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Motor Vehicle A/C Issues The Contaminator; Covering Motor Vehicle Air Conditioning Issues

Newsletter Articles Covering Motor Vehicle Air Conditioning Issues

The following articles have been written by Neutronics, Inc. For more information, please visit their website at

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Alternative Refrigerants...10 Questions

Many new alternative refrigerants marketed for use in the motor vehicle and stationary/commercial sectors are being touted by their manufacturers and distributors. Whether you're a nationwide distribution chain or a one-man service shop, you should take the time to determine how well an alternative will work and whether it may pose any problems for your customers or liability for you. Consider asking your supplier, whether it is the refrigerant manufacturer or a distributor, the following questions.

1. Is the refrigerant on the EPA's SNAP (Significant New Alternatives Policy) Program list of acceptable substitutes, and therefore legal to use as a substitute for a CFC refrigerant? If so, are there any restrictions on how the refrigerant can be used?

EPA's SNAP program determines what risk alternatives to CFC or HCFC refrigerants pose to human health and the environment. EPA evaluates the alternative refrigerant's ozone-depleting potential, global warming potential, flammability, and toxicity. The SNAP evaluation, however, does not determine whether the alternative will provide adequate performance or will be compatible with the components of an A/C or refrigeration system. Call the Hotline number listed above for the SNAP fact sheet on alternative refrigerants and for lists of refrigerants accepted under SNAP, or download a version of the current list.

EPA may place conditions or restrictions on how an alternative can be used. For example, using a motor vehicle A/C refrigerant accepted under SNAP as a CFC-12 substitute requires, among other things, the use of a new label and new fittings unique to the alternative, and the CFC-12 must first be removed from the system. Note that there is no do-it-yourself (DIY) exemption from SNAP requirements. Both service technicians and DIYers who use alternatives found unacceptable under SNAP or ignore use conditions have violated the Clean Air Act. A fact sheet explains the current status of all refrigerants reviewed so far for motor vehicle air conditioning.

2. How much will the alternative refrigerant cost?

Many manufacturers and distributors of alternative refrigerants may point out how much less expensive their product is than the refrigerant it is substituting for. Potential purchasers, however, should compare the cost of the product with the cost of other substitutes. For example, if you are considering purchasing a blend refrigerant that substitutes for CFC-12, consider its cost relative to the cost of HFC-134a, which is generally considerably less expensive than blend refrigerants.3. What does the system manufacturer have to say about this refrigerant and whether it is compatible with system components? Will using a particular refrigerant void any warranties on the system the refrigerant is used in?

Because of the wide range in equipment types and designs, EPA does not issue retrofit procedures. The best source of information on how a given substitute will perform in a system is the manufacturer of the system and its components. Note that lab data has indicated that HCFC-22 refrigerant is not compatible with XH-5 or XH-7 desiccant, and that HCFC-22 can also damage NBR nitrile and HNBR rubber hoses and O-rings. If you are considering using a blend refrigerant that includes HCFC-22 as a major component, then you should ask about these issues before you purchase the refrigerant.

In addition to questions about the alternative's performance in a particular end use, you should determine whether charging a system with a new refrigerant will void any warranty. Many component manufacturers have stated that their warranties will be voided if any refrigerant other than R-12 or R-134a is charged into the system.

4. What recycling and/or reclamation standards apply to the refrigerant? Can the refrigerant be recycled or reclaimed to those standards?

The Clean Air Act requires that EPA establish standards for the recovery, on-site recycling and off-site reclamation of refrigerants, including alternatives accepted under SNAP. The Agency's standards for recovering and recycling refrigerants in motor vehicles are generally based on Society of Automotive Engineers (SAE) standards. EPA's standards for reclaiming refrigerants from motor vehicles and from stationary/commercial A/C and refrigeration systems are generally based on ARI (Air-Conditioning and Refrigeration Institute) standards. If these standards have not been published by EPA for a particular alternative, then they may be under development by EPA, SAE or ARI. Check to make sure that the refrigerant manufacturer intends to work with these organizations to develop uniform methods for extraction, recycling and reclamation. You can call the Hotline number (800-296-1996) listed above to determine the status of EPA standards and requirements.

