Dallas--With a European phase-out of the current automotive refrigerant, HFC-134a, scheduled to begin in 2011, the global auto industry has yet to decide on its replacement.
Dr. Stephen Andersen, architect of the R-12 phase-out in the late ’80s and now director of Strategic Climate Projects at the U.S. Environmental Protection Agency, hosted a meeting at the Hilton Anatole, site of the 2009 convention of the Mobile Air Conditioning Society Worldwide (MACSW), to discuss the commercialization of HFO-1234yf, one of the two leading contenders to be used as the replacement for HFC-134a.
Auto industry technologists are sparring over which refrigerant or refrigerants to use, Andersen told the 160 representatives of OEMs, chemical companies, automotive associations, educators, researchers, tool and equipment makers, and consultants. In addition to the protection of the planet from the global warming effects of 134a, millions of dollars and euros for equipment and parts will ride on what gas or gases will be accepted for the next-generation refrigerant.
HFC-134a was developed as an alternative for R-12 in 1996. Now because 134a is listed as damaging to the ozone layer and a contributor to global warming, Anderson said it will be eliminated by law in new-car use by the European Union (EU) beginning in 2011.
Two camps have emerged, Andersen said. The first can be characterized as the CO2 (known by its refrigerant designation as R-744) camp, and it includes the German Association of the Automotive Industry (VDA) and some suppliers.
The second is the HFO-1234yf camp that claims as supporters automakers and their suppliers, which have 70 percent of the global auto market. In the middle and playing all sides are a number of engineering, tool, consulting, and processing companies that care eager to work with either or both refrigerants, Anderson said.
Further clouding the issue is that one other refrigerant has been recently re-introduced for consideration, he added.
In the past, the transportation OEMs and their suppliers cooperated and agreed on a single refrigerant for the obvious advantages of reducing cost and complexity. Now, the global transportation industry wrestles with the very real possibility that it will have to deal with two refrigerants, Andersen said.
More distressing is the fact that neither of them would be interchangeable with the other, he said. The vehicle air-conditioning systems in which each of the refrigerants would be used have different operating pressures and essentially function differently enough that HFO-1234yf could not be a substitute for R-744. The reverse is true as well.
In opening the meeting, Andersen said the refrigerant of the future was a matter of choice. “Choose it yourself or someone will.”
Although both R-744 and HFO-1234yf offer great advantages in environmental protection over R-134a, each has unique qualities and both face more challenges. R-744 is said to be well-suited for use in mild climates and has a very low Global Warming Potential (GWP) of 1, Andersen said.
Critics of R-744 say there are several challenges facing the adoption of CO2 systems, including a required A/C system redesign, the need for higher operating pressures, cost, and toxicity.
Additional concerns exist about fuel efficiency and cooling for passenger cars, he said.
According to the SAE International Web site, the Global Warming Potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. GWP is calculated as the ratio that would result from the emissions of one kilogram of a greenhouse gas to that from emissions of one kilogram of carbon dioxide over 100 years. GWP is based on a relative scale with the unit for CO2 by definition as one.
HFO-1234yf is said to be a near drop-in for direct, expansion mobile A/C systems in current use. Its system operating pressures are similar to R-134a systems. However, critics point out that HFO-1234yf is mildly flammable, is likely to have a higher refrigerant cost, and is not now available in commercial quantities. Although not as low as R-744, R-1234yf does have a low GWP of 4.
With a deadline approaching and the future of refrigerant up in the air, the transportation industry and regulators have been trying ease the transition by developing standards for R-744 and HFO-1234yf, Andersen said.
The Interior Climate Control Committee of SAE International has 16 new standards in place and two revisions in process.
The standards cover service equipment, recovery and charging, service hoses and fittings, leak detection equipment, trace dyes, technician training and certification, certified new and replacement evaporators; refrigerant purity, measurement of concentrations in passenger compartments, and system component design requirements.
Regardless of the choice of refrigerants, these standards will have an impact on the tools, procedures, parts, training, and certifications required to service automotive air-conditioning systems.
The auto industry is hedging its bets by developing equipment, parts, and standards for both HFO-1234yf and R-744 systems. There are five new standards for HFO-1234yf, four new documents common to HFO-1234yf and R-744, one revised standard for all refrigerants, and six new documents for R-744.
Andersen told the Dallas audience that for HFO-1234yf to move forward in the United States, it will require broad industry support and cooperation. He said the automakers would need to accelerate the commercialization to help satisfy green federal loan conditions.
He urged OEMs, SDOs (standards developing organizations), government partnerships, and suppliers to continue to cooperate on optimizing systems and service procedures.
Andersen said the way forward can be easy or hard. Easy would mean industry leadership ahead of regulation, a global HFO-1234yf transition, and SAE testing and standards. Hard would be a patchwork of treaty, national, and local regulations, each market with a favored refrigerant, trade barriers, and the chaos of inconsistent standards, he warned.
