The 7 Best Air Conditioners of 2021

Stay cool when the weather heats up with these top picks

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Our Top Picks
"This model, which can cool a space up to 550 square feet, can be paired and Amazon Alexa or Apple Smart Home for voice control."
"The eight-way comfort control design ensures air flow, so the whole room cools off, not just the section in front of the unit."
"Featuring two cooling and fan speeds, this compact unit cools small spaces up to 150 square feet."
"This sleek and lightweight portable model cools rooms down quickly with minimal hassle."
"This window unit can cool spaces up to 1,500 sq. ft—enough to keep an entire apartment or floor of your home cool at once."
"This unit checks all the essential boxes for keeping smaller rooms and offices nice and cool."
"The Energy Star-rated model offers many of the benefits of a whole home AC without outfitting your whole home with vents."
In This Article

Setting up your space with air conditioning is essential if you live in a climate where it is hot and humid for all or part of the year. There are a few different types of ACs you can set up in your space, from movable units, like a portable AC, to more permanent options, like central air conditioning or an in-wall unit.

Each type of unit comes with trade-offs in terms of power, energy efficiency, and cost, so determining the right one for you is requires thinking about the size of your space, whether your home is or can be set up for a permanent solution, and your cooling needs.

Here, the best air conditioners for all your cooling needs.

Best Overall: LG Electronics 12,000 BTU Smart Window Air Conditioner

LG Electronics 12,000 BTU Smart Window Air Conditioner
What We Like
  • Compatible with smart home devices

  • Quiet operation

What We Don't Like
  • Steeper price point

With its sleek looks and nearly-instant cooling powers, you can’t go wrong with an LG Electronics air conditioner of any size. At 12,000 BTUs, this one can readily cool rooms up to 550 square feet. This Energy Star Certified Unit has three fan speeds and controls and four way air deflection. It comes with a remote, plus you can also pair it with Amazon Alexa or an Apple Smart Home Kit to use it with voice control or your phone. Even on the highest setting, it’s super quiet, only 52 decibels, which is lower than an average conversation. It’s also a powerful dehumidifier, removing 3.3 pints of water out of the air each hour.

BTU stands for British Thermal Units and measures the amount of heat an AC can cool; the higher the number, the more powerful the unit.

Best Window: Frigidaire 8,000 BTU Window-Mounted Air Conditioner

Frigidaire 8,000 BTU Window-Mounted Air Conditioner
What We Like
  • Built-in air ionizer

  • Easy installation

What We Don't Like
  • Noisy

  • May require additional support

Window air conditioners are a great solution for renters who want to be able to take their AC with them when they move. This 8,000 BTU unit will quickly cool a room down at a price that won’t break the bank. One of the biggest complaints about window units is that they blow air in only one direction; the Frigidaire has a clever solution in its eight-way comfort control design. Other pluses are its built in clean air ionizer that catches pollen and dehumidifier that removes 1.7 pints of water from the air per hour. This pick comes with an installation kit, though you may need to attach a support bracket outside of your window to support its 52 pounds.

Best Budget: LG Electronics 5000 BTU Window Air Conditioner

LG Electronics 5000 BTU Window Air Conditioner
What We Like
  • Affordable

  • Lightweight

What We Don't Like
  • Limited features

Albeit one of the more pared-down picks on our list, this unit from LG performs consistently at a reasonable price, especially when you take into account its lower power output than other, larger units on the market. It features two cooling and fan speeds, two-way air direction, and a window-mounting kit, making it a snap to cool down smaller spaces of up to 150 square feet. The fact that it's relatively lightweight as far air conditioners go, weighing only 40 pounds, makes the installation process particularly swift.

Best Portable: SereneLife 12,000 BTU Portable Air Conditioner + Heater

SereneLife 12,000 BTU Portable Air Conditioner + Heater
What We Like
  • Easy installation

  • Versatile

What We Don't Like
  • Some leaking

  • Noisy

If you don't want to deal with the installation process that goes along with window-mounted air conditioners, a portable unit, like this one from SereneLife, may be right for you. Equipped with wheels and a quick setup guide, this air conditioner installs easily and can be moved from room to room, depending on your cooling needs (it's best suited for rooms up to 450 square feet).

While air conditioning is its default setting, this SereneLife unit also works as a heater, dehumidifier, and fan. Whatever the time of year, you can put this machine to good use around the house.

