Latent heat is absorbed or released during change of
phase (ice/water, water/steam) with no temperature change.
Example: All the water in a boiling pot is at 100°C no matter
how much additional heat is added until all the water is gone.
Sensible heat produces temperature change when added or removed.
Two forms of heat are relevant in air conditioning are
Sensible heat
Latent heat
1. Sensible heat
When an object is heated, its temperature rises as heat is added. The increase in heat is called sensible heat. Similarly, when heat is removed from an object and its temperature falls, the heat removed is also called sensible heat. Heat that causes a change in temperature in an object is called sensible heat.
2.Latent heat
All pure substances in nature are able to change their state. Solids can become liquids (ice to water) and liquids can become gases (water to vapor) but changes such as these require the addition or removal of heat. The heat that causes these changes is called latent heat.Latent heat however, does not affect the temperature of a substance - for example, water remains at 100°C while boiling. The heat added to keep the water boiling is latent heat. Heat that causes a change of state with no change in temperature is called latent heat.
Two forms of heat are relevant in air
conditioning:
Sensible heat
Latent heat
Sensible heat
When an object is heated, its
temperature rises as heat is added. The
increase in heat is called sensible heat.
Similarly, when heat is removed from an
object and its temperature falls, the heat
removed is also called sensible heat.
Heat that causes a change in
temperature in an object is called
sensible heat.
Latent heat
All pure substances in nature are able to
change their state. Solids can become
liquids (ice to water) and liquids can
become gases (water to vapor) but
changes such as these require the
addition or removal of heat. The heat
that causes these changes is called
latent heat.
Latent heat however, does not affect the
temperature of a substance - for
example, water remains at 100°C while
boiling. The heat added to keep the
water boiling is latent heat. Heat that
causes a change of state with no change
in temperature is called latent heat.
Appreciating this difference is
fundamental to understanding why
refrigerant is used in cooling systems. It
also explains why the terms 'total
capacity' (sensible & latent heat) and
'sensible capacity' are used to define a
unit's cooling capacity. During the
cooling cycling, condensation forms
within the unit due to the removal of
latent heat from the air. Sensible
capacity is the capacity required to lower
the temperature and latent capacity is
the capacity to remove the moisture from
the air.
Sensible heat
When an object is heated, its temperature rises as heat is added. The increase in heat is called sensible heat. Similarly, when heat is removed from an object and its temperature falls, the heat removed is also called sensible heat. Heat that causes a change in temperature in an object is called sensible heat.
Latent heat
All pure substances in nature are able to change their state. Solids can become liquids (ice to water) and liquids can become gases (water to vapor) but changes such as these require the addition or removal of heat. The heat that causes these changes is called latent heat.
When heat absorbed/given out by a substance produces a change in temperature of the
substance it is called sensible heat. The amount of heat energy in this case can be measured by
Delta Q = mc(Delta T)., where Delta Q = heat absorbed/given out, m = mass ofthe substance
c = specific heat of the substance and (Delta T) = rise/fall in temperature.
When heat absorbed/given out by a substance produces a change in phase of the substance
(from solid to liquid or vapor, from liquid to vapor / from vapor to liquid or solid, from liquid to
solid) without any change of temperature it is called Latent Heat. The amount of heat in this case
is measured by Delta Q = mL, where L = energy absorbed/given out per unit mass and is called
Latent heat of fusion/solidification, Latent heat of sublimation, Latent heat of vaporisation/
condensation depending on the type of change of phase.
