The Best Air Conditioner
After five summers of researching, testing, and recommending window air conditioners, we’ve learned that quiet and affordable ACs make most people the happiest—and we think the LG LW8016ER will fit the bill in most rooms. It cools as efficiently and effectively as any of the latest ACs with an equal Btu rating, and runs at a lower volume and deeper pitch than others at this price. Little extra nodes of control, like a fresh-air vent, easy-to-control fan blades, and a removable drain plug help set it apart, too. This is a top choice for an office or den, and some people will find it quiet enough for a bedroom, too.
If you’re buying an air conditioner for your bedroom and don’t mind paying a little extra, treat yourself to the Friedrich Chill CP08G10B. It gets quieter than any other window air conditioner in our test group, offers tons of control, and is relatively easy to install.
We also have some thoughts on “smart,” Wi-Fi–controllable air conditioners (and a smart AC accessory) plus recommendations for other kinds of air conditioners, including portables, through-the-wall units, and casement-window models.
Table of contents
- Why you should trust us
- The right air conditioner size for you
- How we picked and tested
- Our pick
- Flaws but not dealbreakers
- Affordable, available, and a bit loud
- Quieter but pricier
- Smart air conditioners
- The competition
- Portable air conditioners
- A good through-the-wall air conditioner
- A casement air conditioner for sliding and crank-open windows
- Care and maintenance
- Long-term test notes
Why you should trust us
This is our fifth year recommending window air conditioners (originally as The Wirecutter, now as The Sweethome), and my third year on this beat, personally. We’ve put in nearly 100 total hours of research and spent more than 30 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). For most people, it’s as simple as that. 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.
You could also check out this ideal-Btu calculator from the Association of Home Appliance Manufacturers if you want to account for conditions that add extra heat to a room, like sun exposure, the number of people in the room, and power consumption by other appliances. But it’s probably overkill for picking a room air conditioner.
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 Max Sherman, a staff senior scientist at Lawrence Berkeley National Laboratory.
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 air won’t flow between your living room and bedroom very well. 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 and tested
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.
If you’re looking to cool a larger or smaller room than the average, most of our picks are available in several different sizes. We didn’t test the other sizes, but we’re pretty confident that our analysis holds up for models between 6,000 and 12,000 Btu.
Our testing began by tracking down about 30 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 seven finalists: Frigidaire FFRE0833S1, an updated version of our top pick from 2015; Frigidaire Gallery Cool Connect FGRC0844S1, a new smart model that you can control with a smartphone app; LG LW8016ER, an updated version of our runner-up pick from 2015; Haier Serenity Series ESAQ408P, marketed as a quieter window AC; Friedrich Chill CP08G10B, marketed as a quiet, sturdy upgrade option; Haier ESA408R; and GE AEM08LV.
Among those finalists, we focused on noise as the primary distinguishing factor. Window air conditioners are all 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 makes 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 (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.
We developed our noise test with the help of audiovisual expert and Wirecutter contributor Geoff Morrison. We connected a calibrated microphone to an iPhone 5S, then fired up the SPLnFFT noise meter app, setting it to C-weighting with a slow response. We stood 6 feet away from each unit and measured volume at the low, medium, and high fan settings, with and without the compressor running. 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 other way we judged our finalists was the level (and quality) of user control they allowed. One important area where window ACs can differ is their fan vents, which control the direction of airflow. If you sleep near your AC, you’ll usually want to be able to point the cold air away from your body, or at least away from your head. But some models have blind spots where airflow can either never reach or always reaches. We also considered the number of fan speeds, extra cooling modes, and the depth of remote control—including any smart, Wi-Fi–controlled features.
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. Though for some people, it’ll be fine in the bedroom, too. Its price is fair, and this model is widely available, so you’ll have no trouble running out and grabbing it for a decent price on short notice—for instance, in the middle of a heat wave, like 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.
