Dawn of a new A/C system era

Air conditioning used to be one of the service technologies that didn’t change much from year to year. The negative effects of R-12 on the ozone layer, the resulting transition to R-134a, and the regulations related to the recovery and recycling of refrigerant changed all that. Now in 2012, we’re on the brink of yet another transition— the switch to HFO-1234yf. This new refrigerant, destined to bring a cascade of changes to the A/C service landscape, is coming soon to a service bay near you. To be ready, you need to be aware and informed.

Q: We’ve heard that cars with HFO-1234yf will be here soon. When’s it actually going to get here?

A: Some domestic models will be using this new refrigerant this spring, with some Subaru models already at dealerships. The Cadillac ATS is also expected to be released by mid-year with a factory fill of HFO-1234yf. Dealerships will need to consider service equipment for HFO-1234yf this year. This may also be the case for collision shops, depending on whether they perform A/C work in-house. Aftermarket shops will need to consider HFO-1234yf-ready equipment within the next couple of years.

Q: Will HFO-1234yf cylinders and containers resemble those of R-134a?

A: First of all, there will be no small containers of HFO-1234yf to placate the DIY market. R-134a cylinders are colored blue, while HFO-1234yf cylinders will be white with a red band. Although the size of an HFO-1234yf cylinder has not yet been determined, it’s expected that the cylinder size will be less than 30 lbs. Also, as is required by EPA, the new refrigerant will require unique fitting sizes so as to minimize the chances of refrigerant cross-contamination.

Q: Will the cost of HFO-1234yf be about the same as R-134a?

A: No, initial estimates claim that HFO-1234yf will be ten times as costly as the current price for R-134a. However, there are a couple of factors that should be considered to keep cost in the proper context.

First, the price of HFO-1234yf will initially reflect limited manufacturing volumes. So, as the availability of this new refrigerant increases with additional manufacturing volume, it should help towards bringing the cost down.

Second, today’s systems leak much less than older systems, resulting in a reduced need for recharging. The system leak rate today is about 12 grams of refrigerant per year, which translates to about six years of vehicle age before the system will require recharge service.

Q: Does the transition to HFO-1234yf mean our shop will need a new recovery/recycling machine?

A: Yes, unique service fittings as well as different performance criteria will dictate that you use a refrigerant recovery and recycling machine dedicated to the new refrigerant. Of special note is that the machine will not recover refrigerant until it first identifies the purity of refrigerant through an integrated refrigerant identifier. If the refrigerant to be recovered does not pass the purity test, the system must be evacuated with recovery-only equipment and disposed of properly. SAE standard J2927 defines the performance criteria for the refrigerant identifier portion of the machine and SAE J2843 defines the performance criteria for the recovery-recycling portion.

Q: Will all refrigerant identifiers for HFO-1234yf be integrated into a recovery/recycling machine?

A: No, stand-alone identifiers will also be available for the new refrigerant as an independent tool to help prevent cross-contamination of refrigerants. When shopping for a compliant identifier, ensure that it shows a label stating, “Certified to meet J2912.”

Q: Can I use my current electronic leak detector to test for leaks in a system charged with HFO-1234yf?

A: No, you will need to get a new leak detector for the new refrigerant, and the detector must meet the minimum performance criteria outlined in SAE J2913. Detectors meeting this standard must bear a label stating, “Design certified by (name of testing lab) to meet SAE J2913.” You may also have an additional leak detection option in the not-too-distant future. SAE is currently working on a standard—designated as J2970 — that addresses leak detection using hydrogen-nitrogen tracer gases. This standard has not yet been finalized.

Q: What if the HFO-1234yf system I’m working on doesn’t pass a purity test according to a refrigerant identifier?

A: If you encounter a system with questionable refrigerant, it must be evacuated with recovery-only equipment and disposed of properly. Recovery-only equipment for HFO-1234yf must meet SAE standard J2851.

Q: Will we be able to retrofit R-134a systems to the new HFO-1234yf refrigerant?

