The HVAC industry has undergone substantial changes in refrigerant usage, with a shift towards environmentally friendly options. Refrigerants, whether in liquid or gas form, play a crucial role in cooling systems by absorbing and releasing heat. The Different Types of Refrigerants in HVAC: Most Common List (2023) included R-12, R-22, R-32, R-134A, R-404A, R-407C, R-410A, and R-454B. While some older refrigerants like R-12 and R-22 have been phased out due to their environmental impact, newer alternatives like R-32 and R-454B offer better efficiency and reduced environmental harm.
The HVAC (Heating, Ventilation, and Air Conditioning) industry has seen a significant evolution in the types of refrigerants used over the years. As technology advances and environmental concerns grow, the industry has been shifting towards more eco-friendly refrigerants. Here we explain the different types of refrigerants in HVAC: the most common list (2023) used in HVAC systems, along with a brief overview of each of these.
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Introduction to Different Types of Refrigerants
A refrigerant is an element in the form of liquid or gas. A specific area in the refrigeration succession cools down using the refrigerant. The process seizes heat from space and then releases it into another space. This is the act of a refrigerant.
Refrigerants in refrigerating systems (air conditioners) absorb fluid and release heat. Apart from this, Thermodynamic phenomena of phase change are also used by refrigerants. This helps the liquid to convert to gas and gas into a liquid.
The process of refrigerant starts in the evaporator component of the system. The refrigerant liquid will absorb heat and change to vapor under low pressure. The vapor travels to the compressor component of the system.
The compressor pressure and temperature tend to increase. The release of heat from the vapor happens at this stage. The release of heat happens in the condenser component.
The refrigerant then changes back to liquid form. It travels back to the evaporator. Repetition of the process happens again and again with the same liquid. There are different types of refrigerants.
Modern refrigerant equipment includes ACs, cooling systems, freezers, and refrigerators. Despite their usefulness, refrigerants also contribute to global warming.
Different Types of Refrigerants In HVAC:
The classification of refrigerants into different groups is due to their chemical composition. The most common refrigerants include Chlorofluorocarbons (CFCs), Hydrochlorofluorocarbons (HCFCs), Hydrofluorocarbons (HFCs), and Natural Refrigerants. Freon or halocarbons are synthetically produced. The classification also depends on their chemical elements Chlorine (CL), Hydrogen (H), Carbon (C), and Fluorine (F).
- Chlorofluorocarbons (CFCs) – R11, R12, R113, R114, R115
- Hydrochlorofluorocarbons (HCFCs) – R22, R123
- Hydrofluorocarbons (HFCs) – R134a, R404a, R407C, R410a
The two numbers that characterize all refrigerants are:
- Ozone Depletion Potential (ODP)
A measure of a substance’s ability to harm the ozone layer compared to the reference substance, trichlorofluoromethane (R-11 or CFC-11). A substance with an ODP of 1 has the same ozone-depleting potential as R-11, while an ODP of 0 has no potential to deplete the ozone layer.
The value range of ODP is 0 – 1. ODP closest to 1 is harmful to the ozone layer. CFCs have significant ODP values. This is because they contain chlorine. Currently, CFCs are not used due to their harmful environmental impact.
- Global Warming Potential (GWP)
A measure of how much heat a greenhouse gas traps in the atmosphere compared to the amount trapped by carbon dioxide (CO2) over a specific period, typically 100 years. A substance with a GWP of 1 has the same climate impact as CO2, while a substance with a higher GWP has a greater impact.
GWP value ranges from 0 to several thousand. If the GWP value is big, the refrigerant is more harmful and can cause global warming. Inorganic refrigerants like carbon dioxide and ammonia have small GWP values. HCFCs are being phased out. The only HCFCs allowed nowadays are those without chlorine.
