After six 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 model with an equal Btu rating, and runs at a lower volume and deeper pitch than others at this price. Little extra features like a fresh-air vent, two-axis 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 our main pick is sold out, grab the Frigidaire FFRE0833S1. It’s a little bit louder and higher-pitched than our new pick, but it’s an equally capable performer that’s usually around the same price. The Frigidaire is also a little bit easier to install because it’s smaller and lighter.
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 ESAQ406T. It’s a 6,000 Btu model, so it’s meant for smaller rooms than our main pick or runner-up—but it’s so much quieter than either of those picks (or their smaller variants) that you should be able to sleep easier all summer. (In late June, we chose this model to replace the Frigidaire Gallery FGRQ08L3T1, which is temporarily out of stock.)
This guide also includes our current thoughts on “smart,” Wi-Fi–controllable air conditioners (and a smart AC accessory), plus recommendations for other kinds of air conditioners, including portable ACs (in a separate guide), through-the-wall units, and casement-window models.
This is our sixth year recommending window air conditioners (originally as The Wirecutter, now as The Sweethome), 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.
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.
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 consider the other sizes, but we’re pretty confident that our findings hold up for models between 6,000 and 12,000 Btu.
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 LW8016ER, our top pick from 2016; Frigidaire FFRE0833S1, our runner-up from 2016; and the newer GE AHM08LW.
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.
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. 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.
Although the overall volume is not much quieter than competing models, the LW8016ER will probably sound quieter to most people. That’s because it’s loudest at low frequencies, peaking around 86 hertz in our tests, and quieter at mid and high frequencies. That means the most prominent sound it makes is a deep hum. It’s almost (almost) relaxing. Compared with other models around 1,500 and 2,000 hertz—the kind of midrange, “whooshy” frequencies that can wear your ears down after a few hours—it’s relatively quiet. We didn’t notice any high-frequency spikes, either, which are the kinds of irritating, whiny noises that most people can’t stand for even a few minutes. That all adds up to mean this AC is easier on the ears than its closest-priced competitors—even if it’s still a little louder overall than most of us would like.
The LW8016ER also offers extra controls that seem really minor, but can make a huge difference. 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 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.
The LW8016ER model also has a dedicated dehumidifier mode, which might find some use on those afternoons in early fall when it’s too chilly to run the AC, but muggy enough that you want some relief. Some window ACs have it, some don’t.
The LG also has all the other basic features that most of us have come to expect from a window AC: An installation kit, a digital thermostat, a remote control, three fan speeds, some foam strips to stuff the gaps around the unit, some foam board to install over the accordion curtains, an energy-saver mode where both the cooling unit and the fan turn off once the room reaches the target temp, and a 24-hour on-off timer.
The LW8016ER uses a different refrigerant than most ACs, and though it didn’t factor into our decision, we think it’s worth pointing out. R32 refrigerant is ever-so-slightly more efficient than the typical R410A refrigerant, and manifests as about $1 per year in energy savings compared with most other 8,000 Btu Energy Star window ACs. It’s not much, but it’s something. Also, R32 is rated to have a much lower global warming potential than R410A. So in the unlikely case that the refrigerant leaks out of your AC and gets into the atmosphere, it’ll trap only about one-third as much heat. R32 is mildly flammable, but it’s been found to be a low safety risk.
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. (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.) 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||Our pick|
|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|
LG released a variant of the LW8016ER for summer 2017, known as LW8016ERY7. According to a representative from LG, this variant is an “engineering revision” but “doesn’t affect operating volume, performance, noise, efficiency,” or other noticeable factors. You probably won’t even notice this new variant in stores, because it will just be sold as the regular LW8016ER. We are confident that both versions perform similarly, though we’ll keep an eye out this summer for user reviews that point out new problems. Revisions like this are a fairly common practice in the appliance industry when models are available for several years; changes in the supply chain can force manufacturers to use a different pump or fan during different production runs, for example. LG did not mention what exactly changed here, but we’re not too worried about it.
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 plenty of 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 Frigidaire Gallery FGRQ08L3T1.
The LW8016ER was the most cumbersome to install of all the window units we tested, but only modestly so. The worst part is that the weight is lopsided toward the back of the unit, so it feels slightly more treacherous to seat on a windowsill. It’s 58 pounds, which is heavy but only 10 pounds heavier than the lightest model we installed. 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.
