needing a second, smaller unit for the bedroom, since we shut the door at night). It’s a large piece of machinery requiring a window opening at least 30 inches wide and 19.5 inches in height, and it gets pretty noisy at 67 dB when at full crank. But it has a cooling capacity that might trick you into believing you have central air, and you can always set the fan speed lower. It’s the most expensive unit featured here, but it’s also far and away the most powerful.
[Editor’s note: The 24,000 BTU version of this AC unit is currently sold out everywhere, but you can sign up for restock notifications on the product pages below.]
Best air conditioner to preserve the view
Compressor: Regular / Noise level: 49 dB / Warranty: 1 Year
The Soleus Air Exclusive is one of only a few units using a new design of window air conditioner that preserves most of the view and light you enjoy from your window. By bridging the sill in an upside-down U shape with the controls and cool air vents hanging inside your home and the condenser portion of the unit hanging down outside, it lets you lose only a few inches of the window opening while gaining an air conditioner that can pump chilled air in as well as any other window air conditioner. That is, provided the over-the-sill air conditioner will work for your space, as not all windows are the same thickness — if your sill is more than 11 inches deep, in our experience, this (and other comparable over-sill options) will not fit. Likewise, some window sills are too narrow or are uneven, mounting this air conditioner may not be possible, either. If you can get it secured in place, you’ll appreciate the remote-control options, which include a 24-hour timer and a quiet sleep mode.
Our experts
• Jonathan Berkson, owner of the AC installation company SuperCoolNYC
• Jesse Mastro, founder of RentAnAC
• Dominique Pariso, Strategist writer
• Lauren Ro, Strategist writer
• Winnie Yang, Strategist senior editor
Additional reporting by Michael Zhao.
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