Most air conditioners are loud, but the LW8016ER is the least-worst of the $250-ish window ACs that we’ve been able to test because 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 only about 1 dBC quieter in cooling modes, and 3 dBC quieter in fan-only mode.
However, most people would probably think that the LW8016ER sounds quieter than its price peers—because it runs at lower frequencies. It peaked at around 86 hertz in our tests, which means that the loudest frequency is a deep hum—it’s almost (almost) relaxing. The response actually drops down between 1,500 and 2,000 hertz, which is a good thing because those are some midrange frequencies that can really wear your ears down after a few hours. We also didn’t notice any mid- or high-frequency spikes, which tend to stand out in your awareness as hard-to-ignore whining or whooshing. That all adds up to an AC that’s easier on the ears than its competitors—even if it’s still a little louder than most of us would like.
The LW8016ER also offers extra controls that seem really minor to most of us but can make a huge difference to some people. For example, the fan blades are as effective as any at directing air where you’d like it to go, and stop it from going where you wouldn’t. That can come in handy if you sleep near the AC, so you can direct the cold air away from your head at night. Some window units struggle with fan direction and have cold spots where they can’t stop blowing air—not a problem with the LG.
The LW8016ER also has a removable drain plug, which lets condensed water flow out of the unit when it gets too deep. Some condensed water is actually a good thing—it helps improve efficiency. But in very humid conditions, the puddle of moisture in the base of the AC can actually get deep enough that the fan sloshes through it, making an unpleasant flickering or bubbling sound. Some ACs don’t have this drain, so the water stays trapped inside the AC until you manually tilt it to drain it.
Unlike most window units, the LW8016ER also has a vent that can mix in about 10 percent fresh, outdoor air, if you choose to open it. So if you neglect to open the window all summer, you at least won’t be breathing the same stale air the whole time. And this model also has a dedicated dehumidifier mode, which might find some use on those early-fall afternoons when it’s too chilly to run the AC, but muggy enough that you want some relief.
The LG also has all the other basic features that most of us have come to expect from a window AC: A digital thermostat, a remote control, three fan speeds, some foam to stuff the gaps in your window, an energy-saver mode where both the cooling unit and the fan turn off once the room reaches the target temp, and a timer that you can set to have the AC turn on or off, up to 24 hours in advance.
Though the fact that the LW8016ER uses a different refrigerant than most ACs didn’t factor into our decision, it’s a fact worth pointing out. R32 refrigerant is ever-so-slightly more efficient than the typical R410A refrigerant, and here it manifests in a slightly higher efficiency rating than other 8,000-Btu Energy Star window ACs. In practical terms, the LG’s superior efficiency saves you less than a buck per year in electricity costs, but hey, take the cash where you can. Also, R32 is rated to have a much lower global warming potential than R410A, so in the highly unlikely case that the refrigerant leaks out of your AC and gets into the atmosphere, it won’t trap as much heat as the alternative. So, if those kinds of things concern you, maybe you’ll feel a little better about yourself by getting the LG.
As we mentioned earlier, you’ll get the best results when you buy an air conditioner with the right Btu rating for the space you want to cool. We specifically tested the 8,000-Btu variant, though others are available from 5,000 Btu up to 24,500 Btu. Here’s a cheat sheet to help you find the right size:
Room size (square feet)
|100 to 150||5,000||LW5016||No remote, no digital thermostat|
|150 to 250||6,000||LW6016R|
|300 to 350||8,000||LW8016ER|
|350 to 450||10,000||LW1016ER|
|450 to 550||12,000||LW1216ER|
|~1,000||18,000||LW1816ER||230 volts required|
|~1,250||24,500||LW2516ER||230 volts required|
The 5,000-Btu model looks like a crappy little air conditioner, so we’d recommend stepping right up to the 6,000-Btu unit if your room is that small.
