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Best thru wall air conditioners 2021

Best thru wall air conditioners 2021
(Image credit: Getty)

Take your pick from the best thru wall air conditioners of 2021 with this handy guide. We’ve got all the advice on what you should consider before choosing a wall air conditioner, and how to know which unit is right for you. 

The good news is that the best thru wall air conditioners aren’t as tricky to install as the best central air conditioners and they don’t normally cost as much either. If you haven’t had a wall air conditioner in your home before, we’d recommend getting a professional to fit one for you. However, if you’re simply replacing an existing wall air conditioner, many are made in a standard size so you’ll be able to fit it yourself. 

How do you know which is the best thru wall air conditioner? Well, that depends on the size of the space you need to cool down. We’ve included a range of units that can handle rooms from 350 square feet up to 700 square feet. If you’ve got an expansive space to cool, you’re going to need a unit that provides more power, but if it’s a smaller room, you won’t need to spend the extra that a more powerful conditioner costs. 

The more expensive the unit, the more features you can expect too. If your budget allows, it’s often worth paying that bit extra for handy features such as adjustable airflow controls. Energy Star certified wall air conditioners will also be cheaper to run. 

1. Whirlpool WHAT142-2AW: Best thru wall air conditioner for features 

Whirlpool WHAT142-2AW review

(Image credit: Walmart)

Whirlpool WHAT142-2AW

The Whirlpool WHAT142-2AW offers a great number of features for what you pay.

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

 Good value 
Cheaper models are available 
Not the more energy efficient

Ideal for large rooms, the Whirlpool WHAT142-2AW can take on spaces as big as 700 square feet. This wall air conditioner has been designed to fit into any existing sleeve and comes from a brand with a stellar reputation. 

There are louvers that channel cool air in eight different directions so that your room can be evenly cooled. You’ll be able to change the cooling temperature, air flow, and fan speed to reach a comfortable temperature too. If you’d rather not play around with the settings, there are four pre-set modes and a sleep mode that brings the temperature up gradually as you sleep. 

The Whirlpool WHAT142-2AW, unfortunately, isn’t Energy Star certified, however, it does come with an Eco mode which automatically turns off the compressor when your room has reached the desired temperature, this helps to save energy. What’s more, because of the power this thru wall air conditioner provides, it will cool your room quickly.  

2. Koldfront WTC8001W: Best thru wall air conditioner for small rooms 

Koldfront WTC8001W review

(Image credit: Walmart)

Koldfront WTC8001W

With a little less power than other units on this list, the Koldfront WTC8001W thru wall air conditioner is great for smaller rooms.

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

Low operating costs
Two-year compressor warranty
Not powerful enough for large rooms

The Koldfront WTC8001W wall air conditioner offers both cooling and heating functionality, but with less cooling power it’s well suited to smaller rooms. The heating functionality, like most other air conditioners with this feature, is designed to be a supplementary heating source, so it’s great to add a little boost in warmth but won’t be effective as a sole heating source.

This unit manages a nice balance between cost and features. It’s not the cheapest thru wall air conditioner on this list, but it’s not far off and it still packs in some good convenience features, like multiple fan speeds, a fan-only mode, and a sleep mode.

As a less-powerful unit, it’s also cheaper to run as it will consume less energy than most more powerful counterparts. The Koldfront WTC8001W feels solid and durable and also comes with a two-year warranty on both parts and labor.

3. Impecca ITAC10-KSA21: Best budget thru wall air conditioner 

The Impecca ITAC10-KSA21 air conditioner

(Image credit: Home Depot)

Impecca ITAC10-KSA21

The Impecca ITAC10-KSA21 is a relatively low-cost option that still effectively cools rooms up to 450 square feet in size.

Cooling capacity: 10000 BTU | Cooling area: 450 sq ft

 Washable filter 
 Sleep mode 
 No heater 
 Not as many features as other models 

Perhaps unsurprisingly for a budget thru wall air conditioner, the Impecca ITAC10-KSA21 is lacking heating functionality, but for a lot of users that won’t be a problem, especially as most AC heating is designed to be supplementary and more of a nice bonus than a must-have feature. 

