|Automotive Air Conditioner - Refrigerants|
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Manufacturers have worked day and night to develop effective alternatives to R-12 that provide efficient cooling with little or no environmental side-effects. Based on the results of extensive research, HFC-134a, commonly known as R-134a, has been chosen as the next refrigerant by consensus within the industry. Hence, car makers are moving ahead swiftly with the use of R-134a. It's estimated that roughly 90% of the 1994 new car and truck fleet will use the new refrigerant. Just a few days before this went to press, Chrysler announced it will use R-134a exclusively in all its new vehicles by January 1, 1994 - two years ahead of the mandate enacted by the Federal Government. Ronald R. Boltz, Chrysler's Vice President of Product Strategy and Regulatory Affairs, remarked, "We've moved as aggressively as possible in removing R-12 from our product line and we believe our rapid deployment of air conditioning systems using R-134a is in the best interest of our consumers and the environment."
In spite of the environmental advantages that R-134a offers, it does have some drawbacks. It is less efficient than R-12, so R134a requires higher operating pressures and larger system components to compensate for the penalty in performance. R134a is also incompatible with R-12, so the two refrigerants should never be mixed. Furthermore, even though R134a is less likely to affect the ozone layer, the new refrigerant still has the capability of contributing to the greenhouse effect (global warming) when released into the air. Consequently, the recovery and recycling of R-134a becomes mandatory on November 15, 1995. In spite of this deadline, it's likely that you may be involved with R134a recovery and recycling somewhat sooner because of this refrigerant's high initial cost and more stringent local regulations.
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A critical portion of the retrofitting procedure involves evacuation of the A/C system. We found that some controversy exists regarding how, and for how long the system should be evacuated. According to SAE J1661, "...evacuate the air conditioning system for a minimum of 30 minutes to remove air and trace R-12 from the system...." The verbiage continues, noting that some manufacturers may require a longer evacuation period for their systems.
According to Simon Oulouhojian, President and Chief Operating Officer of the Mobile Air Conditioning Society (MACS), "J1661 encompasses the collective knowledge of industry experts, many of them at the original equipment manufacturers' level. It's difficult to dispute the findings of such a panel, especially when you consider what they have at stake."
D. Wayne Strout, President and Chief Executive Officer of Refrigerant Technologies, Inc. (RTI), disagrees with the evacuation procedure advocated by SAE and MACS. Strout recommends that the system be evacuated for one hour, then filled with an initial charge of R134a. Next, he recommends running the system, then recovering and recycling the entire fill of refrigerant before charging it into the system once more. This final step, he believes, emulates flushing to remove any residual mineral oil that may have mixed with the ester or PAG oil.
On that note, we'd like to mention a breakthrough in refrigerant oil specifically formulated as a retrofit lubricant. Castrol's Icematic Retro 100 has a unique formula that's compatible with both R-12 and R-134a. Up until now, the refrigerants required mineral (R-12) and PAG or ester (R-134a) oils, which couldn't be mixed. This product promises to make retrofitting less of a headache. MACS estimates the cost of retrofitting older A/C systems will be approximately to , depending on the condition of the system and the age of the vehicle. It's likely that the cost of retrofitting will increase accordingly with a car's age. Since 80 to 100 million vehicles are estimated for retrofit by the year 2000, you may want to look into this flourishing area of A/C service as a new profit center.
As we went to press, Ward Atkinson, MACS technical advisor, advised PTEN that another SAE standard was on the ballot regarding the standardization of retrofit fittings. According to Atkinson, "Some fittings currently on the market may not open when required and others may stick open after service equipment is removed. We're finding that a stack-up of tolerances is often the cause, because many of the internal dimensions are really not specified in any current standard."
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When shopping for a machine, check to see if it's approved by the EPA. In the past, some machines carried a UL label, implying that they were EPA-approved, but really weren't. The label merely meant that one or more internal components, like a transformer, may have passed a UL test. To avoid confusion when shopping, look for verbiage such as "Design certified by (testing organization) for compliance with SAE-J (applicable standard number)." That way you can be sure the equipment you're buying is up to the task.
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The equipment used for the recovery-only of R-12 does not have the capability to recycle refrigerant or recharge a system. The SAE standard addressing recovery-only equipment states, "The equipment discharge or transfer fitting shall be unique to prevent the unintentional use of extracted (recovered) R-12 to be used for recharging auto air conditioners." Recovery-only equipment must also be EPA-approved.