Flaws but not dealbreakers
It bears repeating that the LW8016ER is not quiet, it’s just quieter than other window air conditioners at its price. We imagine many people will have some trouble sleeping in the same room as this thing. If you’re putting an AC in your bedroom and are worried about noise, take a look at our upgrade pick, the Haier Serenity Series ESAQ408P.
The LW8016ER had the most cumbersome installation of all the window units we tested, but really, it’s not that much tougher to install than other window ACs—they’re all heavy and don’t vary much in this respect. This one is 58 pounds, which is heavy but not outrageous for a window AC. Compared with the others, it’s deeper and heavier toward the back, so it’s the trickiest to lift and maneuver onto the windowsill. Another nitpicky, moderately annoying detail: The side curtains screw in, whereas those of most other units slide in. That said, you’ll have to deal with installation only once each spring and once each fall, so it’s not a huge deal. Enlist a buddy, use a support bracket, and installation will be fine.
Compared with other remote controls, the one that comes with the LW8016ER is pretty basic, with no screen and only six buttons. That’s not necessarily a bad thing, though, because the simpler interface means it can run on a single AAA battery rather than a pair. Plus, some people prefer a stripped-down control scheme.
The LW8016ER doesn’t have sleep mode, a feature that gradually raises the temperature throughout the night to save energy because you’ll be conked out anyway and may not notice the temp shift. But not that many people use sleep mode even when it’s available, as far as we’ve been able to tell over the years, so this is no great loss.
Consumer Reports puts the LW8016ER pretty low in its rankings, mainly for this model’s poor noise scores (worse than previous versions of the LG AC, which are still listed in the rankings). According to our measurements, however, this year’s LG runs at just about the same volume as previous versions did. Consumer Reports may have tested a faulty unit.
Affordable, available, and a bit loud
If our main pick is unavailable, the Frigidaire FFRE0833S1 is another affordable, widely available window AC. It’s also the latest version of the air conditioner that was our main pick for three years running, prior to this update.
The FFRE0833S1 is still for the most part a fine window AC, but it’s not our top choice for a couple of reasons. First, it runs slightly louder (63 dBC on the lowest fan setting, and 67 dBC on the max setting) and makes a higher-pitched tone than our main pick does. You’ll have to raise your voice and turn up the TV just that much more, and it’ll be a greater struggle to fall asleep near this thing. (This year’s version is notably louder than last year’s—a change we believe is related to new energy efficiency standards.)
Some little user-control features are lacking, too. The disc-shaped fan blades on the FFRE0833S1 permanently blow at least some air toward the right side of the unit, even if you direct most of it to the left. That can be annoying if it’s near your bed, blowing cold air on your neck all night. It also doesn’t have a drain, so in very humid conditions it can start to make an obnoxious flickering, bubbling noise as the fan passes through the pool of condensed water built up in the baseplate. You’ll need to manually tilt the unit to drain it to make the noise stop.
In its favor, though, the Frigidaire FFRE0833S1 is easier to install than our main pick. It’s 10 pounds lighter, with a smaller chassis and a more-centered weight distribution. Also, its side curtains slide in, rather than screw in, saving a few minutes of work and frustration.
The FFRE0833S1 also has a more-robust remote, with an LCD screen and its own built-in thermostat. The idea is that with the “remote sensing” mode enabled, the AC will keep running until the air near the remote (which could be on the opposite side of the room from the AC unit) reaches the target temperature, rather than the air near the AC itself. That said, the remote thermostat that came with last year’s version of this air conditioner was wildly inaccurate. We’d put it next to the AC unit itself and the readings between the remote’s thermostat and the AC’s thermostat would be off by four or five degrees. Other users shared similar experiences. The latest remote looks identical to the older models’, so though we haven’t tested this particular feature yet, we’d expect the same discrepancy.
