This section summarizes the changes that have been performed on the Buildings library
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Name  Description 

Version_1_3_build1  Version 1.3 build 1 
Version_1_2_build1  Version 1.2 build 1 
Version_1_1_build1  Version 1.1 build 1 
Version_1_0_build2  Version 1.0 build 2 
Version_1_0_build1  Version 1.0 build 1 
Version_0_12_0  Version 0.12.0 
Version_0_11_0  Version 0.11.0 
Version_0_10_0  Version 0.10.0 
Version_0_9_1  Version 0.9.1 
Version_0_9_0  Version 0.9.0 
Version_0_8_0  Version 0.8.0 
Version_0_7_0  Version 0.7.0 
Version_0_6_0  Version 0.6.0 
Version_0_5_0  Version 0.5.0 
Version_0_4_0  Version 0.4.0 
Version_0_3_0  Version 0.3.0 
Version_0_2_0  Version 0.2.0 
Version_0_1_0  Version 0.1.0 
In version 1.3 build 1, models for direct evaporative cooling coils with multiple stages or with a variable speed compressor have been added. This version also contains improvements to the fan and pump models to better treat zero mass flow rate. Various other improvements have been made to improve the numerics and to use consistent variable names. A detailed list of changes is shown below.
The following new libraries have been added:
Buildings.Fluid.HeatExchangers.DXCoils  Library with direct evaporative cooling coils. 
The following new components have been added to existing libraries:
Buildings.Examples  
Buildings.Examples.ChillerPlant.DataCenterContinuousTimeControl  Added chilled water plant model with continuous time control that
replaces the discrete time control in
Buildings.Examples.ChillerPlant.DataCenterDiscreteTimeControl .

Buildings.Utilities  
Buildings.Utilities.Psychrometrics.Functions.X_pSatpphi  Function that computes moisture concentration based on saturation pressure, total pressure and relative humidity. 
Buildings.Utilities.Psychrometrics.TWetBul_TDryBulPhi  Block that computes the wet bulb temperature for given dry bulb temperature, relative humidity and atmospheric pressure. 
Buildings.Utilities.Psychrometrics.WetBul_pTX  Block that computes the temperature and mass fraction at the wet bulb state for given dry bulb temperature, species concentration and atmospheric pressure. 
The following existing components have been improved in a backward compatible way:
Buildings.BoundaryConditions  
Buildings.BoundaryConditions.WeatherData.ReaderTMY3  Added computation of the wet bulb temperature.
Computing the wet bulb temperature introduces a nonlinear
equation. As we have not observed an increase in computing time
because of computing the wet bulb temperature, it is computed
by default. By setting the parameter
computeWetBulbTemperature=false , the computation of the
wet bulb temperature can be removed.

Buildings.Controls  
Buildings.Controls.SetPoints.OccupancySchedule  Added pre operator and relaxed tolerance in assert statement.

Buildings.Fluid  
Buildings.Fluid.Movers.FlowMachine_dp Buildings.Fluid.Movers.FlowMachine_m_flow Buildings.Fluid.Movers.FlowMachine_Nrpm Buildings.Fluid.Movers.FlowMachine_y 
Reformulated implementation of efficiency model to avoid a division by zero at zero mass flow rate for models in which a user specifies a power instead of an efficiency performance curve. 
Buildings.Utilities  
Buildings.Utilities.Psychrometrics.TWetBul_TDryBulXi  Added option to approximate the wet bulb temperature using an explicit equation. Reformulated the original model to change the dimension of the nonlinear system of equations from two to one. 
The following existing components have been improved in a nonbackward compatible way:
Buildings.BoundaryConditions  
Buildings.BoundaryConditions.WeatherData.ReaderTMY3 Buildings.BoundaryConditions.Types 
Improved the optional inputs for the radiation data global horizontal, diffuse horizontal and direct normal radiation. If a user specifies two of them, the third will be automatically calculated. 
Buildings.BoundaryConditions.SkyTemperature.BlackBody  Renamed radHor to radHorIR
to indicate that the radiation is in the infrared
spectrum.

