ht: Heat Transfer component of Chemical Engineering Design Library (ChEDL)


ht is open-source software for engineers and technicians working in the fields of chemical or mechanical engineering. It includes modules for various heat transfer functions.

Among the tasks this library can be used for are:

  • Sizing a Shell & Tube heat exchanger using any of the Zukauskas, ESDU 73031, or Bell methods

  • Calculating pressure drop in a Hairpin heat exchanger

  • Calculating heat loss of objects, including insulated objects

  • Calculating heat loss from buried pipe

  • Performing radiative heat transfer calculations

  • Conderser and Reboiler rating

  • Detailed heat exchanger evaluation; finding fouling factors

  • Heat transfer in packed beds

  • Sizing a Plate and Frame heat exchanger

  • Modeling an Air Cooler

  • Supercritical CO2 or water heat transfer

Version_status Documentation Build_status license Supported_versions Zendo



Get the latest version of ht from

If you have an installation of Python with pip, simple install it with:

$ pip install ht

To get the git version, run:

$ git clone git://

Latest source code

The latest development version of ht’s sources can be obtained at

Bug reports

To report bugs, please use the ht’s Bug Tracker at:

License information

ht is MIT licensed. See LICENSE.txt for information on the terms & conditions for usage of this software, and a DISCLAIMER OF ALL WARRANTIES.

Although not required by the ht license, if it is convenient for you, please cite ht if used in your work. Please also consider contributing any changes you make back, such that they may be incorporated into the main library and all of us will benefit from them.


To cite ht in publications use:

Caleb Bell and Contributors (2016-2023). ht: Heat transfer component of Chemical Engineering Design Library (ChEDL)

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