From what we’ve seen so far, in early summer 2016 the Frigidaire FFRE0833S1 tends to cost about $20 to $30 more than the LG LW8016ER. But every summer that we’ve been paying attention, we’ve seen prices for the Frigidaire and LG models drop as low as $220 at times, and the relative price of each one can change from day to day. Keep your eyes peeled for deals.
Like the LG LWxx16ER, the Frigidaire FFRExx33S1 is available in many different Btu ratings, from 5,000 to 22,000 Btu. It may also be available in “store exclusive” packages, with a slightly different SKU (it will have a “B” for the Best Buy version and an “L” for the Lowe’s version). Generally, the remote control is the only difference.
Quieter but pricier
If you’re installing an air conditioner in your bedroom, or if you just value peace and quiet in any other room, treat yourself to the (relatively) hushed performance of the Friedrich Chill CP08G10B. It usually costs about 35 percent more than our main pick or our runner-up, but it gets very quiet, and you’ll sleep better all summer. (We previously recommended the Haier Serenity Series in this category, but that model has gone out of stock almost everywhere as of August 2016.)
At its lowest fan setting and with the cooling mode turned on, the Friedrich Chill runs at 57 dBC. That’s 5 dBC quieter than our main pick, a substantial difference. At the medium and high fan settings, the Chill is also 5 to 6 dBC quieter than any other window AC. We didn’t register any annoying frequency spikes, either. This model isn’t silent, but if you can fall asleep while you watch TV, you can fall asleep near this air conditioner.
The Chill has the typical operating modes, including an “air sweep” oscillating fan mode, and the remote control offers a screen and several buttons to control all those modes and options.
And for what it’s worth, the Friedrich Chill meets the latest Energy Star specifications and uses R32 refrigerant, which is more efficient and less of a greenhouse gas than older refrigerants found in some ACs.
What are the drawbacks of the Friedrich Chill? It’s on the heavy side for a window AC, and the chassis is bigger than most. The installation process is fine, and it comes with better materials than most models do; the unit itself is just more cumbersome to lift and position. It may fit into fewer windows than other ACs, too.
We hear quality-control complaints about all air conditioners (compressors are delicate, which makes shipping fairly hazardous), but it feels like we hear about people receiving slightly defective Friedrich units somewhat more often than with other brands. Parts rattle when they shouldn’t, or the “air sweep” feature doesn’t work, or it simply doesn’t cool. We’re not sure what the cause or the scale of the problem could be. But maybe before you install a Chill into your window, you should make sure it works first, and get in touch with the retailer immediately if it doesn’t.
Smart air conditioners
If you want to control your air conditioner with your smartphone, your best option is the Frigidaire Gallery Cool Connect FGR0844S1 window AC. But we’re not recommending that you rush out and get this model. Although the AC itself works fine and looks sharp, the companion app is glitchy, which defeats the purpose of spending extra on a smart AC in the first place.
The good parts: The Cool Connect looks a hell of a lot more modern than most window air conditioners, and it even comes with better insulation materials such as foam panels that you can use in place of the typical accordion curtains. Our noise testing showed that in sheer decibels, the Cool Connect is technically as loud as the cheaper FFRE0833S1, our runner-up model. But the Cool Connect sounded quieter to our ears, probably because it runs at a lower pitch, as we found in our test. So it’s likely to be easier on your ears over the course of a few hours.
As for the bad parts, our long-term tester said that the app worked great at first (that was our experience, as well), but then the connection started to be “hit or miss,” tossing up an error message and asking to reconnect the AC to his Wi-Fi network. Even after reconnecting, he’d still run into trouble getting the app to work smoothly or inducing the AC to respond to commands. As a result, the scheduling feature didn’t work very well. Our tester also thinks the AC might have turned itself on, unprompted, on one occasion; that could have been a very delayed response to an app command that he’d forgotten about. After a couple of weeks, he gave up on the app, and he doesn’t bother trying to use it anymore. Overall, he called the Cool Connect a “5 out of 10.”
