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View Full Version : EPA presses for fast switch to A/C refrigerant R-1234yf



Twentyover
04-08-2009, 04:30 AM
FYI

http://www.sae.org/mags/aei/6137

If there were any doubt R-1234yf is on the fast track to be the next auto A/C refrigerant, it was dispelled at the U.S. EPA's R-1234yf Commercialization Meeting held recently in Dallas, TX, in conjunction with the Mobile Air Conditioning Society's (MACS) annual convention. The lead-off presentation—Road Map for R-1234yf Auto Air Conditioning with Federal, State, and Global Cooperation—was delivered by Dr. Stephen O. Andersen, EPA Director of Strategic Climate Projects. He made it clear that even though there is no current U.S. or state regulation, both EPA and CARB (the California Air Resources Board) want the industry to voluntarily beat or at least match the European Community's planned phase-out of R-134a. Having the session at the aftermarket-focused MACS convention gave EPA the chance to assess the service industry's readiness to make the switch.

Andersen said that the European Community's phase-out of R-134a starting in 2011 and concluding in 2017 is "slow" and that a more "rapid phase-out is certain in leadership markets. If EPA grants the California waiver related to greenhouse-gas emissions, as widely expected, it and a dozen other states [would wish to] implement quickly." His statement reinforced the position of CARB as the regulatory leader in this area.

CARB has said that it will accept four refrigerants as "environmentally superior choices." Minimally flammable R-1234yf and R-744 (carbon dioxide as a refrigerant) are the only active prospects. Three refrigerant producers, DuPont, Honeywell, and Arkema, have said they will make R-1234yf. Remaining available but with no front-line support are R-152a (a mildly flammable refrigerant) and AC-4 (a blend offered by Ineos Fluor, a European refrigerant producer).

Andersen said he expects Detroit automakers to "accelerate commercialization of R-1234yf to help satisfy green federal loan conditions." With the Obama administration looking to impose carbon trading, he said he foresees cap and trade prices for R-134a reaching $35/kg ($16/lb).

"It can be easy or hard," said Andersen in urging industry to lead on the matter of refrigerants, rather than letting government lead. "Take your pick, and [hopefully] pick industry leadership ahead of ... a patchwork of treaty, national, and local regulations ... and inconsistent standards."

The service industry reported specific progress on two fronts: equipment development; and a group of nine draft SAE International standards for equipment, components, and training by the Service Group of the SAE Interior Climate Control Committee (ICCC).

R-1234yf will be introduced with unique vehicle service valve fittings (and mating couplings for service equipment hoses) to reduce the possibility of incorrect charge and mixtures, as was done with R-134a. However, that did not prevent cross-contamination problems between R-12, R-134a, and other legal (and illegal) refrigerants, so refrigerant identifiers using infrared technology became important service testers. With a third OE refrigerant in the same pressure-temperature relationship range soon to come, the need for identification is even more important.

Peter Coll, Product Manager for automotive refrigerant identifiers at Neutronics Inc., said it would be possible to change software in identifiers made since 2004 to produce a "fingerprint" reading for R-1234yf. Once the refrigerant is in volume production, identifiers would be introduced that read out the exact percentage of the new refrigerant, plus percentages of other refrigerants and air in the system, Coll added.

Refrigerant identification will be especially important because safe, effective retrofit of R-134a systems to R-1234yf is deemed impractical. Even the retrofit of R-12 systems to R-134a, which was a comparatively simpler task, was not considered successful, said Ward Atkinson, ICCC Chair. Therefore, R-134a production would continue as needed to service the on-the-road fleet.

It may be possible to use electronic leak detectors certified to the new SAE J2791 standard. Basic tests confirm that the detectors will alarm on R-1234yf, although modifications to match their performance with R-134a may be necessary. A new SAE standard would be written to test for equivalent performance with R-1234yf.

The pressure-temperature relationship for R-1234yf is close to R-134a, but an 8% higher pressure develops if there is a 50-50 mixture in the system, such as from topping up an R-1234yf system with R-134a. If pressure gauge readings were relied on, they could lead to misdiagnosis and cross-contamination of refrigerant supply tanks. MACS President Elvis Hoffpauir said his organization would be working to develop service procedures and training for technicians to meet SAE J2845, which will cover the minimum content required for technician training to service R-1234yf, R-744, and R-152a systems.

EPA has advised the industry that like R-12 and R-134a, R-1234yf must be recovered and recycled, not vented to atmosphere. Although the basic recovery/recycle/recharge requirements for R-134a that are met by the SAE J2788 standard will apply to R-1234yf, a specific standard for R-1234yf equipment is being developed, designated SAE J2843. Manufacturers that participate in the ICCC’s Service Group have been testing proposed designs with no major issues reported, said Gary Murray, Engineering Manager, Tools & Equipment, SPX Corp.'s Robinair Brand.