5. What equipment must be used with the alternative refrigerant?

Equipment that is used by a facility to service R-12 or R-134a A/C systems may not be used to charge, recover or recharge a blend refrigerant. Technicians must therefore dedicate newly purchased equipment to that blend. Alternatively, a shop may convert a piece of R-12 or R-134a equipment for permanent use with the blend refrigerant. For more information on equipment requirements, see the EPA document "Just the Facts for MVACs."

6. Has the alternative refrigerant been evaluated by ARI (the Air-Conditioning and Refrigeration Institute)? If an alternative is to be reclaimed, will it be reclaimed to ARI's 700 standard? If not, then how will the purity of the reclaimed alternative refrigerant be assured?

ARI, and A/C and refrigeration manufacturers' trade association, develops standards for the industry. ARI's 700 standard specifies acceptable levels of refrigerant purity for fluorocarbon refrigerants including R-12, R-22, R-134a, R-500, and R-502 and for certain refrigerant blends. The purpose of the 700 standard is to enable users to evaluate and accept or reject refrigerants, whether virgin, reclaimed or repackaged. Reclamation of these refrigerants in both the motor vehicle and stationary/commercial sectors must follow the 700 standard.

7. Is the alternative refrigerant flammable?

Both ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers) and EPA evaluate refrigerant flammability. As part of its SNAP review, EPA requires that a new refrigerant be tested according to the American Society of Testing Materials (ASTM) E-681 testing method. E-681 is used to determine the concentrations in air at which a substance is flammable, at normal atmospheric pressure. In addition to testing the refrigerant itself, if a blend contains a flammable component, EPA requires leak testing to ensure that the composition does not change and become flammable. EPA prohibits the use of any flammable CFC-12 substitutes in motor vehicle A/Cs.

If a substitute is flammable, EPA requires a comprehensive risk assessment for each proposed end-use. This risk assessment estimates the likelihood of fire and the potential results if a fire were to occur, in addition to suggesting measures to mitigate this risk. State governments, fire marshals, building code organizations, and other local authorities may have issued prohibitions or other regulations related to flammable refrigerants. Check with them before buying, selling, or using a flammable refrigerant.

8. Is the refrigerant readily and widely available?

If an automotive service technician charges a system with an alternative refrigerant that later becomes unavailable, or that is not available nationwide, then at the next servicing, the system may have to be retrofitted to another appropriate substitute. The customer may be unwilling to pay for the retrofit, or may be unhappy that his vehicle cannot be Therese serviced at the facility he chooses.

9. What is my liability if I sell an alternative not yet listed as acceptable by EPA or if I put it in a customer's system?

Under EPA regulations, a refrigerant manufacturer must submit information on a new refrigerant for SNAP review at least 90 days before marketing the product. This 90-day period is required by Section 612 of the Clean Air Act, but the Act did not prohibit sale and use of that refrigerant after the 90-day period. Thus, if the Agency is still engaged in its review when the 90 days elapses, the product can be sold and used, even though it is not "EPA acceptable." However, EPA may later determine that the product is unacceptable under SNAP. It makes sense, then, to determine whether SNAP review is complete -- if not, it may be only temporarily legal to use the alternative refrigerant. If you purchased the refrigerant during the SNAP review, and EPA later determines that it is unacceptable, you may be stuck with a large inventory of refrigerant no one can legally use!

The Clean Air Act only granted EPA the authority to regulate the use of alternative refrigerants, not the sale of them. Even if EPA determines that an alternative is unacceptable, it is still legal to sell it. However, putting it in a customer's A/C or refrigeration system is considered use, not sale, so a service technician who charges a system with an unacceptable refrigerant may be subject to a $25,000 fine and up to five years' jail time.

10. Are any alternative refrigerants more environmentally beneficial than others?

HFC-134a does not contain chlorine and therefore does not contribute to ozone depletion, although like other HFCs, it contributes to global warming. HCFC-22 and all other HCFCs contribute to both ozone depletion and global warming. All blend refrigerants listed as acceptable for motor vehicle use contain HCFCs.


R-134a Rationing?

