Refrigeration & Equipment Engineering

Unit 4 - Refrigerants

4.2.4.Physical properties of refrigerants
Stability
An ideal refrigerant should not decompose at any temperature normally encountered in the refrigeration system.

Corrosive
The corrosive property should be taken in to account while selecting the refrigerant. The freon group of refrigerants are non corrosive with all metals practically.Where as Ammonia is used with iron or steel.

Viscosity
The refrigerant in the liquid and vapor states should have low viscosity. The heat transfer through condenser and evaporator is improved at low viscosity.

Thermal conductivity
The refrigerant in the liquid and vapor states should have high thermal conductivity.

Cost and leakage tendency
The cost of refrigerant is also important for industrial and commercial refrigerating system.