Overview of refrigerants
Assessment of refrigerants
Blog article 17.01.2025FOR HEAT PUMPS AND AIR CONDITIONERS
No refrigerant means no heat pump or air conditioner: The refrigerant is drawn in by the compressor and then compressed. This causes the temperature and pressure to rise significantly. Then, in the condenser, it passes its heat to the heating and hot water system. Refrigerant circulation is the reverse for air conditioners.
IMPORTANT TO KNOW
No refrigerant is like another. The physical properties directly impact the design of the compressor. The chosen refrigerant affects the range of potential uses as well as system efficiency during operation. There is simply no universal refrigerant that works properly under all conditions.
So it makes sense to choose a a heat pump or air conditioner that ideally suits the refrigerant. The big question is: What should the system be able to do? A suitable refrigerant has a positive impact on the serviceable life of the system, the efficiency and the costs of operation.
Mitsubishi Electric systems use a variety of different refrigerants – and we take great care to consider the specifications of the F-gas Regulation as well as current requirements relating to high energy efficiency. This section enables you to explore the properties and specific benefits of the respective refrigerants.
Criteria for refrigerants
Criteria for refrigerantsFrom a safety perspective, refrigerants can be assessed in terms of the parameters of toxicity and flammability. ISO 817 and DIN EN 378 classify refrigerants into eight safety groups according to their flammability and toxicity.
The classification of refrigerants in the various safety groups correlates to a parameter from the environmental criteria. It is generally the case for synthetic refrigerants that the higher the flammability of a refrigerant, the lower the global warming potential (GWP).
The ODP (ozone depletion potential) is a value that clarifies the damaging effects a chemical substance has on the ozone layer in the stratosphere. It is a relative value that compares the effects of a chemical substance with the effects of trichlorofluoromethane (R11), which is assigned the ODP value 1 in the Montreal Protocol. Since the mid-1990s, the refrigeration and air conditioning industry has been striving to find alternative, environmentally friendly, efficient and safe refrigerants. For this reason, refrigerants containing chlorine, such as R22, have been banned and the focus has been placed on existing refrigerants with no ozone depletion potential.
The GWP (global warming potential) denotes the potential influence that a specific refrigerant may have on global warming – for example, if it were to escape into the atmosphere due to a leak. It is a relative value, meaning that it compares the influence of the refrigerant in question with the influence of carbon dioxide (CO2) over a period of 100 years. CO2 has a defined GWP of 1. With a GWP of 675, the refrigerant R32 would therefore have a global warming impact 675 times greater than that of CO2 in the first 100 years after its release. The lower the GWP of a refrigerant, the lower its potential global warming impact on the environment. To calculate the CO2 equivalent of a refrigerant, take the charge quantity and multiply it by the GWP value. The next step is to use refrigerants that have no ozone depletion potential and also feature a low global warming potential (GWP). The phase-down in the F-gas Regulation additionally governs the reduction of global warming potential (GWP).
Background
Having entered into force on 1 January 2015, the European F-gas Regulation (regulation no. 517/2014) was intended to gradually limit the amount of partially halogenated hydrofluorocarbons (HFCs) by 2030. The original aim was to reduce the F-gases placed on the market by 79% of the CO2-equivalent emissions as compared to 2015.
Amendment of the EU F-gas regulation 2024
The regulation (EU) No 517/2014 of the European Parliament on Fluorinated Greenhouse Gases (F-gases), which took effect on 1 January 2015, has been revised. EU institutions have been negotiating a new proposal since April 2022. The EU trilogue agreed to the amendment on 5 October 2023. The preliminary legislation was made public on 18 October 2023.
Aims
- Adaptation to the European Green Deal and the European Climate Law (EU carbon neutrality by 2050 + intermediate goals such as a reduction of 55 % in total greenhouse gases by 2030 as compared to 1990 > Fit For 55 <)
- Intensified reduction of emissions of fluorinated greenhouse gases. Emissions will be more tightly regulated by 2050 and should save up to 500 Mt of CO2eq. F-gas Regulation
- Harmonisation with the Montreal Protocol
New adaptations / measures
1) Extension on prohibition of sale of new systems with GWP limits beginning in 2025
2) Restrictions on use of HFC refrigerants for service, repair and maintenance beginning in 2025
3) Stricter HFC phase-down (CO2eq quota mechanism) by 2050 and CO2eq beginning in 2025
4) Handling refrigerants > requirements with regard to training and certification, including for HFC and natural refrigerants
5) Stricter regulations to fight illegal imports of refrigerants into the EU
6) Optimisation of checking and monitoring of compliance with EU regulation
The amended EU F-gas regulation goes into effect during the first half of 2024, once it has been published in the EU Official Journal.
In order to assess the costs of a refrigerant, both the costs of the refrigerant itself and the system efficiency must be considered. The system efficiency depends on a number of factors such as the thermophysical properties of a refrigerant.
Properties that influence the efficiency of the system include:
• Pressure-temperature ratio
• Evaporation enthalpy
• Volumetric refrigeration capacity
• Vapour density
• Refrigerant mass flow
• Energy demand of compression
R410A refrigerant
R410AR140A is a mixture of two substances, consisting of R125a and R32 in equal measure. Its 50% higher volumetric refrigeration capacity enables a significantly smaller layout of the system components than with R22 refrigerant. In addition, R140A systems feature higher efficiency values than their R22 counterparts.
