Freon-11
Freon-22
C02
ammonia.
reduce compressor overheating
reduce compressor discharge temperature
increase cooling effect
ensure that only liquid and not the vapour enters the expansion (throttling) valve
always less than unity
always more than unity
equal to unity
any one of the above
more
less
same
more for small capacity and less for high capacity
of cooling medium
of freezing zone
of evaporator
at which refrigerant gas becomes liquid