Buildings.Fluid  
Buildings.Airflow.Multizone.BaseClasses.DoorDiscretized Buildings.Airflow.Multizone.DoorDiscretizedOpen Buildings.Airflow.Multizone.DoorDiscretizedOperable Buildings.Airflow.Multizone.Orifice Buildings.Airflow.Multizone.ZonalFlow_ACS Buildings.Fluid.Actuators.BaseClasses.PartialDamperExponential Buildings.Fluid.Actuators.Dampers.MixingBox Buildings.Fluid.Actuators.Dampers.VAVBoxExponential Buildings.Fluid.BaseClasses.PartialResistance Buildings.Fluid.Interfaces.TwoPortHeatMassExchanger Buildings.Fluid.Movers.BaseClasses.PowerInterface Buildings.Fluid.Storage.BaseClasses.Buoyancy Buildings.Fluid.HeatExchangers.BaseClasses.MassExchange 
Renamed protected parameters for consistency with the naming conventions.
In previous releases, fluid properties had the suffix 0
or _nominal instead of _default when they
where computed based on the medium default properties.

Buildings.Fluid.Sensors.SensibleEnthalpyFlowRate Buildings.Fluid.Sensors.LatentEnthalpyFlowRate 
Moved computation of parameter i_w to new base class
Buildings.Fluid.BaseClasses.IndexWater
The value of this parameter is now assigned dynamically and does not require to be specified
by the user.

Buildings.Fluid.Storage.BaseClasses.ThirdOrderStratifier  Removed unused protected parameters sta0 and cp0 .

Buildings.Examples  
Buildings.Examples.ChillerPlant.DataCenterDiscreteTimeControl Buildings.Examples.ChillerPlant.BaseClasses.Controls.TrimAndRespond Buildings.Examples.ChillerPlant.BaseClasses.Controls.ZeroOrderHold 
Reimplemented the controls for setpoint reset.
Revised the model TrimAndRespond and deleted the model ZeroOrderHold .
Improved the documentation.

The following critical errors have been fixed (i.e., errors that can lead to wrong simulation results):
Buildings.Examples  
Buildings.Examples.ChillerPlant.DataCenterDiscreteTimeControl  Fixed error in wet bulb temperature. The previous version used a model to compute the wet bulb temperature that takes as an input the relative humidity, but required mass fraction as an input. 
The following uncritical errors have been fixed (i.e., errors that do not lead to wrong simulation results, e.g., units are wrong or errors in documentation):
Buildings.BoundaryConditions  
Buildings.BoundaryConditions.WeatherData.ReaderTMY3 Buildings.BoundaryConditions.SkyTemperature.BlackBody 
Renamed radHor to radHorIR .

Buildings.Fluid  
Buildings.Fluid.BaseClasses.FlowModels.Examples.InverseFlowFunction  Fixed error in the documentation. 
Buildings.Fluid.Interfaces.TwoPortHeatMassExchanger  Fixed broken link in the documentation. 
Buildings.Fluid.Movers.BaseClasses.Characteristics.powerParameters  Fixed wrong displayUnit and
max attribute for power.

Buildings.Fluid.MixingVolumes  In documentation, removed reference to the parameter
use_HeatTransfer which no longer exists.

Buildings.HeatTransfer  
Buildings.HeatTransfer.Windows.Functions.glassPropertyUncoated  Improved the documentation for implementation and added comments for model limitations. 
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
In version 1.2 build 1, models for radiant slabs and window overhangs and sidefins have been added. This version also contains various improvements to existing models. A detailed list of changes is shown below.
The following new libraries have been added:
Buildings.Fluid.HeatExchangers.RadiantSlabs  Package with models for radiant slabs with pipes or a capillary heat exchanger embedded in the construction. 
Buildings.Fluid.Data.Pipes  Package with records for pipes. 
The following new components have been added to existing libraries:
Buildings.HeatTransfer  
Buildings.HeatTransfer.Windows.FixedShade Buildings.HeatTransfer.Windows.Overhang Buildings.HeatTransfer.Windows.SideFins 
For windows with either an overhang or side fins, these blocks output the fraction of the area that is sun exposed. 
Buildings.Rooms  
Buildings.Rooms.Examples.BESTEST  Added BESTEST validation models for case 610, 620, 630, 640, 650FF, 650, 920, 940, 950FF, 950, and 960. 
The following existing components have been improved in a backward compatible way:
Buildings.BoundaryConditions  
Buildings.BoundaryConditions.WeatherData.ReaderTMY3  Removed assignment of HGloHor_in in its declaration,
because this gives an overdetermined system if the input connector
is used.Added new subbus that contains the solar position. This allows reusing the solar position in various other models. 
Buildings.BoundaryConditions.SolarIrradiation.DiffuseIsotropic Buildings.BoundaryConditions.SolarIrradiation.DiffusePerez Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.DiffuseIsotropic Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.DiffusePerez 
Added optional output of diffuse radiation from the sky and ground. This allows reusing the diffuse radiation in solar thermal collector. 
Buildings.BoundaryConditions.SolarGeometry.BaseClasses.SolarAzimuth  Changed implementation to avoid an event at solar noon. 
Buildings.HeatTransfer  
Buildings.HeatTransfer.Data.BoreholeFillings 
Renamed class to BoreholeFillings
to be consistent with data records being plural.

