What kind of HVAC system uses ducts to distribute heated or cooled air?

A central air system is specifically designed to use ducts for the distribution of heated or cooled air throughout a building. This system typically includes a central unit that can either heat or cool the air, which is then distributed via a network of ducts installed in the walls or ceilings.

The use of ducts allows a central air system to efficiently manage indoor climate control by delivering conditioned air directly to multiple rooms or spaces simultaneously. This creates a more uniform temperature throughout the home or building, addressing comfort and air quality.

In contrast, other systems mentioned, such as window air conditioning systems, operate independently and do not utilize ductwork; they cool only the space in which they are installed. While heat pump systems can sometimes be designed to work with ducted systems, they operate in both heating and cooling modes but are not inherently required to use ducts as part of their function. Split systems, similar to heat pumps, typically consist of an outdoor compressor and an indoor unit, which may or may not be ducted, depending on the installation.

In summary, a central air system is distinguished by its reliance on ducts for the distribution of conditioned air, making it the correct choice in this context.