In a nutshell, the automotive airconditioning industry has been forced to find a new refrigerant to satisfy the emission standards set by regulations in the European Union Mobile air-conditioning (MAC) directive – a refrigerant with a low Global Warming Potential (GWP) of less than 150.
R134a has a GWP of 1300, while R1234yf has a GWP of 4!
The trade-off is that it is slightly flammable, being rated at A2L. It is so mild in flammability that it required a new standard to be created, therefore the A2 bracket was split to create the A2L standard.
For R1234yf to ignite, there must be the optimum amount mixture of refrigerant and air. Although very rare, should R1234yf ignite, it burns at approximately 10cm per second, so quite slowly.
WHEN WILL WE SEE IT?
As of January 2017, every new car sold in Europe has to be using a refrigerant that meets this GWP level of less than 150 so will either have R1234yf, or in some Mercedes, CO2. At the end of next year there are expected be 40 million cars around the globe with R1234yf in their a/c systems!
Right now there are numerous models of vehicles on Australian roads that have the new R1234yf, and this number will be rapidly increasing as all European-sold vehicles change to the new refrigerant.
Also accelerating this is that the Australian government have announced a phasedown of R134a beginning in January 2018, reducing the quantity brought in to the country by 85%. The 15% left will remain to service vehicles with R134a systems.
Dealerships and crash repairers will be the first to work with the R1234yf, so if you are one of these, you could come across it any day now!
To clarify, R1234yf is not a drop-in replacement for R134a, so there will be no need for retro-fitting R134a systems to R1234yf.
PRESSURES: R1234yf has very similar pressures to R134a, however the high-side is slightly lower and the low-side is slightly higher.
COMPONENTS: The access ports on R1234yf fittings are different to R134a ports, being a slightly different design and each approximately 1mm bigger.
Each system will have an internal heat exchanger where the suction refrigerant removes heat from the discharge pipe to reach optimum cooling.
One of the major considerations with the mild flammability risk is to minimise any possibility of R1234yf leakage into the cabin. Therefore, all evaporators will be manufactured and certified to a high standard, and all TX valves and connections will be outside the firewall – this should make life easier when changing TX Valves!
Compressors will have a thermal switch to cut the compressor out in the event of high temperatures. The standard says the pressures on the high side must not exceed 600psi, the suction must not exceed 56°C and components need to be able to withstand 12,000 kpa.
CHARGE QUANTITIES: With R1234yf, the gas charge quantity is going to be even more critical. With the use of the heat exchanger, even a small drop in gas levels could result in a significant loss in cooling, as the heat exchanger multiplies any drop in efficiency. Actual charge quantities will be similar to late model vehicle R134a charges.
RECOVERY: Currently, due to its low GWP, there is no licence required to use R1234yf or law stating that it must be recovered. However, with the retail cost of R1234yf at about $600/ kg it makes a lot of sense to recover and re-use R1234yf wherever possible!
If you do wish to vent R1234yf to atmosphere, you need to be sure that there is no ignition source within a 3 metre sphere of the vent source.
WHAT DOES THIS MEAN FOR ME?
There are a few fundamental pieces of equipment that you need for working with R1234yf.
EQUIPMENT: All tools and equipment for R1234yf have to be made to an Australian standard, so that they are spark-proof and ‘intrinsically safe’. The new equipment recommended for R1234yf is;
• Gauge Set (or an Automatic A/C station which covers the gauges, Vacuum pump and recovery unit and also recycles so you can re-use the gas)
• Vacuum Pump – R1234yf vacuum pumps can also be used for R134a.
• Recovery Unit – R1234yf recovery units can also be used for R134a, however you may want to keep the units separate.
• Leak detector – R1234yf leak detectors are also applicable for R134a
• Refrigerant Identifier - every A/C workshop should have a Refrigerant identifier, especially with the introduction of the new R1234yf. As an example, if you were recycling R1234yf and accidentally contaminated the gas with a rogue refrigerant, you would be losing thousands of dollars in good refrigerant, have an underperforming system and an upset customer!
• Vacuum Gauge – a necessity to test you vacuum pump performance
• R1234yf Gas – can be purchased in 4.5kg cylinders, and have a left hand thread.
• Reclaim cylinder – these are different for R1234yf and also have a left-hand thread.
When connecting and disconnecting to an R1234yf system, it is strongly advised to shut down the engine.
The new R1234yf is well established to be the new refrigerant in Mobile airconditioning systems. It is here in Australia in vehicles on our roads right now and the number will be increasing at a fast pace over the next few years. Take the opportunity and be prepared! For more information, call 1800 15 15 15 and speak to one of our friendly specialists! We’re here to help!