Amazon (12,000 BTU)
Amazon (16,000 BTUs)
Amazon (6,000 BTU)
The world is getting warmer. And the weather is getting weirder. Air conditioning isn't the answer, but it does help: Extreme heat is exhausting, and it ages you faster than smoking or drinking. The best window air conditioners—like our top pick, Midea's 8,000 BTU U-Shaped Smart Inverter Window Air Conditioner ($400)—offer sweet relief. This Midea model also has a smart design that still lets you open your window.
Like our other favorite window and portable cooling units, the Midea is among the most energy-efficient on the market, and uses newfangled coolants that don't deplete the ozone like the more damaging ones of yore. Heat pumps are even more efficient, and minisplits like the Della Optima Series 12,000 BTU 23 SEER2 ($970) are becoming increasingly accessible although they require expensive installation.
We've also included the best models for those on a tight budget, such a surprisingly quiet small-room 5,000 BTU air conditioner from GE for a mere $164. But note that budget models generally aren't as efficient, so saving on upfront cost can lead to higher energy bills over time.
Be sure to check out our other air quality guides, including Best Air Purifiers, Best Indoor Air Quality Monitors, and Best Fans.
Updated May 2026: We've added the Della Optima Series 12,000 BTU 23 SEER2 as a heat pump option, and the newly updated Zafro dual-hose portable smart inverter. We've also removed discontinued models and brands such as July, streamlined our top picks, and updated links and pricing throughout.
Amazon (12,000 BTU)
Amazon (8,000 BTU)
Surprise: A window air conditioner that actually lets you open the window. Midea’s U-shaped AC comes with a bracket that balances the unit’s weight by leaning against the exterior wall of your home, so you can open the window without worrying your AC will fall out. The big notch between the front and back also lets you pull down your window deep into the unit, leading to less of an air gap and better efficiency. (It's also nice for soundproofing, noted WIRED senior editor Julian Chokkattu.) Foam padding is included to help seal off the small remaining gap.
This U-shaped AC remains WIRED's favorite after substantial fixes following a voluntary recall last year over worries about mold formation in the fan—largely due to less than ideal installation. The 2026 version includes a redesigned drain plug and seals, easier cleaning access, and bubble levels to ensure the unit is tilted appropriately to drain. I've received the newest model with the fixes, and am keeping an eye out for any condensation. I'm also testing the Midea's newest Inverter Plus line.
For now, no other unit matches this unit's mix of convenience, performance, quietude, and energy-efficiency. Because most of the AC's components are housed outside the window, this AC is among the quietest we've tested. It cools quickly, and is among the most energy efficient on the market. The AC connects to Google Assistant and Amazon Alexa, meaning you can turn it on remotely before you get home, and has an app that tells you when to replace the filter. It also performs exceptionally well with minimal maintenance, according to reviewer Lisa Wood Shapiro's long-term testing. Just note that this video from the company is more helpful than the printed instructions when it comes to installation.
Comes in 8,000, 10,000, and 12,000 BTU
Amazon (16,000 BTUs)
Amazon (12,000 BTUs)
Even though my home has central air, it's a large, ancient house insulated with horsehair and tissue paper—with massive, oddly shaped single-pane windows that are about as thick as cardboard. I also have a taste for ambient temps in the mid-60s Fahrenheit. Restricting 68-degree cooling to just my bedroom and connected home office makes sense financially.
Enter the Zafro Smart Inverter, a powerful portable AC that uses two duct hoses fed into an adjustable panel that slides into your window frame. That design makes this device incredibly flexible for weird windows, and would have saved my ex-wife two days of carpentry when custom-building a frame for the horizontal sliding windows we had in an ’80s-built home out West. Push the power button, and the two vents on the top open to direct air around your room.
In a month of testing, I've found the Zafro delivers the performance and flexibility you'd expect at this price. The model I tested offered an impressive 16,000 BTUs of cooling, more than enough to quickly cool the approximately 400 square feet where I'm using it. There's a system for ejecting condensed water automatically, which works in all but extreme humidity, which I have not yet encountered. In addition to a full suite of buttons on top and an included remote, the device connects via Wi-Fi to an app that allows you to set the temperature and pick between modes (eco, humidity reduction, fan, and a super-powerful extra mode that pins the pedal to the floor and attempts to cool your space to 61 degrees as quickly as possible). The device comes with two types of foam to fill any gaps around the window, though arriving at the right fit is tougher than I'd like and I've learned to live with a quarter-inch gap in several spots.