Benefits:
- High system efficiency
- Low refrigerant charge quantity
- Availability of components
- A1 refrigerant
Drawbacks:
- Relatively high GWP value
- Long-term availability may be limited
- Price level will increase in medium term
R32 refrigerant
R32R32 refrigerant (difluoromethane (CH2F2)) has long been used as a component in R410A. Belonging to the group of HFC refrigerants, R32 stands out thanks to its low GWP value of 675 and ODP of 0. Given its very good thermodynamic properties and low GWP, R32 is now used in air conditioning and heat pump systems with relatively small refrigerant quantities.
Benefits:
- Meets requirements of F-gas Regulation
- High system efficiency
- Low refrigerant charge quantity
- Potential material savings due to smaller pipe diameter
- Availability of components
- Tested and accepted refrigerant
- High volumetric refrigeration capacity
Drawbacks:
- A2L refrigerant
- Application area changed
- Units must be redesigned
R454B refrigerant
R454BR454B is a mildly flammable substitute refrigerant for R410A in air conditioning systems featuring displacement compressors and direct evaporation, heat pumps and chillers. This refrigerant is based on HFO technology and boasts a low GWP of 465, with CO2 emissions 78% lower than R410A and 31% lower than R32.
Benefits:
- Low refrigerant charge quantity
- Availability of components
- No need for redesign of units
- Nearly identical performance to R410A
- Top-up possible (as the refrigerant can be topped up in the event of a leak on the high-pressure or low-pressure side, there is no need to exchange the entire refrigerant)
Drawbacks:
- A2L refrigerant
- Temperature glide: 1.5 K
Comparison of R410A / R32 / R454B
Comparison of R410A / R32 / R454BR32 and R454B are two further refrigerants available as alternatives to the very widely used refrigerant R410A. The refrigerants are compared with one another in the table.
▲ = Slightly higher value compared to R410A
▲▲ = Higher value compared to R410A
▲▲▲ = Considerably higher value compared to R410A
▼ = Slightly lower value compared to R410A
▼▼ = Lower value compared to R410A
▼▼▼ = Considerably lower value compared to R410A
Risk management in 3 steps
Tool/software
THE A2L REFRIGERANT CALCULATOR
Always keep track of your risk management!
R134a refrigerant
R134aGiven their similar properties, R134a refrigerant has previously been used as a substitute for R12. But what sets them apart and makes R134a the clear winner is its ODP of 0.
Benefits:
- Availability of components
- Tested and accepted refrigerant
- A1 refrigerant
Drawbacks:
- Relatively high GWP value
- Long-term availability may be limited
- Price level will increase in medium term
R513A refrigerant
R513AR513A not only features an impressive GWP value of just 629, this A1 refrigerant is neither toxic nor combustible. R513A can be used as a drop-in refrigerant for R134a, meaning that the system properties of the proven cooling technology do not need to be altered during changeover. This helps make the conversion of existing R134a systems a viable option.
Benefits:
- Availability of components
- No need for redesign of units
- 55% lower GWP than R134a
- A1 refrigerant
- Drop-in as replacement for R134a in existing systems
Drawbacks:
- Relatively high GWP value compared to R1234ze
R1234ze refrigerant
R1234zeR1234ze belongs to the group of HFO (hydrofluorolefine) refrigerants, which are characterised above all by their very low GWP. However, their volumetric refrigeration capacity is up to 20% lower than that of R134a. Like R32, the HFO refrigerants are classed as A2L and considered mildly flammable.
Benefits:
- Low GWP value
- Availability of components
- HFO refrigerants are not subject to the F-gas Regulation
Drawbacks:
- A2L refrigerant
- 20–25% lower volumetric refrigeration capacity
- Larger unit dimensions
- Units must be redesigned
Comparison of R134A / R513A / R1234ze
Comparison of R134A / R513A / R1234zeR1234ze refrigerant has been available as an A2L alternative to R134A for many years. The A1 refrigerant R513A was also added several years ago. These three refrigerants are compared in the following table.
▲ = Slightly higher value compared to R134a
▲▲ = Higher value compared to R134a
▲▲▲ = Considerably higher value compared to R134a
▼ = Slightly lower value compared to R134a
▼▼ = Lower value compared to R134a
▼▼▼ = Considerably lower value compared to R134a
R744 refrigerant (CO₂)
R744 (CO₂)Natural refrigerant
Thanks to its very low ODP and GWP values, CO2 is an extremely environmentally protective refrigerant. Given its very good heat transfer coefficient, relative imperviousness to pressure losses and very low viscosity, CO2 boasts a unique set of thermophysical properties.
Benefits:
- Environmentally compatible refrigerant
- Imperviousness to pressure losses
- Not subject to the F-gas Regulation
- Cost-effective
- High volumetric refrigeration capacity
Drawbacks:
- Very high working pressure
- Very low critical temperature (31 °C)
R290 refrigerant (propane)
R290Natural refrigerant
R290 is a natural refrigerant that belongs to the group of hydrocarbons. As it is not part of the group of HFCs (partially fluorinated hydrocarbons) or CFCs (chlorofluorocarbons), it is not affected by the F-gas Regulation or the phase-down. With a GWP of 0,02 (IPCC AR6) and an ODP of 0, it is an environmentally compatible and future-proof solution. R290 belongs to safety group A3 and is therefore highly flammable, meaning that aspects such as protected areas must be observed during installation.Benefits:
Benefits:
- Enables flow temperatures of up to 75 °C in heat pumps
- Lower condensing pressure compared to R32
- 5% extra funding from the German BEG programme for the use of natural refrigerant
Drawbacks:
- Highly flammable