His experience is not uncommon. Reading through user reviews on retailer sites, we saw that trouble with the app comes up pretty regularly, even in reviews with good scores.
At this point, we’d be surprised if a smart appliance actually worked like it’s supposed to. This category has been flirting with the mainstream for a few years now, but such models are generally more trouble than they’re worth. Remember the Quirky Aros air conditioner? That AC looked like it would be the most exciting thing to happen to window air conditioning in decades. But as we reported here, within a few weeks of the Aros’s release in June 2014 early adopters had come up with a laundry list of hardware and software problems—the fan was too loud, the app was too glitchy, the “machine learning” algorithm was not at all useful. The software problems only seemed to get worse as time went on. (Quirky filed for bankruptcy in September 2015.) We’ve also attempted to test the Tado Smart AC Control, a $180 peripheral that turns any AC with a remote control into a smart AC. Three Sweethome staffers have tried to set it up, and we keep running into error messages. One of these days we’ll get around to running through the troubleshooting process, but the errors are such a buzzkill.
The Haier Serenity Series ESAQ408P was our upgrade pick for the first part of the summer, but it’s gone out of stock at just about every major retailer, and third-party sellers are price-gouging on what’s left. We preferred it over the Friedrich Chill because it cost $30 less, was smaller and easier to install, and ran ever-so-slightly quieter on the lowest fan setting. If you have a line on one of these for the regular price ($330 to $340), go ahead and grab it.
Haier makes a cheaper window AC, the ESA408R, and it’s by far the noisiest air conditioner we’ve ever tested. At the highest fan setting, it cracked 70 dBC, which is irritatingly loud.
We hoped to test the GE AEM08LV, but we were not able to track down a unit to review, either from GE or from a nearby store. We may circle back and test this in a few weeks, but honestly, we’re pretty satisfied with the picks we have now.
Sears sells some Kenmore-branded air conditioners. They’re just rebadged versions of Frigidaire ACs, so the same conclusions apply.
We also found about a dozen air conditioners that are carbon copies of each other—all identical machines manufactured by Midea and sold under brands like Danby, Arctic King, Kool King, Comfort Aire, and others you’ve probably never heard of. We considered testing one, but we know that older versions of this AC tended to be loud, and this year’s tighter efficiency standards probably mean that the new models are even louder. Plus, they’re not available through most of the major big-box stores and Internet retailers.
Some older versions of our top picks are floating around: The LG LWxxER and Frigidaire FFRExx331, which are both from the 2015 cooling season. They each use about 5 percent more energy than their newer versions (at least by Department of Energy estimates), which is a good enough reason to choose the latest models in our opinion. That said, we should point out that the older Frigidaire (33Q1) was noticeably quieter in our testing than the newer model (33S1), by about 2 to 3 dBC at each setting. If you see one of the old units available on clearance, it’s not a bad pickup—it’s rated to use about the same amount of energy as our upgrade pick.
Portable air conditioners
Portable air conditioners are so popular now that we gave them their own guide. Just so you know, a portable AC never cools a room as efficiently or effectively as a window or wall AC. Portables are also big, ugly, and expensive. But if you want something for spot cooling that you can wheel from room to room, or if your windows don’t support any other option, we have some recommendations.
A good through-the-wall air conditioner
Picking the right through-the-wall air conditioner can be a little tricky, but the path of least resistance is to just get a universal-fit, rear-breathing AC. Also known as “true wall” or “wall sleeve” air conditioners, these units will work with almost any existing wall sleeve (the technical term for the metal box that juts out through your wall).
We have not tested any wall-sleeve ACs. But we think that the LG LT0816CER is a reasonable bet because it appears to be a modified version of the LG window unit that we recommend above. It also costs less than its chief competition, a Frigidaire model that costs anywhere from $70 to $120 more than the LG and has no obvious advantages (at least on paper). Kenmore also sells a wall AC, but it’s just a rebadged version of the Frigidaire. You might be able to find a cheap wall-sleeve AC made by Midea and sold under various brand names (including Arctic King, Westpointe, and Comfort Aire, among others), but they’re generally not available through major retailers.
