7 Best Through Wall Air Conditioners (Review) In 2022
- The Best Through Wall Air Conditioner
- 1. Koldfront 8,000 BTU Through The Wall Air Conditioner
- 2. Koldfront 12,000 BTU Through Wall Air Conditioner
- 3. Keystone 14,000 BTU Through-The-Wall Air Conditioner
- 4. Frigidaire 12,000 BTU Wall Air Conditioner
- 5. LG 11,800 BTU Through-The-Wall Remote Control Air Conditioner
- 6. Perfect Aire 12,000 BTU Through-The-Wall Air Conditioner
- 7. Friedrich Window/Wall Air Conditioner
Staying cool and comfortable during the scorching and humid summer months should be a god-given right. For many people, they are lucky enough to live somewhere that opening the windows will do a decent enough job at ensuring total comfort. However, not everyone has such a luxury which is where the best through wall air conditioners come in to save the day.
Just like a traditional centralized AC unit, portable ac unit, window air conditioner, the through wall air conditioners will provide you with the vital respite you need to deal with temperatures that can often reach triple digits, especially as we creep closer to summer, with some of you already feeling the heat, even now.
With a wide range of features, including a variety of BTU ratings, convenient remote controls, and simple as well as versatile installation options, the air conditioners will give you the satisfying cooling you need so you can enjoy the comfort of your own home without feeling like you’re covered in a sticky, sweaty film. Some products even bring Heating elements to the table, so you’re not just getting an option for the summer, but all-year round, as well.
The Best Through Wall Air Conditioner
1. Koldfront 8,000 BTU Through The Wall Air Conditioner




Key Features
300 – 350 square foot coverage
Remote control included
2-year warranty
4-way air direction
3 fan speeds
4 operational modes
Ideal for your average sized room and effortlessly simple to use and operate, it’s no wonder the Koldfront 8,000 BTU Through Wall Air Conditioner with 3500 BTU Heater stands out as the best choice wall air conditioner that you can purchase.
It’s so effective that it’s challenging to pinpoint exactly which feature is the best for you. To be honest, every single aspect delivers superb satisfaction that guarantees comfort throughout the humid summer months. It provides 300 – 350 square feet of coverage, while the 4-way air direction allows you to enjoy supreme air circulation wherever you are. The 3 fan speeds also provide decent customization, and they help you adapt to the day rather than rely on a single-speed setting for the whole summer.
The remote control is highly convenient, while the 24-hour timer demonstrates excellent efficiency and means you don’t need to worry about switching it off. Furthermore, installation is one of the easiest you’ll come across, as long as you can decipher the instructions. All necessary hardware is included, and this model is compatible with your existing Koldfront sleeve.
Pros
Compatible with Koldfront AC sleeve
24-hour timer
Installation hardware and seals included
100 square foot heating coverage
Cons
Some concerns over maintaining temperature
Instructions are lacking key details
You might, however, encounter some issues with maintaining the temperature, but this can be easily fixed with regular cleaning and maintenance. Even so, it’s a versatile product that provides suitable performance for both cooling and heating, giving you an all-in-one choice for the whole year.
2. Koldfront 12,000 BTU Through Wall Air Conditioner





Key Features
Cooling and Heating elements
450 – 550 square foot coverage
4-way air directional louvers
Dehumidification capacity
Remote control included
Three fan speeds
The Koldfront 12000 BTU Through Wall Heat/Cool Air Conditioner provides the best heating capacity for your home, which is ideal for anyone who needs both cooling and heating elements to guarantee year-round comfort. Aside from its versatility, it also offers excellent coverage, providing a comprehensive 550 square foot maximum for cooling, while the 10,600 BTU heating range will guarantee comfort once the temperature outside drops.
There are 4 directional louvers that enhance your overall experience, while the dehumidification can produce up to 60 pints every hour. In terms of energy efficiency, this is crucial for saving money and being more eco-conscious. It will also increase the lifespan of the unit so you can enjoy its benefits for longer.
For convenience, you get a remote control included, but you can also operate and adjust the settings on the wall unit itself. The LCD display is easy to read, but also not too bright that it affects sleep quality if the unit is in your bedroom.
