How an Inverter Air Conditioner Can Keep You Cool, Save You Money, and Maybe Even Help You Sleep Better

Inverter air conditioners operate in the middle ground between the on/off extremes of an old-school unit. According to Chris Regan, who led CR’s air conditioner testing program for several years, an inverter has a more sophisticated compressor that can be modulated.

Inverters are more energy-efficient. An air conditioner uses a lot of juice when the compressor kicks on, and a conventional unit continues its power-hungry ways throughout the cooling process. By operating in the middle of the power band, an inverter can be significantly more frugal.

That efficiency saves you money. According to a Department of Energy analysis, a more efficient unit could trim $18 to $21 a year from your power bill. And while that might not sound like much, over the nine-year average lifespan of a window AC, that adds up to $167 to $189.

Better yet, an inverter air conditioner allows you to lower your carbon footprint with no sacrifice in performance.

Inverters are quieter. Because they don’t often run at full blast, inverter ACs tend to be easier on the ears. The quietest ACs in our ratings are all inverter models, with noise readings that are significantly quieter than those for conventional models.

The other advantage? Hearing the compressor kick on and off can be more intrusive than the steady hum of an inverter’s compressor, so an inverter is less likely to wake you up at 3 a.m.

Inverters cool better. “Inverters tend to cool the room more quickly,” Regan says. “So they’ve tended to gravitate toward the top of our comfort ratings.” And because inverters respond to small fluctuations in room temperature, they’re more likely to keep the temp steady once the room is cooled down.

Inverters are easy to operate. While the internals of inverter ACs are more sophisticated than those of old-school units, the models operate in much the same way, with controls you’ll find familiar. You set the temperature, you set the fan speed, and you wait for the AC to cool the room. Easy-peasy.

They come at a modest price premium, though it’s shrinking. Inverter air conditioners have traditionally cost more up front, and on average, they still carry a slight premium over conventional units of the same size. But that gap has narrowed sharply in recent years. Some of the highest-scoring inverters in our ratings now cost the same as—or less than—comparable conventional models. The 8,000-Btu Midea MAW08V1YWT-S, for instance, is an inverter that earns a top-tier Overall Score yet sells for around $250, undercutting many conventional units in its class.

Where the premium does persist, it usually buys you better performance. Compare GE’s two 8,000-Btu window units: the inverter GE AWGP08WWF runs about $549, while the conventional GE Profile AHTT08BC is roughly $359. The inverter costs more, but it also outperforms its conventional sibling in our tests.

“Inverter ACs are more expensive to purchase, but you’re paying less to operate them, so there’s a good chance you’ll recoup the price difference over time,” Regan says.

Sizing is more critical. While any AC benefits from being installed in an optimum-sized room, it’s especially important with an inverter. If you buy a unit that’s too small for the space, the compressor will stay at full blast and never turn down, which defeats the whole purpose of the inverter’s advanced tech.

It’s really a question of priorities. If you’re looking for the cheapest possible air conditioner, you can still find a conventional unit that simply functions well and keeps you cool—and at the smallest sizes, inverters remain relatively scarce.

But for most shoppers, there are a lot of real advantages to buying an inverter, and the value proposition keeps improving. You get a unit that performs better and more quietly, which is what we all want our ACs to do. And in the long run, you’ll probably get back much of any price difference in savings on your electric bill. Just how much depends on the electricity rates in your area and how much you use your inverter AC.

Our current ratings include 32 air conditioners across the three size categories that earn CR’s recommendation; 27 of those are inverter ACs. The inverters have an especially large edge among larger units, where all 16 recommended models feature inverter technology.

These inverter models sit at the top of our ratings for small, medium, and large rooms, respectively.

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 based on the room size each air conditioner is designed to keep cool. We crank the temperature in the chamber up to 90° F, then measure how long it takes the AC to lower the temperature in the chamber by 10° 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 its lowest and highest settings. We test for ease of use, which determines how easy a model is to install and operate. We also take energy efficiency into account, giving higher scores to more efficient models.

In addition to our performance tests, we ask Consumer Reports members about the room air conditioners they already own. Our current ratings for predicted reliability and owner satisfaction, available to members, are based on results for 6,209 room air conditioners purchased new between 2012 and 2022. Get more details in "The Most and Least Reliable Room Air Conditioners.” The survey data becomes part of the unit’s Overall Score.