Keeping Cool Without Ozone Depletion

What's Ahead for Your Porsche Air Conditioner

By Bob Poggi

Page 2 of 2

Upgrading Your Porsche Air Conditioner

Porsche air conditioning systems consist of five major components; the compressor, condenser, orifice expansion valve, evaporator and accumulator-dehydrator. These components perform the following functions.

  1. The compressor brings in the refrigerant gas from the evaporator and compresses it for circulation through the system.

  2. The condenser removes the heat from the refrigerant and condenses the gas to a liquid.

  3. The orifice expansion valve, or tube, regulates the flow of high-pressure liquid refrigerant to the evaporator, thereby lowering the pressure.

  4. The evaporator is used to cool, dry, and clean the air that enters the passenger coil

  5. The accumulator dehydrator separates liquid refrigerant from the gas state before it enters the compressor and removes moisture from the system.

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 that it requires higher operating pressures than that of CFC R-12 because it is less active than R-12. I his results in the gas changing to a liquid at a slower rate. As a result, we are confronted with differences, which have to be addressed when retrofitting the system.

The condenser of certain water-cooled Porsche models (924/944/ 968/928) may have inadequate condenser capacity with space limitations for expanding it. That may restrict the use of a larger condenser. The automotive A/C industry has come up with a new condenser design called "Parallel Flow" which has increased capacity without increasing size. This condenser works on the same principle 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 engine heat, but also the use of multiple condensers. These condensers are mounted in remote locations. The use of high performance parallel-flow condensers and cooling fans will add to the condensing capacity.
The A/C hoses may also need to be replaced with a new barrier-type. The new R-134a gas will permeate older A/C hoses. When upgrading your Porsche's A/C, check hoses to see that they are labeled Barrier. Only barrier-type hoses will work with R-134a systems. Earlier model Porsches do not have barrier-type hoses (they began to be phased in around 1990).
Some A/C systems, after they are upgraded, may operate at 4-6" high vent outlet temperatures. It may be necessary to change thermostat settings expand valve orifice sizes to offset


What does all this mean to the Porsche owner? If you plan on keeping your Porsche for a few years, it may be necessary to upgrade your air conditioning system. If your system is currently not operating properly, you are a prime candidate to upgrade. The cost of R-12 refrigerant is now higher than R-134a and soon may be unavailable to recharge your system when it is repaired. When the existing supply of R-12 is exhausted, the demand for upgrading will increase as will the price. Although this is a repair that can be put off as long as your system is operating properly, it is important to understand what you will face if your air conditioning system goes down. Remember, it is important to stay cool.

NEW A/C RETROFIT KITS - Converter R-12 to R134a -Environmental Upgrades Now available —

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.


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


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

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