Buildings.Media  
Buildings.Media.GasesPTDecoupled.MoistAir Buildings.Media.GasesPTDecoupled.MoistAirUnsaturated Buildings.Media.PerfectGases.MoistAir Buildings.Media.PerfectGases.MoistAirUnsaturated Buildings.Media.GasesConstantDensity.MoistAir Buildings.Media.GasesConstantDensity.MoistAirUnsaturated 
Added redeclaration of ThermodynamicState
to avoid a warning
during model check and translation.

Buildings.Rooms  
Buildings.Rooms.MixedAir  Added a check that ensures that the number of surfaces
are equal to the length of the parameter that contains
the surface area, and added a check to ensure that no surface area
is equal to zero. These checks help detecting erroneous declarations
of the room model. The changes were done in
Buildings.Rooms.MixedAir.PartialSurfaceInterface .

The following existing components have been improved in a nonbackward compatible way:
Buildings.Rooms  
Buildings.Rooms.MixedAir  Added optional modeling of window overhangs and side fins.
The modeling of window overhangs and side fins required the
introduction of the new parameters
hWin for the window height and
wWin for the window width, in addition to the
parameters ove and sidFin which are used
to declare the geometry of overhangs and side fins.
The parameters hWin and wWin
replace the previously used parameter AWin for the
window area.
Users need to manually replace AWin with hWin
and wWin when updating models
from a previous version of the library.See the information section in Buildings.Rooms.MixedAir for how to use these models. 
The following critical errors have been fixed (i.e., errors that can lead to wrong simulation results):
Buildings.Controls  
Buildings.Controls.SetPoints.OccupancySchedule  Fixed a bug that caused an error in the schedule if the simulation start time was negative or equal to the first entry in the schedule. 
Buildings.Fluid  
Buildings.Fluid.Storage.BaseClass.ThirdOrderStratifier  Revised the implementation to reduce the temperature overshoot. 
Buildings.HeatTransfer  
Buildings.HeatTransfer.Windows.BaseClasses.GlassLayer  Fixed the bug in the temperature linearization and in the heat flow through the glass layer if the transmissivity of glass in the infrared regime is nonzero. 
Buildings.HeatTransfer.Windows.BaseClasses.CenterOfGlass  Fixed a bug in the parameter assignment of the instance glass .
Previously, the infrared emissivity of surface a was assigned to the surface b.

Buildings.Utilities  
Buildings.Utilities.IO.BCVTB  Added a call to Buildings.Utilities.IO.BCVTB.BaseClasses.exchangeReals
in the initial algorithm section.
This is needed to propagate the initial condition to the server.
It also leads to one more data exchange, which is correct and avoids the
warning message in Ptolemy that says that the simulation reached its stop time
one time step prior to the final time.

