In practice, all car air conditioning systems create cool air in exactly the same way. All systems compress a refrigerant gas before allowing it to evaporate. Thus, from that standpoint, there is little, if any difference between different car air conditioning systems.
However, there are huge differences in the technical details of old and new climate control systems. For instance, older systems regulated set temperatures by switching themselves “ON” and “OFF”. Newer systems use computers to regulate set temperatures by varying the amount of refrigerant the compressor pumps.
Other differences include the use of-
- denser materials for rubber hoses to limit refrigerant gas losses
- advanced synthetic materials for seals and gaskets
- more efficient refrigerants
- higher system pressures to make the best use of advanced refrigerants
One other major difference involves maintenance costs. While new, computer-controlled systems are more efficient, the cost of servicing, maintaining, and repairing them is somewhat higher than on older systems.
However, air conditioning in cars is a necessity in Australia, not a luxury. Therefore, the higher maintenance costs are perhaps a small price to pay for our air-conditioned comfort.