And it’s debatable how portable they are, since once the hose is connected to the kit in the window, you won’t want to move the unit, especially since they typically weigh 50 to 80 pounds. While they do have wheels, portable air conditioners can be difficult to roll on carpets and over raised thresholds between rooms. They also need their space—the hose is 5 to 7 feet long and the air conditioner must be positioned away from any walls or furniture that may block its airflow.
How we test
In our tests, we measured how long it takes a portable air conditioner to lower the temperature in a room appropriate for its claimed size from 90 degrees to 75. But few made it to even 80 after 100 minutes. None made our list of recommended air conditioners but if you have no alternative, consider the Friedrich ZoneAir P12B, $600. While only fair at cooling, it was a champ in our tests simulating brownout conditions, as were 10 other models.
While we test portable air conditioners the same way we test window units, most manufacturers don’t. The Department of Energy is reviewing the current industry test for portable air conditioner capacity and efficiency. The current test doesn’t account for what is often significant leakage and transfer of hot air into the space being cooled. One alternative being investigated by the DOE is that the industry adopt the window air conditioner test for portables as well, because it more accurately measures actual cooling. This would make it easier for consumers to compare portable and window air conditioners. In the meantime. don’t assume that a portable air conditioner rated at 5,000 to 15,000 British Thermal Units will cool like similarly rated window models.
If a portable is your only choice
Install it right. All portables come with a kit that you install in a window. Make sure all your connections are tight and seal any air gaps.
Get a ceiling fan. Create a cool breeze by running a ceiling fan.
Block the sun. Close the curtains and shades to keep the sun from overheating your room.