TECHNICAL

By retrofitting your Porsche air-conditioning system with R-134a, you can keep yourself and the earth cool

Chilling Out

By ROBERT POGGI

PAGE 2 of 2

Porsche air-conditioning systems consist of five major components; the compressor, condenser, orifice expansion valve, evaporator, accumulator-dehydrator.
The compressor brings in the refrigerant gas from the evaporator and compresses under high pressure for circulation through the system.
The condenser removes heat from the refrigerant and condenses the gas to a liquid.
The orifice expansion valve (or tube) regulates the flow of high-pressure liquid refrigerant to the evaporator, thereby lowering the pressure. The evaporator is used to cool, dry and clean the air that enters the passenger compartment. The accumulator-dehydrator separates liquid refrigerant from the gas state before it enters the compressor and removes moisture from the system. The upgrade process is a complex procedure which requires specific execution in order to ensure a proper retrofit. The system must be thoroughly evacuated, and before replacing the refrigerant, the following steps must be performed.
  1. Check for leaks.
  2. Evacuate the CFC R-12 from the A/C system.
  3. Inspect the hoses, compressor and condenser.
  4. Remove the compressor and drain compressor into a measuring cup.
  5. Replace the same amount of oil with approved HFC R-134a ester oil.
  6. Remove the receiver drier or accumulator.
  7. Install the compressor connect hoses and install HFC R-134a service-port fittings to the compressor. Note: R 34a service-port fittings will prevent R-12 from being reintroduced to the A/C system.
  8. Install a new receiver drier or accumulator valves.
  9. Check all hoses and electrical connections.
  10. Evacuate and charge the system with HFC R-134a refrigerant
 The introduction of HFC R-134a refrigerant has solved the environmental problems of CFC R-12, yet there are new issues which have to be considered. Initial testing of HFC R-134a has shown higher operating pressures than that of CFC R-12. The new gas, R-134a is less active than Freon R-12. This results in the gas changing to a liquid at a slower rate than R-12. Retrofitting an existing R-12 system creates several differences in Porsches that need to be addressed.
The condensers of certain water-cooled Porsche models (924/944/968/928) may have inadequate capacity width and space limitations. This may restrict the use of a larger condenser. The automotive A/C industry has come up with a new condenser design called "Parallel Flow." This condenser works on the same principal as a car radiator rather than an A/C condenser. Porsche 911/912/914/930 models being air cooled create problems with the condenser being exposed not only to the engine heat, but also to the use of multiple condensers these condensers are mounted in remote locations. The use of high-performance parallel-flow-designed condensers and cooling fans will add to the condensing capacity of the A/C system.		 Another difference is in the A/C hoses: they may need to be replaced with a new "barrier" type because the R-134a gas will permeate through older hoses. When upgrading your Porsche's A/C, check the hoses to see if they are labeled barrier only barrier-type hoses will work with R-134a systems. Note: Earlier model Porsches do not have barrier-type hoses. One other consideration is that some A/C systems after upgrading may have a vent-outlet-temperature variance ranging from 4 to 6 degrees higher. As a result, it may be necessary to dial in heat settings and expansion-valve orifice sizes. If you plan on keeping your vehicle for a few years it may be necessary to upgrade your air-conditioning system. If your system is currently not operating properly you are the prime candidate for an upgrade. The cost of R-12 is now higher than R-134a and will soon be unavailable to recharge your system after it has been repaired, When the existing supply of R-12 is exhausted the demand for upgrading will increase as will the price. There are predictions that during the hot summer months there will be waiting periods of 30 days or more to get your A/C repaired and retrofitted. Upgrading your vehicle's A/C will also increase the resale value of your car. In these changing times of heightened environmental consciousness, automobile air conditioners must become environmentally friendly to improve our global ecology.

ICE Inc., a company that has been manufacturing and servicing automotive air-conditioning systems for 36 years. Located in San Diego. ICE Inc., provides both informative data pertinent to the environmentally safe retrofitting of A/Cs as well as upgrade kits to all makes and models of automobiles.

NEW A/C RETROFIT KITS Convert your R-12 to R134a Environmental Upgrades Now Available.

ICE SALES

  • 3275 Market St.
  • San Diego. CA. 92123
  • 800-845-0424

ICE TECH LINK

  • Retrofit Info Hotline
  • Environmental Upgrade
  • 619-338-0995

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