A conventional air conditioner is, by definition, a trade-off. Yes, you get a cooler room, but in exchange you effectively lose one of your windows.
The sash remains closed all summer long and that big, opaque box blocks a good deal of sunlight. It’s enough to make you start pricing central air. But for those in search of a cheaper, more flexible option, there is a compelling alternative: a U-shaped air conditioner that allows you to open your window with the unit installed.
In this article
- Advantages
- Disadvantages
- Should You Buy a U-Shaped Air Conditioner?
- Top-Rated U-Shaped Air Conditioners
- How CR Tests Air Conditioners
More on Air Conditioners
Best Window Air Conditioners
Most and Least Reliable Air Conditioner Brands
How an Inverter Air Conditioner Can Keep You Cool, Save You Money, and Maybe Even Help You Sleep Better
“I’ve been evaluatingwindow air conditioner units for two decades, so I find it interesting to see some manufacturers shifting away from the standard design,”says Chris Regan, who heads CR’s air conditioner testing program.“These units aren’t for everyone, but they can have real advantages in many homes.”
Some models have a slot at the top of the AC that makes room for the window sash to be lowered and raised. Other models, known as inverted U-shaped air conditioners, have a slot at the bottom that allows you to drape the AC over the sill, kind of like a bath towel.
In either case, you don’t need the sash to hold the unit in place, as you normally would with a conventional AC. You use a bracket or other mounting hardware instead (though you may still want to exercise caution when raising the window). Beyond that, U-shaped units operate the same as conventional units, so there’s no learning curve.
Here’s a closer look at the pros and cons of this U-shaped approach.
Advantages of a U-Shaped Air Conditioner
You can open your window. If you have a conventional double-hung window, a U-shaped air conditioner allows you to open the sash and enjoy a cool breeze. This is especially useful in climates where wide temperature swings—90° F today and 68° F tomorrow—are common. The option to open your window for ventilation might even encourage you to install the AC earlier in the season.
It may keep your room cooler. While the ability to open the window is the most striking upside, U-shaped models may also perform well in our lab tests because the window pane insulates the room from the heat outside instead of those sliding plastic panels that fill the gaps. U-shaped models do use some plastic and foam for insulation. On many models, though, the foam is thicker than what you find on conventional ACs.
It might be quieter. In much the same way that the window pane can insulate your room from the heat outside, its tighter seal can also help to block noise from the compressor and other mechanical components on the outer half of your AC.
It lets in more light. With a U-shaped unit in place, you get more clear glass and less opaque plastic in your line of sight. With an inverted U-shaped AC, which dips below the window, there’s even less of a profile to block the rays.
Disadvantages of a U-Shaped Air Conditioner
It can be more difficult to install. You don’t have to have your own HGTV home improvement show to install a U-shaped unit, but it does require a little extra care to properly place the bracket (required by law in some municipalities) beneath the unit. It generally involves a tape measure, a level, a screwdriver, and maybe a cordless drill, along with modest mechanical skills.
It won’t fit in every window. In some cases, the slots in a U-shaped AC are ill-suited for the sashes in older homes or a thicker wall beneath the sill. And a radiator below the window prohibits the installation of inverted units. To avoid frustration, take measurements before you buy, and when you do make a purchase, choose a retailer with a flexible return policy.
It may let in too much light. If the U-shaped AC is in your bedroom and it keeps the shades from coming all the way down, you might find more sunlight streaming in.
It may let bugs in, too. The slots of a U-shaped AC generally don’t accommodate window screens, so when you open the window, you’re letting in more than the fresh air.
It’s more expensive. Low-end models are priced around $350. Others can cost more than $500.
Should You Buy a U-Shaped Air Conditioner?
It’s very much a question of your windows, assuming, of course, that the unit fits. If you have only one or two windows in a room, it might be nice to have the cross-ventilation that a U-shaped model can provide when it’s not blazing hot outside. But if you have a bunch of windows, that’s less of a concern. As for the installation, once the bracket is installed, things do get easier.
As for performance, you can use our ratings to select a U-shaped model and then think of it as a conventional AC with benefits.
“While the ability to open the window some days is a nice feature, it’s likely one that you’ll use less than you think,” says CR’s Regan. “On the other hand, use of the lower window sashprovides improved insulation, which should keep noise and heat outside while allowing more light into your room.”
If you keep your expectations in check, U-shaped units generally perform as well as or better than conventional units at the basic job of cooling a room quickly and quietly. And you get some freedom to open your windows, which was once reserved for those with central AC.
Top-Rated U-Shaped Air Conditioners
These top-rated U-shaped and inverted U-shaped models from our AC ratings are best for small, midsized, and large rooms.
How CR Tests Air Conditioners
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 sizeeach 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 by 10 degrees.
We also gauge how accurate the thermostat is by seeing how close its setting is to the actual room 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, with more efficient models earning higher scores.
In addition to our performance tests, we ask CR members about the room air conditioners they already own. Our currentratings 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. Read more in “Most and Least Reliable Room Air Conditioner Brands.” The survey data becomes part of the unit’s Overall Score.
Allen St. John
Allen St. John has been a senior product editor at CR since 2016, focusing on digital privacy, audio devices, printers, and home products. He was a senior editor at Condé Nast and a contributing editor at publications including Road & Track and The Village Voice. A New York Times bestselling author, he's also written for The New York Times Magazine, The Wall Street Journal, and Rolling Stone. He lives in Montclair, N.J., with his wife, their two children, and their dog, Rugby.
