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 Haier Serenity Series ESAQ408P. It gets quieter than any other window air conditioner we tested, 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) and 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
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 you just value peace and quiet in any other room, treat yourself to the (relatively) hushed performance of the Haier Serenity Series ESAQ408P. It usually costs about 25 percent to 35 percent more than our main pick or runner-up, but it gets quieter than any other AC we tested. You’ll sleep better all summer.
At its lowest fan setting (called “quiet” here) and with the cooling mode turned on, the Serenity Series runs at 56 dBC. That’s 6 dBC quieter than our main pick, which is a substantial difference, and 1 dBC quieter than the next-quietest AC, the Friedrich Chill. (The Chill is quieter than the Serenity Series at faster fan speeds, but our assumption is that you’ll tend to sleep with the lowest fan speed, so the Serenity Series has the edge in that regard.) We didn’t register any annoying frequency spikes, either. It’s not silent, but if you can fall asleep while you watch TV, you can fall asleep near this air conditioner.
The Serenity Series is solid in other respects, too. Installation is easy enough. And this unit is about the same weight as our main pick, but the chassis is smaller and the weight is distributed so that it balances on a windowsill with no problem. Any operating mode you can think of, this thing has it: energy saver, timer, dehumidify, and sleep. And the remote has a screen and tons of buttons to control all those modes and options.
What are the downsides to the Serenity Series? The vents point upward, so they won’t blast cold air directly at your skin unless you’re standing right in front of the unit. This bothers some people, but it cools the room just the same. It’s also somewhat less efficient than other air conditioners that are currently available. That’s because Haier released it in the summer of 2015, when the previous set of Energy Star specifications were in effect. By Department of Energy estimates, the Serenity Series will cost an extra $3 per year to run compared with the other air conditioners we mention here.
Also, unlike most models we recommend in this guide, the Serenity Series is available in only two sizes: 8,000 Btu (ESAQ408P) and 6,500 Btu (ESAQ406P). If you need a quiet AC for a larger space, we recommend grabbing a Friedrich Chill unit of the appropriate size.
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.
It looks a hell of a lot more modern than most window air conditioners, and even comes with better insulation materials like foam panels you can use in place of the typical accordion curtains.
Our noise testing showed that in terms of 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 found in our test. So it’s likely to be easier on the ears over the course of a few hours.
The companion app works. Unlike a real remote, you’ll experience a slight lag between each input and the response, and sometimes the app freezes up a bit. The obvious advantage, though, is that you can control your AC from anywhere with an Internet connection, like the ride home from work. You can also set up an operating schedule and receive alerts when it’s time to clean the filter.
However, we won’t go on record as saying that you should rush out to buy the Cool Connect AC—yet. Smart-home products have been around for a few years now, and we’ve found that most are more trouble than they’re worth. It can take a few months for widespread glitches to show up, and because the 2016 cooling season is still so young, we don’t know what difficulties you might run into with a Cool Connect.
Speaking of difficulties, anybody remember the Quirky Aros? It 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 its release in June 2014 early adopters had come up with a laundry list of its 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.)
To be fair to Frigidaire, it did a sort of “soft launch” of the Cool Connect late last summer, with the FFRC0833R1. Owners seemed to be pretty happy with how that model worked. The newer Gallery Cool Connect FGRC0844S1 runs off essentially the same software as far as we can tell, so it’s probably going to work out just fine. If you’re willing to put up with some potential early-adopter issues, go for it—and let us know how it works.
Other options: Some units of the Frigidaire FFRC0833R1 are still floating around, and usually cost less than the newer Gallery version; it could be an option if you don’t mind the more traditionally homely window AC faceplate. The Kenmore Elite Smart Air Conditioner 77082 is the same machine as the Frigidaire 33R1, and is another reasonable choice. Some old units of the Quirky Aros are still floating around as well, but we’d recommend that you skip it.
Another option is the Tado Smart AC Control, a $180 peripheral that turns any AC with a remote control into a smart AC. We have one on hand but have not had a chance to test it thoroughly yet. We will update this guide as soon as we have something to share, but user reviews seem to be positive so far.
The Friedrich Chill CP08G10B is a great air conditioner made by an American-owned company. We came close to making it our upgrade pick instead of the Haier Serenity Series, but the Chill tends to cost at least $30 more, it’s larger, and it’s ever-so-slightly louder (about 1 dBC) than the Haier on the lowest cooling setting. On the other hand, at the high and medium fan settings, the Chill is quieter than anything else on the market. This was a close call that mostly came down to price and design. But the Chill is an AC you can feel good about buying, if your research leads you in that direction. Plus, as we mentioned earlier, the Chill is available in lots of sizes that the Haier Serenity Series isn’t (anything larger than 8,000 Btu, basically). So if you want a quiet AC for a large room, the Chill is the way to go.
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.
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.
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 just don’t support any other option, check out our forthcoming portable air conditioner 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.
(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