It seems like the world of mobile air conditioning just gets settled into a routine, and all of a sudden a new upstart threatens to change everything again.And so it is with HFO-1234yf, the new refrigerant formula that is safer for the...
It seems like the world of mobile air conditioning just gets settled into a routine, and all of a sudden a new upstart threatens to change everything again. And so it is with HFO-1234yf, the new refrigerant formula that is safer for the environment, and soon to begin making its way through the service channels. While there were many who believed that the new refrigerant might never find its way to North American vehicles in operation, its recent approval by the U.S. Environmental Protection Agency (in February), and the coming equivalent approvals for import and sale in the offing for Canada, indicate that those doubts should evaporate as fast as Freon on a summer’s day. Be prepared for many players and suppliers who have been waiting in the wings for the approvals, and for its installed base to grow, to begin calling on the trade with 1234yf-related offerings. The last time the industry had a shift approximating the enormity of this one was more than 15 years ago, when R-134a come in to supplant R-12, the formula that had served as the refrigerant of choice for vehicle air conditioning systems from the outset. The move to HFO-1234yf is different, though. “We like to put HFO in front to distinguish it from the HFCs,” says Ken Horen, global commercial development manager with Honeywell Specialty Materials, which developed the HFO-1234yf refrigerant together with DuPont. The product’s hydrofluoroolefin (HFO) chemistry is what gives it a big advantage in environmental terms over HFCs (hydrofluorocarbons) like 134a. (R-12, or Freon, was a CFC (chlorofluorocarbon), and was banned due to its ozone-eating qualities.) “The switch from R-12 to R-134a was due to the ozone-depleting potential (ODP) of R-12, and it also had a large reduction of global warming potential (GWP) between the two refrigerants. It was a good intermediate step.” That last statement may rankle those in the service business who thought that the move to R-134a was the endgame. However, says Horen, the move to 1234yf (pronounced “twelve-thirty-four-yf”) represents a 99.7% reduction in GWP over 134a; while HFO-1234yf rings in with a GWP of 4, 134a tips the scales at a comparatively astounding 1430. “What really got the auto OEMs interested in it was an EU directive in 2006 that said, in January 1, 2011, if you go for a new approval, it has to have a refrigerant with a GWP of less than 150. And for the past four years we have been working with the automotive OEMs to try to develop the best solution.” For a time, a number of different alternatives were being considered, but Horen says they didn’t want to take an intermediate step; also, some of the options had other issues to contend with. “When you look at competing technologies, we had R-152 with a GWP at around 140, and CO2 at 1.” He adds that despite the fact that R-152 is approved for use under the U.S. Significant New Alternatives Policy, flammability concerns would require additional precautions in system design such as a secondary loop, which would add cost. System cost factors also made CO2 a tough pill to swallow. It is true, he points out, that HFO-1234yf is technically flammable but to only a very small degree, and extensive crash testing has not revealed any tendency to ignite. CO2 was being considered for a time, but several factors stood in its way. “A CO2 system has more components and is harder to package under a hood, with its high pressure, higher power requirements, and noise. And the fact that you are dealing with higher pressure [means] the expense for recovery equipment goes up.” It is notable that a frontline group representing German automakers, the VDA, had pushed hard for the support of CO2 back in 2007, but has since recanted and thrown its support behind the Honeywell/DuPont alternative. In the end, 1234yf, with its GWP of 4, was judged to be the safest, easiest-to-integrate option that would still deliver on the EU promise for the long term. So where to from here? While the EU rule puts HFO-1234 in new models being introduced now-and all new cars as of 2017-the U.S. is taking a different approach. In the U.S., adoption will be driven by a set of incentives put in place by the government, and naturally those models that have 1234yf installed in the U.S. will end up similarly equipped for the Canadian market. All of which means we could begin seeing 1234yf-equipped vehicles on our roads by this fall, possibly sooner. “Initially it will be in new vehicles, so we believe the initial service will be under warranty as well as collision shops,” says Horen. From a service standpoint, much will appear the same to the untrained eye; this was, after all, a key point in choosing the refrigerant as an alternative. However, there are important differences, even if they are subtle, as follows:
Labelling: This is the first thing that a tech might notice.
Connectors: Unique connectors will be installed on systems using HFO-1234yf, designed to prevent inadvertent mixing of refrigerants.
Components: Very few changes to the architecture of the A/C system, though some cars change the TXV setting, use either a larger-diameter suction line, or an internal heat exchanger.
Lubricant: Some applications will require a different lubricant, though this is possibly not always the case.
Equipment: While recovery and recycling equipment may look similar (and it is), the new refrigerant will require a separate setup to avoid mixing as well as have the right connectors.
Identifiers: While the existing refrigerant identifier should be able to detect HFO-1234yf as a refrigerant that is not 134a, it wouldn’t be able to tell you that it is HFO-1234yf, so it’s advisable to pony up for an identifier that can.
Refrigerant Cost: Costs for the refrigerant are expected to be higher than 134a.
In service, it appears that the temperature pressure values exhibited by HFO-1234yf very closely parallel those of HFC-134a. There is just a slight increase in the pressure at higher temperatures, but technicians should see the same temperature-pressure performance they are used to seeing. Looking ahead, only General Motors has formally announced that it will adopt the refrigerant, in 2013 MY Chevrolet, Buick, GMC, and Cadillac models expected to hit the streets in 2012. Models may show up in service bays sooner, however, if European automakers, seeking to make good on their EU commitment, bring those systems to North America. In any case, it is advisable for shops, and the jobbers who supply them, to start getting their suppliers lined up for the new refrigerant and the equipment required to service systems using it, because while there are some variables regarding timing that are still to be nailed down, 1234yf is coming to a service bay near you and it is good practice to be prepared when it arrives.