Best for Large Rooms: GE 24,000 BTU Electronic Heat/Cool Room Window Air Conditioner

GE 24,000 BTU Electronic Heat/Cool Room Window Air Conditioner
What We LIke
  • Large coverage area

  • Energy efficient

What We Don't Like
  • Expensive

  • Heavy

With 24,000 BTU and 230V, this GE window unit can cool spaces up to 1,500 square feet—that’s enough to cool down an entire apartment or floor of your home. Don’t worry, it comes with a remote control so you won’t have to walk across the room every time you want to adjust the temperature. The in-unit container dehumidifies the air as it cools, with a drain in the back of the unit, so you never have to worry about emptying the container yourself. Plus, it can work as a heater to supplement your regular heat source, though it’s not a replacement for one.

Note that this pick won’t work with a standard 115V household electrical outlet; it requires a special 230V one.

Best for Small Rooms: Midea 5,000 BTU Window-Mounted Air Conditioner

Midea 5,000 BTU Window-Mounted Air Conditioner
What We Like
  • Affordable

  • Quiet operation

What We Don't Like
  • Some drainage issues

This Midea window-mounted air conditioner will quickly cool down rooms up to 150 square feet with 5,000 BTU, making it a perfect choice for a small bedroom or office. With seven temperature settings, two speed settings, and two-way air direction, this unit helps you find just the right temp for your needs and space. Plus, the washable filter traps airborne particles and bacteria, which helps to reduce unwanted odors. It's even Energy Star-certified, so you can be confident that it won’t run up your electric bill.

This unit comes with a remote control, installs easily, and operates quietly. While it may not offer the cooling power of a larger air conditioner, it will be a welcome addition to a smaller room in need of cooling.

Best Wall: Whirlpool 10,000 BTU Through-the-Wall Air Conditioner

Whirlpool 10,000 BTU Through-the-Wall Air Conditioner
What We Like
  • Powerful

  • Flexible settings

  • Secure

What We Don't Like
  • Steeper price point

  • Sleeve sold separately

If your home isn’t fitted for central air, wall units are a smart option. They are safer than window units for two reasons: there’s less risk of them falling out and hurting someone down below and a burglar can’t push them in and gain access to your home. Wall units also offer higher BTU, which translates into greater cooling power for your room.

This Energy Star-rated model can cool a room up to 450 square feet and offers many of the benefits of a whole home AC, including different cooling speeds, different modes (fan, cool, dry, and auto) and programmable functioning so you can set it to be cooler during the hours your home, plus it has an eco-mode. This unit requires a sleeve for installation (sold separately). If your room doesn’t already have a space for a wall unit, you’ll need to call a professional to help with installation.  

Final Verdict

LG Electronics’ 12,000 BTU Smart Window Air Conditioner (view at Walmart) is our best overall pick for its sleek construction, approachable price, and ultra-quiet operation. The fact that it can pair with Alexa or an Apple Smart Home Kit makes it particularly easy to use. If you’re cooling a much smaller space, we recommend the Medea 5,000 BTU Window-Mounted Air Conditioner (view at Lowe's), which operates effectively for rooms up to 150 square feet.

What to Look for in an Air Conditioner


One of the first things you’ll want to consider is the style of air conditioner that works best for you. There are several options available, and they vary widely in terms of cost, capability, and installation requirements.

Two of the most common options for occasional users are portable and window air conditioners. Both of these options are fairly inexpensive and can be easily installed without professional help. However, the downside of these options is that they’re typically only powerful enough to cool one room at a time, which means you’ll need multiple units if you want air conditioning throughout your home.

Another option is a through-the-wall or built-in air conditioner, which is a permanent style. These styles are installed into a “sleeve” in an exterior wall of your home—ideal if your room doesn’t have an acceptable window. However, as you may have guessed, this style of air conditioner requires more complex initial installation, as you’ll need professional help to cut an appropriate-sized hole in the wall.

For more comprehensive air conditioning, you may want to consider a ductless mini-split system. This style of air conditioner has gained popularity lately, as it’s a good permanent alternative for homes without central HVAC. As its name implies, there are no ducts required, and these units are typically more powerful than window units. However, mini-split systems are also fairly expensive and complex to install.

