Air Conditioner Buying Guide

When the weather heats up, thoughts turn to chilling out. For those without a central air conditioning option, room air conditioners can be an inexpensive and energy-efficient alternative for cooling one or two rooms.

If you’re ready to beat the heat, you aren’t alone: Almost 6 million room air conditioners were shipped for sale in 2020, an increase of almost 10 percent over the year before. That’s not surprising, considering that many of us were working from home instead of in an air-conditioned office.

The typical household spends 13 percent of its annual utility bill on cooling, according to Energy Star. So it’s important to choose the right unit. An air conditioner that’s too small will struggle to cool a room. One that’s too big cools so quickly that it doesn’t have time to remove enough moisture, leaving you with a cold, clammy space. 

Read on to find out what factors you should consider when shopping for a room air conditioner, as well as details on how we test models to arrive at our air conditioner ratings

How We Test Room ACs

At Consumer Reports, we test room air conditioners in a special climate-controlled chamber. We test three sizes of window ACs—small, medium, and large—and adjust the size of the chamber to the room size appropriate for each air conditioner. We crank the temperature in the chamber up to 90° F, then measure how long it takes the AC to lower the temperature by 15° F.

We also gauge how well the AC holds the set temperature. And because noisy air conditioners can be annoying, we measure how loud each unit is on the lowest and highest settings.

In addition to our performance tests, we asked CR members about the brands of room air conditioners they purchased new between 2010 and 2020. Based on their responses we rate each brand for predicted reliability and owner satisfaction. And we have good news: Room ACs are one of the most reliable products we test. To see the full results, read “The Most and Least Reliable Room Air Conditioners.” And to see the Overall Score for all the models we test, see our air conditioner ratings.

Things to Consider

Look for Energy Misers
New Energy Star certified room air conditioners come with better insulating materials and clearer instructions to help ensure that you get a good seal around the unit, minimizing leaks.

Note the Noise
Models that earn Excellent or Very Good ratings in our noise tests are so quiet that the only sound you might hear is the fan running. Air conditioners that receive Fair scores for noise could disturb light sleepers when set on low and are distracting to all when set on high.

Factor In the Window Location
Window air conditioners generally do a better job blowing air in one direction. That can be a problem if your window isn’t centered on the wall. To uniformly cool a room, you’ll need to direct air to its center, so check to see whether your AC needs to blow air to the right or to the left. Some have fan arms that swivel.

Install It Correctly
To get the most from your window air conditioner, it must be properly installed. Most units are intended for double-hung windows. If you have casement windows, you may want to consider buying a through-the-wall air conditioner. Make sure your window unit is level so that it drains correctly. And move any heat-generating devices, such as a TV or lamp, away from the unit. For more information, read our AC installation tips. Do you live in an apartment? You may have to take some extra steps, such as getting permission from your landlord, before you install an AC in your apartment

Check Filter Location
Make sure you can easily access the filter for cleaning, something you’ll be doing frequently to keep the unit in tip-top condition.

Consider Intelligent Cooling
Some air conditioners have gotten smarter, allowing you to control and adjust them from your smartphone. You may even be able to interconnect them to other cooling units in your home.

Watch the Warranty
Some air conditioners have longer warranties than others. When you’re buying a new unit, check the manufacturer’s website for information, and ask the retailer about the warranty for the brand and model you’re considering buying.

Sizing Up Your Options

Before you consider price and features, start by determining the size of unit you need for the space you want to cool, as well as deciding where you’ll place the unit. The window air conditioners in our tests have cooling capacities ranging from 5,000 to 12,500 British thermal units (Btu).

To measure your room, multiply the length of the room by the width. But don’t buy by Btu alone. Energy Star recommends that you make allowances for other considerations—such as the height of your ceiling, where the unit will be placed, and the size of your windows and doorways. In addition:
    • If the room is heavily shaded, reduce capacity by 10 percent.
    • If the room is extra sunny, increase capacity by 10 percent.
    • If more than two people regularly occupy the room, add 600 Btu for each additional person.
    • If the unit is used in a kitchen, increase capacity by 4,000 Btu.

A household room with a ceiling fan and window AC unit.
Illustration: Brown Bird Design

Which Model Is Right for You?

Some small window units cost less than $200, which makes them a tempting proposition—but only if you need to cool a very small space. If you need to cool a larger area, you’ll want to focus your search on units that better match your square footage.

