Version 8.1.0

Version 8.1.0 is a minor release that is backwards compatible with version 8.0.0. The library has been tested with Dymola 2022, JModelica (revision 14023), OpenModelica 1.19.0-dev (449+g4f16e6af22), and OPTIMICA (revision OCT-stable-r19089_JM-r14295).

The following changes have been done:

• Added a package to compute undisturbed ground temperatures.
• Added controller for radiant cooling and heating systems.
• Added a package for district cooling applications.
• Added a new boiler model that is suitable for condensing boilers.
• Corrected various errors and improved compliance with Modelica Language Standard.

Version 7.0.2

Version 7.0.2 is a bug fix release. The library has been tested with Dymola 2022, JModelica (revision 14023), OpenModelica 1.19.0-dev (449+g4f16e6af22) and OPTIMICA (revision OCT-stable-r19089_JM-r14295).

The following changes have been done:

• Improved models to comply with Modelica Language Standard. Now all models translate with OpenModelica.
• Corrected chiller models for situation where condenser is air cooled.
• Corrected occupancy models for simulations that do not start at time equal to zero.
• Implemtend various other improvements.

Version 8.0.0

Version 8.0.0 is a major release that contains the first version of the Spawn of EnergyPlus coupling. The library has been tested with Dymola 2021 and 2022, JModelica (revision 14023), and OPTIMICA (revision OCT-stable-r19089_JM-r14295).

The following major changes have been done:

• The package Buildings.ThermalZones.EnergyPlus contains the first version of the Spawn of EnergyPlus coupling that is being developed at https://lbl-srg.github.io/soep. The Spawn coupling allows to model HVAC and controls in Modelica, and graphically connect to EnergyPlus models for thermal zones, schedules, EMS actuators and output variables. This allows for example to model HVAC systems, HVAC controls and controls for active facade systems in Modelica, and use the EnergyPlus envelope model to simulate heat transfer through the building envelope, including the heat and light transmission through the windows for the current control signal of the active shade.
• The package Buildings.Experimental.DHC contains models for district heating and cooling systems that are being developed for the URBANopt District Energy System software.
• The new media Buildings.Media.Antifreeze.PropyleneGlycolWater allows modeling of propylene-glycol water mixtures.
• A new cooling coil model Buildings.Fluid.HeatExchangers.WetCoilEffectivenessNTU has been added. This model is applicable for fully-dry, partially-wet, and fully-wet regimes. In contrast to Buildings.Fluid.HeatExchangers.WetCoilCounterFlow and to Buildings.Fluid.HeatExchangers.WetCoilDiscretized, this model uses the epsilon-NTU relationship rather than a spatial discretization of the coil. This leads to fewer state variables and generally to a faster simulation.
• New simplified door models for bi-directional air exchange between thermal zones are implemented in Buildings.Airflow.Multizone.
• Various other models have been improved or added, in particular for modeling of control sequences using the Control Description Language that has been developed in the OpenBuildingControl project at https://obc.lbl.gov.

Version 7.0.1

Version 7.0.1 is a bug fix release. The library has been tested with Dymola 2021 and 2022, JModelica (revision 14023), and OPTIMICA (revision OCT-stable-r12473_JM-r14295).

The following changes have been done:

• Corrected memory violation on Windows for weather data file with long header lines.
• Corrected various misplaced or missing each declarations.
• Corrected access to protected classes.
• Reformulated replaceable class to avoid access of components that are not in the constraining type.
• Added missing parameter declarations for records.

Version 7.0.0

Version 7.0.0 is a major release that contains various new packages, new models and improvements to existing models. The library has been tested with Dymola 2020x and 2021, JModelica (revision 14023), and OPTIMICA (revision OCT-stable-r12473_JM-r14295).

The following major changes have been done:

• New packages have been added to model building controls (Buildings.Controls.OBC.Utilities) and to support the creation of emulators that compare the performance of building control sequences in the Building Optimization Performance Tests framework BOPTEST.
• Various new control blocks have been added to Buildings.Controls.OBC.CDL.
• Various new equipment models have been added, such as models of absorption chillers, CHP equipment and heat pumps.
• The reduced order building models now also allow modeling air moisture and air contaminant balance.
• A tutorial has been added to explain how to implement control sequences using the Control Description Language that is being developed in the OpenBuildingControl project.
• The icons of many components have been updated so that they visualize temperatures, flow rates or control signals while the simulation is running.
• Results of the ANSI/ASHRAE Standard 14 validation (BESTEST) are now integrated in the user's guide Buildings.ThermalZones.Detailed.Validation.BESTEST.UsersGuide.

Version 6.0.0

Version 6.0.0 is a major new release that contains various new packages, new models and improvements to existing models. The library has been tested with Dymola 2019FD01 and with JModelica (revision 12903).