The different types of refrigerants that make the most common list include:
- R-12
- R-22
- R-32
- R-134A
- R-404A
- R-407C
- R-410A
- R-454B
1. R-12
R-12 has played a significant role in air conditioning and refrigeration history. It is a colorless gas at room temperature and atmospheric pressure. It becomes a liquid under pressure or at cooler temperatures. It has been favored in the past due to its excellent thermodynamic properties, making it efficient as a refrigerant.
Before being phased out, R-12 was widely used in car air conditioning systems, domestic refrigeration, and some commercial applications. R-12 is non-flammable under normal conditions and has low toxicity. However, when exposed to high temperatures or flames, it can decompose and produce toxic substances, including phosgene gas, which is harmful when inhaled.
Proper ventilation and safety precautions are essential when working with or around R-12. Due to its harmful effects on the ozone layer, the production and usage of R-12 were phased out under the Montreal Protocol, an international treaty designed to protect the ozone layer. By the mid-1990s, R-12 was largely replaced by R-134a in automotive air conditioning systems, a refrigerant that does not have ozone-depleting properties. R-134a is the primary replacement for R-12 in automotive air conditioning.
In other applications, various other refrigerants might be used as alternatives, depending on the system’s specific requirements. If you have a system that still uses R-12, it’s essential to handle the refrigerant carefully, ensuring no leaks or releases into the atmosphere. When servicing or disposing of the system, it’s crucial to capture, recycle, or reclaim the R-12, following local regulations and guidelines.
2. R-22
R-22 is another refrigerant that has been extensively used in the HVAC industry. It, again, is a colorless gas at room temperature and atmospheric pressure. When compressed or cooled, it becomes a clear, colorless liquid. Its thermodynamic properties made it an efficient refrigerant for various applications.
R-22 was the refrigerant for residential heat pumps and air-conditioning systems for several decades. It was also used in some commercial cooling applications and cold storage. While R-22 is less harmful to the ozone layer than some earlier refrigerants like R-12, it still has ozone-depleting potential.
The chlorine in R-22 can break down ozone molecules in the stratosphere, contributing to the ozone layer’s depletion. Additionally, R-22 is a greenhouse gas, which means it has the potential to contribute to global warming when released into the atmosphere.
Due to environmental concerns, the production and import of R-22 were phased out in many countries under the Montreal Protocol. In the U.S., for instance, R-22 was entirely phased out by 2020. However, it can still be found in older systems, and servicing those systems with recycled or stockpiled R-22 is allowed.
3. R-32
R-32 is a colorless gas at room temperature and atmospheric pressure. It becomes a liquid under pressure or when cooled. It is mildly flammable, which is a departure from many traditional refrigerants like R-22 and R-410A, which are non-flammable. This flammability has led to new safety standards and procedures for handling, storing, and using R-32. However, with proper precautions and equipment, R-32 can be used safely and effectively.
The refrigerant is used both on its own and as a component in refrigerant blends. One of the most well-known blends is R-410A, a 50/50 mixture of R-32 and R-125. However, due to the higher GWP of R-125, there has been a push to use R-32 in its pure form in some applications, especially in split air conditioning systems.
R-32 is an emerging refrigerant that offers several advantages regarding efficiency and environmental impact. As the HVAC industry continues to evolve and prioritize sustainability, R-32 will likely play a significant role in future cooling solutions.
4. R-134A
This is also a halo alkaline refrigerant. It has thermodynamic properties. Norflurane is often referred to as R-134A. A single component makes R-134A. It is not blended like R-22 and also as an R-12. This means the refrigerant doesn’t need the use of many recovery machines.
The Environmental Protection Agency regulations specify that any product that recycles or uses a blend will need a separate machine for each component.
R-134A is also the only refrigerant as an alternative to retrofit R-12 air conditioning systems in all types of vehicles. The retrofitting process should follow proper procedures to avoid safety hazards and other problems. Retrofitting is a challenging process. The process also involves changing the vehicle’s dryer/receiver or accumulator. Remove the old compressor oil.
Replace the high-pressure switch off the vehicle’s air conditioner after this process is complete. Do the entire process thoroughly and carefully to avoid contamination. Cross-contamination can happen if any R-22 is still left in the system.
