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psychrochart 0.1.5

A Python 3 library to make psychrometric charts and overlay information on them.

Latest Version: 0.1.6

It implements a useful collection of psychrometric equations for moisture and humid air calculations, and the generation of beautiful and high customizable psychrometric charts in SVG with matplotlib.

Calculations are made by implementing experimental equations extracted from recognized sources, such as the 2009 ASHRAE Handbook—Fundamentals (SI).


Clone it from Github if you want to run the tests, or simply:

pip install psychrochart


  • SI units (with temperatures in celsius for better readability).
  • Easy style customization with a JSON template (colors, line styles and line widths).
  • Psychrometric charts within temperature and humidity ratio ranges, for any pressure, with:
    • Saturation line
    • Constant RH lines
    • Constant enthalpy lines
    • Constant wet-bulb temperature lines
    • Constant specific volume lines
    • Constant dry-bulb temperature lines (internal orthogonal grid, vertical)
    • Constant humidity ratio lines (internal orthogonal grid, horizontal)
  • Plot legend for each family of lines
  • Specify labels for each family of lines
  • Overlay points and zones
  • Export SVG files
  • Tested against example tables from
  • 100 % code coverage.

The ranges of temperature, humidity and pressure where this library should provide good results are within the normal environments for people to live in. Don’t expect right results if doing other type of thermodynamic calculations. Over saturated water vapor states are not implemented.


  • v0.1.0: Initial version.
  • v0.1.1: Minor plotting fixes, set axis position, define P with altitude_m or pressure_kpa, reuse plot removing annotations (chart.remove_annotations). Axes as internal prop, lazy plotting, save to disk helper (
  • v0.1.2: Add agg module to set that matplotlib backend.
  • v0.1.3: Add custom params for plotting styles, option to exclude first and last tick (constant_{humid/temp}_label_include_limits).
  • v0.1.4: Customize labels and its locations for families of psychrometric curves.
  • v0.1.5: Add Arrows, compatibility with the Home Assistant component psychrometrics.


from psychrochart.chart import PsychroChart

# Load default style:
chart_default = PsychroChart()
axes = chart_default.plot()


To run the tests, clone the repository and run:

py.test --cov=psychrochart -v --cov-report html

to generate the coverage reports.


MIT license, so do with it as you like ;-)

File Type Py Version Uploaded on Size
psychrochart-0.1.5-py2.py3-none-any.whl (md5) Python Wheel py2.py3 2017-07-17 22KB
psychrochart-0.1.5-py3.5.egg (md5) Python Egg 3.5 2017-07-17 37KB
psychrochart-0.1.5.tar.gz (md5) Source 2017-07-17 19KB