Car Air-Conditioning Mechanisms and the Role of Compressors

Liquid (refrigerant) is cycled throughout a sealed air conditioning system in a repeated process of vaporization (evaporation), liquefaction, and re-vaporization. It is necessary for a gas to give off heat to liquefy (condense). If the refrigerant gas is pressurized, and the pressure is increased, it becomes comparatively easier to liquefy. Our company manufactures compressors, which are devices that pressurize the refrigerant gas.

The Cooling Principle

Air conditioners work on the principle that "liquids absorb heat when they become a gas (evaporate)."
For example, when alcohol is rubbed on the skin, it feels cool. This is because the alcohol absorbs heat from its surroundings when it evaporates. It is well known that heat is necessary to change a liquid to a gas. Heat is absorbed from the area in contact with the liquid, thereby cooling it. This extremely simple principle is the basis for cooling systems, such as air conditioners and refrigerators.


Refrigerant is a substance that carries out the "transfer of heat process" by cycling through the air conditioning system and absorbing heat when becoming a gas, and giving off heat when becoming a liquid.
* HFC-134a (R134a) is used in air conditioners because it evaporates and liquefies easily, and has chemically stable and non-degenerative properties.

Major Structural Components of a Car Air Conditioner