Best thru wall air conditioners: space-saving solutions for efficient cooling, reduced noise levels, and improved air quality

LG LT1016CER thru wall air conditioner installed close to ground in living space
(Image credit: LG)

The best thru-wall air conditioners are the cost-effective cooling solution for your home. They are more affordable than many other types, and their installation doesn't require expensive ductwork, making them a budget-friendly choice.

Unlike the best central air conditioners, through-wall air conditioners are installed into a wall sleeve, saving valuable living space. They don’t obstruct your room like freestanding units or dominate your window like window air conditioners.

Thru-wall air conditioners may not be the most stylish option, but what they lack in appearance, they make up for in features. Basic thru-wall air conditioners cost as little as $400 and include the essentials, such as various fan speeds and cooling modes, which allow you to control the volume of cool air they produce. More premium models might also have a remote control and app connectivity.

When choosing a through-wall air conditioner, it's crucial to consider the unit's power in British Thermal Units (BTU) with your room size. The larger your room and the lower your patience, the higher the BTU rating should be for effective cooling. Our top picks, including Whirlpool, LG, Keystone, and others, stand out with their excellent BTU ratings and other features.

The quick list

Below, we’ve provided an overview of the important details you need to know about each product immediately so you can buy quickly if you're in a hurry. If something catches your eye, use the links to delve deeper into the analysis provided for each product further down the page.

The best thru wall air conditioners we recommend

Why you can trust Top Ten Reviews Our expert reviewers spend hours testing and comparing products and services so you can choose the best for you. Find out more about how we test.

The best thru wall air conditioner overall

Best thru wall air conditioners: Whirlpool WHAT142-2AW review

(Image credit: Walmart)

1. Whirlpool WHAT142-2AW

The best thru wall air conditioner overall

Specifications

Cooling power: 14,000 BTU
Cooling area: 700 sq ft

Reasons to buy

+
Can cool rooms up to 700 sqft
+
Can channel air in eight directions
+
Customizable temperature, airflow, and fan speed with four pre-sets

Reasons to avoid

-
Not Energy Star certified
-
Shorter warranty
-
Requires a specific 230-Volt/20 Amp electrical outlet

The Whirlpool WHAT142-2AW thru-wall air conditioner is a solid choice for cooling large rooms. It can effectively cool spaces up to 700 square feet, and it's a powerful unit with many good features.

The air conditioner can channel air in eight directions, meaning your room can be evenly cooled, which is especially important in larger spaces. The unit also allows you to change the cooling temperature, airflow, and fan speed to reach a comfortable level.

If you're unsure how to customize the settings to your liking, there are four pre-set modes and a sleep mode that gradually increases the temperature as you sleep. While the Whirlpool WHAT142-2AW is not Energy Star certified, it does come with an Eco mode that automatically turns off the compressor when your room has reached the desired temperature. This helps save energy and reduce the unit's environmental impact.

However, it lacks Energy Star certification. While the Eco mode can help reduce energy usage, you may still experience higher energy bills than if you went with a certified unit.

The Whirlpool WHAT142-2AW is competitively priced at around $630. It also offers an excellent power-to-price ratio with 14,000 BTU of cooling power. In addition, the unit provides a range of features designed to customize your airflow. You can set the airflow exactly how you like it, from louvers that reach eight directions to multiple fan speeds. This level of customization is great for those who are particular about their air quality and comfort.

One potential downside to the WHAT142-2AW is its warranty on the shorter side of the spectrum at just one year. It's also worth noting that the unit requires a particular 230-Volt/20 Amp electrical outlet and will not operate with a standard 115-Volt household electrical outlet.

User reviews on Home Depot give the unit an average of 3.7 out of five stars. Positive reviews praise the unit's quick cooling and quiet operation, and users appreciate its easy use. However, some users have mentioned that the unit was less effective at cooling their room than they had hoped.

The best thru wall air conditioner for small rooms

Best thru wall air conditioners: Koldfront WTC8001W review

(Image credit: Walmart)

2. Koldfront WTC8001W

The best thru wall air conditioner for small rooms

Specifications

Cooling area: 350 Sq. Ft.
Cooling power: 8000 BTU

Reasons to buy

+
Good for smaller rooms
+
Reasonably priced
+
Easy to use with two-year warranty

Reasons to avoid

-
Heating feature only somewhat effective
-
Not suitable for larger spaces

The Koldfront WTC8001W may not have the same cooling power as other models, but it is still an excellent option for smaller rooms. The heating feature is designed to be a supplementary source of warmth, so it won't be effective as a sole heating source, but it is still a nice extra to have in the cooler months.

