Latent heat can be understood as heat energy in hidden form which is supplied or extracted to change the state of a substance without changing its temperature. Examples are
The term was introduced around 1762 by
In contrast to latent heat,
The terms ″sensible heat″ and ″latent heat″ refer to types of heat transfer between a body and its surroundings; they depend on the properties of the body. ″Sensible heat″ is ″sensed″ or felt in a process as a change in the body's temperature. ″Latent heat″ is heat transferred in a process without change of the body's temperature, for example, in a phase change ( solid / liquid / gas ).
Both sensible and latent heats are observed in many processes of transfer of energy in nature. Latent heat is associated with the change of phase of atmospheric or ocean water,
The original usage of the term, as introduced by Black, was applied to systems that were intentionally held at constant temperature. Such usage referred to latent heat of expansion and several other related latent heats. These latent heats are defined independently of the conceptual framework of thermodynamics.
When a body is heated at constant temperature by thermal radiation in a microwave field for example, it may expand by an amount described by its latent heat with respect to volume or latent heat of expansion, or increase its pressure by an amount described by its latent heat with respect to pressure. Latent heat is energy released or absorbed, by a body or a
In both cases the change is
If the vapor then condenses to a liquid on a surface, then the vapor's latent energy absorbed during evaporation is released as the liquid's
The large value of the