Pros
4 modes
Easy-read LCD display
Auto options
Energy saver mode
Cons
Loud operation
Difficult to assemble
Such features combine to create a very impressive model. However, as it is so powerful, particularly with the heating element, it also suffers from being noisy. This may not be an issue if it is in a room that’s out of the way, but it could be a problem if too close to the TV or bedroom. Despite this, you can take advantage of the energy saver and sleep mode to reduce noise while keeping the room air comfortable.
3. Keystone 14,000 BTU Through-The-Wall Air Conditioner


Key Features
LCD remote
Wide range of size and BTU options
Variety of Cool/Heat styles
3 cooling modes / 3 heating options
Multiple modes
Programmable 24-hour timer
The Keystone 14,000 BTU Through-The-Wall Air Conditioner is an excellent choice if you’re chasing a large room pick, and it comes in a wide range of sizes to ensure that you can feel comfortable in any sized room and square feet measurement you like.
There are three cooling modes and 3 heating options to provide expansive versatility, and the LCD remote control is easy to operate, allowing you to adjust the settings and modes from a distance, which is perfect for those days where it’s so humid that it’s an effort to even think about moving.
Speaking of the multiple modes, you can take advantage of whichever you prefer to make your experience as comfortable as possible. There are 3 pre-programmed fan speeds, while you can also use energy saver mode to keep your electricity bills low, and this is backed-up by its Energy Star rating. Furthermore, there’s a 24-hour timer, which is one of the best features you can get with air conditioners, and this can also reduce usage costs.
Pros
Compatible with existing sleeves
6.5-foot power cord
Convenient remote operation
Energy saver mode
Cons
Loud even on the lowest setting
Not as durable as other options
It can be quite loud, even on its lowest setting, and it also doesn’t seem as durable as other options. However, you will find it is easy to clean, and relatively easy to install, especially if you already have an air conditioner sleeve handy, which is not something you can say about all the products we’ve selected.
4. Frigidaire 12,000 BTU Wall Air Conditioner




Key Features
550 square feet cooling
Heating and Cooling capability
LED temperature controls
Memory feature
Compressor delay for long life
Remote Control included
If you need an option for a medium room, the Frigidaire 12,000 BTU Wall Air Conditioner is just what you need. It’s BTU rating is just right for a standard room measuring 550 square feet, while the Heating and Cooling combination design ensure versatility from the summer all the way through to winter.
Its most striking and useful feature is the memory function, which remembers the setting you were using in the event of a power outage. For places where storms and unreliable electricity are common, this is excellent for maintaining comfortable room air and guaranteeing ease of use. The LED temperature controls will also contribute to simplicity, while the additional remote control ensures convenience.
The Compressor delay system is also essential, especially if you want to extend the lifespan, which is likely if you use it throughout the year. The three-speed motor gives you plenty of comfort options, and with evaporator freeze protection, you’re looking at an air conditioner that provides high performance and ensures durability.
Pros
Three-speed motor
Durable parts and construction
Evaporator freeze protection
1-year warranty
Cons
Sleeve not included
On the loud side
It can be a little tricky to install, and this is mainly because the sleeve is not included, so you’ll need to purchase that separately, which could affect an overall value for money. It’s also slightly too loud for some, so it’s only suitable for nothing less than a medium-sized room.
5. LG 11,800 BTU Through-The-Wall Remote Control Air Conditioner




Key Features
3 BTU levels
Energy Efficiency Ratio of 10.6
3 cooling speeds
3 pre-programmed modes
Anti-corrosion coating
530 square foot coverage
Discreet but effective, the LG 115V Through-the-Wall Remote Control Air Conditioner is a fine choice for those looking for a smart air conditioner pick to enhance their overall comfort during the summer months. It’s one of those air conditioners that come in a wide range of BTU rating options, so you can find a suitable product for any sized room, and enjoy total relaxation once the temperature creeps into triple digits.
It’s an Energy Star rated product, with an EER of 10.6, putting it up there amongst the very best, which is perfect for those looking to enjoy cool room air comfort while also saving on energy bills. You can also select between 3 cooling speeds and 3 pre-programmed modes to enhance your experience while also making it easy to use every single time, even if you’ve never had air conditioners in your house before.
Pros
Energy saver mode
Dry mode
4-way air direction
Durable and long-lasting
Cons
Not suitable for window installation
Noise level rises after a few years
As far as through-the-wall air conditioners go, it’s got plenty going for it. You will find it’s one of the most durable options around thanks to the anti-corrosion coating. With this, you can trust that all the parts stay working to their optimal level, and it will resist potential damp and weather damage.
