Refrigerants play a vital role in helping refrigerators, freezers, air-conditioning units, and fire suppression systems function.
Unfortunately, these chemical compounds were known to be damaging to the environment in the past. However, modern versions of refrigerants are designed to be more eco-friendly.
This guide will examine the best eco-friendly refrigerants currently available. However, before we get to our list, it is worth examining what refrigerants are and how they were developed.
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What are Refrigerants?
Refrigerants are unique compounds sold in a liquid or gaseous state. They are designed to absorb heat from the surrounding environment and cool it readily.
When used with other equipment such as evaporators and compressors, refrigerants can provide air conditioning or refrigeration, making them essential in refrigerators, freezers, air conditioning units, and fire suppression systems.
Are Refrigerants Eco-Friendly?
Refrigerants were initially developed in 1840 to create ice in ice machines. They were then adapted for use in air conditioning systems.
Early refrigerants were known to be flammable, and it wasn’t until 1928 that non-flammable chlorofluorocarbon (CFC) refrigerants were introduced. Among these was the hydrochlorofluorocarbon (HCFC) R-22, which became the standard refrigerant used in AC systems.
R-22 continued to be famous for many decades until scientists discovered that chlorine in CFCs and HCFCs was damaging the ozone layer.
Experts then raced to create more environmentally friendly refrigerants that could be utilized so that the non-eco-friendly ones could be phased out, leading to the development of hydrofluorocarbons (HFC) and hydrofluoro-olefins (HFO).
HFCs aren’t perfect and are believed to contribute to global warming. However, they do not impact the ozone layer directly, making them relatively eco-friendly compared to earlier generations of refrigerants.
As the name implies, HFOs are made from hydrogen, fluorine, and oxygen and have zero ozone-depleting and very low global warming potential. These qualities make HFOs the most environmentally friendly refrigerants available today.
The Best Affordable Eco-Friendly Refrigerants
There are many modern eco-friendly refrigerants available currently, including:
R-134a or Tetrafluoroethane is a popular refrigerant used for numerous air conditioning applications. It is recognizable for the distinct blue cylinders it is packaged in.
This HFC has zero ozone-depletion potential and contributes very little to the greenhouse effect (GWP of 1300). Therefore, it can be used as a pure refrigerant or in mixtures.
R-134a was initially developed to replace the R12 refrigerant used in car air-conditioning systems. It is also an excellent replacement for the R12 and R500 used in coolers.
R-134a also functions well in medium-temperature systems for residential and commercial buildings.
R-152a or Difluoroethane is another a zeotropic HFC similar to R-134a. Its a zeotropic properties mean its chemical composition remains the same, whether in a liquid or vapor state.
This refrigerant also does not damage the ozone layer. It has a low Global Warming Potential (GWP) similar to R-134a.
R-152a is also known for its excellent chemical and thermal stability, moderate flammability, and low toxicity. It can be readily used in components, equipment, joints, and lubricants designed to handle R-134a.
This eco-friendly refrigerant’s discharge pressure is approximately 30% lower than R-134a’s discharge pressure.
R290 is a refined refrigerant-grade variant of propane.
It was initially introduced as a replacement for R22 and R502 and today is used in low, medium, and high-temperature refrigeration applications. It is also widely used in air conditioning.
R290 is a hydrocarbon and does not damage the ozone layer, making it safer to handle than HFCs that are dangerous when exposed to skin or inhaled.
R290 also has a low Global Warming Potential (GWP of 20). It serves as an excellent replacement for R134a used for refrigerators and R404a used for freezers.
Propane’s properties do offer the risk of explosions. However, it is believed there is less than a 0.001% chance of this ever occurring in propane-operated refrigerators.
R600a or Isobutane is a natural refrigerant that has been used for many years. It is utilized in many applications and is an excellent replacement for R12, R22, and other HFCs and CFCs.
R600a is used for geothermal power generation, industrial refrigeration dehumidifiers, beverage dispensers, vending machines, and aerosol sprays. This refrigerant does not contribute to ozone depletion and has a relatively low GWP of 3.
This eco-friendly refrigerant is flammable but safely used in modern domestic refrigerators. It has low operating pressure. Users should avoid using this compound in air-cooled refrigerators or large-dose filling refrigerators.
R404a or Pentafluoroethane Trifluoroethane Tetrafluoroethane is an HFC refrigerant that consists of a blend of R125, R134a, and R143a.
It is frequently used for low and medium-temperature refrigeration. It’s not uncommon to see supermarkets use this refrigerant in the refrigerated products section. The transport industry also uses this refrigerant for refrigerated transportation.
R404a was designed to replace both R-22 and R-502 in commercial refrigerator equipment. This eco-friendly refrigerant does not contribute to ozone depletion. However, it has a relatively high GWP of 3922, meaning it is a highly potent greenhouse gas and should only be used for situations not suited for other refrigerants.
