Is a U-Shaped Air Conditioner Right for You?

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.

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.

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 sash provides 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.

These top-rated U-shaped and inverted U-shaped models from our AC ratings are best for small, midsized, and large rooms.

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 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 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. Read more in “Most and Least Reliable Room Air Conditioner Brands.” The survey data becomes part of the unit’s Overall Score.