If your cooling system uses large centrifugal chillers, you’re probably familiar with R123 refrigerant. However, as many countries move towards greener solutions, you have to change your R123 refrigerant.
In this guide, you’ll learn everything you need to know about R123, including where it is used, its benefits, and the best alternatives to consider for your cooling system upgrade.
What is R123 Refrigerant?
R123, or trifluorodichloroethane (CF₃CHCl₂), is a widely used HCFC refrigerant, especially in large-scale cooling systems. R123 operates at low pressure, with a saturated vapor pressure of just 91.29 kPa at 25°C. It makes R123 refrigerant an excellent choice for large centrifugal chillers, which is why R123 has become a good choice in the industry.
Characteristics of R123 Refrigerant
Physical Properties
R123 is used for its low-pressure operation. Under standard operating conditions, the saturated vapor pressure of R123 is only about one-third that of R134a. The refrigeration system runs at a stable pressure below 1.5 MPa, which brings several operational benefits.
First, the risk of refrigerant leaks is reduced. In actual systems, R123 tends to have lower annual leakage rates compared to high-pressure refrigerants like R410A.
Additionally, the operational environment at low pressure reduces the compressor load, improving the unit’s efficiency by 8%–12%. It leads to energy savings during continuous operation.
Here’s a quick look at the properties of R123 refrigerant:
| Properties | R123 refrigerant |
| Chemical formula | C2HCl2F3 |
| Density | 1.4638 g/cm3 |
| Melting point | −107 °C (−161 °F) |
| Boiling point | 27.82 °C (82.08 °F) |
| Critical temperature | 183.7℃ |
| Vapor pressure | 89.3 kPa |
| ODP | 0.012 |
| GWP | 120 |
| Safety classification | B1 |
| Oil | MO, AB |
Chemical Properties
R123 is chemically stable, so it makes it ideal for long-term use in both industrial and commercial refrigeration systems. While the chlorine atoms in the R123 molecule participate in ozone decomposition reactions, their content (2 atoms) is far lower than that of R11 (3 atoms). Because of the number of chlorine atoms, R123’s ODP is only 0.012 (compared to 1.0 for R11).
It has stable properties over a wide temperature range, remaining undecomposed from -40°C to 150°C. It can adapt to the wide temperature range of commercial air conditioning and industrial refrigeration, and will not corrode equipment, pipes, or heat exchangers during long-term cyclic use.
In terms of lubricant compatibility, R123 exhibits good miscibility with mineral oil (MO) and alkylbenzene oil (AB), avoiding problems such as insufficient compressor lubrication, abnormal wear, and shortened lifespan caused by refrigerant and lubricant separation.
Here is the chart about pressure and temperature. You can see:
| R-123 | °F | °C |
| 27.8 | -20 | -28.9 |
| 27.4 | -15 | -26.1 |
| 26.9 | -10 | -23.3 |
| 26.4 | -5 | -20.6 |
| 25.9 | 0 | -17.8 |
| 25.2 | 5 | -15 |
| 24.5 | 10 | -12.2 |
| 23.8 | 15 | -9.4 |
| 22.8 | 20 | -6.7 |
| 21.8 | 25 | -3.9 |
| 20.7 | 30 | -1.1 |
| 19.5 | 35 | 1.7 |
| 18.1 | 40 | 4.4 |
| 16.6 | 45 | 7.2 |
| 14.9 | 50 | 10 |
| 13 | 55 | 12.8 |
| 11.2 | 60 | 15.6 |
| 8.9 | 65 | 18.3 |
| 6.5 | 70 | 21.1 |
| 4.1 | 75 | 23.9 |
| 1.2 | 80 | 26.7 |
| 0.9 | 85 | 29.4 |
| 2.5 | 90 | 32.2 |
| 4.3 | 95 | 35 |
| 6.1 | 100 | 37.8 |
| 8.1 | 105 | 40.6 |
| 10.3 | 110 | 43.3 |
| 12.6 | 115 | 46.1 |
| 15.1 | 120 | 48.9 |
| 17.8 | 125 | 51.7 |
| 20.6 | 130 | 54.6 |
| 23.6 | 135 | 57.2 |
| 26.8 | 140 | 60 |
| 30.2 | 145 | 62.8 |
| 33.9 | 150 | 65.6 |
Advantages of R123 Refrigerant
Lower Environmental Impact
R123’s ODP is just 0.012. It is 1/16th that of R11, greatly reducing its ozone-depleting potential. Although it still needs to be phased out, R123 ranks among the best in terms of environmental performance among HCFCs. Its Global Warming Potential (GWP) is 120, much lower than R134a (1430) and R410A (2088). So it is more environmentally friendly, and you can more easily comply with current regulations.
Economic Efficiency
For existing R11 systems, R123 can be replaced by simple modifications, through changing sealing materials and adjusting the lubricant formula. The modification cost is only 30%-50% of a complete system replacement. For example, using R123 refrigerant in a large commercial building can reduce 20% annual energy costs.
Safety
R123 is rated B1 (low toxicity, non-flammable) by ASHRAE. In a closed computer room environment, even if a leak occurs, its concentration is unlikely to reach the safety threshold (AEL value of 30 × 10⁻⁶). In most cases, you won’t need specialized explosion-proof equipment, which helps you reduce installation and maintenance costs. In contrast, ammonia (R717), while having a zero GWP, has limitations in its application in densely populated areas because of its toxicity and flammability.
Disadvantages of R123 Refrigerant
Toxicity
While R123 is considered low-toxicity, long-term exposure may still have health risks. Animal studies show that long-term exposure to 100 ppm of R123 can cause liver damage. Although real-world leak concentrations are far below this level, and acute poisoning is unlikely, environmental and health agencies in many countries still limit its use by strict restrictions.
