Air Conditioning Fundamentals
TC070-05-01S
4 – PRINCIPLES OF
REFRIGERATION
18
Principle Two: Temperature and Mass
According to Principle Two, the mass of an object remains the same
regardless of its heat content. For example, the pan of water in Figure
3 weighs one pound whether it is at its freezing point or boiling point.
Principle Three: Latent Heat of Vaporization
Principle Three states that when matter changes from a liquid to a
vapor, it absorbs a large amount of heat without changing
temperature.
Figure 4 illustrates this principle. At sea level, water exists as a liquid
between 32° and 212° F (0° and 100° C). At exactly 212° F (100° C),
water can be either a liquid or a vapor, depending on how much heat it
contains. By adding more heat to the water, you can eventually
convert it to steam, but the temperature of the steam will remain 212°
F (100° C).
FIGURE 3. Principle
Two – The mass of an
object remains the
same regardless of its
temperature.
FIGURE 4. Principle
Three – When matter
changes from a liquid
to a vapor, it absorbs
large amounts of heat
without changing
temperature
212°F
1 lb. water
1 lb. water
Add heat
Solid
Liquid
Vapor
Remove heat