According to a recent article in the March 15, 1999, issue of The NEWS magazine, there may not be enough HFC-134a (R-134a) to go around.

Jay Kestenbaum of Refron, a Long Island refrigerant distributor, believes that this summer mobile A/C technicians may experience a shortage in R-134a. Early warnings from the European market have begun, where supplies have tightened severely, according to Kestenbaum. This situation could easily spill over into the US mobile A/C market, where demand is very strong.

An estimated 50 million cars will need supplies of R-134a and R-12 to keep their cooling systems operating between now and 2006, according to a federal study. Another indicator of this situation is the recent price hike of R-134a. With an anticipated shortage, the price has gone up by 50% over last year's prices.

The shortage can be traced back to a problem with the supply of precursor chemicals like trichlorethylene in the manufacture of the refrigerant, said Kestenbaum. HVAC markets may not experience the same shortage as the MVAC market where many chiller manufacturers have contracts with R-134a suppliers.


Composition of Refrigerant Blends & The Neutronics Fingerprint Chart

More Information About Alternative Refrigerants

The "ACTUAL" table below shows the percentages of gases within refrigerant blends which have been found "acceptable for use" as a substitute for CFC-12 (R-12). The "FINGERPRINT" chart is a list of possible refrigerant readings you may see when using the Neutronics Refrigerant Diagnostic Tool.

The ACTUAL composition of Alternative Refrigerant Blends

Trade Name


22 124 142b

134a 152a 227ea

butane HCs isobutane
R-600 R-600a



53% 34%




61% 28%




55% 41%




60% 25% 15%






Free Zone (2% is lubricant)




65% 31%


Hot Shot


50% 39% 9.5%




51% 28.5% 16.5%


Freeze 12




41% 15%



The "FINGERPRINT"of select Alternative Refrigerant Blends

Trade Name


22 124 142b

134a 152a 227ea








Free Zone (2% is lubricant)



Hot Shot












Freeze 12




Where to Send Contaminated Refrigerant

Getting rid of your contaminated refrigerant can be a confusing chore for most shops. A small hand-full of companies make this chore easy and, in some cases, profitable. These companies will accept contaminated refrigerant from you - and in some cases - will actually pay you for the shipping or for the volume of refrigerant you have.  Typically a shop can expect to pay between $1 and $4 per pound for disposal, which, over the course of a year, can equal hundreds of dollars for a small shop. Avoid these charges by contacting one of the companies listed below.  They make EPA compliance easier.


RemTec International
6150 Merger Dr.
Holland, OH 43528


Full Circle
(with 11 Regional Offices)
121 S. Norwood Dr.
Hurst, TX 76053
817-282-0022 (x220)


Refrigerant Reclaim
805 Tile Dr.
Red Wing, MN 55066
860-651-6114 or


List of Reclaimers



Ozone 101: The Problem of CFCs

So you've learned how to handle R-12, you know how to retrofit an A/C system, and you even know about the "SNAP" Rules, but why? Why can't we still produce R-12? Why can't we vent it? What's the big deal? Well, for those of you who are asking these questions, here's your chance to get some quick answers and to understand the impact of chlorofluorocarbons, CFCs, on our world.

Since the early 1970s scientists have been watching a hole in the ozone layer grow. And because of this ozone problem, over 150 countries agreed to stop the production of CFCs. This agreement, signed in the late 1980s, is known as the Montreal Protocol. In 1990, President Bush signed the Clean Air Act which empowered the EPA to set forth and enforce rules and regulations regarding CFCs.

CFCs destroy the ozone layer. The ozone layer (in the stratosphere, between 10 – 30 miles above earth's surface) keeps 95 – 99% of the sun's ultraviolet radiation (UV) from striking the earth. The ozone layer is made up of O3 molecules (three oxygen molecules bound together). When one CFC (R-12) molecule is struck by sunlight, it releases a chlorine atom. The chlorine atom and ozone molecules set off a chain reaction. Once the reaction is complete, that one chlorine atom has just destroyed 100,000 molecules of ozone from our atmosphere.

