Physical Properties:

Leakage and Detection

As usually pressures higher than atmospheric are working in refrigeration systems, there is a possibility of leakage of refrigerants after a long period of operation. This is wanted to detect this leak early on else the system would operate under compact capacity or prevent functioning altogether. Therefore, this is desirable that the refrigerant contain a pungent smell in order that its leakage may be detected immediately.

Miscibility with Oil

The refrigerant must not be miscible along the oil else the lubricating strength shall be reduced.

Viscosity

This must be as small as possible to ensure that the pressure fall in the system is as small as possible. A low viscosity refrigerant shall need less energy for its circulation via the refrigeration system.