While quiet at first, it seems to run louder after a few years, but you can avoid this with regular cleaning, and this is easier than doing so with a central air system.
6. Perfect Aire 12,000 BTU Through-The-Wall Air Conditioner



Key Features
Remote control
Wide range of BTU levels
Cool only or Heat/Cool models
Easy-to-adjust temperature range
Auto, Sleep, Dry, and Energy Saver mode
Front-mountable reusable air filter
The Perfect Aire 12,000 BTU Through-The-Wall Air Conditioner is a marvelous choice if you’re looking for an air conditioning unit that provides plenty of size and power options, as well as varying voltages to ensure it is suitable for any house anywhere in the world.
You can select either solo Cool or Heat/Cool models to maximize versatility and potential, and whichever you choose, you can enjoy easily adjustable temperatures, thanks to the straightforward, if a little busy control panel. You also get a remote control included so you can change the settings wherever you are in the room.
Like any decent air conditioner, you can take advantage of multiple modes to guarantee you enjoy the comfort and cool feeling you deserve. These include Auto Mode, Sleep Mode, and Energy Saver Mode, all of which improve operation as well as help to prevent overworking the wall unit and providing long-lasting quality which means you get your money’s worth. The reusable air filter will also keep the cooling capacity sustainable, and there are 3 fan speeds that will give you options depending on how hot it gets.
Pros
Three speeds for cool and fan modes
450 – 550 square foot coverage
Full function remote control
Easy to customize
Cons
Customer support is lacking
No condensation overflow drain hole
While you can take steps to ensure longevity, the customer support is, unfortunately, a little lacking should you encounter any problems, especially if you’re unable to diagnose or solve problems yourself. There’s also no drain hole for condensation overflow, and if you know anything about air conditioners, you know that this is essential for any unit.
7. Friedrich Window/Wall Air Conditioner


Key Features
4 BTU levels
1000 square foot coverage
Continuous Auto Air Sweep louvers
Ultra-quiet operation
Power cord flexibility
Modern design
The Friedrich Window/Wall Air Conditioner is what we have selected as having the highest BTU rating that you can find, and this makes it an ideal choice for larger rooms such as hotel dining halls, schools, and offices, but it could easily work in your mansion, too.
It boasts continuous Auto Air Sweep louvers to guarantee fantastic and consistent air circulation so that there are no areas that are too hot or too cold. When compared to window units, this is a definite tick in the plus column if you’re still unsure whether a wall AC unit is right for you. This model, however, can double as a window unit, meaning you’ve got the very best of both worlds.
It does something that other wall AC products don’t provide, and that is a modern design that is both attractive but also subtle. For contemporary spaces concerned with minimalism combined with comfort, this is essential, and it is part of what makes it one of the best through the wall air conditioning and cooling options around.
Pros
Can be installed on wall or window
Clear LCD screen
Washable antimicrobial air filter
24-hour timer
Cons
Noticeable vibration
Unreliable warranty policy
The antimicrobial air filter will improve the air quality, and the clear LCD screen is easy to read, even from a distance. There is, however, noticeable vibration, and this could pose a problem if fitted as in place of window units, but with a sturdy and reliable sleeve, you should be able to overcome this issue if you decide to fit it to the wall, and this is where you will get the most from it.
Features To Consider With Through Wall AC Units
BTUs
The BTU, or British Thermal Unit rating of a through-the-wall air conditioner will determine how powerful it is. BTUs determine how much heat is needed to raise the temperature of a single pound of water by a single degree of Fahrenheit. Higher BTU ratings are better for larger rooms, and this will help you get an idea of which unit to buy based on your room size.
There is a wide range of BTU ratings for all of these AC units, and many options come with a variety of power levels, so even if one model doesn't have the appropriate BTU rating, you may be able to select the same brand with a more compatible rating.
Controls
The unit controls will help you find the optimal setting for your AC unit. Through-the-wall air conditioners come with a plethora of control options, including those on the unit as well as remote controls. This ensures convenience that will allow you to adjust the temperature settings and modes from anywhere in the room, which is perfect for a hot and sweaty day where the very thought of moving makes you groan with dread. Through-the-wall air conditioners come with various levels of controls, and these will determine the cost and user-friendliness of each unit.