It should be noted that R404a is currently being phased out in the UK and EU, including a Europe-wide ban on the sale of new air conditioning and refrigeration equipment that utilize this compound.
R-407c or Difluoromethane, Pentafluoroethane, Tetrafluoroethane is a non-azeotropic refrigerant that consists of a blend of R-32, R-125, and R134a. This makeup means its chemical composition in the liquid state differs from its vapor state.
R-407c was designed as a substitute for R-22. It is used in medium-temperature applications in chillers and air conditioning equipment.
This eco-friendly refrigerant does not contribute to ozone depletion but has a moderate GWP of 1774. R-407c is known to have a good energy efficiency ratio and a relatively low compression pressure.
Note that the use of R-407c is restricted in the EU due to its GWP.
R-410a or difluoromethane pentafluoroethane is a zeotropic refrigerant. It is a 50/50 blend of R-32 and R-125 used in various heat pump and air conditioning applications. It is distinguishable due to being sold in rose-colored cylinders.
Honeywell initially developed R-410a in 1991 to replace R-22. It was quickly adopted for residential and commercial air conditioning units in the United States, Europe, and Japan.
R-410a works only for equipment that has been specifically designed to handle it because it requires a higher operating pressure than other refrigerants.
This eco-friendly refrigerant is ozone-friendly but has a moderately high Global Warming Potential of 2088.
R-413a is a zeotropic blend of R-218, R134a, and R600a. It is an HFC refrigerant designed to replace R12 for direct expansion air conditioning systems and medium to high-temperature refrigeration systems.
This compound is also used in car air conditioning systems, refrigerated mobile containers, display cabinets, chilled cold stores, and domestic refrigerators. It has zero ozone-depleting potential but a moderate GWP of 2053.
R-413a is not flammable in the air under ambient conditions. However, it may become flammable when placed under pressure with air.
This eco-friendly refrigerant is an excellent choice for commercial applications where R12 is being phased out. It can be used in direct-expansion refrigeration and air conditioning units without modification.
R170 or Ethane is a natural refrigerant suitable for very low-temperature applications.
It is non-toxic and possesses zero Ozone Depletion Potential and a low GWP of 10. However, this compound is highly flammable, so it is not suitable for refrigerant systems retrofitted for fluorocarbons.
R170 is used as a replacement for R13 and R503. It can be used in its pure form or after being mixed with another lower temperature refrigerant.
R170 is also compatible with conventional lubricants used in the refrigeration industry. However, R170 cylinders must be stored away from fire, direct sunlight, and direct heat sources to prevent fire hazards.
R-744 or carbon dioxide is a natural refrigerant used as a viable replacement for R404A and R134a in ultra-low, low, and medium-temperature refrigeration uses.
This refrigerant has gained popularity over the years for its excellent properties. It has zero Ozone Depleting Potential and a low Global Warming Potential of 1.
R-744 is non-toxic and non-flammable. However, users should be cautious about using this refrigerant in enclosed spaces as it may displace oxygen and cause suffocation.
R-744 is also more energy-efficient than HFC refrigerants and has a low compression pressure ratio, leading to excellent volumetric efficiency.
This refrigerant has high operating pressure, meaning the components and parts that utilize R-744 tend to be small in size and require a modest overall charge.
R-717 or Ammonia is another natural refrigerant. This compound is also a typical household and manufacturing chemical widely available.
R-717’s properties make it an excellent eco-friendly refrigerant for commercial and industrial refrigeration applications. The compound is also widely used in marine and naval applications.
Ammonia is frequently utilized in large-scale freezing in commercial plants. It is often called “anhydrous ammonia” because it contains little to no water. It makes a great refrigerant because it is 3% to 10% more efficient than HFCs and CFCs.
Ammonia has zero ozone depletion potential. It also has an astounding GWP of 0, making it one of the most eco-friendly refrigerants out there.
However, it is highly toxic and flammable, limiting its uses to specific applications. R-717 is also incompatible with copper, so it cannot be used in systems that contain copper pipes.
What is the Best Eco-Friendly Refrigerant?
After reviewing the above list, you may be wondering: “what is the best eco-friendly refrigerant?”
The answer will vary depending on your exact needs. The wide range of available refrigerants means numerous options for people seeking an environmentally friendly compound for a specific application.
For example, R-717 is an excellent choice if you seek a refrigerant with zero Ozone Depletion Potential and zero GWP. R-134a, on the other hand, works as an excellent substitute for R-12 in car air conditioners and cooling systems.
Individuals seeking a non-toxic and non-flammable refrigerant that is also affordable should go with R-744.
It should be noted that even the safest refrigerants can become dangerous if they are not appropriately handled. Therefore, individuals who purchase these refrigerants should understand proper handling and storage procedures to reduce the risk of injury or death.
When used correctly, refrigerants can make your cooling systems function at their best for many years. So be sure to review the above list the next time you want to try out a new refrigerant.