1. Characteristics of refrigerant
1.1 Temperature-pressure relationships in saturated condition
1.2 Strong/weak points of freon
1.2.1 Strong points
1) Chemical stability
2) No toxicity
3) By little corrosive action on metals, it is applicable to almost all metals.
4) The ratio of Cp/Cv is lower than ammonia and the discharge gas temperature is low, so air cooling type is available.
1.2.2 Weak points
1) A little amount of evaporation heat should circulate a great deal of liquid at the same refrigerating capacity.
2) When using for iron steels, scale occurs more rapidly than ammonia use due to hydrolysis .
3) Generally it is fused in lubricant.
4) Since it is not melted in water, water is separated and water closing occurs in capillary tube.
5) High price
-10
0
10
20
30
40
50
60
70
80
0
5
10
15
20
25
30
35
Saturation curve
Temperature(
°
C)
Pressure (kg/cm2 G)
R-22
R-12
INSTALLATION
TCL Air Conditioner Service Manual
2