The other best reason to buy this device is a capability I haven't even used yet: the ability to easily roll it between rooms and set it up in a different window. Like all portable window devices WIRED recommends, this is a dual-hose system that does not create the depressurization "vacuum" effect that's common in single-hose units. —Martin Cizmar
Amazon (6,000 BTU)
The cheaper you go, the fewer features you’ll get and the less efficient your AC unit will be. You can check a model's efficiency by looking for its combined energy-efficiency ratio, or CEER, which measures the unit's cooling capacity as compared to the power input, in both cooling and in standby mode. The higher the rating, the better. Essentially, you pay less in electrical bills over time. The Midea AC in this guide has a CEER of 15, one of the highest you'll find. This GE model, on the other hand, has an 11.1 CEER rating.
Still, your budget right now might be tight. If that's the case, I've had a great experience with this model over the span of a year. It doesn't include a bracket, but it's still easy to install. It's a smaller 6,000-BTU model and can cool rooms up to 250 square feet—it cooled my 150-square-foot bedroom so well (with the door closed) that I had to throw on blankets in the middle of the night. You'll notice its effects quickly, but it does take some time to cool the whole space. It's one of the louder window units on this list (around 65 decibels). Annoyingly, every time I turn it on, it forgets my preferred settings. I got around this by connecting it to a smart plug, which made it remember my modes and also let me control the AC with Google Assistant. —Julian Chokkattu
Comes in 5,000 or 6,000 BTU
Look, at 5,000 BTU, this GE window air conditioner isn't that powerful. There's no app and no remote. Airflow options are limited: You can't direct air up and down, only left and right. But it's the cheapest model we recommend, relatively easy to install, and much quieter than you'd expect for the price. It'll cool a small 150-square-foot space quickly and mostly frictionlessly. As an added bonus, its sleek black exterior also doesn't attract fingerprints, noted WIRED reviewer Lisa Wood Shapiro. —Matthew Korfhage
Comes in 5,000 BTU
Windmill excels at removing the annoyances we've all come to accept from window air conditioners. Namely, they're usually ugly, loud, and hard to install. When longtime WIRED reviewer Adrienne So tested the first model of the 8,000 BTU Windmill window unit (8/10, WIRED Recommends), she declared it the first AC she “didn't want to bash out of my window with a hammer” for being so ugly.
The window install kit comes pre-assembled, which makes installation a 15-minute affair. The newest WhisperTech model is also relatively quiet (if not as quiet as our top pick Midea), ranging from the barely-audible hum of a white-noise machine to around 50 decibels. You may need to raise the volume on your television, but not by much, noted reviewer Lisa Wood Shapiro, who tested the newer model.
The unit’s magnetic face comes off for easy access to the filter, and there’s a holder for the additional small patch of activated carbon filter. The Windmill is compatible with Google Home and has an app you can use remotely if you want to start cooling your house before you get home. Advance scheduling is also possible. The unit’s buttons are easy to see, and it has an auto-dimming LED display. Windmill partners with EcoCart for carbon offsets, and New York and California customers can sign up for an Eco Rewards program designed to relieve the energy load during heat waves. Signing up gives Windmill agency to adjust the settings on your unit, taking stress off the power grid. In return, you get cash or free filters for not opting out. —Matthew Korfhage
Comes in 6,000 BTU, 8,000 BTU, and 8,000 BTU with WhisperTech.
The EcoFlow Wave 3 is not for the weak, wrote WIRED reviewer Lisa Wood Shapiro: It weighs nearly 56 pounds when attached to its 22-pound lithium battery, so “portable” doesn't mean you'll be carting this 6,100 BTU air conditioner and heater around on foot. Rather, the Wave 3 is portable because it's battery-powered. Thus, it's suitable to cool off-the-grid spaces like cars, RVs, tents, or boats—or perhaps errant rooms in your home without a suitable place for a window air conditioner. WIRED senior editor Julian Chokkattu tested previous models of the EcoFlow in his wife's office for years, while Wood Shapiro used hers to cool down her van for her dog on hot days. Just note that before use, you need to leave the Wave 3 in a flat, fixed position for at least two hours, and avoid tilting it beyond 15 degrees.
