Whats is R1234YF refrigerant?
R1234yf is a new synthetic HFO refrigerant that has been developed as a successor to R134a for automotive air-conditioning applications. Due to its composition, R1234yf does not damage the ozone layer or has minimal global warming impact.
What equipment does a mechanic need to handle R1234yf?
The general requirement for R1234yf tools is that they are “ignition proof”. Ignition proof tooling provides a spark free tool / work environment.
Equipment requirements for R1234yf:
- A R1234yf calibrated manifold gauge set with dedicated R1234yf couplers. As R1234yf is an A2L mildly flammable substance, SAE standards have been developed for hoses and couplings.
- Red and blue service hoses, the fittings are 12mm O Ring fittings male with a hexagon nut, (R134a is 1/2” acme female. R12 - commercial industry standard - is 1/4” flare female with a knurled nut).
- R1234yf has a unique vehicle quick release fitting, to prevent use of incorrect equipment not fit for this type of refrigerant.
- Yellow service hose 1/2” LH acme thread (an adaptor is available to fit a universal vacuum pump).
- The manifold gauge set is designed to take the male fittings of the hose set and are calibrated to read R1234yf temperatures.
- Electronic refrigerant leak detector (A2L compliant).
- Vacuum pump (A2L compliant).
- Recovery/reclamation equipment (A2L compliant). Although it is not mandatory to recover R1234yf, it is still good environmental practice and, due to the cost of this refrigerant, it would be advisable to do so. Some suppliers can clean recovered refrigerant for re-use.
- Dedicated cylinders for recovered or new R1234yf have a left-hand valve thread and require a suitable adaptor to connect to the gauge set charge hose. As R1234yf is a mildly flammable gas, cylinder storage and transport practices will differ to R134a cylinders. Check out the relevant dangerous goods handling and storage requirements for your State or Territory.
- A refrigerant identifier is also recommended to ensure you are handling pure R1234yf, free of contaminants such as air or other refrigerants.
Is R1234yf compatible with existing R134a equipment?
No. The R1234yf system refrigerant circuit is accessed using service couplers that are a different size to those of a R134a system. The service coupler hose connection also has a left-hand thread that requires a matching hose for connection. Hence the need for an R1234yf gauge set.
R1234yf is classified as an A2L mildly flammable refrigerant, and requires the use of equipment designed for use with such a refrigerant.
Can I convert an R134a system to R1234yf?
No. R134a systems were not designed to operate using a flammable refrigerant.
R134a systems should not be converted to use R1234yf as these systems are unable to be converted to a level that satisfies the requirements of international standards (SAE J639 and SAE J2842) set for systems that use R1234yf.
The standards lay down specific requirements for system design. For example, the R1234yf evaporator is significantly stronger than the one you would commonly find in an R134a system.
Aside from the safety aspects, although the two refrigerants have similar thermodynamic properties, they are not the same. Therefore, compressor damage or system performance limitations may be experienced by attempting to convert an R134a system to R1234yf.
Safety issues to be aware of when handling R1234YF:
R1234yf is classified as A2L mildly flammable. Technicians need to take the relevant safety measures for the correct transport, storage and handling of a flammable gas. This would include, but is not limited to, ensuring no open flames (including smoking) near the system. It is also worth noting that highly toxic substances are created when this gas is burnt.