The following major changes have been done:

• Various new packages have been added, such as:
  • A package for simulating occupancy and occupancy that resulted from IEA EBC Annex 66.
  • A package with models for geothermal borefields.
  • A package with blocks for control of shades and of outdoor lights.
  • A package with blocks that allow generating time series and scatter plots, and writing these plots to one or several html files.
  • A package with blocks for unit conversion.
• Various new control blocks have been added to Buildings.Controls.OBC.CDL.

Version 5.1.0

Version 5.1.0 adds new libraries, adds new components and improves various existing components. Version 5.1.0 updates the license to a 3-clause BSD license. It is backward compatible with versions 5.0.0 and 5.0.1.

This release adds a model for propylene glycol - water mixtures, a model for long pipes suited for district heating and cooling simulations, a new valve model whose opening characteristics can be fit to measured data, and idealized models that allow to prescribe the temperature and humidity in any part of a fluid flow system.

Version 5.0.1

Version 5.0.1 corrects an error in Buildings.Fluid.SolarCollectors that led to too small heat losses if a collector has more than one panel. Also, Dymola specific annotations to load data files in a GUI have been replaced for compatibility with other tools. Otherwise, version 5.0.1 is identical to 5.0.0.

All models simulate with Dymola 2017FD01, Dymola 2018 and JModelica (revision 10374).

Version 5.0.0

Version 5.0.0 is a major new release that contains new packages to model control sequences, a package with control sequences from ASHRAE Guideline 36 and a package with pre-configured models for data center chilled water plants. All models simulate with Dymola 2017FD01, Dymola 2018 and with JModelica (revision 10374).

The following major changes have been done:

• The package Buildings.Controls.OBC.CDL has been added. This package provides elementary blocks to implemented control sequences. The blocks conform to the Control Description Language specification published at http://obc.lbl.gov.
• The package Buildings.Controls.OBC.ASHRAE.G36_PR1 has been added. This package contains control sequences for variable air volume flow systems according to ASHRAE Guideline 36, public review draft 1. The implementation uses blocks from the above described Buildings.Controls.OBC.CDL package, and conforms to the Control Description Language specification.
• New models for ideal heaters and sensible coolers, and ideal humidifiers have been added.
• Various models have been improved.

Version 4.0.0

Version 4.0.0 is a major new release. It is the first release that is based on the Modelica IBPSA Library (https://github.com/ibpsa/modelica). All models simulate with Dymola 2017 FD01 and with JModelica, and the results of these simulators have been cross-compared and are equal within the expected tolerance.

The following major changes have been done:

• It no longer uses the Modelica_StateGraph2 library. Instead, it uses Modelica.StateGraph which is part of the Modelica Standard Library.
• The models in Buildings.Fluid.Movers have been refactored to increase the numerical robustness at very low speed when the fans or pumps are switched on or off.
• The following new packages have been added:
  • Buildings.Experimental.DistrictHeatingCooling with models for district heating and cooling with bi-directional flow in the distribution pipes.
  • Buildings.Fluid.FMI.Adaptors and Buildings.Fluid.FMI.ExportContainers, which allow export of HVAC systems and of thermal zones as Functional Mockup Units.
  • Buildings.Fluid.HeatExchangers.ActiveBeams, with active beams for cooling and heating.
  • Buildings.Fluid.HeatExchangers.DXCoils.WaterCooled, with water-cooled direct expansion cooling coils.
  • Buildings.ThermalZones.ReducedOrder, with reduced order models of thermal zones based on VDI 6007 that are suitable for district energy simulation.
• The package Buildings.Rooms has been renamed to Buildings.ThermalZones.Detailed. This was done because of the introduction of Buildings.ThermalZones.ReducedOrder, which is from the Annex60 library, in order for thermal zones to be in the same top-level package.
  For Dymola, the conversion script will update models that use any model of the package Buildings.Rooms.
• The model Buildings.Fluid.FixedResistances.FixedResistanceDpM has been refactored. Now, if the hydraulic diameter is not yet known, one can use the simpler model Buildings.Fluid.FixedResistances.PressureDrop, otherwise the model Buildings.Fluid.FixedResistances.HydraulicDiameter may be used. With this refactoring, also the model Buildings.Fluid.FixedResistances.SplitterFixedResistanceDpM has been renamed to Buildings.Fluid.FixedResistances.Junction and parameters that use the hydraulic diameter have been removed.
• The models Buildings.HeatTransfer.Conduction.SingleLayer, Buildings.HeatTransfer.Conduction.MultiLayer, and Buildings.HeatTransfer.Windows.Window have been refactored to add the option to place a state at the surface of a construction. This leads in many examples that use the room model to a smaller number of non-linear system of equations and a 20% to 40% faster simulation.
• The models Buildings.Fluid.HeatPumps.ReciprocatingWaterToWater and Buildings.Fluid.HeatPumps.ScrollWaterToWater have been added. Parameters to these models rely on calibration with tabulated heat pump performance data. Python scripts for the calibration of the heat pump models are in Buildings/Resources/src/fluid/heatpumps/calibration.