Living Psychrometrics

This app offers three different calculations illustrating animated psychrometrics diagrams: the necessary capacity to heat up or cool down an air volume, the probability of carburetor icing and using a heat exchanger for heat recovery in rooms.

This app runs on Android devices and preferably on tablets. On devices with smaller screens, you may need to zoom.

The three different calculations are:

  • CapacitiesCapacities

Calculates the required capacity to heat up or cool down a given amount of air (e.g. air in your room) and shows the results both in a pane and on a diagram.




  • Heat exchangerHeatExchange

Calculates how warm room air heats up cool ambient air before supplying it as fresh air to the room. While heating up the ambient air, the heat exchanger cools down the room air, which may result in condensate. To prevent this, this calculation dimensions an electric heater when the ambient air would be too cold.




  • Carburetor icingIcing

Given a temperature and a dew point temperature, calculates the probability of icing in an airplane carburetor. Graphically shows the danger zones on a diagram.




These three calculations show the results in a panel, but also graphically in a diagram. You can choose between three different diagrams:

  • PsychrometricsPsychrometrics

This is the classic diagram representing different kinds of air properties into a single diagram. You find detailed descriptions in standard books about air treatment, such as ASHRAE. This diagram shows lines of constant temperature, humidity ratio, relative humidity, enthalpy, wet bulb temperature and specific volume.






  • MollierMollier

This is probably the oldest diagram to represent air properties and named after its inventor Richard Mollier (1863-1935). To get a psychrometrics diagram from a Mollier diagram, swap it along the vertical axis and rotate it 900

The Mollier diagram is heavily used in Eastern Europe and Germany and shows the same lines as in the psychrometrics diagram.





  • DewpointDewpoint

This diagram is meant for meteorologists and pilots. It is easy to read important weather data, such as temperature, dew point and relative humidity. However, this diagram shows the same constant lines as for the other two. Interestingly, the straight lines in the other two diagrams become curved lines in this one and vice versa.






  • Select two air properties to define a point: dry bulb temperature, wet bulb temperature, humidity ratio, relative humidity, enthalpy, specific volume and moist air density.
  • No need for a keyboard: move point over a diagram to change its air properties. Change other values using a slider.
  • Choose between metric or imperial unit dimensions, e.g. 0C and 0F or kW and BTU/h.
  • See immediate results of any change on the diagrams and the result panel shows detailed information about a point on the diagram.
  • Choose one of the diagram types (Psychrometrics, Mollier or Dewpoint) for the graphical results. Hide some constant lines on the selected diagram to simplify it or change the colors of the constant lines in the diagrams.
  • Define the efficiency properties of a heat exchanger, giving you professional results.
  • Tap the explain tab to get a short explanation of a calculation or a diagram.
  • Zoom in (two fingers gesture) and pan (one finger gesture) to enlarge a part of the diagram.
  • The app saves your latest settings and starts up with those settings.
  • Detects the language settings on the Android device and, if possible, changes its language (French, German, Spanish and Dutch). Otherwise keeps using English.
  • Adapts its user interface when you rotate your screen.

Video Demo

Watch the demonstration video.


This app is available on Apple Store, Google Play and Microsoft Store