A portable air conditioner does not work without an exhaust vent; however, it is possible to minimize the hose length by installing vent similar to the one used for a dryer to exhaust the unit. Portable air conditioners work by moving heat from the room and must vent to cool.
All air conditioning systems require a connection to the outside to remove heat from an area. With central air conditioning and window units, the system transports the heat to the evaporator coils outside using refrigerant. With the portable unit, the evaporator coils are inside the home. A fan pushes air through the coils and vent to the outside.
Air is less efficient at transporting heat than refrigerant. This makes portable air conditioners less efficient at cooling than either window units or central cooling systems.
Portable air conditioners are small units on wheels that allow the owner to move them to the desired location for use. Once in location, the hose connects to a port on the back of the air conditioner. The easiest way to exhaust the system is to connect the hose to a sliding window using the small expanding panel the venting kit supplies. For casement windows, owners often choose a plexiglass panel to replace the window glass for venting. However, the dryer vent connection allows the user to hide the hose behind the unit without blocking a window.