One of the best things about the Koldfront WTC8001W is that it balances cost and features. While it may not be the cheapest option, it is still reasonably priced and includes excellent convenience features like multiple fan speeds, a fan-only mode, and a sleep mode. Plus, as a less-powerful unit, it consumes less energy than many of its more powerful counterparts.

The Koldfront WTC8001W is easy to use. It has a simple digital display and electronic touch controls make it easy to adjust temperature and fan speeds or set up a programmable timer. The remote control is also handy, especially if your air conditioner unit is a little out-of-the-way.

If you're concerned about longevity, you'll be happy that the Koldfront WTC8001W is solidly built with durability in mind. It also comes with a two-year warranty on parts and labor. User reviews for the Koldfront WTC8001W are overwhelmingly positive, too, with many users noting that it's easy to use and gets the job done. One reviewer said it quickly cooled a space towards the top of the 350 square-foot range and was reasonably quiet when operating.

While there were a few notes that the heater struggled to combat cold air from outside, users love this unit.

The best thru wall air conditioner for large rooms

Best thru wall air conditioners: Keystone KSTAT14-2C

(Image credit: Home Depot)

3. Keystone KSTAT14-2C

The best thru wall air conditioner for large rooms

Specifications

Cooling capacity: 14,000 BTU
Cooling area: 700 sq ft

Reasons to buy

+
Energy Star certified
+
Also works as a dehumidifier
+
Remote control has integrated thermostat

Reasons to avoid

-
No built-in heater
-
Can be noisy
-
Some users noted durability issues

The Keystone KSTAT14-2C is an excellent option for cooling larger spaces. Its Energy Star certification also means it won't break the bank (or the planet) when it comes to powering it. It also has the bonus of acting as a dehumidifier, capable of removing up to 2.9 pints of moisture every hour.

While the unit has no built-in heater, it has many other well-thought-out features. For example, it comes with a remote control with an integrated thermostat, which reads the room's temperature and adjusts the settings accordingly, ensuring the space is evenly cooled throughout. The air conditioner will automatically save your original settings and default to those whenever needed.

The wall air conditioner also has three cooling speeds, making it easy to customize the air output. The filter can be easily accessed from the front and quickly slides out for easy cleaning. The KSTAT14-2C also has enough power to effectively cool up to 700 square feet, making it an excellent option for larger rooms.

Cleaning the filter is easy, as it can be accessed from the front and quickly slides out for a quick clean. When the filter needs cleaning, an alert will sound on your unit so you know it's time to take it out and look. The Keystone KSTAT14-2C also has a 24-hour timer, allowing for a cooling routine that suits you. If you're planning on using the Keystone KSTAT14-2C in your bedroom, the night mode is a great feature that works by slowly increasing the temperature in your room.

The Keystone KSTAT14-2C has a one-year parts and labor warranty, but a four-year warranty covers the sealed system. Reviews for this thru-wall air conditioner are generally positive, with many users mentioning its effectiveness and energy efficiency. However, some users have noted that it is noisy and only suitable for small rooms. Others have had issues with the durability of the screws and kit included to install the unit.

The best budget thru wall air conditioner

Best thru wall air conditioners: The Impecca ITAC10-KSA21 air conditioner

(Image credit: Home Depot)

4. Impecca ITAC10-KSA21

The best budget thru wall air conditioner

Specifications

Cooling capacity: 10000 BTU
Cooling area: 450 sq ft

Reasons to buy

+
Affordable
+
Cools room up to 450 sqft
+
Washable filters

Reasons to avoid

-
No heating functionality
-
Not the most powerful in this list
-
Fewer customization options

The Impecca ITAC10-KSA21 is an excellent option for effective cooling without breaking the bank. While it does lack heating functionality, this is not a problem for many users as AC heating is often designed as a supplementary feature.

The Impecca wall air conditioner can cool rooms up to 450 square feet, making it suitable for most people. The unit is close to the Koldfront WTC8001W, but it has enough power to beat it in terms of the cooling area it can reach. It's the least expensive option in our round-up but still provides good features (although no heating functionality).

One of the advantages of this unit is that it utilizes washable filters, so you won't need to factor in the cost of regular replacements over its lifespan. It also has a filter indicator, which helps alert you when it needs cleaning.

It also offers a good range of settings, with three cooling and three fan speeds, allowing you to customize the air output and select lower speeds for quieter operation. The sleep mode on this unit adjusts the output for a comfortable snooze while reducing energy use, and there's an energy-save mode, too, which switches off the AC when your desired temperature is reached. Even better, this model is Energy Star certified.