Finally, there are central air systems, which require ductwork throughout your home. These are the most expensive and complicated to install and, as such, are typically most common on new construction.

Unit size

If you’re going with a window or wall unit, measure the height and width of the opening to ensure you pick a compatible unit. It’s also beneficial to consider the weight of the unit, as this will determine whether you’ll need help moving and installing it.

Room size and location

Next, you’ll want to consider where you plan to put the air conditioner and how much square footage it needs to cool. The amount of heat an air conditioner can remove from a room is measured in BTUs, or British Thermal Units—larger rooms require a unit with a higher BTU.

Here’s a general breakdown of the recommended room size and BTU:

  • 100-300 square feet: 5,000-7,000 BTU per hour
  • 300-450 square feet: 8,000-10,000 BTU
  • 450-550 square feet: 10,000-12,000 BTU
  • 550-700 square feet: 13,000-14,000 BTU
  • 700-1,000 square feet: 18,000 BTU
  • 1,000+ square feet: 20,000 BTU and up

You’ll also want to consider the location of the room as you decide what BTU is best. For instance, a room that has several large windows and gets direct sunlight for several hours a day will likely be hotter and therefore need a more powerful air conditioner. In this situation, experts recommend increasing the BTU by at least 10 percent. Similarly, if your air conditioner will be in the kitchen—and, as a result, will have to combat heat from the stove—you’ll want to bump up the capacity by about 4,000 BTU.

Noise level

If you plan to use your air conditioner in your bedroom or living room, you may be concerned with how much noise it produces. The noise level of appliances is typically measured in decibels, but since we don’t use this measurement in our daily lives, most people don’t know what “40 decibels” sound like. This can make it tricky to pick the best option for your needs.

In general, a standard air conditioner operates between 40 and 60 decibels. For reference, TVs usually operate at around 60 decibels, and normal talking falls between 40 and 60 decibels. So if you buy an air conditioner that operates at 60 decibels, it may interfere with your conversations or TV show. The quietest air conditioners out there operate at around 35 to 40 decibels, and their noise level is compared to that of a desk fan.


How do air conditioners work?

All types of air conditioners work in pretty much the same way. First, they extract air and filter out any dust or impurities. That air is then passed over the cooling or evaporating coil, and the coil absorbs the heat. At the same time, during this step, moisture from the air is reduced to dew on the surface of the coil, effectively decreasing the humidity level in the room. Finally, the air is pushed back out of the device, lowering the room's overall temperature.

What types of air conditioners are there?

There are several different types of air conditioners. Window units tend to be the most popular because they're affordable and easy to install, though some homes and apartments with unusually shaped windows may not accommodate them. Portable units are a great pick because they can be moved from room to room, but they also require more maintenance and aren't as efficient. Built-in or split systems offer a more permanent solution but require professional installation and can be costly.

How do you clean a window air conditioner?

Check the filter of your window air conditioner each month, and clean it as needed. Also, take a look at the water pan inside the unit, and wipe it with a rag or sponge—this will help ensure proper drainage of the condensate created by the unit. It also helps prevent mold growth.

How do you install a window air conditioner?

If you have basic DIY skills and some tools you most likely can install a window air conditioner yourself—although, because some units are very heavy and cumbersome, you might want to enlist a friend to help you. For those who aren't confident about installing an air conditioner themselves, you can ask the retailer when you're purchasing a new one, or try a service like HomeAdvisor.

How much does an air conditioner cost?

The cost of an air conditioner varies by type and functionality—you can spend anywhere from $100 to several thousand dollars. Window models start at around $100 but can cost upward of $1,000 if you need one with advanced features and a high BTU capacity. Portable air conditioners tend to be slightly more expensive, typically costing between $200 and $500. Wall air conditioners generally cost $400 or more, and mini-split options start at around $800—plus the cost of installation. Central air systems are often desirable because they can be used for heating, as well, but you’ll likely pay several thousand dollars for the system and installation.

What are BTUs and why do they matter?

The amount of heat an air conditioner can remove from a room is measured in BTUs, or British Thermal Units—larger rooms require a unit with a higher BTU. Energy Star recommends units around 6,000 BTU for rooms up to 250 square feet; 8,000 BTU units up to 350 square feet; 10,000 BTU units up to 450 square feet; and 12,000 BTU units up to 550 square feet.

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