Illustration of a portable AC for an office.

Does it get so stuffy in your basement home office that some days you can barely focus on working? Or are you calling into your Zoom meetings from a hot attic, hoping the video is fuzzy enough to hide the sweat on your forehead?

More attics, basements, and other nooks and crannies have become makeshift offices. And often these out-of-the-way spaces don’t benefit from the air conditioning that you may have in the main part of your home. So what to do?

The best solution, of course, is a window air conditioner. But they’re made to fit in a standard double-hung window, which you may not have in the basement or attic.

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A portable air conditioner can solve that problem. The unit itself sits in your room; all you need is an opening to the outside to install the exhaust hose kit, which adjusts to the width of the opening and is 6 to 8 inches high. (If you have casement windows, it can be tricky to install the exhaust, but there are plenty of hacks online that show you how to use plexiglass to get the job done.)

Though portable air conditioners aren’t as effective at cooling or as energy-efficient as window units, we found in our tests that they can still do a good job of keeping you comfortable.

Here’s what to consider if you’re thinking of buying a portable AC unit.

What to Know About Portable ACs

They aren’t so portable. True, portable ACs come on casters, and you can put them in any room where you can install an exhaust to the outside. But portable ACs can weigh between 50 and 80 pounds, so you might want a friend to assist you with moving it if you’re going up or down stairs,” says Chris Regan, the engineer who oversees CR’s air conditioner testing. And once you go to the trouble of installing the exhaust, you probably won’t want to move the unit.

You may need extra materials to create a tight seal around the exhaust. Models come with exhaust window installation kits, but you may need additional materials to make sure there aren't any gaps where air can get in. “A trip to your local hardware store might be necessary to purchase soft foam, foam panels, or plexiglass,” Regan says.

Their Btu ratings can be misleading. Portable ACs typically have a higher Btu rating than window ACs, but that doesn’t mean they’re better at cooling. A window AC rated at 6,000 Btu will deliver more cooling than a portable AC unit rated at 6,000 Btu, because window ACs are more energy-efficient. (Portable models don’t have to meet the same Energy Star standards required of window units.)

They’re noisy. With a window AC, the noisy parts—the condenser and compressor—sit outside the window. But with a portable, all the mechanicals are in the unit that you place in your room, so they’re fairly noisy. Most of the portables in our tests earn an average rating of just Good or worse for noise. The best window ACs are quieter, earning a Very Good rating and sometimes an Excellent one. So you may have to turn off your portable when you hop on those Zoom meetings.

They need their space. The exhaust hose of a portable AC can be 5 to 7 feet long, and the air conditioner needs to be 2 feet away from any walls or furniture that may block its airflow. So it’s like adding another piece of furniture to your room.

For more information on portable ACs, see our air conditioner buying guide and ratings. Thinking of taking the plunge and getting a central AC system? Find out what the most reliable central air conditioning brands are from Consumer Reports’ member survey.

CR members can read on for the details on five top portable air conditioners from Consumer Reports’ tests. 

Top Portable Air Conditioners

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Indoor noise high


Indoor noise high
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