Wow, what a year we all just had! In February of last year in the mobile A/C world, we had just come off one of our most successful annual events (the MACS 2020 Training Event and Trade Show was held last year at Nashville’s Gaylord Opryland Resort), and then two weeks later COVID-19 happened! Like you we’ve had to adjust for the health and safety of our industry and our MACS members, and one of the biggest changes we made this year was to postpone our 2021 event until September 30 (we’re still going to the Rosen Centre in Orlando).
New year, new MACS!
During the last year or so, the MACS Board of Directors, along with key staff, have been working on a rebranding project to bring MACS into its next 40 years. No longer will we be the Mobile Air Conditioning Society. Rather, we are now the Mobile Air Climate Systems Association (MACS) – a better reflection of the whole of our efforts as system technology experts and as an inclusive organization dedicated to advancing the next generation of professionals (Figure 1). Our tagline, “Cooling What Moves You,” encapsulates mobility and speaks directly to climate control in a short, memorable statement. Our new website is www.macsmobileairclimate.org. Check it out to learn more about the new MACS!
Regulatory update
Let’s begin with an update on EPA’s MVAC servicing program (motor vehicle air conditioners), which falls under Section 609 of the U.S. Clean Air Act (CAA). In March 2020, the EPA issued a proposed rule to incorporate by reference three existing SAE Standards for R-1234yf servicing equipment. The Standards are:
SAE J2843: R-1234yf (HFO-1234yf) Recovery/Recycling/Recharging Equipment for Flammable Refrigerants for Mobile Air Conditioning Systems (Figure 2)
SAE J2851: Recovery Equipment for Contaminated R-134a or R-1234yf Refrigerant from Mobile Automotive Air Conditioning Systems (Figure 3)
SAE J3030: Automotive Refrigerant Recovery/Recycling/Recharging Equipment Intended for use with Both R-1234yf and R-134a (Figure 4)
Since the establishment of the 609 program back in 1990, the EPA has adopted various SAE Standards for the servicing equipment that we use out in the shop each day. Now that we've had R-1234yf ("yf") for so long, it's funny to think that there has been no "regulatory requirement" in place, which says that we are "required" to use yf equipment to service yf vehicles. That may sound like a no-brainer (of course you have to use a yf machine to service a yf vehicle), but up until now, there was no specific rule or requirement for technicians and shops to do so.
Even though there was no rule per se, you were still not allowed to use (for example) an R-134a machine or an R-12 machine, to service an R-1234yf vehicle. The existing rules that have already been in place say that you must use an approved machine that’s design certified for a particular refrigerant to service that particular refrigerant in a vehicle. So, if one should ask, “Can’t I just take my old R-134a machine and convert it over to work with R-1234yf?” the answer would be no, because even if it could work (which would not be recommended due to the lack of yf safety considerations in R-134a equipment), that R-134a machine was originally designed and certified to work with R-134a, and not R-1234yf. This distinction makes converting an older machine illegal.
In the end, this new EPA rule just makes it a requirement to do what we are already doing: use equipment designed and certified for a particular refrigerant to service that particular refrigerant (and don’t mix them up!). The official rule was signed on 1/11/2021.
Turning to the SNAP rules
Most of the refrigerant regulations that pertain to MVACs are part of the EPA’s SNAP (Significant New Alternatives Policy) Program. Over the years, the EPA has issued new rules, and we’re going to cover one of them here. Rule #20 was issued in July 2015, which changed the listing status of certain HFC (hydrofluorocarbon) and HFC-blend refrigerants from acceptable to unacceptable in some refrigerant, aerosol, and foam blowing uses. In our case, the EPA's rule said that beginning with the 2021 model year, vehicle manufacturers would not be allowed to use R-134a refrigerant in new light-duty passenger vehicles. The EPA was sued in federal court over this, and in August 2017 the DC Circuit Court of Appeals vacated their 2015 Rule, “to the extent it requires manufacturers to replace HFCs”, and remanded it back to the EPA. In April 2019, the court issued a similar ruling for EPA’s 2016 rule.
