**condensation,**latent heat effects associated with the phase change are significant, similarly as for boiling, but in reverse. Note that the

**enthalpy of condensation**(or

**heat of condensation**) is by definition equal to the enthalpy of vaporization with the opposite sign. Latent heat is the amount of heat added to or removed from a substance to produce a change in phase. During vaporisation, this energy breaks down the intermolecular attractive forces, and also must provide the energy necessary to expand the gas (the

**pΔV work**). When latent heat is added or removed, no temperature change occurs. The enthalpy of vaporization is a function of the pressure at which that transformation takes place.

Latent heat of condensation – water at 0.1 MPa (atmospheric pressure)

**h**_{lg}** = – 2257 kJ/kg**

Latent heat of condensation – water at 3 MPa

**h**_{lg}** = – 1795 kJ/kg**

Latent heat of condensation – water at 16 MPa (pressure inside a pressurizer)

**h**_{lg}** = – 931 kJ/kg**

The **heat of condensation** diminishes with increasing pressure, while the boiling point increases. It vanishes completely at a certain point called the critical point. Above the critical point, the liquid and vapor phases are indistinguishable, and the substance is called a supercritical fluid.

The heat of condensation is the heat released to completely condendse a unit of saturated vapor and it equal to – **h _{lg} =h_{l} – h_{g}**.

The heat that is necessary to melt (or freeze) a unit mass at the substance at constant pressure is the heat of fusion and is equal to **h _{sl} = h_{l} − h_{s}**, where h

_{s }is the enthalpy of saturated solid and h

_{l}is the enthalpy of saturated liquid.

We hope, this article, **Latent Heat of Condensation – Enthalpy of Condensation**, helps you. If so, **give us a like** in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about thermal engineering.