Specific latent heat means the amount of heat energy needed to convert a phase to another phase of a unit mass of a substance completely. However, when this phase change occurs at this temperature, heat energy is absorbed by water molecules, to break the bonds, but it will not increase the temperature more. For water, this phase change occurs at 100вЊ (boiling point of water). For this, energy is needed, and this energy is known as the latent heat of vaporization. So, when water molecules are evaporating, the hydrogen bonds between the water molecules have to be broken. But, when heating at the boiling point, most of the water molecules will be released to the vapor state. At normal temperature, there will be equilibrium between the vapor state and liquid state water molecules. However, some water molecules are capable of escaping to the vapor state if they have high kinetic energy. Compared to this, liquid state water molecules have low energies. They move around as single water molecules. And there are no intermolecular attraction forces. For example, in the vapor state, water molecules are highly energetic. The phase change absorbs energy/ heat (endothermic) when going from solid to liquid or liquid to gas. The phase change releases heat (exothermic) when converting gas to liquid or liquid to solid. And latent heat of vaporization takes place during boiling or condensing. Latent heat of fusion takes place during melting or freezing. So the two forms of latent heat are latent heat of fusion and latent heat of vaporization. It is a spontaneous conversion and occurs at a characteristic temperature for a given pressure. A phase change means a solid going to the gaseous phase or a liquid going to a solid phase or vice versa. This heat changes do not cause temperature changes as they are absorbed or released. Latent heat is the heat that is being absorbed or released from a substance during a phase change. When a substance undergoes a phase change, the energy is absorbed or released as heat. Heat transfer takes place from high temperature to low temperature, which is according to a temperature gradient. When the energy of a system changes because of a temperature difference between the system and its surroundings, we say that energy has been transferred as heat (q).

Latent heat formula hvac