For many, the best use will be cooling off pets in Pet Mode, which activates at temperatures above 77 degrees Fahrenheit. The Wave 3 was able to drop the temperature in a Toyota Sienna van from 85 to 76 degrees in 15 minutes, in a baking parking lot—offering comfort to a pair of dogs who promptly stopped panting. Wood Shapiro was able to control fan speed through the intuitive EcoFlow app, which she found easier to use than the control panel.
The Wave 3 isn't quiet, exactly, but its 60-decibel hum has the approximate character of a white-noise machine. As a safety note, the EcoFlow Wave 3 uses R290 refrigerant, also known as refrigerant-grade propane. This is a good choice for the environment and has been used in air conditioners in Europe for decades. But like all propane, R290 is flammable, so avoid placing the EcoFlow in direct sunlight on very hot days (this makes using its solar charging panels a bit of a creative endeavor.) The Wave 3 also can't get wet, so check the weather first if you plan on camping and placing the Wave 3 outside your tent. —Matthew Korfhage
Comes in 6,100 BTU
Heat pump technology keeps getting more accessible, which is terrific: It's far more efficient than air conditioner technology as a means of heating and cooling the house. I'm still waiting for window-unit mini-splits to become available, but in the meantime, mini-splits like this Della can now be ordered at less than $1,000 on Amazon, installation very much not included.
WIRED reviewer Chris Null tested the Della Optima Series 12,000 BTU 23 SEER2 in his Texas home, and found it performed well at an excellent price, with admirable features despite a couple rough edges. It's quiet, never more than a whispering 40 decibels. The app is intuitive and allows scheduling based on the time or day of week. The unit also supports Alexa and Google Assistant, though without a logging system to track a running history of operations. A geofencing system, alas, was difficult to get up and running.
You might find international models for less, but they likely won't come with a lifetime warranty. Note, however, that you'll need a certified HVAC technician to install your unit if you want to activate the warranty—and unless you're quite handy, you'll almost certainly want a pro anyway. Unfortunately, installation will likely run multiple times the cost of the actual unit. —Matthew Korfhage
Comes in 9,000, 12,000, 18,000, and 23,000 BTU cooling.
LG 12,000 BTU Air Conditioner for $379: The LG 12,000 BTU Smart Window Air Conditioner offers efficient large-room cooling at a surprisingly low price. It weighs 90 pounds and requires professional installation with a bracket. Its 60-decibel operation places it squarely in the middle of the pack on noise. This said, WIRED reviewer Lisa Wood Shapiro found it blends into a room well with its white-on-white design, and that the filter replacement indicator light is useful. The app was laggy and difficult to use during Wood Shapiro's testing, but there is a remote.
Friedrich Kuhl Air Conditioner for $1,228: This unit from Friedrich is among the most expensive we've tested, and one of the heaviest—in part because of a metal chassis designed to provide easy maintenance access and deter first-floor break-ins. This model allows adding a custom Friedrich FreshAire MERV 13 filter to clean the air as it cools. The screen is easy to read, and the device comes with a remote. An app lets you schedule the unit's use over the course of the week, but note that connection with the smart app was a little janky, and paired only with 2.4 Ghz signals.
EcoFlow Wave 2 for $1,299 (but usually on sale for much less): Wood Shapiro tested the newest model, but previous models of the EcoFlow are often available at steep discounts. After happily testing the EcoFlow Wave 1 for more than a year in his wife's office, WIRED senior editor Julian Chokkattu far preferred the EcoFlow Wave 2 (8/10, WIRED Recommends) because it's both lighter and more cost-friendly, with a higher 5,100 BTU rating (up from 4,000). A heating mode rated at 6,100 BTU means you can keep using it in the winter to warm up. The company says it's best for rooms up to 107 square feet. You do need to place it near a window to have one of the included ducts connected to the vent to take hot exhaust from the back of the unit out of the room. What makes this unit versatile is its alternate power sources. You can use a standard AC outlet, but you can also buy an add-on battery to keep it working when you don't have access to electricity, or hook it up to solar panels.