The new equipment will require safety features to cover the R-1234yf flammability issue, including components that: have voltage and current limits; if exposed, will have a surface temperature limit of 405°C (761°F); and are non-arcing and/or arc-suppressed. In addition, the very small amounts of refrigerant that are vented in equipment operation (air purge, oil drain, and vacuum pump use) must be collected and directed into a garage venting system to outside air. SAE J2810, an R-134a recovery-only standard (for equipment typically used by salvage yards), is based in part on SAE J2788, and a similar one for R-1234yf, to be designated J2851, also is being developed.

Although the members of VDA (the German auto manufacturers association) remain officially committed to R-744, all other carmakers have endorsed R-1234yf. No vehicle manufacturer has made a formal announcement for any specific refrigerant, and no plants to produce R-1234yf are near completion. The move to this refrigerant is expected to take off following the SAE Congress, according to attendees at the EPA event.

There still are many regulatory issues facing both R-1234yf and R-744 at the state level (Kansas, Texas, Utah, Washington, Louisiana, North Dakota, and Oklahoma are in various stages of changing laws). Further, EPA will not have a formal proposal to allow the four fluids as A/C refrigerants until late this year, so agency approval likely will not come until 2010. It will take simultaneous development at the automotive engineering level to be able to market any new A/C system, even in small numbers, any time in 2011, with 2012 more likely the earliest for any real volume. EPA approvals for R-1234yf, R-152a, and R-744 will require some safety mitigation to prevent dangerous passenger cabin concentrations — R1234yf and R-152a for flammability and R-744 for its effect on the motorist's respiratory function.

The minimal flammability of R-1234yf is expected to lead to labeling with A2L, a forthcoming classification from the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) and ISO (International Standards Organization). A2L, when officially in effect, will be a flammability level lower than the current A2 level at which R-152a is posted.

by Paul Weissler

T_Raven
04-08-2009, 08:33 AM
Interesting, this is the first I've heard about it. Anybody know what about R-1234yf is suppose to be better or safer for the environment? And why such a long dang name? lol

86Cutlass383SR
04-08-2009, 03:00 PM
Admittedly I didn't read it word for word. I scanned through it and I'm wondering how is this going to affect our older cars. Can it be retro-fitted and what all needs to be changed. things that make you go hmmmmm........

Twentyover
04-08-2009, 04:14 PM
First, this is not an exposition on the science, or lack thereof, of global warming and mankind's impact on it. This is merely an explanation of the regulatory reasoning for shifting refrigerants

Back in olde days when we were only worried about holes in the ozone layer, the big deal was to get R12 changed out as quickly as possible. There were two characteristic values associated with molecules in play then- Ozone Depletion Potential (ODP) and Global Warming Potential (GWP). Both R12 and R134a have pretty big GWP values, but the ODP of 134a is a small fraction of R12.

Anyway, the hole in the ozone has apparently closed, keeping all the heat on the planet's surface, and we are now melting the polar icecaps (but not Detroit), so GWP is now under the microscope. Carbon dioxide has a GWP of 1, R134a about 3500, and it hangs around for a while. GWP is based on how much radiant heat a chemical absorbs, and it's decay rate, so something like water vapor, which is hugely aggressive at absorbing radiant heat, only lasts until the next rainfall, so it's time integrated GWP is relatively small. There are some chemicals that decay over generations, and even if they absorbed just a little radiant heat, they'd be doing it for a long time, so they chalk up a big number.

R134a is considered a problem because of it's value and the volume that's released annually, like every time some cell phone jabbering kid rearends another car and breeches the condenser.

Currently,there are 4 chemicals under consideration, with 1234yf and 722 the current frontrunners. 1234yf has a small problem (it is slightly flamable), and 722 has a design problem, as it uses pressures an order of magnitude higher than current systems. R722 is the industry name for- hold on- carbon dioxide

TD509EFI
04-10-2009, 07:29 AM
Greg,

Thanks for forwarding a very interesting article. I probably won't have my a/c installed and running until next year. Obviously, the 722 refrigerant wont work with R12/134a equipment and auto refrigerant systems, but have you heard anything about R-1234yf?

John

Damn True
04-10-2009, 07:54 AM
Because the R-134 transition went so well.

Twentyover
04-10-2009, 08:02 AM
509-

Responding directly to your q, no. I worked in A/C design (until a couple months ago) and we heardalot of talk, but didn't see parts like we did in the 134a adoption in the early 90's.