Regions such as the EU explicitly require computer rooms using R123 to be ventilated at least six times per hour. Higher ventilation standards directly increase investment in computer room renovations and ventilation equipment.
If you use R123 in poorly ventilated spaces, you will have other costs. The person who works in this place for a long time needs regular health tests. It increases management costs and compliance pressure. Compared to completely non-toxic and harmless new low-GWP refrigerants, the toxicity of R123 is one of the important reasons for its accelerated replacement.
Risk of Replacement
As an HCFC, R123 is included in the mandatory phase-out list under the Montreal Protocol. Developed countries are required to ban the use of R123 in new equipment from 2020 and achieve a complete phase-out by 2030. Developing countries also have clear phase-out deadlines.
Because of regulations, R123 is a short-term solution and cannot be used for long-term stability. You’ll need to start planning a replacement sooner rather than later.
Cost
Tighter policies have led to a continuous reduction in R123 production and imports. It means your procurement costs will increase year by year, and refueling existing equipment will become increasingly difficult.
Many currently operating R123 refrigerant units have a design life of 20-30 years, with many still in their optimal service life. The conflict between the planned retirement date and the remaining time of the equipment directly leads to idle assets and waste.
Applications of R123 Refrigerant
Large Centrifugal Chillers
R123’s low-pressure properties make it suitable for use in centrifugal chillers. In high-rise buildings, large convention centers, and data centers, R123 units can provide 1000-10000 tons of cooling capacity, meeting the needs of large-scale spaces. It performs well at 30% load, saving 40% energy compared to reciprocating chillers.
Industrial Refrigeration
In chemical, pharmaceutical, and other industrial sectors, R123 can be used in low-temperature refrigeration systems (e.g., -40℃ to -10℃). Its chemical stability allows it to be used in acidic environments. Its low-pressure characteristics reduce corrosion on the equipment.
For example, a chemical company was able to maintain a reactor temperature of -25°C using an R123 system, improving product quality by 15% and extending maintenance intervals to three years.
Regional Energy Systems
R123 can be combined with absorption refrigeration technology to achieve combined heat, power, and cooling (CHP). In gas turbine waste heat recovery projects, R123 is used as an intermediate refrigerant to convert heat into cooling capacity, achieving a system energy efficiency of 85%.
Alternatives to R123 Refrigerant
HFO-1233zd(E)— Best Direct Replacement
HFO-1233zd(E) has a GWP of only 4.5. It is non-flammable, non-toxic, and its operating performance is very close to that of R123. It can be directly used in existing centrifugal chillers without large-scale modifications to piping and equipment, and is currently the industry-recognized dedicated replacement for R123.
R514A— Best for Retrofits
R514A, an azeotropic mixture of R123/HFO-1233zd(E), reduces GWP by 97% while keeping the performance of R123. This synthetic refrigerant is perfectly suited for upgrading your equipment. It can satisfy performance, efficiency, and environmental requirements. You can use it as the most reliable choice for the transition phase. This type of refrigerant does not require replacing the main unit, resulting in low retrofit costs, rapid implementation, and low risk. If you are a commercial building or industrial user, R514A is a preferred alternative for you.
R717 / R744 — Long-Term Solution
Natural refrigerants represent a long-term alternative with zero environmental impact. The mainstream products are ammonia (R717) and carbon dioxide (R744).
Ammonia has zero ODP and zero GWP, low procurement costs, and high heat exchange efficiency. It makes it one of the most environmentally friendly refrigerants. However, it is limited by its toxicity and flammability in traditional applications.
Modern ammonia/CO₂ cascade systems effectively solve safety issues by confining the ammonia loop to the equipment room and using CO₂ as the refrigerant in personnel activity areas. You can widely use them now in large cold storage facilities, food processing plants, and cold chain companies.
Carbon dioxide (R744) also possesses zero ODP and extremely low GWP environmental characteristics. It performs excellently in transcritical cycles, exhibits outstanding high-temperature resistance, and is suitable for hot regions and high-temperature operating conditions. It is a natural, safe, and long-lasting alternative, especially suitable for new projects. If your project requires an extremely high environment, you can use R744refrigerant to replace R123 refrigerant.
Absorption Refrigeration
Absorption refrigeration utilizes thermal energy to drive the refrigeration cycle. It usually uses the lithium bromide-water system. The system is powered by natural gas, industrial waste heat, solar energy, and waste heat. Worked by thermal energy, it does not use any synthetic refrigerants. It really achieves zero ODP and GWP and optimal environmental performance.
It can realize combined heat and power (CHP), highly adaptable to regional energy systems, with high energy utilization efficiency, quiet operation, and no risk of refrigerant leakage.
To Wrap Up
R123 is still in use, but its phase-out is inevitable. Choosing the right refrigerant to replace now will save you time, money, and ensure compliance with future regulations.
Ready to upgrade your cooling system? Get in touch to explore R123 alternatives, and I will give you some suitable suggestions.
FAQ
Is R123 refrigerant banned?
R123 is being phased out under the Montreal Protocol. New equipment is no longer allowed in many countries.
What is the best replacement for R123?
HFO-1233zd(E) is considered the common replacement for most systems.
Can you retrofit systems that use R123 refrigerant?
Yes. Many systems can be retrofitted with R514A or HFO refrigerants with minimal modifications.
Can I retrofit my R11 chiller to R123?
Yes. Only the seals need to be replaced and the lubricating oil adjusted. The modification cost is low, and the compatibility is good.
You may also find this related blog post very useful:
R744 vs R134a: Differences, Performance, Cost, and Which to Choose