When the protective ozone is destroyed, UV rays become stronger and more harmful to plants and animals. Increased exposure to UV radiation is partially responsible for the alarming increase in skin cancer – the rate of which is tenfold higher today than it was in the 1950s. And according to the National Academy of Sciences, for each 1 percent decline in ozone levels, humans will suffer as much as 2 to 3 percent increase in the incidence of certain skin cancers.

Remember, no refrigerant can be vented! It's against the law!


609 Certification, SNAP & The EPA— What do they mean?

If you've been performing A/C service for over 5 years, chances are you haven't heard of a set of rules for handling refrigerants called the "SNAP PROGRAM" (Significant New Alternatives Policy). The EPA has mandated that you follow the rules of this program completely.

According to the EPAs "How to Survive a EPA Clean Air Act Title VI Refrigerant Regulations Compliance Inspection" document, if you break any one of these rules and are convicted, here's what you can expect:

    1. Civil penalties of $27,500 per day of violation.

    2. Criminal penalties up to 5 years of federal imprisonment for knowing or willful violations, and 2 years imprisonment for submission of false records.

How does the EPA catch you? The EPA routinely conducts surprise or unannounced inspections to verify compliance requirements. In addition, EPA pays up to $10,000 reward to individuals reporting violations that result in successful court cases and/or convictions under "Citizen Award Program."

What a technician must know:

    1. Topping off like A/C systems with the same refrigerant already installed is perfectly legal. However, you cannot top off any A/C system refrigerant with another A/C refrigerant. It is illegal to mix any refrigerants.

    2. Only SNAP "Acceptable subject to use conditions" refrigerants can be used in cars.

    3. Unique fittings and labels are required. The "subject to use conditions" wording in the EPA regulations refers to the mandatory use of separate and unique fittings and labels for each and every new SNAP acceptable refrigerant. As part of the EPA "acceptable for use" criteria, the refrigerant manufacturers must prove they have created unique fittings and labels to support the sale and use of their product.

    4. No refrigerant can be vented! Even R-134a. The EPA is proposing that the only refrigerant that can be vented is 100% hydrocarbons. If a system is identified as having 100% hydrocarbons, the system could legally be vented. Recovery in this situation would pose too much of a human hazard. For more information see Federal Register/Vol. 63, No. 112.

    5. "Recycling" of blends is now legal, however transfer of ownership is not (except in fleets). And the technician must use dedicated recycling equipment for each refrigerant used in the shop, and it must meet the new UL (Underwriters Laboratories) Standard.

    6. Hydrocarbons are illegal to use in cars!


Additionally, Section 609 Certification covers new blends, no new certification is required. However if you were certified 5+ years ago, you may not know or remember these rules.


What else should you be doing to protect yourself from an EPA audit? Records should be maintained on refrigerant handling from point of purchase through final usage or disposal. This includes maintaining records for ALL service work performed on vehicles regardless of size, quantity or refrigerant. You should maintain information on file for three years.


To learn more, contact EPA at www.EPA.gov.


It's Now O.K. to Recycle Blends

Contaminated refrigerants – it's a problem that will only get worse. For those who choose to deal with this potential headache, there are rewards: Profits. Turning the handling of contaminated refrigerant into its own profit center in your shop could be the raise you've been looking for. But first you'll need to know few things…
  1. Identify the refrigerant. Use a refrigerant identifier with 98%+ accuracy.
  2. Recover the contaminated refrigerant. Dedicate an R-12 recovery-only machine, or buy a special machine for this purpose.
  3. Store the refrigerant in an 'approved' cylinder, a standard DOT-certified grey w/yellow top tank.
  4. Dispose of the contaminated refrigerant.


Identify the Refrigerant

Checking refrigerant pressures does not help you recognize refrigerants, especially if the refrigerant is contaminated or is a brand that is unfamiliar with you. Using a refrigerant identifier can help pinpoint many refrigerant identification problems, and EPA strongly recommends (but does not require) that techs obtain this equipment. A unit that can help you identify the chemical composition of the refrigerant more specifically can be an important diagnostic tool, so that the extra cost may be well worth it. Finally, using this tool may build your customer's confidence in your diagnostic abilities. Be certain when purchasing your identifier that it meets the SAEJ1771 standard, which is an indication that the unit accurately identifies refrigerants.