The remote control that comes with the LW8016ER is pretty basic, compared with those of other ACs, with no screen and only six buttons. That’s not necessarily a bad thing, 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.
Consumer Reports puts the LW8016ER pretty low in its rankings, mainly for poor noise scores (worse than previous versions of the LG AC, which are still listed in the rankings at the time of writing). According to our measurements, however, this year’s LG runs at just about the same volume as previous versions did. We’re not sure how they came up with this result.
If our main pick is unavailable, the Frigidaire FFRE0833S1 is another affordable, widely available window AC. On cooling performance, the FFRE0833S1 works just like our main pick, and its price is also often similar.
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 with a more noticeable, higher-pitched whine. 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.
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 if that happens to you.
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 feature-heavy remote control, including a built-in thermostat and a basic screen. 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, we’ve tested multiple versions of this remote over the last few years and it’s always been wildly inaccurate. The calibration is way off, by about four degrees compared with the main unit. Other users shared similar experiences. But the remote didn’t influence our pick one way or the other.
Pricewise, our main pick and runner-up can jump all over the place, from day to day. However, every summer that we’ve paid attention, we’ve seen prices for the Frigidaire and LG models settle around $220 by mid-summer and drop as low as $200 at times. 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. 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.
If you’re installing an air conditioner in your bedroom, or if you just value peace and quiet in any other room, a few ACs are noticeably quieter than our main pick or runner-up. They cost more, but can help you sleep better all summer.
Our favorite bedroom AC, the Frigidaire Gallery FGRQ08L3T1, has gone out of stock for a few weeks as of late June 2017. While we wait for it to come back, we recommend the Haier Serenity Series ESAQ406T in its place. The only caveat is that the Haier model is available only in a 6,000 Btu version—it’s suited for rooms smaller than 300 square feet. That should be fine for most city bedrooms, but you would be wise to double-check your measurements before you buy.
At its lowest fan setting and with the cooling mode turned on, the Haier ESAQ406T runs at just 54.5 dBC. That’s almost 8 dBC quieter than our main pick, a very obvious difference. At the high fan setting, the ESAQ406T is also at least 6 dBC quieter than any other run-of-the-mill window AC. Our tests didn’t register any annoying frequency spikes, and the sound of the compressor switching on should be less jarring than that of other window units available. It’s just about the quietest AC you can get—ever so slightly louder than the Frigidaire Gallery FGRQ08L3T1 that we prefer. If you can fall asleep while you watch TV, you can fall asleep near this air conditioner.
As for cooling performance and energy efficiency, the ESAQ406T is a 6,000 Btu model, so it’s weaker than our main pick and runner-up, as well as slightly less efficient with an EER of 11.2 (down from 12.1). However, since window ACs are so tightly regulated by the Department of Energy, we’re confident that it will perform similarly to the 6,000 Btu variants of our main pick and runner-up.
Although the ESAQ406T is relatively quiet, it’s definitely not silent, and it may still be too loud for light sleepers. Just as with any air conditioner, the compressor kicks a little when it starts up. The compressor also hums a bit more than those of other bedroom-oriented units we tested this year, though that kind of low-frequency sound can be soothing for some people. If you can’t sleep near this thing, you probably won’t be able to sleep near any air conditioner. Try earplugs.
Installation can feel a little scary, because the weight is skewed to the back corner of the unit, so it doesn’t balance on a window frame as easily as some other ACs. It’s also pretty heavy for its size, about the same weight as our 8,000 Btu main pick. Ask a buddy to help out if this makes you nervous.
The fan is also angled upward, so it can’t blow cold air directly at you while you’re lying in bed. This limitation bothers some people.
If 6,000 Btu isn’t enough but you can’t wait for our favorite 8,000 Btu bedroom unit to come back in stock, your other choice is the Friedrich Chill series, our upgrade pick for the latter part of summer 2016. These ACs are louder, larger, and more expensive than the new 2017 Frigidaire or Haier models; on top of that, the packaging is not as sturdy, so they are also more prone to arriving damaged. However, they are widely available, and they come in a wider range of sizes, from 5,000 Btu up to 24,000 Btu, including the 8,000 Btu Friedrich Chill CP08G10B.