The other kind of AC you can install in a wall is called a slide-out-chassis air conditioner, also called a “window/wall AC” because—hey!—it works in either a wall or a window. You don’t need a separate sleeve for this kind of AC because the casing doubles as a sleeve. The downside is that you probably can’t use one if your building has brick or concrete walls—the walls are too thick and will block the vents.
Also, no, you should not put a regular window AC unit through your wall, unless the documentation specifically says that it’s suitable for a wall installation. The vents on a typical window unit aren’t positioned to breathe properly in a standard wall sleeve, so it can’t work as effectively or efficiently, and will burn out its compressor much sooner than it should. It’s not a safety hazard or anything, just kind of a blockheaded thing to do.
A casement air conditioner for sliding and crank-open windows
This style of air conditioner installs into a horizontal-sliding window, or a crank-out window. Casement air conditioners are more expensive than a typical double-hung-window unit, but cost about the same as portable air conditioners and work much, much more effectively.
This is not a common style of air conditioner, but that kind of works to your advantage because you don’t have to worry about what model to buy: The Frigidaire FFRS0822S1 is the only widely available unit (apart from the Kenmore 77223, which is a rebadged version of the Frigidaire anyway). It comes with everything you need for installation in a sliding window, though if you’re installing it in a crank window, you’ll probably need to buy (and cut) a piece of plexiglass.
If you’ve come here looking for info on central air or mini-split ductless systems, sorry, we have nothing valuable to add. Those are permanent installations with too many factors unique to each home for us to cover effectively here. Talk to a professional if you’re interested in a system like that.
Care and maintenance
For starters, follow the installation instructions that come with the machine. They are never difficult, but the idea is to keep the AC secure in the window frame, with the back of the unit angled slightly toward the ground so that condensed water has a chance to drain out of the machine. Brace the machine on proper brackets, not a stack of old magazines.
After you turn on the AC for the first time, if you hear any obvious high-pitched whining for more than a few minutes, you might have gotten a dud. ACs aren’t supposed to sound like that, and it’s worth trying to exchange the unit.
Every air conditioner has a filter to block dust from getting into the important parts of the system. It’s sort of like the lint filter on a clothes dryer. It usually slides out from the front of the unit. You should clean this every month to keep air flowing properly. Most modern units (including all the models we tested) will have a light to remind you to do this after every 250 hours of use.
At the end of every cooling season, you should drain condensed water from the AC by tilting the outer grille toward the ground for about 20 seconds. If you’re nervous about doing this out of a window, do it in your bathtub instead. Mildew can grow inside a wet AC, especially if it’s shoved into a dark closet over the winter, and the AC will blow that musty smell everywhere when you turn it on.
Speaking of seasonality, you should really remove all of your window air conditioners before heating season begins. The gaps around the AC will leak heat, so it’s best to just shut your windows. If you prefer not to do that, at least cover the top of the AC with a piece of plywood to help stop debris from getting into the system.
Long-term test notes
We’ve had testers using all our top picks since early June, and so far we’ve had no complaints—just sweet, cool air all summer long.
(Photos by Liam McCabe.)
- staff senior scientist, Lawrence Berkeley National Laboratory, phone and email interview, April 2015 , ,
- Energy Star Program, Environmental Protection Agency, email interview, April 2015 , ,
- Window air conditioner rankings, Consumer Reports (subscription required), May 2016
- Air Conditioners - Pre-Existing Sleeve Installation, YouTube, 2015 ,
- How powerful an air conditioner do you need?, Association of Home Appliance Manufacturers
- Room Air Conditioners Specification Version 4.0, Energy Star/Environmental Protection Agency, May 2015
Originally published: May 19, 2016