Recover the Contaminated Refrigerant

As a first step, the contaminated or unfamiliar refrigerant must be recovered. EPA prohibits venting any automotive refrigerants (including unacceptable refrigerants) no matter what combination of chemicals is in the refrigerant. The best way today that a tech can recover contaminated or unfamiliar refrigerant is to dedicate a recover-only unit to anything that is not pure R-12 or pure R-134a. Some equipment manufacturers are also marketing new types of recover only stations specifically designed to remove these refrigerants.


If the refrigerant you extract into a recovery unit contains a high level of flammable substances such as propane or butane, a fire hazard may result if the refrigerant comes into contact with an ignition source within the equipment. Whether you are purchasing a new piece of equipment to handle your contaminated and unfamiliar refrigerants, or you are converting a piece of existing equipment for this purpose, make sure you talk to your sales representative about what features have been incorporated into the equipment to guard against risks of ignition.


Store the refrigerant in an approved cylinder

Refrigerant should be recovered into the standard DOT-certified, gray-with-yellow-top recovery tank, and if the tank is not equipped with a float valve (which serves as overfill protection), make sure it never gets filled beyond 60% of its gross weighted capacity, as specified in the SAE J1989 and J2211 standards.


Dispose of the contaminated refrigerant

Once the refrigerant has been recovered, if you can't recycle it, what do you do with it? The answer, naturally, is that it depends. If the refrigerant in your "junk" tank contains significant amounts of flammable substances, it may be considered hazardous and you should make sure you follow any local ordinances that govern the storage of combustible mixtures. In addition, if your shop generates over 100 kilograms (220 pounds) of hazardous wastes per month (including used coolant, paint, rust, removers, solvents, degreasers, and battery acids), then your shop must meet certain storage and transportation requirements under the Resource, Conservation and Recovery Act (RCRA). For more details, call the RCRA Hotline at 800-424-9346 and ask for EPA publication 530-K-95-001, the 1996 update of "Understanding the Hazardous Waste Rules—A handbook for Small Businesses." You may also wish to check out the World Wide Web site of the Coordinating Committee for Automotive Repair at


If the refrigerant in your "junk" recovery tank is a chemical "soup" – wither contaminated R-12 and R-134a, or a mixture of those contaminated refrigerants and some blend refrigerants that you are familiar with, then the contents should be destroyed. If you have a contract in place with a waste hauler, contact the hauler to see if they can handle the material. Waste haulers may require that the contents be identified first and may charge you for this identification procedure. They are most likely to send the tank to an incinerator for destruction. You may also want o contact one or more reclaimers, who will send the refrigerant off-site either for destruction, or for reclamation, which involves breaking it up into its chemical components and purifying each of the components.


Some reclaimers can handle tanks sent to them from anywhere in the nation. A reclaimer does not necessarily have to be located in your area.

EPA maintains a list of reclaimers that is available through the Hotline at 800-296-1996. EPA will update this fact sheet in the event that the Agency receives more specific information about which reclaimers will accept mystery mixtures of refrigerant.

If you have questions about disposing of specific blend refrigerants, call the refrigerant manufacturer. Most manufacturers of blend refrigerants have made arrangements with specific reclaimers to handle their used refrigerant. For a list of these telephone numbers, see the EPA fact sheet "Choosing and Using Alternative Refrigerants," available from the Hotline.
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EPA Enforcement: A Reality


EPA announced that 266 criminal cases were referred to the Department of Justice in 1998 and $92.8 million in criminal fines were assessed in fiscal year 1998. EPA also referred 411 civil cases and assessed $91.8 million in civil penalties. The combined 677 referrals and $184.6 million in fines and penalties were second only to the 704 referrals and $264.4 million in fines and penalties assessed in fiscal year 1997.

For the third year, the Agency reported performance measure data on pollution reduction amounts result from enforcement actions. The data show that during FY 1998, chlorofluorocarbons were reduced by over five million pounds.