Zero Breeze Mark II for $999: With its 2,300 BTU, the Zero Breeze (7/10, WIRED Review) won't have the same cooling power as the EcoFlow Wave, but it's much lighter at 17 pounds. This bundle includes a battery that makes the whole thing weigh about 30 pounds, but you'll get four hours of use without needing to be near a wall outlet. Like the EcoFlow, you get a few vent pipes to direct exhaust away and direct cool air to a specific area, but unlike the EcoFlow, you can't charge the battery and use the AC at the same time.
Zero Breeze Mark III for $1,399: As WIRED reviewer Chris Null notes (7/10, WIRED Review), the Mark III is both larger than the Mark II and quite a bit heavier, now 22 pounds. Add on the 1,022-Wh battery pack and you’ll pack on another 14 pounds, though that frees you from having to be near a power outlet. New for the Mark III is the fact that batteries can now be stacked and charged in sequence, each daisy-chained to the next (though at $600+ per battery, this can get pricey fast). Each Mark III battery also has extra outputs that can be used for other devices—one USB-C port, one USB-A port, and a 12-volt DC socket. However, the Mark II battery had all of the above plus a second USB-A port. No word on why this was removed. However, the new version is a bigger, punchier unit by most standards and a worthwhile buy for outdoors enthusiasts
What Size Air Conditioner Do I Need?
Look for the BTU, or British thermal units. In the case of air conditioners, BTUs per hour measures how much heat the compressor can remove from a room. It's a quick and easy way to figure out whether an AC unit is powerful enough to cool your space.
The BTU rating also helps you avoid using too powerful a unit, which will cool too quickly without dehumidifying, possibly leading to mold formation in the room and within the device.
To find the right power air conditioner for your room, you'll want to find the square footage of your room by multiplying its length and its width. The US Department of Energy's guidelines call for a minimum of 20 BTUs for every square foot of space. But this figure also assumes optimal conditions and good efficiency. For a 150-square-foot room, more typical recommendations are to opt for a 5,000 BTU AC unit. If the room is especially sunny, high-ceilinged, or has poor insulation, you may even want a 6,000 to 7,000 BTU unit for that space.
When in doubt, your best bet is to use a BTU calculator. For a truly precise estimate, here's a complex whole-house BTU calculator that takes into account building layout and construction, plus your location and climate. For a fast and dirty rule-of-thumb BTU calculator, try here.
Additional AC Tips
Check the combined energy-efficiency ratio (CEER) rating. The specs on any air conditioner you buy should list a CEER rating, which is one of the best ways of checking the energy efficiency of a unit. You'll usually see a number between 9 and 15. The higher the number, the less you'll pay when the electricity bill comes around. A cheap window AC unit will save you money at first, but you may end up shelling out more in the long run. The US Energy Star program has a website that lets you browse AC units based on their CEER ratings.
Check local laws. Some cities, like New York, require installing brackets to support your window AC. A simple one like this model should do the trick, though we haven't tried it out. You may also need to head to a hardware store for some plywood to make sure your window sill sits flat, but this depends on the type of windows you have and the AC model you buy. Get a friend to help you out with installation. These units can be heavy and difficult to hold, and the last thing you want is to drop one out the window.
Measure your window. Before you buy, read up on the supported window types and sizes for the AC unit you're looking at, and measure your window to be safe. Make sure to seal any gaps as best you can with the included foam. (You can always buy more if you need it.)
Power up with unlimited access to WIRED. Get best-in-class reporting that's too important to ignore. Includes unlimited digital access and exclusive subscriber-only content. Subscribe today.
10% Off Exclusive Squarespace Promo Code 2026
Memorial Day Appliance Deals + Up to an Extra $1000 Off + Free Delivery on appliance purchases $998+
LG Discount Code: 10% Off Sitewide
10% Off Dell Coupon Code for New Customers
30% Samsung Coupon - Offer Program 2026
Doordash Coupon $20 Off
Source: Wired
