ALTERNATIVE REFRIGERANTS
the ability to propagate a fl ame. A2L refrigerants will burn, but their burning speed is below 10cm/s, which is lower than an A3 refrigerant such as R290 which actually burn explosively when ignited; hence the new classifi cation. In practical terms, it is very diffi cult to ignite 2L gases, but some precautions must be taken to prevent accidental build-up of refrigerant, particularly during charging of systems. Manufacturers are suggesting that extract fans be used during this process, especially if the outdoor unit is in an enclosed area
A2L refrigerants – and the same applies to
refrigerants using DSEAR (Dangerous Substances and Explosive Atmospheres Regulation) in the UK and ATEX guidance in Europe. This requires a risk assessment to be undertaken, reviewing the application, location of components and the installed refrigerant charge. In these circumstances, installation guidelines can form the framework for such risk assessments. By choosing the right refrigerant, equipment and location as dictated by EN378 the probability of forming a fl ammable atmosphere can be eliminated, making this assessment potentially very straightforward.
Common refrigerants (all class A1) Refrigerant HCFC 22
GWP* 1810
HFC 407C 1774 Current refrigerants
The vast majority of HFC and HFC/HFO blend refrigerants in current use are classifi ed as A1. It is vital to understand what refrigerants are in your system, and to make sure that the system complies with the requirements for leak checking and the phase down schedule of your particular gas (see table below).
What is an A2L refrigerant? The main diff erences between A1 refrigerants such as R410A, R134a, R407C and A2L refrigerants such as R32, R1234yf and R1234ze is
other fl ammable refrigerants – will not ignite if the concentration level in a room stays below their lower fl ammability limit (LFL). International and European safety legislation and standards such as EN 60335-2-40 and EN 378 defi ne requirements to remain far below the lower fl ammable limit in case of accidental leakage.
It is also worth pointing out that ammonia, which has been in use for many years, is also classifi ed as 2L for fl ammability.
Applications
From 1 January 2017, most new cars produced in Europe will contain an A2L refrigerant in their A/C system (R1234yf). There are currently over 4m cars on European roads which use this refrigerant. The automotive industry carried out exhaustive tests and risk assessments before using R1234yf,
Comments
This refrigerant is now banned, but can be used until a component in the refrigeration circuit fails at which point the system CANNOT be repaired.
AC/HP most DX systems using this refrigerant are now several years old so having a replacement plan would be advisable. Some chiller manufactures are still using this refrigerant in new equipment so check that this is the best refrigerant to use for your application.
HFC 407A/F
2107/1825 These refrigerants are being used in commercial refrigeration as an interim replacement for systems currently using R404A
HFO/HFC 448A/449A ~1400
These refrigerant blends are now being used in commercial refrigera- tion as a longer term replacement for systems currently using R404A/ R507.
HFC 410A 2088
This refrigerant is predominately used in DX equipment in the A/C industry and will remain in use until after 2030 until a viable replace- ment is available, but only in smaller DX systems.
HFC 404A HFC 134a 3922 1430
This refrigerant will be banned in new equipment and for service use from 2020.
This refrigerant has applications in A/C and refrigeration. It has a medium GWP so will be phased down by 2030. As of January 2017, R134a cannot be used in passenger vehicles.
*Taken from the IPCC 4 assessment.
www.acr-news.com December 2016 29
New equipment should not be installed using R-404A/507
New equipment should not be installed using R-404A/507 Plan to retrofi t existing equipment with R448A/ R449A
Ensure that when using R410A that the correct F-Gas checks are in place. If installing small systems, try to use lower GWP refrigerants such as R32 or R32/HFO blends where possible.
Plan to replace this gas as soon as possible using either R407A/F, or one of the lower GWP HFO blends such as R448A or R449A.
This gas can continue to be used for the time being, but it is sensible to review the alternatives available.
Suggested Action Plan for immediate replacement
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