Former California resident pleaded guilty in U.S. District Court for the Central District of California in Los Angeles on July 31 for violating the Clean Air Act. He admitted to illegally venting CFC-12 into the atmosphere at the Santa Anna, CA-based C&C Distribution. The illegal venting took place when he installed the replacement refrigerant HC-12a into automobile air conditioning systems. The EPA has prohibited the use of HC-12a as a replacement for CFC-12 in automobile A/C systems because the substance is flammable and potentially explosive. He could serve up to five years in prison and be fined as much as $250,000.



On August 29, a resident of North Miami Beach, FLA, was sentenced to serve 37 months in prison and three years supervised release and was ordered to pay a $375,000 fine by the U.S. District Court for the Southern District of Florida in Miami. As part of his guilty plea, resident will forfeit over $13 million in assets including: property in Miami valued in excess of $1.5 million; 11,200 thirty pound cylinders of chlorofluorocarbon gas worth over $6.7 million; almost $5 million in illegal proceeds held in European banks; an apartment in London valued at $395,000 and stock in a local bank worth over $80,000. 

This man previously pleaded guilty to illegally diverting 4,000 tons of ozone depleting CFC refrigerants into commerce in the United States.



California man became the first person to be convicted under the Clean Air Act of selling improperly recycled chlorofluorocarbon (CFC) refrigerants. He sold the Los Angeles Department of Water and Power 2,600 pounds of recycled CFC refrigerants that did not meet the level of purity prescribed by federal law. His company had been certified as a refrigerant reclaimer by EPA since approximately 1993. When sentenced, this man faces a maximum of up to five years in federal prison and/or a maximum fine of $250,000.



EPA cited a company for alleged violations of stratospheric ozone regulations. EPA said the company, which makes a substitute refrigerant called HOT SPOT and a refrigerant recovery device called Spooter II, failed to: equip small cans of HOT SPOT with required fittings; maintain certification of Spooter II equipment by an EPA-approved testing organization; and properly label Spooter II equipment.



During summer months of 1998, contact inspectors from EPA Headquarters inspected motor vehicle air conditioner shops in Alabama, Florida, Georgia, and Mississippi. EPA Region 4 received approximately 300 inspection reports and reviewed each for compliance with the requirements of Title VI of the Clean Air Act. One hundred facilities were in full compliance, 150 facilities required the submission of additional information to determine compliance, and 43 facilities were issued Administrative Orders for non-compliance.

A listing of facilities is available who were cited for failure to certify to the Administrator of EPA that it had acquired and was properly using approved MVAC equipment and that each individual authorized to use the equipment is properly trained and certified.



A U.S. District Court judge in Maine has sentenced two Canadians who were found guilty of importing into the United States 75 tons of Freon, an ozone-depleting chemical. The couple pleaded guilty to shipping chlorofluorocarbon (CFC) chemicals to U.S. automotive shops. They did not have the necessary authorization to make the shipments.



An EPA administrative law judge recently ruled that a trucking company in Wheeling, WV had violated section 609 of the Clean Air Act by allowing an uncertified employee to perform service on mobile vehicle air conditioners (MVACs) involving refrigerants, and fined the company $25,363. The judge had previously found the company had also failed to use approved refrigerant recycling equipment, nor did it submit the approved equipment and training certifications to EPA.

After receiving a "citizens tip", EPA sent a letter to the company requesting information regarding the number of MVACs serviced on or after August 13, 1992, invoices for the purchase of approved refrigerants, invoices for any service on an MVAC, the name of every technician performing service on MVACs, and a copy of each technician's refrigerant recycling certificate and the company's certification to use EPA-approved equipment.

The company's legal counsel responded to the requests saying, "The company was under the assumption that since the company was only doing work on its own vehicles, it was not doing work for consideration and that this equipment was not mandatory.

EPA sued the company alleging three violations: repair or service of MVACs involving refrigerant without using approved refrigerant recycling equipment, repair or service of MVACs by company employees without training and certification in refrigerant recycling, and repair or service of MVACs without submitting the approved equipment and training certification.



What is an Air-Purge System and What Makes One System Different From Another?

What is an air-purge system? An air purge system is a technology which allows and A/C technician to purge air from pure (98%+) R-12 or R-134a.

