1. In a cascade system a series of refrigerants with progressively lower boiling points are
used in a series of single stage units.
2. The condenser of lower stage system is coupled to the evaporator of the next higher stage
system and so on.
3. The component where heat of condensation of lower stage refrigerant is supplied for
vaporisation of next level refrigerant is called as cascade condenser.
4. This system employs two different refrigerants operating in two individual cycles.
5. They are thermally coupled in the cascade condenser. The refrigerants selected should
have suitable pressure-temperature characteristics.