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User's Guide


The Modelica Annex60 library is a free open-source library with classes (models, functions, etc.) that codify and demonstrate best practices for the implementation of models for building and community energy and control systems. The library is developed within the Annex 60 project of the International Energy Agency's Energy in Buildings and Communities Programme.

Many models are based on models from the package Modelica.Fluid and use the same ports to ensure compatibility with models from that library. However, a design change is that models from the Annex60 library do not require the use of Modelica.Fluid.System as applications in buildings often have multiple fluids with largely varying flow rates, and therefore a global declaration is impractical.

The development page for this library has been Future development will continue on We welcome contributions from different users to further advance this library, whether it is through collaborative model development, through model use and testing or through requirements definition or by providing feedback regarding the model applicability to solve specific problems.

The library has the following User's Guides:

Fluid Package for one-dimensional fluid in piping networks with heat exchangers, valves, etc.
Fluid.Actuators Package with valves and air dampers.
Fluid.Movers Package with fans and pumps.
Fluid.Sensors Package with sensors.
Fluid.Interfaces Base models that can be used by developers to implement new models.

Extends from Modelica.Icons.Information (Icon for general information packages).

Package Content

Name Description
Annex60.UsersGuide.Conventions Conventions Conventions
Annex60.UsersGuide.ReleaseNotes ReleaseNotes Release notes
Annex60.UsersGuide.Contact Contact Contact
Annex60.UsersGuide.Acknowledgements Acknowledgements Acknowledgements
Annex60.UsersGuide.License License Modelica License 2
Annex60.UsersGuide.Copyright Copyright Copyright

Annex60.UsersGuide.Conventions Annex60.UsersGuide.Conventions



This library follows the conventions of the Modelica Standard Library, which are as follows:

Note, in the html documentation of any Modelica library, the headings "h1, h2, h3" should not be used, because they are utilized from the automatically generated documentation/headings. Additional headings in the html documentation should start with "h4".

In the Modelica package the following conventions are used:

  1. Class and instance names are written in upper and lower case letters, e.g., "ElectricCurrent", and may contain numbers. An underscore is only used at the end of a name to characterize a lower or upper index, e.g., "pin_a".
  2. Class names start always with an upper case letter.
  3. Instance names, i.e., names of component instances and of variables (with the exception of constants), start usually with a lower case letter with only a few exceptions if this is common sense (such as "T" for a temperature variable).
  4. Constant names, i.e., names of variables declared with the "constant" prefix, follow the usual naming conventions (= upper and lower case letters) and start usually with an upper case letter, e.g. UniformGravity, SteadyState, with only few exceptions such as "pi" and "h_fg".
  5. The two connectors of a domain that have identical declarations and different icons are usually distinguished by "_a", "_b" or "_p", "_n", e.g., Flange_a/Flange_b, HeatPort_a, HeatPort_b.
  6. The instance name of a component is always displayed in its icon (= text string "%name") in blue color. A connector class has the instance name definition in the diagram layer and not in the icon layer. If displayed, parameter values, e.g., resistance, mass, gear ratio, are displayed in the icon in black color in a smaller font size as the instance name.
  7. Packages have usually the following subpackages:

The Annex60 library uses the following conventions in addition to the ones of the Modelica Standard Library:

  1. The nomenclature used in the package Annex60.Utilities.Psychrometrics is as follows,
  2. Names of models, blocks and packages should start with an upper-case letter and be a noun or a noun with a combination of adjectives and nouns. Use camel-case notation to combine multiple words, such as HeatTransfer.
  3. Parameter and variables names are usually a character, such as T for temperature and p for pressure, or a combination of the first three characters of a word, such as higPreSetPoi for high pressure set point.
  4. Comments should be added to each class (package, model, function etc.). The first character should be upper case. For one-line comments of parameters, variables and classes, no period should be used at the end of the comment.
  5. All variables that have a physical correspondence, including physical ratios, must have a unit. Use (derived) SI units. Non-SI units are to be kept at an absolute minimum, and they must be declared as protected.
  6. To indicate that a class (i.e., a package, model, block etc.) has not been extensively tested or validated, its class name ends with the string Beta.