The following uncritical errors have been fixed (i.e., errors that do not lead to wrong simulation results, e.g., units are wrong or errors in documentation):
Buildings.BoundaryConditions  
Buildings.BoundaryConditions.WeatherData.ReaderTMY3  Corrected the documentation of the unit requirement for input files, parameters and connectors. 
Buildings.Fluid  
Buildings.Fluid.Interfaces.PartialFourPortInterface Buildings.Fluid.Interfaces.PartialTwoPortInterface 
Replaced the erroneous function call Medium.density with
Medium1.density and Medium2.density in
PartialFourPortInterface .
Changed condition to remove sta_a1 and
sta_a2 in PartialFourPortInterface , and
sta_a in PartialTwoPortInterface , to also
compute the state at the inlet port if show_V_flow=true .The previous implementation resulted in a translation error if show_V_flow=true , but worked correctly otherwise
because the erroneous function call is removed if show_V_flow=false .

Buildings.Fluid.Chillers.Examples.BaseClasses.PartialElectric  Corrected the nominal mass flow rate used in the mass flow source. 
The following trac tickets have been fixed:
Heat transfer in glass layer  
#56  Fixed bug in heat flow through the glass layer if the infrared transmissivity is nonzero. 
#57  Fixed bug in temperature linearization of window glass. 
Overshooting in enhanced stratified tank  
#15  Revised the implementation to reduce the temperature overshoot. 
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Version 1.1 build 1 contains improvements to models that address numerical problems. In particular, flow machines and actuators now have an optional filter that converts step changes in the input signal to a smooth change in speed or actuator position. Also, ( Buildings.Examples.Tutorial) has been added to provide stepbystep instruction for how to build system models.
The following new libraries have been added:
Buildings.Examples.Tutorial  Tutorial with step by step instructions for how to build system models. 
The following new components have been added to existing libraries:
Buildings.Fluid  
Buildings.Fluid.FixedResistances.Pipe  Added a model for a pipe with transport delay and optional heat exchange with the environment. 
Buildings.Fluid.Actuators.UsersGuide  Added a user's guide for actuator models. 
Buildings.Fluid.Interfaces.ConservationEquation Buildings.Fluid.Interfaces.StaticConservationEquation 
These base classes have been added to simplify the implementation of dynamic and steadystate thermofluid models. 
Buildings.Fluid.Data.Fuels  Package with physical properties of fuels that are used by the boiler model. 
The following existing components have been improved in a backward compatible way:
Buildings.Fluid  
Buildings.Fluid.Actuators.Dampers.Exponential Buildings.Fluid.Actuators.Dampers.VAVBoxExponential Buildings.Fluid.Actuators.Dampers.MixingBox Buildings.Fluid.Actuators.Dampers.MixingBoxMinimumFlow Buildings.Fluid.Actuators.Valves.ThreeWayEqualPercentageLinear Buildings.Fluid.Actuators.Valves.ThreeWayLinear Buildings.Fluid.Actuators.Valves.TwoWayEqualPercentage Buildings.Fluid.Actuators.Valves.TwoWayLinear Buildings.Fluid.Actuators.Valves.TwoWayQuickOpening 
Added an optional 2nd order lowpass filter for the input signal.
The filter approximates the travel time of the actuators.
It also makes the system of equations easier to solve
because a step change in the input signal causes a gradual change in the actuator
position. Note that this filter affects the time response of closed loop control. Therefore, enabling the filter may require retuning of control loops. See the user's guide of the Buildings.Fluid.Actuators package. 
Buildings.Fluid.Boilers.BoilerPolynomial  Added computation of fuel usage and improved the documentation. 
Buildings.Fluid.Movers.FlowMachine_y Buildings.Fluid.Movers.FlowMachine_Nrpm Buildings.Fluid.Movers.FlowMachine_dp Buildings.Fluid.Movers.FlowMachine_m_flow 
Added a 2nd order lowpass filter to the input signal.
The filter approximates the startup and shutdown transients of fans or pumps.
It also makes the system of equations easier to solve
because a step change in the input signal causes a gradual change in the
mass flow rate. Note that this filter affects the time response of closed loop control. Therefore, enabling the filter may require retuning of control loops. See the user's guide of the Buildings.Fluid.Movers package. 
Buildings.Fluid.Interfaces.StaticTwoPortHeatMassExchanger  Changed model to use graphical implementation of models for pressure drop and conservation equations. 
Buildings.Fluid.BaseClasses.PartialResistance Buildings.Fluid.FixedResistances.FixedResistanceDpM Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve Buildings.Fluid.Actuators.BaseClasses.PartialDamperExponential 
Revised base classes and models to simplify object inheritance tree.
Set m_flow_small to final in Buildings.Fluid.BaseClasses.PartialResistance,
and removed its assignment in the other classes.

