What are the two types of air conditioning systems commonly used in HVAC?

The two types of air conditioning systems commonly used in HVAC are central and ductless (mini-split) systems. Central air conditioning systems are designed to cool an entire building or space by circulating cooled air through ducts. This type of system typically consists of an outdoor condensing unit and an indoor air handler, allowing it to effectively control temperature and humidity across multiple rooms.

On the other hand, ductless systems, often referred to as mini-split systems, provide an alternative where ducts may not be feasible or desired. These systems consist of an outdoor compressor unit connected to one or more indoor air handling units. Each indoor unit can be controlled independently, providing flexibility in cooling different areas of a building according to specific needs.

Ductless systems are particularly useful in retrofitting homes where installing ductwork would be difficult or expensive. The versatility of both central and ductless systems allows for a wide range of applications, making them the most common types found in HVAC.