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If you want to service automotive air conditioning systems today, you'll need most or all of the following:
Gauge sets (2) One for older R12 A/C systems and one for newer R134a A/C systems. Two separate gauge sets are necessary because the hose connections are different, and you also want to avoid cross- contamination of refrigerants.
A gauge set is used to read the high and low side pressures in an A/C system. These readings can provide essential diagnostic information for troubleshooting cooling problems. The gauge set is also used when recharging the system with refrigerant.
Minimum requirements: The low pressure gauge should be capable of reading from zero to 30 inches of vacuum Hg, and zero to 250 psi. The high pressure gauge should have a range of zero to 500 psi.
Refrigerant recovery equipment -- It is illegal to vent ANY type of refrigerant into the atmosphere. Federal clean air regulations require the recovery and recycling of the refrigerant from a vehicle's A/C system prior to performing any type of service work that involves opening up the system.
Refrigerant recovery and recycling equipment must meet Society of Automotive Engineers (SAE) standards. In addition, different types of refrigerant must not be intermixed. This requires a separate recovery/recycling machine for each type of refrigerant used: one for R12, one for R134a (or a combination machine that includes separate circuits and storage tanks for R12 and R134a), and one additional recovery machine for any other "alternative" refrigerants that may be used (this includes blended refrigerants as well as RVs & trailers using R-22).
What's more, every professional technician who does A/C work must also be "certified" as having successfully passed an EPA-approved training course on recycling and recovery procedures. If you do not yet have the required certification, you must obtain it before you can legally do any type of A/C repair work.
Thermometer -- For measuring air temperature at the A/C outlets to diagnose cooling performance. A thermometer should be capable of measuring air temperature from 20 degrees up to 100 degrees Fahrenheit. A non-contact infrared thermometer is also a useful tool for measuring the surface temperature of A/C hoses, the condenser and radiator.
Leak detector Two basic types: active and passive. Active sensors include electronic leak detectors that are capable of detecting both R12 and R134a leaks (halogenated refrigerants). Sensitivity depends on the model, but most can detect leaks as small as 0.1 to 0.4 ounces per year. Passive leak detection equipment consists of dyes that are injected into the system and an ultraviolet light that makes the dye glow to reveal any leaks.
Vacuum pump -- For purging air and moisture from the A/C system prior to recharging it with refrigerant. The pump should be capable of pulling a minimum of 29.5 inches of vacuum Hg. (This is included in almost all recovery and recharging stations.)
Refrigerant identifier -- To identify and verify the type of refrigerant in a vehicle's A/C system, and to minimize the risk of cross-contaminating your recovery/recycling equipment and the vehiclesyou work on with the wrong refrigerant or flammable refrigerants. The more sophisticated equipment will even tell you the exact percentages of various refrigerants and contaminants in the system.
There's no way to know for sure what kind of refrigerant is in a vehicle, or how pure it is without a refrigerant identifier. Contaminated refrigerants can increase system pressures and cause cooling performance problems. Flammable refrigerants such as propane or butane (which are illegal in mobile A/C systems but are permitted in truck trailer refrigeration units and RVs) can pose a serious explosion hazard to vehicle occupants as well as technicians.
REQUIRED EQUIPMENT:
The only service equipment required by federal regulations is recovery and recycling equipment. But in the state of California, all of the above (except a leak detector) are now required for repair shops doing A/C service work (Regulation 3351.6, effective 1/19/2001).
FOR ADVANCED SERVICE & DIAGNOSTIC WORK:
Combination recovery/recycling/charging station. The latest generation of A/C service equipment combines recovery/recycling, vacuum purging, recharging, pressure readings and refrigerant identification into one machine. On the more sophisticated models, most of these functions are automated so an operator doesn't have to babysit the machine while it pulls out the refrigerant and recharges the system. Additional features may include automatic oil purging after recovery, automatic air purging from the recovery tank to minimize the risk of air contamination, and the ability to capture and record important system data (minimum and maximum system pressure, outlet duct temperatures, amount of refrigerant charge in system, etc.), and to generate a printed report for the customer. Most vehicles today have reduced refrigerant capacity (under 2 lbs.), which means charging accuracy is extremely important to avoid overcharging the system. This requires a highly accurate scale (plus or minus 1 oz.) for measuring the amount of refrigerant used.
Scan Tool -- On vehicles with automatic climate control systems, a scan tool is needed to tap into the onboard self-diagnostics. Basic scan tools, as a rule, can only access engine codes and "generic" OBD2 codes. To access the vehicle manufacturer's "enhanced" codes, HVAC codes and other body-related codes, a scan tool may require an additional module or software upgrade.
Flushing Equipment -- To clean debris and contaminants from the condenser, hoses and evaporator following a compressor failure. Flushing with solvent or refrigerant is not approved by some vehicle manufacturers, but it is by Ford. A closed loop setup is necessary to recover the flush.
A/C Specialty Tools -- This includes hose repair and forming tools, tools for removing/installing orifice tubes, tools for releasing spring-lock hose couplings, compressor clutch and seal service tools, etc. Such tools can save time and expense, and are a "must have"' for many types of repair jobs.
ADDITIONAL RESOURCES
EPA-approved certification programs for A/C technicians are available through numerous industry and aftermarket sources. These include the Mobile Air Conditioning Society (MACS), the International Mobile Air Conditioning Association (AMACA), the National Institute for Automotive Service Excellence (ASE), plus various service equipment manufacturers and vehicle manufacturers.
The certification programs cover the use of recycling equipment in compliance with SAE Standard J-1989, the regulatory requirements for recovery and recycling, the importance of preventing refrigerant contamination, and the effects of ozone depletion.
To become certified, a technician must study a workbook and pass a written exam to demonstrate his knowledge of these subjects. The MACS workbook, for example, is 40 pages long and has a 25 question exam.
A list of approved certification courses can be obtained by calling the EPAs Ozone Hotline at 1-800-296-1996 or by visiting their website at
www.epa.gov/omswwwOther A/C resources you may find helpful include:
Mobile Air Conditioning Society (MACS) at
www.macsw.orgInternational Mobile Air Conditioning Society (IMACA) at
www.imaca.orgThe Greenlink site for A/C shops at:
www.ccar-greenlink.orgFor detailed information about converting older R12 systems to R134a, see R134a Retrofit Guide.
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