Almost all the window units we test meet the latest Energy Star standards, which require models to be at least 10 percent more efficient than those without that certification. Standout models have quiet operation and convenient controls, and they work under brownout conditions. Check our air conditioner ratings to see to how models stack up.

A window air conditioner.

Window Air Conditioners

Small: Capacity ranges from 5,000 to 6,500 Btu, and these units cool roughly 100 to 300 square feet. They’re the smallest, lightest, and least expensive, but they can’t adequately cool a room measuring more than 300 square feet.
Cost: $180 to $350.

Medium: Capacity ranges from 7,000 to 8,200 Btu, and these models cool roughly 250 to 400 square feet. Prices start creeping up, and their size and weight can make them more difficult to install and remove for winter storage.
Cost: $240 to $400.

Large: Capacity ranges from 9,800 to 12,500 Btu, and these units cool between 350 and 650 square feet. They’re best for cooling a large room, but the bulk and weight make these models awkward and difficult to install.
Cost: $350 to $600.

Window Air Conditioners Ratings
A portable air conditioner.

Portable Air Conditioners

Portable models are intended for homes in which window configurations or building regulations prevent installation of window units. The portable air conditioners in our tests range from 9,000 to 15,500 Btu. But don’t compare portable and window air conditioners by that measurement alone.

Our latest air-conditioner tests find that portables aren’t as good at cooling as manufacturers claim. Plus they’re pricey and use more energy than similarly sized window units. And because all the mechanicals are sitting in the room, they tend to be noisier than window-mounted units. And “portable” is a misnomer—their 50- to 80-pound weight can make them cumbersome and ungainly to roll across carpets or thresholds.
Cost: $350 to $700.

Portable Air Conditioners Ratings
A split ductless air conditioner.

Split Ductless Air Conditioners

Split ductless is a smart way to add air conditioning to a limited number of rooms without having to open up walls to install ductwork—as you would with a central-air system—or install and remove multiple window units each year. Though we haven’t tested split ductless recently, in our past tests all did an excellent job cooling and were much quieter indoors and out than window air conditioners.

Split ductless is pricier than window or portable units (and professional installation is recommended) but less expensive than central air if you are cooling only a few rooms. However, if you are looking to cool the majority of your home, a central air-conditioning system is probably the more cost-effective choice.
Cost: $1,000 and up.

Window Air Conditioners Ratings

Video Buying Guide

For more information, watch our buying guide below.

Smart Features to Help You Chill Out

All the units in our air-conditioner ratings do an excellent job of cooling. They also come with convenient features, such as digital displays, built-in timers, and remote controls. Some units have touchpad controls, and a few change the direction of the airflow automatically to better disperse cool air throughout the room. Look for air-conditioner features that affect performance and efficiency.


All the brands below make window air conditioners that are Energy Star certified.

Friedrich is a smaller manufacturer of more expensive window air conditioners available at regional appliance retailers. Window units range in price from $200 to $1,200. Friedrich makes models with Btu from 5,000 to 24,000.
Frigidaire air conditioners are available in independent and regional appliance retailers, as well as at Best Buy and Lowe’s. Units range in price from $100 to $800, and in Btu from 5,000 to 28,000.
GE is the market-share leader in window air conditioners. This brand is available at a wide variety of independent and regional appliance retailers and at Home Depot, Lowe’s, Sam’s Club, and Walmart. GE’s window units range in price from $150 to $400, and in Btu from 5,000 to 25,000. GE is owned by Haier.
Haier is available at BJ’s, Walmart, and independent appliance dealers. Prices range from $100 to $500, and Btu from 5,000 to 24,000.
Kenmore air conditioners are made by LG and are sold at Sears and Kmart, and now on Amazon, for $100 to $700. Kenmore markets units with Btu from 5,000 to 24,000.
LG is a national brand available at a wide variety of independent and regional appliance retailers, as well as Home Depot. Window units range in price from $150 to $500, and in Btu from 5,000 to 14,000.
Midea air conditioners are fairly new to our ratings. Based in China, the company manufactures commercial heating, ventilating, and air conditioning products in addition to its innovative consumer line. Prices range from $180 to $470. Models we’ve tested range in Btu from 6,000 to 12,000.
We also test air conditioners from Amana, Black+Decker, Emerson, Keystone, TCL, Toshiba, and Whirlpool.
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