Dehumidification
Dehumidification is an excellent feature to look for when purchasing an air conditioner. A unit with a dehumidifier will often boast a better Energy Star rating, as it is more energy efficient compared to standard options. It allows the unit to waste less energy while also making it possible to run the unit at a higher temperature, which will have a positive effect on your energy bills.
Displays
Most wall air conditioner models will come with a display, and they are useful because you can be certain of the temperature level and the settings, even from a distance. Some options come with remote controls that also use an LCD display, making it even easier to use if you don't want to get up. The display is not usually too distracting, but it could provide an unfortunate blue or red glow if the AC unit is in the same room as where you sleep.
Energy Efficiency
An energy-efficient through-the-wall air conditioner will save you money on energy bills through the summer. This is another time where you should look for an Energy Star rating, as it will give you an obvious indication of how dependable your unit will be, and how much money you can save throughout the year. Wall AC units are more energy efficient compared to central air systems anyway, so you can already enjoy the financial benefits of that, and you can look for the Energy Efficiency Rating (or EER), to determine which option is most suitable for your home. Of course, you should also consider the size of the unit and the size of your house or room to get the best and most thorough idea of which is right.
Filters
As AC unit filters will catch plenty of dust, allergens, and particles, you want to make sure they are easy to clean. However, even if they are easy to clean, the filter should also be replaceable, as this will ensure the best quality performance possible for your wall air conditioner. If you neglect to clean or replace the filters for too long, it can affect the cooling capacity of your unit, and this could cause it to a malfunction or waste precious energy without providing the best results.
Heating Option
While most of these wall AC units are primarily used for cooling the home, some also include a Heating Option. This can represent excellent value for money, and it may even help your home be more energy efficient in the winter, as you'll not need to rely on the central heating system to get comfortable.
Wall air conditioners with a heating function are ideal for areas that get scorching summers and frigid winters, but neither is too much. They provide an excellent respite from the temperature on both ends of the spectrum and will be more manageable rather than trying to work two unique systems.
Modes
The best through the wall AC unit will come packed with a wide range of modes that make it suitable for a range of different temperatures and climates just like window units. These can include sleep mode, as well as Fan-only and Dehumidification modes. If you want to get the most from your air conditioner, it's essential to find one that comes with as many modes as possible. This gives you greater control over comfort and also helps you save energy while extending the lifespan.
Noise Level
It's to be expected that a wall air conditioner will bring a bit of noise with it, but too much noise can be distracting. Overly loud air conditioning will ruin the experience you have in your home. It might make it difficult to hear the TV or listen to music, and you could even struggle to hear conversations. Furthermore, if your AC unit is fitted in your bedroom, it can hinder your sleep, which is never good for your health, especially as it can get very hot overnight in some parts of the world.
Room Size
The room size and BTUs are linked because of the amount of power that the unit can produce. Before deciding which AC unit is the best one for your home, make sure you understand the dimensions of the room in square feet. Doing this will give you a good idea of the power level required to sufficiently cool (or heat) the room. As a rule, the standard 450 square feet room size requires around 12000 BTU to provide comfortable cooling. However, this can vary depending on the shape of the room, the height of the ceiling, and any obstructions. If you don't have much space, you can look into smaller units like mini split air conditioners.
Timers
An air conditioner that has been fitted with a timer is a superb way to guarantee that you do not leave it on overnight or when you are out of the house. You will find options that come with a Sleep mode timer, but also a 24-hour timer that you can adjust to suit you. If you are someone who likes to go to sleep in a cool room but doesn't want it to still be on when you wake up, these timers are an excellent solution for doing so and will guarantee that you save energy.
Unit Size
The size of the unit is usually related to the BTUs and room size. However, this can vary, and you may find bigger units that are not as powerful as smaller units and vice versa, depending on the brand. A critical thing to consider about the unit size is that it will affect the ease of installation. The bigger and heavier the unit, the more difficult it will be to install. A larger unit will also take up more space along the wall which may not be suitable for the aesthetics you are looking for.
Voltage
The voltage requirements for your through-the-wall air conditioner must be compatible with the voltage in your home. Mostly, this isn't a problem, but failing to find appropriate voltage can damage the mains, and even short circuit the system. Newer air conditioners work on around 110V - 120v, while older models are typically around the 220v level. If the voltage demands don't align with what you have, then you will need to install specific wiring to make them compatible.
