Two of the main advantages of ductless minisplit central air conditioning systems, beyond the fact that they can bring comfortable central air to homes with no pre-existing ductwork, is that they are both extremely flexible and energy-efficient.  Given their small size and flexible installation, ductless systems can be easily zoned to cool individual rooms or areas of your home. Basic models usually have 2-3 zones, while more advanced models for larger homes has as many as 4 indoor air handling units.  No matter how many zones your ductless system will be set up to cool, you still only need one outdoor unit.  Thus you can cool only that part of your home that needs cooling, and not pay for the other zones to be cool as well.  (And of course many systems have timers allowing you to control exactly when each area is cool)

Already you would be saving money on your ductless system already, given that you don’t have to use it to cool your entire house at the same time and can zone it instead.  But ductless central air conditioning systems are also energy efficient in their general operation.  Conventional ductwork loses much of its efficiency as it’s cooling radiates out of the ducts before it reaches it’s destination.  For example, imagine metal ducts running through a hot attack – the cool air is fighting against the hot ait just outside the ducts before reaching the room to be cooled!  Your ductless system will be more energy efficient than many other central air conditioning systems, and is certainly more efficient (and elegant!) than window boxes.

Given that the primary disadvantage of ductless air conditioning systems are cost, the fact that money can be saved through increased efficiency is a significant advantage!