If you’re shopping for a portable air conditioner, one of the first decisions you’ll face is whether to choose a dual-hose vs single-hose portable AC. At first glance, these two types might look similar, but the way they operate makes a big difference in how effectively they cool. Dual-hose units use one hose to draw in outdoor air to cool the condenser, while another hose expels hot air outside. Single-hose models, on the other hand, rely on just one hose to push hot air out, pulling replacement air from inside the room. This can make them slightly less efficient.

Determining which style is best for your home depends on factors like room size, local climate, noise preferences and even how often you plan to move the unit around. Regardless of the type you settle on, selecting an appropriate level of cooling power (measured in BTUs) is crucial. “If the unit isn’t powerful enough for the space, it’ll run constantly without cooling effectively,” says Geno Caccia, CEO of Caccia Plumbing. “A good rule of thumb is to match the unit’s BTUs to the square footage of the room.”

To help you choose between dual- and single-hose models, we’ve spoken with HVAC experts and tested the best portable air conditioners to clearly break down the differences. Here's everything you need to know about both designs, so you can find the option that best fits your home, lifestyle and cooling needs.