What is the difference between a single-hose design and a dual-hose design?
Some portable air conditioners have one hot air exhaust hose, and some have two air hoses: one for air intake and one for hot air exhaust. A single-hose portable air conditioner will take air from the room that it is in, cool it, and return most of that air back into the room. During this process, a small amount of that air will be used to cool the unit and will be subsequently blown out of the air conditioner’s exhaust hose. This creates slightly negative pressure within the room being cooled, as a small amount of air is constantly being removed from the room. If this negative pressure is anticipated by drawing unconditioned air into the room from adjacent spaces, then the cooling efficiency is slightly affected. A dual-hose portable air conditioner, such as the Friedrich P12B, works by taking in air from the outside through one hose and using that air to cool the unit. The hot exhaust air is then expelled through the second hose. This process does not create negative pressure inside