We’ve been expecting to find out what the EPA plans to do about this, but to date, we haven’t heard much. There was talk of a revision last year, but then COVID-19 happened, and at our last fall update we received no new information. But it may be a moot point at this time. The purpose of that 2015 rule appeared to be aimed at nudging the industry away from using high GWP (global warming potential) refrigerants, and instead towards more environmentally friendly ones like R-1234yf. A recent MACS study calculated that approximately 83 percent of new model vehicles are being manufactured with yf, and while we haven’t been able to conduct our annual survey yet for 2021 (the auto shows have either been canceled or pushed off until the end of the year), we expect those numbers to be even higher this year.
Off-road yf
EPA continues to get submissions under SNAP for the use of R-1234yf in various MVAC applications. Two recent submissions were for the use of yf in small cans for DIY use (which is why you’ve probably seen small cans of the new refrigerant available for sale at many auto parts stores). They also received five submissions for the use of R-1234yf in heavy-duty MVAC, including off-road construction and agricultural equipment (Figure 5). These include agricultural tractors under 40HP, self-propelled agricultural machinery, compact equipment (like skid steers), construction, forestry, and mining equipment. Reviews for these submissions have now been completed, and manufacturers can begin using yf in these systems. To date, however, EPA has not received a submission for yf in busses or trains, nor heavy-duty, on-road trucks (Class 4 through 8, including over-the-road trucks and tractor trailers). Thus, using R-1234yf in these vehicles is not allowed.
Safety alert: Small cans for MVAC servicing
The EPA has been made aware of online sales of a product marketed for use in MVACs which has not been approved under SNAP. Specifically, a product marketed as “Cool Penguin F-12” brings forth safety concerns, as its use may pose a safety risk. It’s primarily because they don’t know the chemical makeup of the various cans (Figure 6). Certain cans tested by the EPA were found to contain a mixture of ozone-depleting substances (ODS), such as CFC-12, CFC-114, HCFC-142b, and HCFC-22, along with non-ODS, including R-134a and R-40 (Methyl Chloride). These cans have a variety of substances that may or may not be flammable or toxic, so EPA wants to notify the public about the risks associated with these cans if used to service their MVAC systems. Under current CAA regulations, it is illegal to import cans containing any percent of the ODS listed above into the United States. No person may sell or distribute, or offer for sale or distribution, any regulated ODS that they know, or have reason to know, was imported illegally. There is also a growing concern about small cans of hydrocarbon refrigerants, such as propane, which are highly flammable and are not acceptable alternatives for MVACs. EPA wants to get the message out that these cans should not be used for MVAC servicing.
2020 ozone layer protection milestones
EPA has been running a new website that highlights the many achievements and projects made possible because of Title 6 of the U.S. Clean Air Act, which focuses on Stratospheric Ozone Protection (and in our case, motor vehicle air conditioning servicing (Figure 7). They even have a special section dedicated to celebrating the MVAC servicing program under Section 609, so if you have a chance to check it out, here’s a link: https://www.epa.gov/ozone-layer-protection-milestones-clean-air-act. There’s also an interactive webpage where users can explore how ozone layer protection affects many aspects of everyday life. https://www.epa.gov/ozone-layer-protection-milestones-clean-air-act/strat-city-usa
Celebrating the CAAA’s 30th anniversary
It was 2:30 in the afternoon on Friday, November 15, 1990, when politicians and the media met in the East Room at the White House to greet President George H. W. Bush just moments before he would sign the most comprehensive update to our nation’s environmental laws in 30 years. Of course, I’m talking about the Clean Air Act Amendments of 1990, which received overwhelming bipartisan support. Specifically, the amendments were designed to curb four major threats to the environment and public health: acid rain, urban air pollution, toxic air emissions, and stratospheric ozone depletion. The amendments also established a national operating permits program and strengthened enforcement. They featured several progressive and creative new approaches for effectively achieving the air quality goals and regulatory reform expected from these far-reaching amendments. A summary of EPA documents explains.