Wall Sleeve
The last feature to look for in the best through-the-wall air conditioners is the wall sleeve. These are what helps to support the unit when installed while also protecting it from coming into contact with the brick and other parts of the home. Most products will come with a wall sleeve, but others require you to purchase one separately. If you already own a specific brand of wall sleeve, your new air conditioner may be compatible with that, but you should make sure before doing anything.
Through Wall Air Conditioner FAQ
Q: How long do through the wall air conditioners last?
Through the wall air conditioners will typically last anywhere between 10 and 15 years, so while it may seem like a significant cost when looking at it, you will get plenty of value for money after buying one. The quality of the AC unit will also come into play, so this is something to consider when searching for the perfect wall air conditioner.
You can extend the life of you through the wall air conditioner by taking excellent care of it. To get the most from your air conditioner through the wall unit, make sure to:
- Scheduling maintenance and servicing at the right time
Annual tune-ups should take place in the spring prior to the temperature rising. You can contact an HVAC expert to carry out this servicing, as they will be able to spot issues that you may not realize. They will also be able to carry out essential maintenance that you are not trained for, including tightening connections, lubricating the fans, and cleaning out the system. Furthermore, they will check the coolant level and spot any leaks that could cause your unit not to perform below par.
- Changing the air filter
The air filter is an essential part of your AC unit so you need to keep it as clean as possible. Over time, it will capture particles and dust, which will affect how well the unit performs as it blocks the airflow, hindering energy efficiency and cooling capacity. By cleaning out, or even replacing the filter, you can keep it operating at the highest level and enjoy the cool air inside the house.
- Clean the return air ducts
The air return ducts are another component that keeps your air conditioning unit working to its best ability. Like the filter, these can become clogged with dirt and dust, which will affect how efficiently it works. When cleaning the filter, take care to check the air ducts, too. Even if you don't think they need cleaning right now, it's always worth doing so to ensure your wall AC unit works properly.
- Check the pipe insulation
The pipe insulation is what prevents the water from freezing during the winter, and damaged or torn insulation can affect the cooling power. When carrying out your yearly maintenance, check the condition of the insulation, and replace if necessary. They are easy enough to remove if you need to, and replacement insulation foam is cheap to source.
- Keep an eye on ductwork
Even if you live in a new build home, the ductwork could still be grimy and dirty because of dust from the construction. You could even find leftovers from any infestations. This can cause a drop in air quality, as the air filters through, bringing microscopic particles with it. When the air returns to the wall unit, it can further hinder the quality performance.
You may also find the ductwork is leaking or has loosened joints. This is especially common in older homes, and it causes air to escape, which means the through-the-wall air conditioners need to work even harder to sufficiently cool your home. Use aluminum foil or other insulation materials to patch and cover these areas.
- Inspect wiring
Checking the wiring is another way to extend the lifespan of your air conditioner. Problems will arise and persist if there are faulty or worn-away parts of the wires from overheating. As the wires carry an electrical current, it's crucial to remember to switch the entire unit off before making any repairs. If the wires are frayed or scorched, then it's best to hire a professional if you are not one already.
- Clean the exterior compressor
One aspect that first-time owners of through-the-wall air conditioners don't always realize is the compressor and condenser, but these components are arguably two of the most crucial factors in what makes your wall unit as efficient as possible. Typically, though, this is included as part of the tune-up, so you may not always need to worry about it. That being said, it's still useful to know how to clean the coils, and it is as simple as using a garden hose, but you must make sure not to get any of the electrical components wet. As these parts are delicate, you must be careful with them to ensure they do not break.
You can also clear out grass, dirt, leaves, and twigs that may have accumulated around the back of the unit, as this will make massive improvements on the overall air conditioning quality.
- Don't overwork it
Like with any electrical device, it's essential that you do not overwork the wall AC unit, especially when it is not needed. If possible, open the windows before resorting to switching it on, and monitor any leaks or gaps around the house that could affect energy efficiency. You can also consider switching to smart meters that allow you to control the room air temperature wherever you are, which will ensure you don't waste energy by leaving the AC unit running when you are not at home.
Q: What is the difference between through the wall and window air conditioner?
The most obvious difference between through the wall and window air conditioners is the placement. You don't need to be an expert on air conditioning to realize that one fits in one part of the home, and the other fits elsewhere.
Window air conditioners are installed at the window and fit on the windowsill to keep them balanced. Most of the time, they are secure enough to fit into standard windows, although this will vary depending on the size of your unit and the size of your window. You may need to renovate the window if your AC unit is too large, or even too small, to fit comfortably and securely.