In addition to those modes, the Impecca ITAC10-KSA21 has a programmable timer, allowing you to customize your air output 24/7. For anyone who finds programming AC units frustrating, the Impecca ITAC10-KSA21 has an auto-restart mode that automatically resumes your previous settings when the unit turns back on. While the Impecca ITAC10-KSA21 is a budget model, it still has a good warranty, covering it for two years for parts and labor.

The best thru wall air conditioner for energy efficiency

Best thru wall air conditioners: LG LT1016CER

(Image credit: Amazon)

5. LG LT1016CER

The best thru wall air conditioner for energy efficiency

Specifications

Cooling power: 10,000 BTU
Cooling area: 450 sq ft

Reasons to buy

+
Energy Star certified
+
Can cool rooms up to 450 sqft
+
Dry mode remove moisture for air

Reasons to avoid

-
Lacks heating functionality
-
Can be noisy
-
Feels a little flimsy

The LG LT1016CER may lack a few features and isn't as durable as some other models, but it is still an affordable option that offers good cooling power. The unit is designed with function in mind and has a relatively simplistic design, which may not suit those looking for a more advanced unit.

However, its output is strong enough to effectively cool rooms up to 450 square feet in size, which should be sufficient for most homes. Compared to other models in our round-up, like the Whirlpool WHAT142-2AW, the LG LT1016CER may lack some features, but it does have a range of cooling and fan speeds, and it's also Energy Star certified, which means it's designed to be energy-efficient and could help lower your monthly energy bills.

One feature that sets the LG LT1016CER apart from other models is its dry mode, which allows it to remove moisture from the air it outputs. It can remove up to 2.9 pints of water in an hour, more than some standard dehumidifiers. When customizing your airflow, the LG LT1016CER also gives you the choice of three cooling speeds and utilizes a four-way air deflection technique, which means you can direct the airflow wherever you need it.

However, it doesn't have heating functionality, which may be a downside for some users. The LT1016CER is priced towards the middle of the market at $550, making it more expensive than our budget pick, but only by about $70. It's also only $50 more than the Koldfront WTC8001W, but it has more power and can cover larger rooms.

One downside to the LG LT1016CER is that it feels less durable than some other units from competitors. However, it utilizes anti-corrosion technology to lengthen the unit's lifespan, and the LG-patented Gold Fin coating provides a protective shield to keep the unit cooling longer.

The unit is easy to install, with a universal fit for the sleeve structure. It also comes with insulation foam for a better fit, although some users have noted that the installation instructions in the manual could be more straightforward. Overall, users have given the LG LT1016CER an average score of 4.2 out of five on Amazon, with positive reviews noting its effectiveness in cooling and dehumidifying their home spaces.

Some users also appreciated the easy installation process. However, negative reviews have mentioned that the unit can be noisy and feel flimsy, and some have had issues with the unit breaking down after a year or so of usage.

The best thru wall air conditioner for consistent temperature control

Frigidaire 24" Through The Wall Air Conditioner

(Image credit: Frigidaire)

6. Frigidaire FFTA123WA1

The best thru wall air conditioner for consistent temperature control

Specifications

Cooling power: 12,000 BTU
Cooling area: 550 square feet

Reasons to buy

+
Highly efficient
+
Compact size
+
Wireless remote and programmable timer

Reasons to avoid

-
No in-built heater
-
Quite loud
-
Ionizing air purifiers have their detractors

The Frigidaire FFTA123WA1 is an efficient air conditioner perfect for maintaining a consistent room temperature. Its compact size allows it to fit into any living room, bedroom, or kitchen, though it does not produce heat.

The unit has a wireless remote controller, allowing you to control the air conditioner from anywhere in the room, and a programmable timer to customize cooling to fit your schedule. The timer can be set in half-hour increments and turns on and off automatically. The unit also comes with a sleep mode that gradually increases the temperature a few degrees over the evening while keeping the fan at a low speed.

The FFTA123WA1 has a cooling area of 550 sq. ft., making it suitable for larger rooms. You can choose from three different cooling speeds, and the air conditioner has an adjustable direction feature that allows you to direct the cool air wherever you need it. The unit also comes with a washable air filter that helps capture dust. The filter is easy to clean, and the air conditioner also uses R-32 refrigerant - an environmentally friendly refrigerant that does not harm the ozone layer.

The unit features an ionizer that purifies the room's air. This ionizer helps remove allergens, bacteria, and other airborne particles that can cause health problems, but be sure to research ionizing air purifiers first.

The Frigidaire FFTA123WA1 is energy efficient, with an ENERGY STAR certification and an energy-saver mode that helps reduce your energy bills. The air conditioner's inherent efficiency, automatic temperature control, and energy-saver mode help keep operating costs relatively low.