Air quality
• Air quality has improved significantly in our nation, reducing health threats such as lung damage, asthma, heart attacks, and premature death. All 41 areas that had unhealthy levels of carbon monoxide pollution in 1991 now have levels that meet the health-based national air quality standard. More than 90 percent of areas originally identified as not meeting the 1997 ozone air quality standards now meet those standards. Since 1990, particle pollution levels have improved by 36 percent.
• Performance standards for new vehicles are met by a combination of cleaner fuels and vehicle technologies. Under the 1990 amendments, new cars, SUVs and pickup trucks, heavy-duty trucks, and buses have become dramatically cleaner. The same is true of non-road engines such as those used in industrial, farm, and recreational equipment, locomotives, and marine vessels.
• State and EPA programs to cut interstate air pollution have reduced pollution regionally and have helped most downwind areas to meet the 1997 and 2006 air quality standards for ozone and fine particles.
Acid rain and regional haze
• An innovative market-based system of pollution allowances has dramatically cut sulfur dioxide emissions, reducing acid rain as well as fine particle pollution that contributes to premature death. This federal program also has significantly reduced damage to water quality in lakes and streams and improved the health of ecosystems and forests.
• Also, the scenic vistas in our national parks are clearer due to reductions in pollution caused by haze.
Toxic air pollution
• Industrial and other stationary sources emit about 1.5 million tons less toxic air pollution per year than in 1990. These standards set a level playing field by requiring higher emitting sources to achieve the cleaner level of performance achieved by the best performing similar sources.
Ozone layer protection
• To protect the ozone layer, the U.S. has phased out the ozone-depleting substances that Congress identified as "most damaging," including CFCs (in our case, R-12 refrigerant) and halons while promoting cost-effective alternatives. Actions to protect the ozone layer are saving millions of people from fatal skin cancers and eye cataracts over periods of several decades (Figure 8).
A peer-reviewed EPA study found that the 1990 Amendments are achieving large health benefits that will grow further over time. For example, the study estimates that in 2020, the Clean Air Act Amendments will avoid more than 230,000 early deaths, as well as large numbers of other adverse health effects, through improvements in fine particles and ozone levels. The economic value of the air quality improvements is estimated to reach almost $2 trillion for 2021, a value that vastly exceeds the costs of efforts to comply with the 1990 Clean Air Act. Although important air pollution challenges remain, and we have much work left to do, the 1990 Amendments have had impressive results.
Electric yf
Let’s take a closer look at what’s happening with R-1234yf in hybrid and battery electric vehicles (BEVs). We surveyed almost 180 vehicles at the 2020 Philadelphia Auto Show, and more than 75 percent of them use yf. Twelve of those were either hybrids or full battery electric vehicles, all of which use an electric compressor (Figure 9). Of those twelve, eight systems use R-1234yf, which comes out to about 67 percent.
Looking at those which are still using R-134a, we find Volvo's XC60 and XC90 T8 hybrids, Hyundai's Loniq hybrid, and the iconic Toyota Prius. All of these have been around for a while (Prius since 1997, XC60 and Loniq since 2016, and XC90 since 2017), and so they were developed at a time when R-134a was still mainstream. Now we're in the fourth generation of Toyota's Prius family, and going by their history, we should see a new generation in either 2021 or 2022 (their gens usually last six or seven years on average). We're expecting with the next iteration we'll see the most popular green vehicle finally change to yf. The same goes for Loniq and the Volvos — as their platforms advance, we expect them to also use yf going forward.
Just as a side note, some of these electric A/C systems are getting feature-rich. Take the XC60 for example. It uses what they call a "preconditioning" algorithm that can prepare the cabin climate with a few simple settings in the dashboard screen or an app that you can install on your smartphone (Figure 10). It can use direct start or be set via a timer, and the function uses several systems in different cases. When it’s cold outside, the parking heater can warm up the cabin to a comfortable temperature, and when it’s hot, it switches to A/C cooling. You can also select activation of the steering wheel heater and heated seats. The heated windows and mirrors are activated automatically. Preconditioning for heating is only available when the vehicle is plugged in, but the A/C can work anytime.