Conversely, Through the wall air conditioners are fitted into the wall, and it's no surprise where the name came from. Engineers will install them in an exterior wall (not between your living room and dining room wall, for example) and they use coils to bring in and generate air from outside, transferring it to cold air to cool your house.
Window air conditioners are less efficient compared to their wall alternatives. However, they are more affordable, easier to install, and also flexible. Wall air conditioners are a little trickier to set up, and they will require a sleeve to help support them without damaging the wall, as these units are heavier than other options. They also may not provide as wide of a total coverage area compared to other options, especially centralized air conditioner systems.
Despite this, through wall air conditioners are efficient and save space in the room, while the durability means they are arguably the best bet for anyone who wants to enjoy a cool and comfortable home throughout the hottest months of the year.
Q: Do wall AC Units need recharging?
Wall AC units may not need recharging in the modern sense, which is hooking them up to a plug socket and relying on the battery until it runs down, as you can plug them into the mains. However, they may require a different type of recharging.
This recharging relates to the refrigerant, which is what transforms the outside air into cool air to make your home more comfortable to sit in on a summery day. If your air conditioner starts generating air that doesn't feel as cool as it should, especially on the lowest setting, then it could be a sign that you need to recharge it.
However, it's essential that you don't recharge the refrigerant without first checking whether the unit needs cleaning. In many cases, the filter may be clogged up with dust, debris, and even mold if it has been a while since you last serviced it. Clean out the filter before anything else and then test the unit. Most of the time, it will start to perform as normal, but if it doesn't, then it is a sign that you need to recharge it.
Recharging your AC unit is not something that you should do yourself, however. Because of the pollutants found in the refrigerant formula, this is something that only a certified HVAC engineer is qualified to do, so get in touch with your local service to see what they can do for you.
Q: How do you install a through wall air conditioner?
Through wall air conditioners can be complicated to install the first time, so if you're not completely confident, it's best to hire an engineer to do the work for you. If this is not possible, then we've put together a short and informative guide to help guide you through the installation process.
First, you need to identify the best place to install the unit. This isn't just about which room you choose, but also the part of the wall. Finding the best place to install your through wall air conditioner will ensure that you get the most consistent and broad air coverage for the room size, rather than causing some parts of the room to be too warm or too cold. You also need to think about how it will look at both the outside of the house and the inside, too. While the center of the living room may provide the best circulation, it won't look good if you can see the unit from the driveway of the street.
Most people will install the AC unit in the room that can provide the best overall coverage to the entire house, but this must be a room that has an easy-to-access exterior wall. Typically, this is the living room, but it could also be the dining room if that is more convenient.
When installing your AC unit, you must also be careful with interior wires, pipes, or electrical fittings. If you cut away a part of the wall where these are present, it could cause substantial damage to the house, which will be costly to repair. It also goes without saying that you should wear gloves and other protective equipment, as well as have a First Aid kit nearby in case you suffer an injury.
Once you have decided on an appropriate location, you will need to measure the dimensions of the unit and mark these dimensions on the wall. To ensure that you get the measurements spot on, check the length several times. If you don't trust yourself to do this, then it is always worth hiring a contractor to do the work for you. Their professional expertise will guarantee a consistent and reliable job.
Your wall unit should always be in a frame or sleeve to help support the weight while also protecting it from moisture and the passage of the current, which could damage the house. However, you can also install the sleeve prior to fitting the unit. This method could be easier if you are doing the installation yourself and also minimizes the risk of damaging any parts.
Following fitting the sleeve and unit, you must fill in any gaps or holes with sealant. Not only will this ensure moisture protection, but it will also ensure the wall unit works to its best ability, with no wasted air or energy.
It's vital that you do not switch the main electrical circuit back on until you are sure that you have finished the installation entirely.
To ensure your unit runs at the best level possible, there are some precautionary measures that you need to take. Primarily, it's vital that you keep the exterior part of the unit clear from dust, debris, moisture, grass, leaves, and more. Failing to do so could affect the overall performance, cause it to overheat, and damage your AC beyond repair.
Sources
How Do I Take Care of My Air Conditioner in the Summer? - Direct Energy
Window AC vs Wall AC - Which Air Conditioner is Right for You? - Total Homes
How to Install a Wall-mounted or Through-wall Air Conditioner (Split AC or Window Type) - Bright Hub Engineering