Refrigerant
1.What is refrigerant?
Refrigerant is a heat exchanging substance that circulates in the refrigerant cycle. It removes the heat when it evaporates and releases its heat when it liquidizes.
At present, HCF-134a (R134a) is used as a refrigerant.
2.Required condition of refrigerant
For refrigerant for car A/C, the following conditions are required.
Ease of evaporation and liquidization
Safety
Scientific stability and the quality does not change.
3.Characteristics of refrigerant
The left chart shows the pressure and boiling point of HCF-134a (R134a).
Under low pressure, HCF-134a evaporates in low temperature, but if the pressure becomes higher, it remains liquid state without being evaporated even in high temperature.
A car A/C utilizes this characteristic, and makes it easier to liquidize the refrigerant by applying pressure using the compressor.
For example, cooling the 70