Electric compressor oil
Since these systems are using electric compressors, you might expect them to also use POE (polyol ester) oil (since we’ve been taught for years now that PAG + motor windings = no good), but you’d be wrong about that. The main concern we’ve had with oil and electric compressors is that even minute traces of PAG oil (as little as one percent) can contaminate the system to the point where it won’t work — or worse, you run the risk of electric shock or even death. The reason of course is that PAG (polyalkylene glycol) oil is hygroscopic, which means that it absorbs moisture, sometimes right out of the air. And if it were to be mixed into an electric A/C system, the moisture it could contain may be enough to provide an electrical path from the compressor's motor windings to the ground.
Depending on the system you’re working on, the vehicle’s PCM may detect this electrical leakage and report it through the check engine light with an associated trouble code(s), along with disabling the high voltage compressor system. The 2013 Toyota Prius for example will output DTC P0AA6-611 (Hybrid Battery Voltage System Isolation Fault) if there is insulation trouble with the high voltage circuits in the A/C system. This code may indicate a problem with either the compressor or the HVAC inverter, but can also show up if any oil other than ND-OIL 11 is used (Figure 11). Their service information also says that, if it can be confirmed that any oil other than ND-OIL 11 has been used in the vehicle, “replace the air conditioning cycle” (which is a mistranslation that means “replace the air conditioning system”).
That may sound far out, but you have to think about it from an OEM point of view. Their premise is that even 1 percent contamination can cause a problem. So, in a system like the 2013 Prius, which calls for 4.4-4.9 ounces of oil, one percent is about 0.05 ounces. So that's, what — maybe a few drops? It's about the amount you'd get out of a glass medicine dropper (Figure 12). I use the ones pictured for putting mineral oil onto O-ring seals that call for it, and they can hold 0.03 ounces. Not much more than that is enough to contaminate an electric A/C system, and since most OEs want to build a quality product that's going to last while maintaining their warranty, integrity, and legal liability, they do what it takes to make it happen.
That’s why so many compressor manufacturers and vehicle OEMs are using some type of POE oil formulations. Denso’s ND-OIL 11 which is mentioned above, is a formulation of POE oil. It has higher dielectric properties than PAG, which helps it to be more electrically insulating. This is required because the high voltage motor is built into the compressor and is cooled directly with the refrigerant. Since the oil is carried by the refrigerant, it’s also going to be all over those motor windings. Plus, some amount of the oil is going to spread throughout the entire system, and since it’s not possible to flush every internal surface of every component, the only way to be sure that you’ve removed all traces of an incorrect oil is to replace each system component (hence Toyota’s recommendation above).
What about the non-POE oil?
But as I hinted above, not all OEs are using POE oil with their electric compressor systems, and Volvo is the first example that we’ve found. Two of their hybrids that we saw in Philadelphia use a Sanden electric compressor with R-134a refrigerant, but they don’t use POE oil. Instead, they use what’s called “Volvo-PAG” as indicated on the under hood label (Figure 13). The compressor label, however, says that SP-A2 oil should be used (Figure 14), which is also what it says in the owner’s manual (Figure 15).
Mechanics like things to be simple, and this throws a monkey wrench into training. Now we have to add the caveat that Volvo hybrids that use either R-134a or R-1234yf and that use Sanden electric compressors, don't use POE oil, but instead, use a very specific PAG oil called SP-A2. Sanden gave a presentation about this oil at the MACS 2020 Training Event and Trade Show, and a question from the audience pretty much summed it up: “What type of oil is that SP-A2, and what is the viscosity?” The presenter, Señor José Miguel Díaz Sastre, Regional Manager for Spain and Portugal for Sanden Europe, said that it is made with the same base oil as SP-10 (which is a 46 viscosity PAG oil), but that they have engineered it with special additives to increase its electrical insulation. He also remarked to another question as to how an electrical leak is detected in their compressor circuits. Asked if there is a special sensor that is looking for a certain amount of ohms, or is there another way they are detecting the fault, Sr. Díaz replied that the compressor does have to be connected to the vehicle chassis for the detection to work (which is accomplished through the compressor’s mounting brackets to the engine block itself), but that no discrete sensor signal is used for this detection.