One of the few complaints about the Frigidaire FFTA123WA1 is its noise level. Some users have stated that it is too loud to be left on while watching TV or having a meal. However, this is a minor issue, and the air conditioner's many benefits may outweigh this drawback.

How to choose the best thru wall air conditioner

There’s a lot to think about when you're choosing an in-wall air conditioner, but first on your radar should be the following factors:

Room size and the cooling performance

Your thru-wall air conditioner must be powerful enough to handle the space. That’s why it’s so important to consider the appliance’s British Thermal Units (BTU). A room measuring up to 150 square feet should be on track with an air conditioner rating of 5,000 BTU. However, rooms up to 300 square feet need a unit with a little more oomph. Around 7,000 BTU should suffice.

If unsure, a BTU calculator will help you gauge the ideal BTU for your room’s measurements. Still, things like the model’s airflow (calculated in cubic feet per minute or CFM) also impact cooling performance. The higher the number, the better the airflow.

Efficiency ratings and certification

Your air conditioning unit's energy efficiency ratio (EER) is just as important. Most window air conditioners in our lineup have an average EER of 10.3, but those with a rating over 10.7 are excellent examples of efficiency. In short, the higher the ratio, the more efficient your unit is.

It’s also a good idea to look for UL-listed products or AHAM-certified units. UL-listed units have undergone testing from Underwriters Labaroties, a safety consulting company. AHAM-certified units must have achieved performance standards the Association of Home Appliance Manufacturers set.

Cost

Cost is always a significant consideration when purchasing, and choosing an in-wall air conditioner is no exception. It's important to compare the features of different models to determine the best value for your budget.

Operation modes

Operation modes are a key feature of wall-mounted AC units. They offer a high level of customization and control over comfort. Understanding and utilizing these modes allows you to tailor your cooling experience to your specific needs.

Great wall-mounted AC unit features are all about customization and control. One of your priorities should be a good range of cooling modes, and then adjustable fan speeds and fan-only modes will let you fully take the reins.

If your home is in a hot and humid climate, units with a dehumidifying mode will help to suck out some of the moisture from the air. Other features will depend upon your preferences. For example, sleep modes keep the noise down at night and slowly produce less cool air into the night to save energy.

Thru wall air conditioner FAQs

How do thru wall air conditioners work?

Thru wall air conditioners cleverly extract the heat from your room by sucking the hot air into the unit. Rather than spitting it back out, the heat is absorbed into evaporator coils and worked on by a compressor to increase the refrigerant temperature. Then, while the hot air is pumped out through the wall into the outdoors, cool air is sent as a replacement into your room.

The thru-wall air conditioner has several benefits compared to other air conditioners, such as window air conditioners. While window-mounted air conditioners are often stored out of sight in the winter, the thru-wall conditioner is a more permanent solution, meaning it will always be on hand in case there’s a sudden heat wave. Some thru-wall air conditioners also double up as a heater, saving you bucks on a separate appliance.

As they’re slotted firmly into a sleeve in the wall, these air conditioners look less obtrusive for one. However, the design also works undercover to put a stopper on any cold drafts from gaps in the wall. This is a plus for energy efficiency, meaning it’s relatively cheaper to run than other types of AC units.

What's the right BTU rating for my room?

Through-the-wall air conditioners can have capacities of up to 18,000 BTUs, which can cool rooms up to 750 square feet.

A room's BTU rating depends on its size (measured in square feet) and several other factors, such as insulation and climate. For a 400-square-foot room, an air conditioner with about 8,000 BTUs is recommended. For bigger spaces, multiply the square footage by 20 to determine the needed BTUs. For a home with 2,000 square feet, you'd need 40,000 BTUs.

In a kitchen, you should add 4,000 BTUs to account for the heat generated by cooking appliances. Homes in warmer climates or with poor insulation may need higher BTU ratings.

In a 150-square-foot room, a 12,000 BTU unit will cool the space too quickly, causing inefficient operation and poor humidity control, while an underpowered unit will struggle to cool the space effectively.

Measure your room's length and width to calculate its square footage (10 by 15 equals 150 square feet). Then, use a BTU chart or calculator to match the square footage with the right BTU rating.

Can you put a wall air conditioner in a window? 

You can't install a wall air conditioner through a window. They need the wall to support them, and placing one in a window might cause an insecure seal, causing the glass to crack. Because the two types of air conditioners aren't interchangeable, you'd need a window air conditioner instead. You can sometimes put a wall air conditioner in a window, but it depends on how it's designed.