A: No, it’s illegal to retrofit R-134a systems to HFO-1234yf, so this is not like the change from R-12 to R-134a. Now, here’s an interesting twist: There’s currently no regulation on the books that makes it illegal to put R-134a into systems originally filled with HFO-1234yf. So, to be clear, the feds say it’s illegal to put HFO-1234yf in R-134a systems, but there’s nothing on the books to prevent you from putting R-134a into an HFO-1234yf system. Go figure.

Remember, though, that laws change, and states and localities have the right to supersede the federal laws if they choose. Also, under no circumstances, should the two refrigerants ever be mixed and as with all refrigerants, HFO-1234yf uses different service fittings. These will be compliant with the October 2011 revision of SAE standard J2844. A system charged with HFO-1234yf will also display a unique label representing the original refrigerant fill and any cautions and warnings.

Q: When compared to R-134a systems, how different are systems that come charged with HFO-1234yf?

A: For the most part, systems filled with HFO-1234yf are substantially identical to R-134a systems. Both systems work at very similar pressures, which became an attractive trait in helping the industry choose HFO-1234yf over carbon dioxide (CO2), which requires higher pressures. Of course, HFO-1234yf must have its own fittings and service label, as is typical for each different refrigerant.

Q: Other than refrigerant, are there any other important engineering or design distinctions found in HFO-1234yf systems?

A: Yes, we’re beginning to see a large migration away from orifice tubes and cycling compressor clutches. In their place, we’re seeing an evolution towards thermostatic expansion valves (TXVs) and variable-displacement compressors.

Fuel economy is the driving force behind these changes, with manufacturers seeking optimum A/C system performance with the lowest possible engine load. There’s one key difference when it comes to servicing HFO-1234yf systems: If you need to replace the system’s evaporator, make sure that the new one bears a label stating that it meets SAE J2842, the standard addressing evaporator design criteria.

Q: Our tool dealer mentioned something to one of our techs about counterfeit and contaminated R-134a. Should we be concerned?

A: There have been confirmed reports of counterfeit/contaminated R134a cylinders appearing in some parts of the middle-east and the Mediterranean. Problem cylinders were first found in Greece. The problem has spread quickly in that part of the world, demonstrated by the fact that some U.S. military vehicles in Afghanistan have this rogue refrigerant in their A/C systems.

The affected cylinders most often contain R40, which is toxic, flammable and highly reactive when exposed to aluminum. When R40 reacts with aluminum, it forms a third, highly unstable compound that can react violently with air. Even worse, when R40 is combined and cross-contaminated with R134a, it assumes the same troubling properties as R40. The presence of R40 cannot be detected using standard pressure/temperature measurements for non-condensable gases (NCGs). To make matters worse, counterfeiting of the associated cylinder packaging is so well done that even the smallest details from legitimate packaging have been replicated. The only way to tell for sure that a cylinder is legit is to use a refrigerant identifier.

So, yes, you should be concerned and wary of anything suspicious when purchasing R-134a. A deal that’s too good to pass up may be one hint that you’re being solicited with bogus R-134a. As of this writing, none of the problem refrigerant had yet been found in the U.S., but the likelihood of it showing up will certainly increase by the time summer rolls around this year.

Q: Will servicing HFO-1234yf systems require different or additional certifications for my technicians?

A: Yes, there will be new certification provisions for Section 609 programs that you will need to meet when servicing vehicles with HFO-1234yf systems. The exact details of those provisions have not yet been determined by the EPA, but they’re likely to resemble the content and structure for R-12 and R-134a procedures. One area that will require special treatment is the fact that HFO-1234yf is mildly flammable, and must be handled accordingly. Once more, service procedures in this amended portion for Section 609 training and certification programs must be used with equipment meeting SAE standards and approved by the EPA. The EPA is expected to release guidance on the new program requirements later this year, and we’ll pass those details on when they become available.


Stay tuned to PTEN for the latest developments related to the rollout of HFO-1234yf. Indeed, this new era of A/C service certainly presents some challenges, but it also presents a wealth of new service opportunities.


Thanks for checking out this month’s Tool Q&A column. Remember, this is your column, because it’s based off your questions. So, let PTEN know what’s on your mind when it comes to tools and equipment.