Single-zone ductless mini-split air conditioners are reversible systems that provide cooling and heating through a single air handler. They consist of an indoor air handler and an outdoor condenser sized for one air handler. These single-zone mini-splits are typically used for climate control in one room or area and are ideal for room additions, outbuildings, modular buildings, attics, and other areas without ductwork. They're also used to supplement a central system for room-specific heating and cooling.