Design and Support: Through-the-wall air conditioners are usually designed to be installed in a wall sleeve, which provides support and ventilation. These units are generally unsuitable for window installation because they are self-contained and vent heat through the back.

Dual-purpose air conditioners: Some are designed to work in wall sleeves and windows, providing more installation flexibility.

Ventilation Concerns: When you use a wall AC in a window, you have to worry about ventilation. Wall ACs vent heat primarily through the back, while window ACs vent through the sides. If a wall unit's side vents become obstructed, you might overheat, wasting energy.

Safety: Installing a wall air conditioner in a window without proper support poses safety risks, such as the unit falling or damaging the window frame. If you use a wall air conditioner in a window, ensure the unit is designed for dual use (wall/window). Improper installation can also lead to air leaks and decreased cooling performance. Get a dedicated one if you want to install an air conditioner properly in a window.

When buying a through-the-wall air conditioner, what features should I look for?

Several key features should be included in through-the-wall air conditioners to ensure they are efficient, meet your cooling needs, and fit your space.

Cooling Capacity (BTU Rating): The cooling capacity, measured in BTUs, should match the size of the room you want to cool. For example, a room of 400 square feet typically needs 8,000 BTUs. If you have an oversized unit, you might not be able to dehumidify the air well, and if you have an undersized unit, you might not be able to keep it cool.

Energy Efficiency: To save money on energy bills, choose units that are Energy Star certified or have a high Energy Efficiency Ratio (EER). Some units have energy-saving modes, like automatic shutoff or fan-only options, to further reduce power consumption.

Installation Requirements: The unit needs to vent heat outside, so it must fit the dimensions of your wall sleeve. If you are replacing an old unit, the new unit must fit the existing sleeve.

Noise Levels: If you're installing the unit in a bedroom or other quiet space, look for it with quiet modes or low decibel ratings.

Smart Controls: Many modern units are equipped with Wi-Fi connectivity, allowing you to adjust the temperature using a smartphone app or a voice assistant. Thanks to a remote control, you can change settings without having to get up. Additionally, you can program the unit to turn on and off at specific times, making it more energy-efficient and convenient.

Heating Capability: A few through-the-wall air conditioners have a heat mode so they can be used year-round. They usually use a heat pump or electric heating system to keep the room warm.

Maintenance Features: Self-diagnostic tools can help identify problems quickly, reducing the need for professional service. Look for units with washable filters and filter change reminders.

Voltage Requirements: Check the unit's voltage requirements. Some high-capacity models might require a 220-volt outlet.

How much does installation cost, and do I need a professional?

Through-the-wall air conditioners require a wall sleeve, which can be costly. Professional installation is often recommended.

Through-the-wall air conditioning can cost a lot, depending on the complexity of the installation, the size of the unit, and whether you hire a professional or do it yourself. In general, a through-the-wall air conditioner for a 340 sq. ft. room costs around $1,349. The price includes labor and materials, but it may change depending on where you live and what you need.

More complex installations, like cutting a hole in the wall or reinforcing a load-bearing wall, can cost more. A carpenter might charge about $730 for that.

You can save money by doing it yourself. A DIY installation costs around $540, which covers materials but not labor.

If you want to cut a new hole in the wall or modify an existing wall sleeve, it's highly recommended that you hire a professional to ensure its structural integrity and proper sealing to prevent air leaks. A licensed electrician should also do the electrical work on the unit if it requires a 220-volt outlet.

If you're replacing an old unit with a new one of the same size and the wall sleeve already exists, DIY installation can be a cost-effective option. Just make sure to follow the manufacturer's instructions.

If your house doesn't already have one, wall sleeves cost between $50 and $150, depending on the size and brand.

Electrical modifications cost an extra $200 to $500 if the unit needs a dedicated circuit or a 220-volt outlet.

A permit may be required for wall modifications in some areas, which can add to the cost.

Are through the wall air conditioners a standard size? 

Many sizes are available for through-the-wall air conditioners, as the size of the room you want to cool varies greatly. If you choose one too small, you will struggle to cool the room and waste energy. You also need to work out the ceiling height and how much sunlight the room receives.

Caroline Preece
Deputy Editor

Caroline is the Deputy Editor of Top Ten Reviews. Joining Future at the start of 2021, she has since served her time across all of the company’s home titles, including Real Homes, Ideal Home, Livingetc, and Homes & Gardens. Caroline has spent years testing out products for the home, which she trials in her cozy one-bedroom basement apartment in Suffolk, UK. She’s passionate about helping people choose the very best appliances, tech, and anything else that might make their lives easier, more cost-efficient, or just more fun.