Refrigerants; Terminology; R-450A Refrigerant - Traulsen G Series Service Manual

1.5

Refrigerants

1.5.1

Terminology:

Zeotropic Blend – A mixture of two or more refrigerants that have different boiling points that evaporate or
condense at different temperatures. All 400 Series Refrigerants are zeotropic blends.
Azeotropic Blend – A mixture of two or more refrigerants that boil at the same temperature so that they
evaporate and condense together. All 500 Series Refrigerants are azeotropic blends.
Temperature Glide – The temperature difference between the starting and ending temperature of a
refrigerant phase change within a system at a constant pressure. This can be seen on a Pressure Temperature
chart as the difference between bubble and dew temperatures.
Fractionation of Refrigerant – The change in composition of a blend because one or more of the components
is lost or removed faster than the others.
Bubble Point – The temperature at which the liquid of a refrigerant blend starts to boil.
Dew Point – The temperature at which the vapor of a refrigerant blend starts to condense.
Superheat – The heat added to a refrigerant after its saturation point. Or in other words, heat added to a
refrigerant after it boils.
Subcooling – The removed from a refrigerant after its saturation point. Or in other words, heat removed from
a refrigerant after it condenses.

1.5.2 R-450A Refrigerant

R-450 Refrigerant is a refrigerant Traulsen uses in medium temperature applications. This refrigerant is
technically a zeotropic blend but has such a small temperature glide that it could be considered a near
azeotropic blend.
Figure 3: Understanding Traulsen Serial Number
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