The Impecca ITAC10-KSA21 is close in price to the Koldfront WTC8001W, but it has enough power to beat it in terms of the cooling area it can reach, The Impecca wall air conditioner can cool rooms up to 450 square feet. As a budget model it is a little on the simple side, but it provides effective cooling and is a good option if you’re wondering whether a thru wall air conditioner is right for you.

This unit also utilizes washable filters, so you won’t need to factor in the cost of regular replacements over its lifespan. It also has a clean filter indicator, which is really useful for alerting you when the filter needs a clean.

4. Keystone KSTAT14-2C: Best value thru wall air conditioner 

Keystone KSTAT14-2C

(Image credit: Home Depot)

Keystone KSTAT14-2C

The Keystone KSTAT14-2C is an ideal choice for larger rooms.

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

 Great for large rooms 
 No heater 

The Keystone KSTAT14-2C is a powerful thru wall air conditioner that has been designed to effectively cool down rooms as big as 700 square feet. This model is Energy Star certified so it won’t cost as much to power, and it also acts as a dehumidifier with the capability to collect 2.9 pints of moisture every hour.

There isn’t a heater built into this wall air conditioner which is a bit disappointing, however, its other features are well thought-out. The Keystone thru wall air conditioner has a remote control that has an integrated thermostat. This control will then read the temperature in the room and instruct the air conditioner to adjust its settings to ensure the room is evenly cooled throughout. 

As well as three fan speeds and three cooling speeds, this wall air conditioner has been designed so that it’s easy to clean and maintain. The filter simply slides out of the front of the unit so that you can give it a quick clean before putting it back. 

5. LG LT1016CER: Best for energy efficiency 


(Image credit: Amazon)


This Energy Star qualified unit from LG is powerful enough to effectively cool most rooms.

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

The LG LT1016CER is an effective thru wall air conditioner with enough cooling power to adequately cool rooms up to 450 square feet in size. Price wise, it sits around the middle of the market, but is still only $70 more expensive than our budget choice, the Impecca ITAC10-KSA21. 

Like the Impecca ITAC10-KSA21, it doesn’t have heating functionality, but it does have a good range of airflow functionality. Between the choice of three cooling speeds and four-way swing functionality, it offers a good range of airflow options that allow you to customize how this unit cools your home.

The LG LT1016CER is Energy Star certified, so it was designed with energy efficiency in mind. As a result, it helps keep your energy bills lower than some other units. It’s also an effective dehumidifier, able to remove up to 2.9 pints of water in an hour.

Things to consider when choosing an in-wall air conditioner

Before buying a through wall air conditioning unit it is best to consider the following things:- 

1. Room size & cooling performance

Air conditioners use British thermal units (BTU) to indicate the size of the room they can cool. Using a calculation from the Energy Star organization, an air conditioner rated at 5,000 BTU can cool rooms up to 150 square feet, whereas a unit with 7,000 Btu can cool rooms up to 300 square feet. An easy way to check BTU is through a BTU calculator. Just bear in mind there are a range of factors that could affect your through-the-wall air conditioner’s cooling capacity. 

The next thing to consider is the model's maximum airflow, measured in cubic feet per minute (CFM). A higher CFM means better airflow in a room, which helps improve cooling performance.

2. Efficiency ratings & certification

Every air conditioner has an energy efficiency ratio (EER), and the higher the EER, the more efficient the air conditioner is. The average EER of the window air conditioners we compared is 10.3, with the most efficient unit having an EER rating over 10.7. Typically, appliances that are Energy Star certified are 20 to 30 percent more efficient than the minimum requirements.

UL Listed products have been tested by Underwriters Laboratories, which is a safety consulting company. AHAM-certified units have passed performance evaluations by Association of Home Appliance Manufacturers.

3. How much does a through-the-wall air conditioner cost? 

Cost is another important consideration. The wall ACs in our comparison range between about $400 and $800. Our side-by-side comparison will help you find the unit with the features you need at the most reasonable price. 

4. Wall-mounted AC units operation modes

Regardless of which air conditioner you purchase, you want one with customizable modes that can match your preferences. Choose a unit with cooling modes, fan-only modes, and adjustable fan speeds. If you live in a humid environment, look for one with a dehumidifying mode that pulls excess moisture out of the air. If you plan to use the air conditioner while you sleep, consider a model with a sleep mode, which gradually raises the temperature during the night, helping save energy while keeping you comfortable.