What is AC Refrigerant?
AC refrigerant is an essential working medium of any air conditioning compressor. It's a chemical compound that absorbs heat from interior spaces and releases it outdoors to maintain a cool and comfortable indoor environment. Without refrigerant, an AC unit would be rendered non-functional.
How AC Refrigerant Works
1) When the air conditioner works, the low-temperature and low-pressure refrigerant gas is sucked into the compressor and pressurized to be high-temperature and high-pressure refrigerant gas.
2) The refrigerant gas at a high temperature and pressure flows through the condenser. The outdoor heat exchanger releases heat and transforms it into a liquid at medium temperature and high pressure (the outdoor circulating air dissipates the heat).
3) The medium-temperature and high-pressure liquid is then reduced in pressure through capillary expansion to become a low-temperature and low-pressure liquid. The liquid refrigerant passes through the evaporator (indoor unit copper tube) to absorb heat and evaporates to become a low-temperature and low-pressure gas again. Then the refrigerant gas sucks into the compressor to begin the new refrigeration cycle.
Common AC Refrigerants
Several AC refrigerants are available, each with distinct advantages and disadvantages. The most commonly used refrigerants include R-22, R-410A, and R-32. R-22, also known as Freon, some of which are being phased out due to its detrimental environmental impact. R-410A, a more environmentally friendly alternative, is a widely used refrigerant. R-32, the newest option, offers superior efficiency and is gaining traction in the market.
Two Categories of AC Refrigerant
Sometimes, we divide AC refrigerants into Home AC refrigerants and Car AC refrigerants.
Home AC Refrigerant
Modern residential air conditioning systems primarily use refrigerants such as R-410A, R-32, R-290, R-134a, R-600a, R-454B, and R-1234yf. With increasing environmental regulations, low-GWP (Global Warming Potential) refrigerants like R-32, R-290, and R-1234yf gradually replace high-GWP options.
R-22 (Chlorodifluoromethane, HCFC-22)
Characteristics: Once widely used, R22 is harmful to the ozone layer;
Current Status: R22 has been phased out under the Montreal Protocol, and many countries are banning its use in most equipment;
R-410A
Characteristics: R410A is an ozone-friendly blend of R-32 and R-125 with a high GWP;
Applications: The most common refrigerant in residential AC systems is replacing R-22;
R-32 (Difluoromethane, HFC-32)
Characteristics: R32 refrigerant has lower GWP, high energy efficiency, and better environmental performance than R-410A;
Applications: HFC-32 mainly uses in new residential AC systems, particularly in Asian markets;
R-290 (Propane, HC-290)
Characteristics: R290 refrigerant is a natural refrigerant with extremely low GWP and excellent environmental performance, but it is flammable;
Applications: We use HC-290 primarily in small residential AC units and portable air conditioners;
R-134a (Tetrafluoroethane, HFC-134a)
Characteristics: Ozone-friendly but with a high GWP;
Applications: Mainly used in automotive AC systems, with limited use in residential AC;
R-600a (Isobutane, HC-600a)
Characteristics: R600a is a natural refrigerant with very low GWP and excellent environmental performance, but flammable;
Applications: Commonly used in refrigerators and small cooling devices, with some use in residential AC;
R-454B
Characteristics: R454B blends with R-32 and R-123yf with lower GWP and better environmental performance than R-410A;
Applications: Gradually being adopted in new residential AC systems;
R-1234yf (Tetrafluoropropene, HFO-1234yf)
Characteristics: Extremely low GWP and excellent environmental performance;
Applications: Primarily used in automotive AC systems, with potential future use in residential AC.
Car AC Refrigerant
Automotive air conditioning systems have undergone several refrigerant transitions. The primary refrigerants currently in use include:
R-134a (Tetrafluoroethane, HFC-134a)
Characteristics: Ozone-friendly but with a high GWP.
Applications: Once widely used, more environmentally friendly alternatives are now being replaced.
R-1234yf (Tetrafluoropropene, HFO-1234yf)
Characteristics: Extremely low GWP and excellent environmental performance are the primary replacements for R-134a.
Applications: This refrigerant has been used in most modern vehicles.
R-744 (Carbon Dioxide, CO₂)
Characteristics: R744 is a natural refrigerant with a very low GWP and excellent environmental performance but requires high operating pressures.
Applications: People use R744 mainly in some high-end and electric vehicles.
R-12 (Dichlorodifluoromethane, CFC-12)
Characteristics: Once widely used but highly damaging to the ozone layer.
Current Status: Completely phased out under the Montreal Protocol.
R-152a (Difluoroethane, HFC-152a)
Characteristics: R152a with lower GWP and better environmental performance, but it is flammable.
Applications: 152a is used in some specialized vehicles and experimental applications.
Blended Refrigerants
Characteristics: HFC-152a mixes various refrigerants designed to balance performance and environmental requirements.
Applications: R152a refrigerant is used by some automotive manufacturers to meet specific needs.
