What is Freon?

refrigerantFor most homeowners, renters, and automobile owners, refrigerant is a word heard from time to time. And if you happen to have a refrigerator lying around somewhere, freon may also be a familiar word. However, not everyone knows exactly what a refrigerant is, or why it’s used in HVAC systems. Fortunately, everything you could know about refrigerants like freon is discussed here. Refrigerants are a crucial part of heating, ventilation, and cooling systems (HVAC). Without them, refrigeration would be nearly impossible. 


Refrigerants are a class of chemicals that can be used to exchange temperature with the surrounding environment. They’re typically in a gaseous state, but can move between liquid and gas form. Due to this state of flux, they’ve become a major component in HVAC systems for buildings and automobiles, but they also have other applications. Since their creation, there have been multiple generations of refrigerants, and even bans on some older ones that proved to be harmful for the environment. 

How they Work

Refrigerants are based on principles of heat transfer (thermodynamics), fluid dynamics, and transitions between states of matter (phase transitions). Refrigerants that are utilized are desirable because they aren’t corrosive to mechanical materials, aren’t flammable, they aren’t toxic, and are safe to use. Another desirable trait is a minimal environmental impact. For instance, certain previous types of refrigerants were undesirable because their use proved to deplete gases in the ozone layer. 

Refrigerants work by exchanging temperatures with the surrounding environment. In an HVAC system, this is done by pushing the refrigerant through a closed loop of copper or aluminum coils. These coils are what allow the refrigerant to “interact” with the surrounding environment, as these metals are easily affected by temperatures but also resistant to corrosion. There are other components involved in the system, and they include a condenser, evaporator, compressor, and a special valve (TX valve) that affects the state and temperature of the refrigerant. At higher temperatures, the refrigerant releases heat to the surrounding environment, and at its lowest temperatures, it removes heat from the surrounding environment. 


While refrigerants are most notable for being used in air-conditioning systems for building, they also have other applications aside from that. Refrigerants are also used in cooling systems for marine shipping (shipping via waterways), chemical/pharmaceutical industries, and has even been used in certain types of pest control systems. However, the refrigerant used for this purpose hasn’t been produced since 1996. Refrigerant is also used in facilities that require controlled environments, like medical facilities or laboratories. 

Considering the wide array of applications, one can surmise that HVAC technicians are a crucial aspect to maintaining the proper working conditions of facilities and equipment where refrigerant is used. One way a technician does this is by testing the pressure of the system to determine if there are any leaks or other issues. In most cases, low refrigerant levels can cause pressure drops. If that’s the case, the technician will notify you and help resolve the situation. 

Types of Refrigerants

Although freon may be the most familiar refrigerant name, there are actually multiple generations/types of refrigerants. Due to certain chemical properties and issues with safety, some have been discontinued, while others are used in different systems based on these properties. For instance, refrigerants that were made of chlorofluorocarbons (CFCs) were banned due to their depletion of the ozone layer. These types were known as R-12 refrigerants. They were the safest to use despite their harmful effects to the environment. Other refrigerants are still in use today include the following: 

  • Hydrochlorofluorocarbons (HCFC)/R-22: Hydrochlorofluorocarbons are a type of synthetic refrigerant also known as R-22 or Freon 22. In R22, the R stands for Refrigerant, and the 22 denotes the number of fluorine atoms in the compound. Freon is an R22 refrigerant, but is also the registered trademark of DuPont corp. Freon is typically used in small air conditioners and household refrigerators.
  • Ammonia/R717: Ammonia is a refrigerant mostly used in industrial cooling systems such as ice rinks, meat packing plants, and liquid storage facilities.
  • Hydrofluorocarbons (HFC)/R-134a: Hydrofluorocarbons are a newer type of refrigerants that will be used to replace R-22 Refrigerants. They are mostly used in home cooling units, automobile air conditioning, and commercial refrigeration systems. They’re non-toxic, non-flammable, and have a minimal effect on the environment.

While there are multiple types of refrigerants, each one serves a specific purpose in HVAC systems. Freon has been the most widely used and most notable brand of refrigerant, however. It has many uses and is known even by individuals outside of the HVAC profession. If you are in need of heating and cooling services, contact Hammock’s AC! We aren’t comfortable until you are!