A/C Service

What Technicians Need to Know

While Opteon™YF (HFO-1234yf) closely matches the operating pressures, temperatures and characteristics of R-134a, there are key differences of which technicians need to be aware. The SAE Standard references below are applicable to North America. Please follow equivalent standards for regions outside of North America.

Key HFO-1234yf systems differences:

  • Quick connect type service ports with different dimensions versus R-134a.
  • Evaporators that meet SAE J2842.
  • Internal Heat Exchanger (IHX) is now typical. The IHX contains no moving parts and improves cooling efficiency.

HFO-1234yf service modifications:

  • Requires an SAE J2842 compliant evaporator. If there is a need to replace the evaporator, a re-built or R-134a evaporator cannot be used. This is one of the main reasons that reverse retrofits, at this time, will not be possible per regulations.
  • Requires an SAE Recovery, recycle, recharge (R/R/R) machine certified to SAE J2843.
  • Refrigerant identifier certified to SAE J2912 or J2927. Some R/R/R machines may already have this built in.
  • Refrigerant leak detector certified to SAE J2913.

Most importantly, equipment certification should be checked on the SAE mobile A/C database at macdb.sae.org.

As always, Technicians must complete an EPA-approved Section 609 Training and Certification program.

HFO-1234yf flammability:

Automotive OEMs safely use flammable fluids in vehicles today, including gasoline, diesel and brake fluid.

engine fluid flammability comparison chart

HFO-1234yf technician training requirements:

There is an SAE servicing training standard, SAE J2845. That standard requires that service training should:

  1. Include the unique characteristics of R-134a and HFO-1234yf refrigerant
  2. Provide technician information on how to:
    • Recognize which refrigerant is used
    • Handle each refrigerant safely
    • Determine proper equipment and tools for each refrigerant

Therefore, automotive A/C service technicians should look for training that meets SAE J2845

HFO-1234yf legal considerations:

Using R-134a in any system originally equipped with HFO-1234yf is illegal, according to David Cappert, Automotive Service Excellence (ASE) Executive Director of Special Projects.

In fact, using any refrigerant other than HFO-1234yf in an HFO-1234yf system may constitute emissions tampering if the manufacturer counts air conditioning credits (use of HFO-1234yf) towards U.S. light-duty, greenhouse gas (LD GHG) compliance.

Read our Opteon™ YF FAQs to learn more >