Buildings.Fluid.FixedResistances.FixedResistanceDpM Buildings.Fluid.FixedResistances.SplitterFixedResistanceDpM 
Improved documentation. 
Buildings.HeatTransfer  
Buildings.HeatTransfer.Windows.Functions.glassProperty  Added the function glassPropertyUncoated that calculates the property for uncoated glass.

Buildings.Rooms  
Buildings.Rooms.MixedAir  Changed model to use new implementation of Buildings.HeatTransfer.Radiosity.OutdoorRadiosity in its base classes. This change leads to the use of the same equations for the radiative heat transfer between window and ambient as is used for the opaque constructions. 
The following existing components have been improved in a nonbackward compatible way:
Buildings.Fluid  
Buildings.Fluid.Actuators.Valves.ThreeWayEqualPercentageLinear Buildings.Fluid.Actuators.Valves.ThreeWayLinear Buildings.Fluid.Actuators.Valves.TwoWayEqualPercentage Buildings.Fluid.Actuators.Valves.TwoWayLinear Buildings.Fluid.Actuators.Valves.TwoWayQuickOpening 
Changed models to allow modeling of a fixed resistance that is
within the controlled flow leg. This allows in some cases
the avoidance of a nonlinear equation if a flow resistance is
in series to the valve.
This change required changing the parameter for the valve resistance
dp_nominal to dpValve_nominal ,
and introducing the parameter
dpFixed_nominal , with dpFixed_nominal=0
as its default value.
Previous models that instantiate these components need to change the
assignment of dp_nominal to an assignment of
dpValve_nominal .
See also
Buildings.Fluid.Actuators.UsersGuide.

Buildings.HeatTransfer  
Buildings.HeatTransfer.Radiosity.OutdoorRadiosity Buildings.HeatTransfer.Windows.ExteriorHeatTransfer 
Changed model to use new implementation of Buildings.HeatTransfer.Radiosity.OutdoorRadiosity. This change leads to the use of the same equations for the radiative heat transfer between window and ambient as is used for the opaque constructions. 
Buildings.Controls  
Buildings.Controls.SetPoints.OccupancySchedule  Changed model to fix a bug that caused the output of the block
to be incorrect when the simulation started
at a time different from zero.
When fixing this bug, the parameter startTime was removed,
and the parameter endTime was renamed to period .
The period always starts at t=0 seconds.

The following critical errors have been fixed (i.e., errors that can lead to wrong simulation results):
Buildings.Controls  
Buildings.Controls.SetPoints.OccupancySchedule  The output of the block was incorrect when the simulation started at a time different from zero. 
Buildings.Fluid.HeatExchangers  
Buildings.Fluid.HeatExchangers.DryCoilCounterFlow Buildings.Fluid.HeatExchangers.WetCoilCounterFlow 
Corrected error in assignment of dp2_nominal .
The previous assignment caused a pressure drop in all except one element,
instead of the opposite. This caused too high a flow resistance
of the heat exchanger.

The following uncritical errors have been fixed (i.e., errors that do not lead to wrong simulation results, e.g., units are wrong or errors in documentation):
Buildings.BoundaryConditions  
Buildings.BoundaryConditions.SkyTemperature.BlackBody  Fixed error in BlackBody model that was causing a translation error when calTSky was set to Buildings.BoundaryConditions.Types.SkyTemperatureCalculation.HorizontalRadiation .

