Subject : Refrigeration and Air Conditioning

Topic : Vapour Compression Refrigeration System

Difficulty : Medium

The desirable properties of a refrigerant are as follows:

1. High critical temperature to have large isothermal energy transfer.
2. The specific heat of liquid should be as small as possible and of vapour should be as high as possible to give less superheating of vapour.
3. High latent heat of vaporization to get more refrigeration effect.
4. Large conductivity to reduce size of condenser and evaporator.
5. Low specific volume of vapour
6. Low freezing point such that there is no blockage during flow through evaporator.
7. Non corrosive to metal and inert so as to not react with other materials and commodities of the refrigeration system.
8. Non-toxic
9. Low boiling point
10. Non-flammable and non-explosive
11. Low cost and easily available
12. Easy to liquefy at moderate pressure and temperature
13. Easy of locating leaks by odour or suitable indicator
14. Mixes well with oil.
15. Low viscosity so that pressure drop is small.