14 TRG-TRC003-EN
notes
period two
Refrigerants

The quantity of heat that must be added to the water in order for it to evaporate

cannot be sensed by an ordinary thermometer. This is because both the water

and steam remain at the same temperature during this phase change.

This kind of heat is called latent heat, which is dormant or concealed heat

energy. Latent heat is the energy involved in changing the phase of a

substance—from a liquid to a vapor in this example.

In contrast, sensible heat is heat energy that, when added to or removed from

a substance, results in a measurable change in temperature.

Refrigerants can absorb a significant amount of heat when they change phase;

much more than if they just change temperature. Different substances have

different specific temperatures at which these phase changes occur, and

different quantities of heat are required for this change to take place. They also

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