Guide: Mollier to illustrate heating, cooling and humidification processes

Relative humidity and enthalpy are plotted in a diagram against temperature and specific humidity to form the Mollier diagram. The curved lines in the diagram are relative humidity while the diagonal lines are enthalpy.

The diagram is used to illustrate heating, cooling and humidification processes. The effect thereof is visualized, as well as how it relates to requirements for comfort conditions in a room.

The equations used to plot the Mollier chart are used in selection programs to calculate results of, for instance, change in temperature and humidity, as well as power consumption etc.

There are in fact two types of diagrams for visualisation of this kind. The Mollier diagram is mainly used outside of the English speaking countries, which instead uses a Psychrometric chart for the same information.

Learn more in our guide

Mollier diagram