Extends from Modelica.Icons.Information (Icon for general information packages).

Modelica definition

class Conventions "Conventions" extends Modelica.Icons.Information; end Conventions;

Annex60.UsersGuide.Contact Annex60.UsersGuide.Contact




The development of the Annex60 library is done through the Annex 60 project of the Energy in Buildings and Communities Programme of the International Energy Agency.

Library point of contact
Michael Wetter
Lawrence Berkeley National Laboratory (LBNL)
One Cyclotron Road
Bldg. 90-3147
Berkeley, CA 94720

Extends from Modelica.Icons.Contact (Icon for contact information).

Modelica definition

class Contact "Contact" extends Modelica.Icons.Contact; end Contact;

Annex60.UsersGuide.Acknowledgements Annex60.UsersGuide.Acknowledgements




The following grants supported the development of the Annex60 library:

The following people have directly contributed to the implementation of the Annex60 library (many others have contributed by other means than model implementation):

Extends from Modelica.Icons.Information (Icon for general information packages).

Modelica definition

class Acknowledgements "Acknowledgements" extends Modelica.Icons.Information; end Acknowledgements;

Annex60.UsersGuide.License Annex60.UsersGuide.License

Modelica License 2


The Modelica License 2

Preamble. The goal of this license is that Modelica related model libraries, software, images, documents, data files etc. can be used freely in the original or a modified form, in open source and in commercial environments (as long as the license conditions below are fulfilled, in particular sections 2c) and 2d). The Original Work is provided free of charge and the use is completely at your own risk. Developers of free Modelica packages are encouraged to utilize this license for their work.

The Modelica License applies to any Original Work that contains the following licensing notice adjacent to the copyright notice(s) for this Original Work:

Note. This is the standard Modelica License 2, except for the following changes: the parenthetical in paragraph 7., paragraph 5., and the addition of paragraph 15.d).

Licensed by The Regents of the University of California, through Lawrence Berkeley National Laboratory under the Modelica License 2

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15. Miscellaneous

  1. If any provision of this License is held to be unenforceable, such provision shall be reformed only to the extent necessary to make it enforceable.
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How to Apply the Modelica License 2

At the top level of your Modelica package and at every important subpackage, add the following notices in the info layer of the package:

Include a copy of the Modelica License 2 under <library>.UsersGuide.ModelicaLicense2 (use Furthermore, add the list of authors and contributors under <library>.UsersGuide.Contributors or <library>.UsersGuide.Contact

For example, sublibrary Modelica.Blocks of the Modelica Standard Library may have the following notices:

For C-source code and documents, add similar notices in the corresponding file.

For images, add a "readme.txt" file to the directories where the images are stored and include a similar notice in this file.

In these cases, save a copy of the Modelica License 2 in one directory of the distribution, e.g., in directory <library>/help/documentation/ModelicaLicense2.html.

Extends from Modelica.Icons.Information (Icon for general information packages).

Modelica definition

class License "Modelica License 2" extends Modelica.Icons.Information; end License;

Annex60.UsersGuide.Copyright Annex60.UsersGuide.Copyright




Copyright (c) 2009-2017, The Regents of the University of California, through Lawrence Berkeley National Laboratory (subject to receipt of any required approvals from the U.S. Dept. of Energy). All rights reserved.

If you have questions about your rights to use or distribute this software, please contact Berkeley Lab's Technology Transfer Department at

NOTICE. This software was developed under partial funding from the U.S. Department of Energy. As such, the U.S. Government has been granted for itself and others acting on its behalf a paid-up, nonexclusive, irrevocable, worldwide license in the Software to reproduce, prepare derivative works, and perform publicly and display publicly. Beginning five (5) years after the date permission to assert copyright is obtained from the U.S. Department of Energy, and subject to any subsequent five (5) year renewals, the U.S. Government is granted for itself and others acting on its behalf a paid-up, nonexclusive, irrevocable, worldwide license in the Software to reproduce, prepare derivative works, distribute copies to the public, perform publicly and display publicly, and to permit others to do so.

Extends from Modelica.Icons.Information (Icon for general information packages).

Modelica definition

class Copyright "Copyright" extends Modelica.Icons.Information; end Copyright;