Explain the problem of air. Air is a contaminant of refrigerant that can enter an A/C system or cylinder and create A/C performance problems. Non-condensable gases (NCG or "air"), which are mainly comprised of ambient air commonly contaminate refrigerant storage cylinders and air conditioning systems. Contamination enters into the refrigerant from sources such as leaking joints on vehicle air conditioning systems, improper handling of refrigerant recovery and recycling equipment or failure of recovery and recycling equipment. Air contamination will lead to a number of vehicle air conditioning system problems including increased compressor heat and wear due to increased head pressures, added stress of components due to increased head pressure and reduction of system efficiency due to dilution of refrigerant by the air.

According to MACS (Mobile Air Conditioning Society) statistics, the most consistent problem in a vehicle's poor air conditioning performance is the presence of air in the system. Air, when mixed with refrigerant, changes the pressure of that gas and causes and A/C system to exhibit poor cooling properties. In the 1996 MACS study, 111 automotive repair facilities were checked in Florida to qualify/quantify the A/C contamination problem, 27 facilities (24%) indicated that excess air was their biggest problem/contaminant.

What air-purge systems are available?

  1. Recovery/Recycling machines
  2. Temperature/Pressure measurements
  3. Robinair Air I.D.
  4. Neutronics Air-Radicator

Recovery/Recycling Machines can be used to purge air from A/C systems or cylinders. This process involves pulling a vacuum on the system, and allowing the machine to purge the air automatically. This process, however, can take upwards of an hour to complete and may not be able to remove all air.

Temperature/Pressure measurements allow a user to make some assumptions about air content based on the readings of two variables, temperature and pressure. This method is in no way 'automatic', and requires hours of 'babysitting'. Essentially a refrigerant storage cylinder must first temperature stabilize (room temperature is ideal) to the ambient air conditions. Next, the refrigerant will "read" a pressure for that specific ambient temperature. If the pressure is higher than it should be for the ambient temperature, an "assumption" is made that there is air in the cylinder. By opening the cylinder valve, slowly the air is vented. However, when air is vented from the cylinder, the refrigerant will automatically begin to cool itself, so the technician will need to close the valve and allow the cylinder to temperature stabilize again. Allowing a cylinder to temperature stabilize can in some cases take over 12 hours depending on ambient conditions. This process is repeated until the cylinder has stabilized and reads the correct pressure for the temperature.

The Robinair I.D. uses an air detection instrument which is an "oxygen sensor" based analyzer. The instrument looks for oxygen. When a storage cylinder is stabilized (when the gases inside find their equilibrium) which may take 15 minutes, the Air I.D. is attached to the cylinder and the valve is opened to allow the Air I.D. to operate. The Air I.D. will slowly bleed a sample of the gas and 'looks' for oxygen. Once oxygen is depleted from the cylinder, the Air I.D. will stop purging. The use of an oxygen sensor in this type of application can lead to inaccurate air readings because some refrigerant gases can react with the 'chemistry' of the oxygen sensor. The oxygen sensor is an electrochemical fuel cell which, overtime, will lose its ability to provide accurate readings and will need to be replaced – very similar to the technology used in an alkaline battery. Finally, this oxygen sensor based analyzer requires several hours to identify and purge air from a bulk refrigerant storage cylinder.

The Air-Radicator (manufactured by Neutronics) is an automatic air purge system. Purging of air is achieved through a direct measurement of gases via the use of an infrared technology. This technology is not dependent upon pressure or temperature measurements or an oxygen sensor. A technician will attach the Air Radicator to the vapor port of a cylinder or vehicle's A/C system and follow the instrument's easy instructions. The Air-Radicator accurately measures the air in R-12 or R-134a and automatically shuts off when the air is successfully purged. A typical 32 ounce A/C system with 8% air will only take about 3-5 minutes to purge.

Which system is better for me? The system best for you depends upon the demand your customers place on you to perform A/C service, quickly. If you do not perform many A/C jobs, your recovery/recycling machine may suffice. If you get a constant flow of customers needing A/C work, the Air-Radicator is your better choice. Whatever instrument or method you choose, you'll need to weigh your needs, the importance of using reliable technology, and the financial impact of using 'slower' technologies or methods.

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