Best Window Air Conditioners of 2021

Top choices for small, midsized, and large rooms from Consumer Reports' tests

Consumer Reports' Chris Regan testing window air conditioners.
Test engineer Chris Regan moves a window air conditioner into Consumer Reports' testing chamber.
Photo: John Walsh/Consumer Reports

All of the window air conditioners in Consumer Reports’ latest tests do a good enough job at keeping you cool. What distinguishes one from another is how quickly and quietly it cools a room—and how easy it is to operate.

And you don’t have to pay a lot to get relief from the heat.

The window air conditioners in our tests range from $150 to $470, with prices climbing as size and capacity (Btu) increase. (One outlier is the midsized Friedrich Kuhl, which costs $850.)

To help a window unit run more efficiently, look for a model equipped with insulating panels. “Most new window ACs come with panels you place over the plastic adjustable side panels to boost efficiency,” says Chris Regan, CR’s senior test engineer for air conditioners. Adding weather stripping around the perimeter will also prevent air from leaking in or out.

For more on getting the best fit, we have a breakdown on how to size a window air conditioner

How We Test Window ACs
After installing the unit in a double-hung window in our testing chamber, we crank up the air temperature to 90° F, then measure how long it takes the AC to cool the room by 10° F. The best units hit the mark in less than 15 minutes. We also gauge how accurately the AC reaches its set temperature, whether it can recover from a simulated brownout, the intuitiveness of the controls, and how loud each unit is when running on low and high.

CR members can read on for ratings and reviews of three top picks for each room size, based on our latest tests. There are even more choices in our full air conditioner ratings. For more intel on your options aside from central air, see our air conditioner buying guide, which covers portable and split ductless ACs, too.

Below, details on nine of the top window ACs from our tests.