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The second standard released by SAE addressing leak detection, SAE J1628, involves the procedure for use of a detector meeting the first standard. Among other things, the standard defines the rate of movement for the detector's probe, a critical part of finding leaks. Currently, no standards exist regarding gas leak detectors, because they can't "sniff" R-134a and the previously-mentioned standards address R-12, R-22 and R-134a.
There are no standards currently available on leak-tracing dyes. That's because an equivalency for dye-indicated leaks and electronically-sensed leaks couldn't be determined at the time the previous SAE standards were adopted. It's only a matter of time, however, because SAE is currently working to provide guidance on the use of leak-tracing dyes.
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The opposite end of low-and high-side R-134a service hoses can connect directly to a quick-coupler that connects to the vehicle, or an optional M14 x 1.5 fitting can be used between the hose and quick coupler. Unlike R-12 systems, which typically use threaded service fittings for the high and low sides, R-134a systems use quick-coupler fittings without external threads. To ensure proper connection of service hoses, the high-side fitting has a 16.0 mm O.D. and the low-side fitting has a 13.0 mm O.D.
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Typically, a cross-charged system will perform poorly and suffer damage from chemical breakdown and lubrication problems. Should a recovery/recycling machine be connected to a cross-contaminated system, the machine will have to be cleaned out completely, including replacement of major components like filters and dryers. Furthermore, if a contaminated machine is connected to other A/C systems before the problem is discovered, those systems, too, will become infected.
Presently, cross-charging is difficult to detect on-site. Leak detectors using current technology provide unreliable results when sniffing mixed refrigerants. Although the only exacting way to assess a refrigerant is by sending it to a lab. Robinair is currently working on some affordable testers that will be capable of determining the type of refrigerant right for your shop.
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Also recognizing the importance of such a campaign, the National Automotive Dealers Association (NADA) issued a press release with a "don't blame the dealer" theme. The release was a direct response to consumer alarm over how much the price of A/C service had risen.
The business of servicing automotive air conditioning systems will continue to change as R-134a gradually becomes the most widely used refrigerant. This doesn't mean, however, that recovery and recycling will end once R-12 is no longer produced. The remaining supply will have to be conserved with diligence, a responsibility that both you and the environment can benefit from.
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If you have any questions regarding the CFC program requirements call EPA toll-free at 1-800-296-1996.
Repair dealers may wish to consult their local air pollution control districts, air quality management districts, city or county governments to determine if there are local CFC regulations that also affect their businesses. The following districts and cities have adopted CFC rules that may differ from those adopted by the EPA:
The following districts and cities have proposed CFC rules that may also differ from those adopted by the EPA:
Some states have also passed "can ban" legislation of their own that outlaws or restricts the sale of the small cans to professionals as well as do-it-yourselfers. Check with state officials for what applies in your area. Keeping current on local mandates is important.
Such laws do not necessarily mean do-it-yourselfers will no longer be able to buy refrigerant to recharge their own A/C systems. A loophole in the federal law still permits the sale of the small cans of refrigerant that contain dye for leak detection purposes.
As the deadline approaches, here is what will happen; most retail parts stores will probably dispose of their existing inventories of R-12 refrigerant to effectively prevent the sale of small cans to noncertified professionals. Traditional parts stores will likely move their R-12 cans to the back shelf and sell it by request only to their professional clientele (who usually buy 30 pound bulk containers anyway).
The new restrictions are a result of the new Clean Air Act that became a law back in November 1990. To reduce the amount of CFCs that are being released into the atmosphere, Congress decided to:
By making R-12 unavailable to the general public, people will be forced to take their cars to a professional for service. The professional, in turn, will find and fix their leaks before recharging their A/C system with refrigerant, recover and recycle their old refrigerant, and save the ozone from destruction.
Here is what is happening today. Mechanics are getting certified in huge numbers and shops are buying and using the required recovery/recycling equipment. R-12 production will end in this country by the end of 1995, but it will probably continue to be produced in Third World countries, which may lead to a black market in R-12.
Car makers are starting to phase in the new generation of A/C systems using ozone friendly (and expensive) R-134a refrigerant. Everybody is wondering what will happen to the market price of R-12 as supplies dwindle and there are no direct drop-in substitutes available. Several under development do not yet have industry approval.
R-134a cannot be used in place of R-12 in existing A/C systems without expensive modifications. Compressor oils that the two different refrigerants use are totally incompatible. An R-12 system would have to be thoroughly cleaned prior to converting to R-134a. Different pressure switches would also be required and possibly different hoses and other parts.