An older Haier Serenity Series model, the ESAQ406P, is still available on the Amazon Marketplace. It was one of our upgrade picks for a part of summer 2016, until availability dried up. This older model uses about $3 to $5 more energy per year than the new one (based on DOE estimates) but is otherwise similar. Buying this model now is a gamble: It’s a discontinued model, no longer sold by major retailers, so you may have trouble with returns or exchanges through the smaller retailers. And as far as we’ve seen, the prices are marked up higher than those of the current models.
The GE AHM08LW is louder than our main pick by 2 dBC at the highest fan setting, with more of a midrange “whoosh,” so we think it’ll be harder to sit near for prolonged periods. It often costs more than our main pick, too (though at ABT it’s usually cheaper). Not a bad AC, but not one of our picks either.
Some older versions of our top picks are still floating around, namely the LG LWxx15ER and Frigidaire FFRExx33Q1, 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.
Haier makes a cheaper window AC, the ESA408R, which we tested in summer 2016. It’s by far the noisiest air conditioner we’ve ever heard. 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 the current 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.
If you want to control your air conditioner from a smartphone—to get the cold air cranking in your apartment while you’re still on your way home from work, for example—you have some options.
The simplest way to do it is to rig up a regular dumb digital AC to a smart plug like the Belkin WeMo. That will let you turn the AC on or off from a smartphone app, or with Alexa voice commands. You won’t be able to adjust the temperature or fan settings, but most people who have this setup seem comfortable with that limitation. Check to see if your electric company is giving away smart plugs, like this Con Edison program in New York City.
If you want more control, your options are not good—we don’t recommend any smart ACs or other smart AC peripherals. Our rule of thumb is that if a smart appliance actually makes your life harder, it is not worth owning. We’ve tested just about every smart (Wi-Fi–connected) AC model that has ever been available in the US, and we’ve yet to find one that works reliably. The extra frustration that they can bring will, for many people, outweigh the modest benefits.
The Frigidaire Gallery Cool Connect FGRC0844S1, for example, seemed decent when we first tested it in summer 2016. It’s a relatively quiet, good-looking unit, and the companion app looks slick and responded quickly to us—at first. But after a few weeks, the app started tossing up error messages every couple of days, asking us to reconnect the AC to our Wi-Fi network. Since we constantly had to reset the machine, the scheduling feature didn’t work very well. We also think that on one occasion, the AC turned itself on, unprompted; however, that also could have been a very delayed response to an app command that we’d forgotten about from hours or days earlier. Our long-term tester gave up on trying to use the app after a couple of weeks. Owner reviews commonly cite these same problems, and the average customer rating is mediocre.
We ran into similar problems with the old Quirky Aros back in 2014, as well as with the new GE AEC08LW in 2017.
True story: I had just finished writing a cautious recommendation of the AEC08LW, for people who really, really wanted a smart AC. It seemed to be the most stable, responsive model we’d tested. It works with both Alexa and Google Home voice assistants, which is neat, and the iPhone app is pretty slick and user friendly. Owner reviews haven’t complained about poor connectivity, either (though this model hardly has any reviews at all).
We’ve also been testing the new LG LW8017ERSM, which is essentially our main pick with a Wi-Fi antenna. It’s a quieter air conditioner than the GE AEC08LW, but the connectivity is clearly an afterthought. The app is ugly, with mismatching fonts and poorly translated English. It doesn’t work with any voice assistants, either. At some point, the app logged me out, and after five minutes of password recovery I discovered that the AC had also disconnected itself from my wireless network.
A company called Tado makes a Smart AC Control, a $180 peripheral that turns any AC with a digital thermostat into a smart AC. However, three of our staff members tried and failed to even set the thing up last summer, and the customer reviews are poor.
All that said, some people have no trouble at all with their smart ACs. If you’re willing to try one out, that’s your prerogative—don’t let us talk you out of it. Just set your expectations accordingly.
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 that you can wheel from room to room, or if your windows don’t support any other option, we have some recommendations.
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.
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 as much as a good portable air conditioner, and work more efficiently.
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.
Unfortunately, casement-window ACs won’t actually fit into all slider or casement windows. The model we recommend needs an opening of about 15 inches across, 21 inches tall, and 24 inches deep. So if your windows are very narrow, or don’t crank all the way open, you might have to go with a portable AC anyway. One of those only needs an opening of about 6 inches across, 12 inches tall, and maybe 2 inches deep, so it’s a lot more flexible.
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.
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. Wait 24 hours to give the refrigerant a chance to settle, and try again. If it doesn’t improve, exchange the unit. ACs aren’t supposed to sound like that.
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.)