To revisit this article, visit My Profile, then View saved stories.To revisit this article, select My Account, then View saved storiesJulian ChokkattuIf you buy something using links in our stories, we may earn a commission. This helps support our journalism. Learn more. Please also consider subscribing to WIREDIt’s hot. Unlike in the winter, when you can just bundle up to stay warm, there are only so many clothes you can strip off to cool down. If you don’t have central air in your home, a window air conditioner is the next best thing. They’re heavy machines but are relatively easy to install, and they immediately provide relief to your swelteringly hot space.I feel a pang of guilt when I turn mine on. The planet is warming up because of climate change, and even the best window Air Conditioners contribute to this. But it’s important to stay cool during these hot months, or it can seriously affect your sleep. The window AC units in this guide are ones we’ve tested for months, if not years. However, there’s a ginormous number of these machines out there on the market from a dizzying number of brands—we’ll keep testing more and update this guide as we go. Be sure to read our How to Stay Cool Without Air Conditioning guide for tips on keeping your home chilly without mounting an AC.Updated July 2023: We've added the Frigidaire Gallery U-Shape AC and EcoFlow Wave 2.Special offer for Gear readers: Get a 1-Year Subscription to WIRED for $5 ($25 off). This includes unlimited access to WIRED.com and our print magazine (if you'd like). Subscriptions help fund the work we do every day.Window air conditioners usually mean you lose the ability to open the window, but that's no issue with Midea's U-Shaped AC (8/10, WIRED Recommends). It comes with a bracket that balances the AC's weight by leaning against the exterior wall of your home. That lets you open up the window without worrying that the AC will fall out. Per the name, this Midea unit also has a big notch between the front and back, allowing you to pull your window deep into the unit. This helps in a few ways: There's less of a gap around the sides, so your precious cold air won't seep out, and it also means you get better soundproofing. Midea provides lots of foam padding to seal off the few remaining gaps.The AC itself is among the quietest we've tested since most of its components are housed in the part of the machine that sits outside the window. It cools down a room pretty quickly and can connect to Google Assistant and Amazon Alexa, meaning you can turn it on remotely before you get home. It's the window AC we've tested for the longest time (three years) and it has performed exceptionally well with minimal maintenance (Midea's app will even tell you when to clean the filter). The only main kink is the installation process, which isn't as easy to follow along as I'd like. I recommend you ditch the vague steps in the manual and watch this video from the company instead (I found it more helpful).Comes in 8,000, 10,000, and 12,000 BTU.The cheaper you go, the fewer features you'll get, and the less efficient the unit will be. For example, the Midea, Frigidaire, and LG AC units in this guide each have a Combined Energy-Efficiency Ratio (CEER) of 15. The CEER 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; 15 is one of the highest ratings you'll find. Essentially, you pay less in electrical bills over time with one of those over this GE model, which has an 11.1 CEER rating.Still, your budget might be tight. If that's the case, I've had a pretty great experience with this model over the span of a year. GE doesn't include a bracket, but I still found it 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) 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.Comes in 5,000 or 6,000 BTU.I've been using the 2022 model of LG's Dual Inverter Air Conditioner for more than a full year. The biggest difference over the previous version (8/10, WIRED Recommends) is that it has a higher CEER rating (15), meaning it is slightly more energy-efficient. LG's dual-inverter tech means there are two compressors and two chambers inside; where a single inverter AC would have a compressor that turns on and off, the dual system lets the compressors adjust speed based on the temperature of the room. That makes it quieter, faster, and more energy efficient. It cools my room quickly, and it's pretty quiet (it's a smidge louder than the Midea at 55 decibels). I don't recommend using the Energy Saver mode though, as it will start and stop during the night and it has woken me up. Just lower the fan speed.You can use LG's ThinQ app to turn the AC off or on remotely, change the fan speed and temperature, or set a schedule. It can connect to Amazon Alexa and Google Assistant too, which is nice. If you have a mesh router that doesn't let you change your Wi-Fi band, you might have a hard time connecting this LG AC to Wi-Fi, as it only works on the 2.4 GHz band. I set up a guest network on my Nest Wifi, which only uses the 2.4-GHz band, and was able to make it work. Installation instructions are clear, though you may need to head to the hardware store to grab some plywood to make your window sill flush.Comes in 8,000, 10,000, 12,000, 14,000, 18,000, and 23,500 BTU.This Frigidaire takes everything about the Midea unit and improves on it, while also commanding a higher price. It has a U-Shape and comes with a bracket, so you can open your window completely without the AC falling onto some poor sod on the street, and I found it easier to install. At 47 decibels, it's almost as quiet as the Midea, too. There's Google Assistant and Amazon Alexa support, and you can