Referred to as split because it has two primary units: An internal wall mounted radiator with circulation fan; A compressor located outside on the roof, exterior wall or placed on the ground. They are connected by copper pipes that circulate refrigerant through the system to generate either heated or cold air. Split systems circulate air inside the space where the radiator is located. Ventilation is by exhaust fan to the outside atmosphere. Fresh air is introduced through doors, windows or purpose designed ventilators

Ducted air conditioners are common in large commercial building and multi-floor towers. They feature a central air treatment plant usually on the roof top that heats or cools as required. Air is dispersed by fan through ducts to levels and rooms as required. Ducted systems circulate air from the central treatment plant to each zone with volumes regulated by dampers. Old air is returned the plant via common return air duct/s Ventilation is by measured exhaust partially from the central plant and particially by door and windows to the outside atmosphere. Fresh air is introduced through the central plant.