Compared to other areas of automotive technology, A/C used to be one area that changed little. R-12 had been around since the beginning of automotive A/C, but that quickly became history once scientific evidence began to spread about the ozone hole. Since then, A/C service has undergone non-stop change, with most of it tied to regulatory changes.
For 2007, the crusade of changes continues as new forces drive what happens in the service bay. Here's a look at the not-too-distant future of A/C service.
New standard for recovery/recycling A/C equipment
Section 609 regulations established by the EPA include the basic framework for what must be covered in technician "certification" programs, which essentially include a training and test component on required knowledge to minimize the release of refrigerant. These regulations also spell out the requirements for equipment qualifications. Much of this framework comes from various standards published by the Society of Automotive Engineers. This all boils down to the fact that technicians must perform established procedures in a given way with equipment meeting certain performance criteria.
The new SAE standard J2788, released in December 2006, impacts R-134a recovery/recycling/recharging equipment. The standard ups the ante considerably for this type of equipment, previously established in SAE J2210. The old standard specified pulling a vacuum to 102mm (4" Hg). The new standard far exceeds that by requiring equipment to remove 95 percent of the refrigerant in 30 minutes or less from a 2005 Chevrolet Suburban with front and rear A/C and a refrigerant capacity of 3lbs.
J2788 also requires that the amount of refrigerant removed be accurate to within 1oz. of what's shown on the machine's display. The equipment must also be able to fill the system to within 0.5oz. of the factory-specified charge level. There are many other parameters of J2788, but all together the enhanced performance criteria means that any equipment meeting this new standard will do the job faster and with much more accuracy.
"We are aware of the new SAE J2788 standard and understand this new standard will supersede the current J2210 recovery/recycling standard effective December 2007," wrote Drusilla Husford, director of the Stratospheric Protection Division of the EPA, in a March 15, 2007, letter. "We anticipate publishing a regulation in the Federal Register updating our reference to J2788. This regulation will address machines submitted for EPA approval."
The adoption of J2788 doesn't make your equipment useless because it meets the old standard. Even newer machines that meet J2210 do a better job than older ones. What it does mean is that if you're in the market for a new machine, it would be worthwhile to get one that meets J2788 because of the better performance. (There are already some J2788-compliant machines on the street.)
New find in leak detection
SAE published another new standard related to A/C service in January, encompassing performance criteria for the sensitivity of electronic leak detectors used to find R-134a "leaks." Known as J2791, the new standard includes sensitivity (including in a contaminated environment) and durability in its criteria.
J2791 surpasses the performance of J1627 standard for electronic leak detectors. For instance, J1627-compliant leak detectors could sense a leak at the rate of 0.5oz./year, with the sensing probe 1/4" from the actual leak. J2791-compliant leak detectors can identify a leak at the rate of 0.15oz./year, with the sensing probe 3/8" from the actual leak — a marked improvement in sensitivity. (The procedure for properly using an electronic leak detector is covered in SAE J1628, which came out some years back, and specifies the movement rate for the probe among other things.)
As with recovery/recycling equipment, it's wise to look for a leak detector that meets the newer standard. Shop around.
System charge levels
Over the years, system charge levels have been dropping, making them more sensitive to leaks and improper charging. Unlike the old days of say, 3lbs. systems, many of today's systems only hold around 1lbs. refrigerant. While their engineering is sound from a technical perspective, they don't have much margin for error when the refrigerant charge goes awry. This factor was key in the new standards for recovery/recycling equipment and electronic leak detectors.
Refrigerants – Where to next?
OK, so we made the move from R-12 to R-134a. It eliminated the harmful chlorine component that erodes the ozone layer, but now there's a growing concern about greenhouse gases. R-134a is a greenhouse gas with 1,300 times the global warming potential of carbon dioxide. Manufacturers of R-134a systems will likely be under increasing pressure to change to something else. Europe was looking heavily at using carbon dioxide as a refrigerant, but may have changed course now that some other refrigerants are available for review. Europe plans to eliminate R-134a in light-duty vehicles by 2017, so what happens there may eventually influence what happens here.
The world of A/C service will continue to bring change and new challenges. Stay tuned to PTEN for new details as they unfold.