Open source library for design and operation of building and district energy and control systems

The Modelica Buildings library is a free open-source library with dynamic simulation models for building and district energy and control systems. Its primary use is for flexible and fast modeling to accelerate transition towards decarbonized energy systems for new and existing buildings and district energy systems. The library is particularly suited for

  • rapid prototyping, design and analysis of new building and district energy and control systems,
  • testing of integrated energy systems and products to reduce their risk prior to field demonstrations or deployment,
  • controls development, specification, verification and deployment within a model-based design process,
  • analysis of the operation of existing building systems, and
  • export of digital twins to support operation for functional testing, verification of control sequences, energy-minimizing controls, fault detection and diagnostics.

The library contains models for

  • HVAC systems,
  • energy storage (water and ice tanks, borehole and borefields, PCM, and battery),
  • controls, including a reference implementation of ASHRAE Standard 231P,
  • heat transfer among rooms and the outside, either
    • natively in Modelica with a detailed or a reduced order model, or
    • integrated run-time coupling with EnergyPlus, aka, Spawn of EnergyPlus
  • multizone airflow, including natural ventilation and contaminant transport,
  • single-zone computational fluid dynamics coupled to heat transfer and HVAC systems,
  • data-driven load prediction for demand response applications, and
  • electrical DC and AC systems with two- or three-phases that can be balanced and unbalanced.

Projects that use this library include:

All development is open-source and we welcome contributions.

The models are available under the following open-source license.