use the app to remotely control the AC or even schedule when you want it on or off. Just make sure you download the right app. I first downloaded and paired the AC using the Frigidaire app, only for the app to tell me I'm using the wrong one and prompting me to install the Frigidaire 2.0 app (Android, iOS). Weird. This AC can also show you the current temperature of your room via the app, and it did a great job of quickly bringing my bedroom to the target temperature I wanted before bed.What I like most about the Frigidaire is that it comes with an air quality sensor that shows what the air is like via the LED strip on the front of the unit. Green means your air quality is good, but red or orange means it detects pollutants. It works! It was red when we had a lot of smog from Canada's wildfires here in New York City, and orange when my wife was cooking up some bacon. Better yet, you can purchase and install Frigidaire's PureAir RAC-8 filter to clean the air of allergens, dust, smoke, and pet dander. You'll need to replace it every three months though. I didn't try the filter, but it's worth noting it's MERV 14-rated, not HEPA-rated, so you probably should still get a HEPA air purifier for the room.Comes in 8,000, 10,000, and 12,000 BTU.Justin PotParker HallParker HallEric RavenscraftThe Windmill AC (8/10, WIRED Recommends) was one of the first air-conditioners to start replacing the commonly used refrigerant 410a with R32, a refrigerant with much less global warming potential. All the window air conditioners listed above now use R32 as well, but Windmill is also one of the only companies promising to offset the carbon emissions of every unit purchased, and it will recycle old models. It's also the easiest to install, taking us around 15 minutes in total thanks to the clear instructions in the manual. You can connect it to Alexa or Google Assistant, use the Windmill app, or use the buttons on the top of the intake panel to control it. It cools small rooms really well, though it is louder than the Midea and the LG AC above, coming in at around 60 decibels.One perk? This model has an outflow that sits at the very top of the unit, meaning you can't blast cool air at your face or torso to cool it off. Instead, this cool air goes to the top of the room where all the hot air resides, which in our testing seemed to circulate the air faster. It's helpful if your room is small and you have no choice but to put a desk next to the window—the Windmill won't blow all your papers off. The company has since added a model with a feature it calls WhisperTech, which uses a variable speed compressor much like the LG and Midea units above to make the appliance even quieter, but we haven't tested this version.Comes in 6,000 and 8,000 BTU.Portable air conditioners aren't as energy efficient or effective at adequately cooling a room. You'll need to spend a lot of money to get adequate cooling, and the two models below are the ones we like. They're often louder, and uh, not very portable.EcoFlow Wave 2 for $1,299: The EcoFlow Wave 1 has cooled down my wife's office for more than a year just fine—we can't use a window AC there because it would block the fire escape. Lo and behold, there's a new version that's slightly cheaper (8/10, WIRED Recommends). It's a little lighter than its predecessor at 32 pounds, yet has a higher 5,100 BTU rating (up from 4,000). New here is a heating mode rated at 6,100 BTU, so you can keep using it in the winter to warm up a room. 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 how you can power it. You can use a standard AC outlet, but you can buy the version with a battery to keep it working when you don't have access to power, or you can hook it up to solar panels.Zero Breeze Mark II for $1,499: At 2,300 BTU, you won't be able to get the same cooling power as the EcoFlow Wave, but the Zero Breeze (7/10, WIRED Review) is much lighter at 17 pounds. This bundle includes a battery that will make 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.Here are a few terms you'll come across when shopping for a window air conditioner, plus some other tips after our years of testing them.BTU stands for British Thermal Units. In the case of air conditioners, BTU is a way to measure 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. First, you'll want to find the square footage of your room by multiplying the length and width. Then, use the US Department of Energy's guidance on the BTU capacity you need. For example, a 150 to 250-square-foot room needs a 6,000 BTU AC unit or higher for adequate cooling.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 might 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 City, 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. When installing, you should get a friend to help you out. 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).Justin PotParker HallParker HallEric RavenscraftJulian ChokkattuJulian ChokkattuMedea GiordanoLouryn StrampeTurboTax coupon: Up to an extra $15 off all tax servicesExtra 20% off sitewide - Dyson promo codeGoPro Promo Code: 10% Off all sitewide purchases + Free shipping+30% Off with this Samsung couponUnlock 15% off keyboards - Dell coupon codeTake as much as $800 Off iPhone 14 series with Best Buy discount CodeMore From WIREDContact© 2023 Condé Nast. All rights reserved. Use of this site constitutes acceptance of our User Agreement and Privacy Policy and Cookie Statement and Your California Privacy Rights. WIRED may earn a portion of sales from products that are purchased through our site as part of our Affiliate Partnerships with retailers. 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