Which Air Conditioner
This is our sixth year recommending best air conditioner, and my fourth year on this beat, personally. We’ve put in about 115 total hours of research and spent more than 40 hours doing real-world testing, along with more than 1,000 hours of being cooled off by the models we’ve recommended. Our expert sources include a representative for the Environmental Protection Agency, which administers the Energy Star program, as well as Max Sherman, an HVAC+R (heating, ventilation, air conditioning, and refrigeration) engineer who works as a staff senior scientist at Lawrence Berkeley National Laboratory.
The right air conditioner size for you
Measure the square footage of the room you need to cool, then look at this Energy Star chart to find the appropriate cooling capacity, as measured in British thermal units (Btu). Sun exposure, ceiling height, appliance heat, and the number of people that’ll usually be in the room can impact the capacity you’ll need, but floor size is the most important factor. You won’t always be able to find an AC with the perfect Btu rating, so you might have to round up. For example, nobody makes a 9,000 Btu window AC, so a 10,000 Btu window AC is the next-best option in that case.
Don’t fall into the trap of buying a significantly under- or overpowered air conditioner. Smaller units cost less, so you may be tempted to size down if you’re looking to save a few bucks. But an underpowered AC will run constantly, trying and failing to get the room down to the target temperature and a comfortable humidity. That’s a waste of energy, and you won’t even be that comfortable. If you get a unit that’s too big, it can leave your room feeling clammy because it reduces temperature faster than it removes moisture from the air. “It’s going to cycle on and off more, and then you’re going to lose some of your humidity control,” said Sherman.
Need to cool multiple rooms? It’s more effective to get several smaller air conditioners and put one in each room, rather than to buy one big unit. When two rooms are separated by a doorway, they’re “thermally separated,” as Sherman put it. That means an AC in your living room won’t do much to cool your bedroom. Sure, you’ll have to spend more money to buy two 6,000 Btu ACs than you would to just get a 12,000 Btu AC. But you get much more accurate, comfortable climate control when you use the right machine for each room.
How we picked
The best window air conditioner makes you the most comfortable in your home. For most people, that means picking a quiet AC without jarring whines, whooshes, or whirs, and with as much control over climate settings and air direction as possible. Ideally, the best air conditioner will pass the bedroom test: If it’s good enough to sleep near, it’s good enough for any other room in your house.
Everything else is much less important. Installation and maintenance should be easy, but they don’t vary too much from model to model, and you have to deal with them only a couple times per year. And cooling power and energy efficiency are so, so similar for window ACs at a given Btu rating that it’s barely worth worrying about. When comparing models, the difference in reaching a target temperature is never more than a few minutes, and the difference in an annual cost to operate is never more than a few dollars.
For this guide, we focused on 8,000-Btu window air conditioners because it’s the most popular size at retail, which implies that it’s what most people need. These ACs are suited for spaces between 300 and 350 square feet, roughly the size of a comfy living room or large master bedroom. (Sticking to a common Btu rating also helped us make apples-to-apples comparisons between our top contenders.) Air conditioners at this size can cost anywhere from $180 to $730, but you can get a good-enough model for $220 on sale, and the best model you’d reasonably want costs around $370.
How we tested
In 2017, our testing began by tracking down about 45 current-model window air conditioners with that cooling capacity. Based on specs, features, price, and our experience with older versions of some models, we settled on eight finalists, split into three subgroups.
The first group is just standard, affordable, Energy Star qualified window units including: LG, our top pick from 2016; Frigidaire FFRE0833S1, our runner-up from 2016; and the newer GE AHM08LW.
The next group is made up of quieter models, including: Friedrich Chill CP08G10B, one of our upgrade picks from 2016; Haier Serenity Series ESAQ406T, which is a new 6,000 Btu model—it’s not available in an 8,000 Btu variant, but we wanted to test it anyway; and the new Frigidaire Gallery FGRQ08L3T1.
Finally, the smart ACs, which have Wi-Fi antennas that let them work with smartphone apps or other smart-home systems: GE AEC08LW, which works with an app as well as Alexa; and LG LW8017ERSM, which is essentially our main pick but with app control.
Among those finalists, we focused on noise as the primary distinguishing factor. Window air conditioners can be pretty damn loud these days, louder than they used to be. Some people find that the hum of the compressor and whoosh of the fan make it difficult to sleep in the same room as a window AC. If it’s in a living room, expect to raise your voice and turn up the TV. According to this Energy Star memo (PDF; page 2), manufacturers claim that this volume creep is a side effect of stricter efficiency standards. (That’s probably true, though it’s also a time-honored tradition for industry groups to drag their feet and whine about regulations.) But some models are easier on the ears than others, and we heavily favored air conditioners with a lower operating volume and a smoother frequency response.
During that testing, we made note of any frequency spikes, which your ears would hear as irritating, high-pitched whining, or the kind of midrange whooshing that you don’t even realize is giving you a headache until it stops running.
The LG LW8016ER is the window AC you should probably get, especially if it’s for an office, den, or other room where you won’t be sleeping. For some people, it’ll be fine in a bedroom, too. It’s widely available and the price is fair, so you shouldn’t have any trouble finding it on short notice—for instance, in the middle of a heat wave, which is when you’re probably reading this article. Compared with other ACs at this price, it’s quieter and hums along at a lower pitch, so it’s easier on the ears. And though AC controls aren’t rocket science, this one offers a greater level of flexibility in total than most of its competitors, covering all the little details, from the fan’s directional controls and outdoor-air vent to the dehumidifier mode and removable drain plug. This is the second summer in a row that we’ve recommended the LW8016ER as our top pick.
This AC is easier on the ears than its closest-priced competitors.
Most air conditioners are loud, but the LW8016ER is the least-worst of the $250-ish, 8,000-Btu window ACs. It’s a bit quieter overall and sounds lower-pitched. At its absolute loudest, with the compressor on and the fan at full speed, we measured it running at 66 dBC (that is the C-weighted decibel scale). At the slowest fan setting and with the compressor on we measured about 62 dBC. The lowest fan-only (no-cool) setting is about 60 dBC. Relative to our runner-up pick, that’s about 1 dBC quieter in cooling modes, and 3 dBC quieter in fan-only mode.
The LW8016ER also has a removable drain plug on the backside of the unit, a handy feature for humid climates. This lets condensed water flow out of the base of the unit when too much builds up, as can happen when it’s very humid and the AC needs to run for hours and hours on end. Having some condensed water in the base of the AC can be good, because it helps improve efficiency. The air-circulating fan has special “slinger” tips that skim the top of the puddle and splash a little water onto the condenser coils to help cool them off faster. But when it’s very humid, the puddle gets deeper and the fan starts to make the flickering or bubbling sound, sort of like a water fountain. Some ACs don’t have this drain, so the water stays trapped inside the AC until you manually tilt it to drain it. Others situate the drain plug on the bottom, where it’s much harder to reach without uninstalling the whole unit.Unlike most window ACs, the LW8016ER also has a vent that can mix in about 10 percent fresh, outdoor air, if you choose to open it. It’s a good idea to get new air into your home from time to time, so if you can’t open the window while the AC is installed, this is a fine workaround.