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 range 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 all of CR’s air conditioning 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 rate an average of just Good or worse for how noisy they are. The best window ACs are quieter, rating a Very Good and sometimes Excellent. 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.