Which type of air conditioning system does not require ductwork?

Window air conditioning units are designed to fit into a window opening and do not require ductwork for their operation. They draw in air from the room, cool it, and then recirculate it back into the space. This self-contained system is convenient for cooling single rooms and is particularly useful in situations where ducted systems would be impractical or too expensive to install.

The other systems mentioned typically require ductwork for their operation. Central air conditioning systems circulate cooled air through a network of ducts, which is essential for distributing air to multiple rooms. Split air conditioning systems consist of an indoor unit and an outdoor condenser, and while they do not require ductwork in the same way that central systems do, they often have a refrigerant line that connects both units. Portable air conditioning units also do not require permanent ductwork but usually come with exhaust hoses that need to be vented out of a window or door. However, they cannot be installed in the same manner as window units and often need a means to vent hot air. Therefore, window air conditioning units are distinct in their design and installation requirements.