There are currently no plans to retrofit 134a systems w/1234yf, but plans have been known to change.

From article-
"Refrigerant identification will be especially important because safe, effective retrofit of R-134a systems to R-1234yf is deemed impractical. Even the retrofit of R-12 systems to R-134a, which was a comparatively simpler task, was not considered successful..."

Big issue will be cross contamination with other legaland illegal refrigerants. More amd more shops are adopting refrigerant analysis equipment and doing chemistry before they'll evacuate the refrigerant from your car.

I'd not worry about it at this point. OEM's will be installing 134a for the next couple years, and I doubt it will become scarce for quite a while.

TD509EFI
04-11-2009, 11:07 AM
Thanks for the clarification, don't know why I missed that excerpt in the article.

Thanks,

John

Twentyover
12-02-2009, 08:41 PM
A small update on point.

New car platforms destined for delivery in the EU will begin using R1234yf in 2011 model year. EU regulations state that by 2017 all mobile A/C must use a refrigerant with a Global Warming potential (GWP) of 12 or less.

The EPA is encouragng rapid implementation in the US by offering Green House Gas (GHG) credits. Functionally what this means is that, since the 36.5 mpg fuel economy requirements (evaluated by measuring the amount of CO2 produced, not by measuring actual fuel consumption) currently scheduled for staggered phase in between now and 2016, can be offset or bought down by reducing the generation and/or release of other GHG.

Since the GWP of R134a is about 1400 (not the 3500 I previously stated- sorry, my bad), and the GWP of R1234yf is 4, early implementation of 1234yf is encouraged because it buys them some relief on fuel mileage requirements. Other actions under consideration are further integration of fitting designs using more than a single O-Ring (some fittings currently in use use multiple O-rings. The intent is to expand the scope of this feature.)

Will these differ from current system design? Overaall, not significantly; in detail, hugely. My understanding is that it will require about 15% more heat exchanger (I think mostly on the condenser only, but i can't say for sure- my job directs my interest on the air handling components of the HVAC system); and there is study underway on coaxial liquid and suction lines, using the cool suction side gas to pull heat out of the liquid heading for the TXV or orfice tube, driving down enthalpy and increasing the amount of subcooling. Obviously TXV settings will change, and I understand compressor oil will as well.

Other than that, no significant changes will be visible

TD509EFI
12-03-2009, 09:08 PM
Thanks for the update Twentyover. Looks as if I should stuff the biggest / most efficient condenser up front and hope that it will handle future refrigerant changes!

John

Twentyover
12-04-2009, 06:57 PM
I wouldn't worry about it. R134a will be used in new cars for another 6 or 7 years, and I'd wager it will remain avaiable through at least 2035 if the R12 experience is any indication. R12, last used in production cars about 1995, is still available 15 years after new volume production stops. This is with a product that was not recycled until just a few years before cessation of volume production. I still got a couple 30 lb jugs in the garage at home.

With 134a's recycling scheme in place for 15 years, the technology to reclaim and reuse the existing stocks should easily extend the supply for the over 15 years after cessation of volume production as we have seen with R12

BonzoHansen
12-04-2009, 07:53 PM
Cool, it's only 'Minimally flammable'.

Twentyover
12-05-2009, 11:27 PM
Cool, it's only 'Minimally flammable'.


You may be surprised at some of the products being sold as drop in replacements for R12. Include, but not limited to, blends containing propane and isobutane. Not particulary legal, and you didn't hear it from me.

These may be considered more than 'minimally flammable'

BonzoHansen
12-06-2009, 05:28 AM
Oh, I've seen that. I was just amused to see the term here

Twentyover
03-02-2011, 07:10 PM
Latest update


EPA clears new refrigerant for light-vehicle A/C systems

A new air-conditioning refrigerant can now be used by automakers in new cars and light trucks to help meet federal standards for greenhouse gas emissions, the EPA said, Automotive News reported.

The chemical, HFO-1234yf, has a global-warming potential that is 99.7 percent less than the current chemical, HFC-134a, used in most car air conditioners, the agency said, the trade paper reported. The EPA is following the lead set by the European Union, which is requiring all new vehicle models sold in Europe by 2017 to use a refrigerant with low-global warming potential, the paper said.

Under federal standards approved last year, automakers can receive greenhouse-gas emission credits for 2012-2016 models by adopting a refrigerant with less climate impact, the report said. “We have been urging EPA to approve these refrigerants for several years,” said Gloria Bergquist, spokeswoman for the Alliance of Automobile Manufacturers, which represents the Detroit 3, Toyota and eight other foreign automakers. (Automotive News)