Now, this doesn't mean that you can go ahead and use PAG oil in a pinch in an electric vehicle. That could be one of the worst mistakes you'd make in working on one of these systems. I mean, sure, there have been plenty of reports about guys who've done this (usually by mistake) and later said that nothing ever happened (so then it must be ok, right?). But you'd be taking a huge risk that simply isn't worth the added expense of buying the right oil as called for by the OEM, nor the time it takes to get the oil (even if no one in your area has it in stock and you have to wait a few days for it to come in). Think about it — you can either wait a few days (which takes no effort at all, other than maybe having to close up the system and put the vehicle outside until the parts arrive), explain the situation to the customer (in which it may be tough having to "hear it from them" if they aren't happy about the delay), or you can use the wrong oil, risk an immediate or future failure (which will surely be blamed on you or your shop) and have to make more costly repairs at your expense.
In the end, we just have to repeat what we say pretty much any time that we try making sense out of a complicated and potentially costly topic like this: Always check with the vehicle manufacturer’s service information for the specific vehicle you’re working on to find out exactly which oil they recommend (and their recommended replacement procedures). Particularly when it comes to hybrids and battery electrics, it’s just not worth taking a chance.
Back to basics
No doubt that when it starts getting hot outside, your shop gets slammed with customers asking for help with their A/C systems. The same thing happens here at MACS, except we get slammed with A/C tech support calls. Most calls are nothing special to talk about. Refrigerant charge amount, oil type, and sensor locations are pretty common, particularly for oddball vehicles and trucks with limited information resources (and technicians unfamiliar with a particular make/model/system). We get lots of requests for wiring diagrams and pressure gauge troubleshooting help, too. Plus, there are the many not-well-known TSBs that seem to keep coming up (Ford Escapes come to mind here).
Every once in a while, I get a tech call from one of our local member shops near MACS HQ, and when it's a tough problem, I like to stop by and check it out for myself (of course, wearing a mask and practicing social distancing, as things are nowadays). A local shop owner called me asking for help with a 2004 Honda CR-V with the 2.4-liter, four-cylinder engine. The technician had already replaced the compressor (the clutch would not engage), condenser with integrated receiver dryer, and discharge line, but even after evacuation with an overnight leak test and proper recharge amount, the system still was not cooling. He said every time they started the engine and turned on the A/C, the high side pressure gauge would almost instantly climb up to around 400 psi.
Now, I know these guys, and they're pretty good at service work, especially when it comes to popular daily drivers like this one. But their technician was relatively new to A/C work, so I wasn't surprised by his answer to my first question. Of course, I'm talking about cooling fans, and were they running along with the compressor clutch? He said no, and that he didn't think they were supposed to be. He thought that the system would have to run for a while, and then when it was necessary, the computer would turn on the cooling fans at the right time. I explained that in fact, the cooling fans should come on all the time (or at least within a second or two) of when the clutch is engaged. Since they were only a few blocks away, I offered to stop by and take a look.
The install looked typical — the bumper cover, headlights, and other front-end components had been removed for access and care was taken not to damage any fins of the condenser (Figure 16). They hooked up gauges to show me what was happening, and sure enough, after starting the engine and pressing the A/C button, the condenser fans did not turn on. Just like they said, the high side gauge jumped to 400 psi, and we shut the system down.
Something had to be done about those fans, and a quick voltmeter test indicated that power and ground were indeed going to each fan's wiring connector, but neither one would spin. A new set of fans solved this perplexing problem. In the end, they were surprised that both fans failed at the same time, but more so to find out just how high (and how fast) the high side pressure gauge can get when air isn’t flowing over the condenser. Sometimes, it’s good to get back to basics.
