What type of refrigerant is typically used in most residential air conditioning systems?

Freon is a brand name that refers to a class of refrigerants, specifically chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs), which have been commonly used in residential air conditioning systems for decades. The widespread usage of Freon is largely due to its efficient heat transfer properties, stability, and non-flammability, making it suitable for both cooling and comfort in homes. Additionally, Freon has been formulated in various types, such as R-22 and R-410A, which have specific applications in different system designs.

In contrast, ammonia is primarily used in industrial refrigeration systems due to its high efficiency but is toxic and not suitable for residential use. Propane, while a viable refrigerant option under certain conditions, is flammable and typically not used in standard residential air conditioning systems. Carbon dioxide, although gaining some traction as a refrigerant due to its low environmental impact, is still not commonly utilized in most residential air conditioning setups. Thus, Freon remains the prevalent choice for residential air conditioning due to its balance of performance and safety characteristics.