Cross-contamination of E-134A and R-22 will affect the cooling system of the vehicle. It will make it less reliable. The compressor’s head pressure goes up to dangerous levels. The system will fail when the pressure goes beyond the permissible levels. R-134A uses a unique oil blend of polyol ester or polyethylene. R-134A refrigerant is a better choice for the environment.
5. R-404A
R-404A is a safe alternative to R-22. The refrigerant is used in refrigeration systems that also require a temperature between -45° C and 15° C. This translates to -49° F and 59° F. The wide temperature range makes it useful in industrial and commercial transport industries.
The properties of this refrigerant are similar to R-22. This also offers better performance. R-404A does not react rapidly with air or water. This makes it safe for many uses. It is also colorless, non-inflammable, and odorless.
Users should take adequate safety precautions when using refrigerant. Direct contact with R-404A can cause frostbite. Exposure to high heat or fire can rupture the refrigerant tank. R-404A is available in stores that sell cooling as well as heating products.
6. R-407C
This refrigerant has thermodynamic properties. It is a common replacement refrigerant to retrofit R-22 equipment. The mix of hydrofluorocarbons includes a blend of difluoromethane, pentafluoroethane, and 1,1,1,2-tetrafluoro-ethane.
Ductless split systems, packaged air conditioners, and also water chillers use refrigerant. It is also present in direct expansion systems and light air conditioning found in commercial, residential, and industrial properties.
R-407C also works in refrigeration systems with medium temperatures. Many new appliances use R-407C. New appliances that use nitrogen as a holding charge will work best with R-407C. This is because it uses polyol ester oil.
R-407C is quite common in new refrigeration systems and appliances. R-407C is also present on some R-22 systems. The procedure involves an oil change when retrofitting. R-407C is an alternative to Freon. It is safe for the environment.
7. R-410A
This refrigerant is a blend of difluoromethane, hydrofluorocarbon refrigerants, and pentafluoroethane. R-410A is a non-ozone-depleting refrigerant. It provides more energy efficiency than R-407C and R-22. Chlorine is not even there.
The high refrigeration capacity and pressure make it more suitable than R-22. This helps in providing better performance.
The process of buying an R-410A is easy. Companies that manufacture refrigeration systems and air conditioning make units that use R-410A. R-410A is popular for air conditioning, commercial refrigeration, and chilling units.
The alternative to Freon will not be effective in R-22 a/c units. This is because of the higher pressure in R-410A. The need is for a different pressure gauge than what is usually there in R-22. The charge of the refrigerant is in its liquid form. The charge is only in short bursts.
8. R-454B
R-454B is one of the newer refrigerants introduced to the market as a more environmentally friendly alternative to some of the older, high-GWP refrigerants. It is a blend of two hydrofluoroolefins (HFOs): 68.9% R-32 (Difluoromethane) and 31.1% R-1234yf (Tetrafluoropropene).
It has been designed to closely match the properties of R-410A, making it a potential drop-in replacement in some systems. Furthermore, R-454B does not deplete the ozone layer. It is classified as an A2L refrigerant, meaning it’s of low toxicity (A) and mildly flammable (2L). The mild flammability requires specific handling and installation procedures to ensure safety. However, it can be used safely in various applications with the right precautions.
R-454B is a promising refrigerant that offers a balance between performance and environmental responsibility. As the HVAC industry continues its shift towards more sustainable solutions, refrigerants like R-454B are likely to become more prevalent.
The Future of Refrigerants in HVAC
So there you have it – Different Types of Refrigerants in HVAC: Most Common List (2023).
The HVAC industry is continually evolving, with a clear trend towards environmentally friendly refrigerants. As research continues, we can expect the introduction of newer refrigerants with even lower environmental impacts.
So, when choosing a refrigerant for an HVAC system, it is essential to consider not only its cooling properties but also its environmental impact, safety, and cost. As the industry moves forward, we hope to find a balance that offers efficient cooling while minimizing harm to our planet.
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