Most home ducted systems are in the form of split ducted systems. There are two main types used in residential cooling.
Add-on cooling which is most competitive in terms of price but is a
compromise due to sharing heating components and ductwork. Air
conditioning is best installed in the ceiling as cool air falls, but
most ducted heating is in the floor and there’s a minimum duct size of
6” for heating whereas cooling requires 8” so ducts have to be redone.
Dedicated ducted splits are slightly more expensive to install but
offer the benefit of being an engineered package. You also have more
choice of manufacturers than add on solutions.
Either way you can zone the ducts to allow a smaller unit to cool
sections of a house or to turn off unwanted sections on a whole house
setup. In my opinion ducted is preferable to multi head splits as they
have fewer parts, fewer electronics and fewer potential refrigerant
leaks. It is said that split systems are more efficient, but this is
only because a ducted split system has heat losses in the ductwork.
Comparative systems are just as efficient. (ducted systems also provide
far less accurate temperature control and uniformity).
