Moist Air - the Mollier Diagram
The Mollier diagram is a graphic representation of the relationship between air temperature, moisture content and enthalpy - and is a basic design tool for building engineers and designers.
Air is a mixture of mostly oxygen, nitrogen and water vapor. The Mollier diagram is a graphic representation of the relationship between air temperature, moisture content and enthalpy, and is a basic design tool for building engineers and designers.
Download and print Mollier diagram
- common psychrometrics terms
The Mollier diagram is a variant of the psychrometric chart.
- Transform between Mollier diagram and psychrometric chart
Example - How to use the Mollier Chart
The state of air with dry bulb temperature 21 oC and relative humidity 50% is indicated in the Moliier chart below:
From the Mollier chart the enthalpy of the moist air is approximately 40 kJ/kg. The wet bulb temperature is approximately 14.5 oC. The specific humidity is approximately 0.0076 kg/kg.
Alternatively - if the dry bulb temperature is 19 oC and the wet bulb temperature is 12 oC - the state of the air can be visualized in the Mollier chart like:
From the chart we can see that the enthalpy of the air is approximately 33 kJ/kg and the specific humidity is approximately 0.0056 kg/kg.