Buildings.Fluid  
Buildings.Fluid.Interfaces.TwoPortHeatMassExchanger  Fixed wrong class reference in information section. 
Buildings.Utilities  
Buildings.Utilities.IO.BCVTB.Examples.MoistAir  Updated fan parameters, which were still for version 0.12 of the Buildings library and hence caused a translation error with version 1.0 or higher. 
The following trac tickets have been fixed:
Exterior longwave radiation exchange in window model  
#51  Changed model to use new implementation of Buildings.HeatTransfer.Radiosity.OutdoorRadiosity. This change leads to the use of the same equations for the radiative heat transfer between window and ambient as is used for the opaque constructions. 
#53  Fixed bug in Buildings.Controls.SetPoints.OccupancySchedule that led to wrong results when the simulation started at a time different from zero. 
Note:
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Version 1.0 build 2 has been released to correct model errors that were present in version 1.0 build 1. Both versions are compatible. In addition, version 1.0 build 2 contains improved documentation of various example models.
The following existing components have been improved in a backward compatible way:
Buildings.Controls  
Buildings.Controls.Continuous Buildings.Controls.Discrete Buildings.Controls.SetPoints 
Improved documentation of models and of examples. 
Buildings.Airflow.Multizone  
Buildings.Airflow.Multizone.DoorDiscretizedOpen Buildings.Airflow.Multizone.DoorDiscretizedOperable 
Changed the computation of the discharge coefficient to use the
nominal density instead of the actual density.
Computing sqrt(2/rho) sometimes causes warnings from the solver,
as it seems to try negative values for the density during iterative solutions.

Buildings.Airflow.Multizone.Examples  Improved documentation of examples. 
Buildings.Examples.DualFanDualDuct  
Buildings.Examples.DualFanDualDuct.Controls.RoomMixingBox  Improved control of minimum air flow rate to avoid overheating. 
The following critical errors have been fixed (i.e., errors that can lead to wrong simulation results):
Buildings.HeatTransfer  
Buildings.HeatTransfer.Convection.Exterior  Fixed error in assignment of windbased convection coefficient. The old implementation did not take into account the surface roughness. 
Buildings.Rooms  
Buildings.Rooms.BaseClasses.SolarRadiationExchange  In the previous version, the radiative properties of the longwave spectrum instead of the solar spectrum have been used to compute the distribution of the solar radiation among the surfaces inside the room. 
Buildings.Rooms.BaseClasses.MixedAir  Added missing connect statement between window frame surface and window frame convection model. Prior to this bug fix, no convective heat transfer was computed between window frame and room air. 
Buildings.Rooms.BaseClasses.HeatGain  Fixed bug that caused convective heat gains to be removed from the room instead of added to the room. 
The following trac tickets have been fixed:
Buildings.Fluid.HeatExchangers.Boreholes  
#45  Dymola 2012 FD01 hangs when simulating a borehole heat exchanger.
This was caused by a wrong release of memory in freeArray.c .

Buildings.Rooms  
#46  The convective internal heat gain has the wrong sign. 
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Version 1.0 is the first official release of the Buildings
library.
Compared to the last prerelease, which is version 0.12, this version contains
new models as well as significant improvements to the model formulation
that leads to faster and more robust simulation. A detailed list of changes is shown below.
Version 1.0 is not backward compatible to version 0.12, i.e., models developed with versions 0.12 will require some changes in their parameters to work with version 1.0. The conversion script Buildings/Resources/Scripts/Dymola/ConvertBuildings_from_0.12_to_1.0.mos can help in converting old models to this version of the library.
The following new libraries have been added:
Buildings.Fluid.HeatExchangers.Boreholes  This is a library with a model for a borehole heat exchanger. 
The following new components have been added to existing libraries:
Buildings.Airflow.Multizone  
Buildings.Airflow.Multizone.BaseClasses.windPressureLowRise  Added a function that computes wind pressure on the facade of lowrise buildings. 
Buildings.Examples  
Buildings.Examples.ChillerPlant  Added an example for a chilled water plant model. 
Buildings.Fluid.Interfaces  
Buildings.Fluid.Interfaces.UsersGuide  Added a user's guide that describes the main functionality of all base classes. 
Buildings.Fluid.Sources  
Buildings.Fluid.Sources.Outside_Cp Buildings.Fluid.Sources.Outside_CpLowRise 
Added models to compute wind pressure on building facades. 
Buildings.HeatTransfer  
Buildings.HeatTransfer.Conductor  Added a model for heat conduction in circular coordinates. 
Buildings.Rooms.Examples  
Buildings.Rooms.Examples.BESTEST  Added BESTEST validation models. 
Buildings.Utilities.Math  
Buildings.Utilities.Math.Functions.cubicHermiteLinearExtrapolation Buildings.Utilities.Math.Functions.splineDerivatives. 
Added functions for cubic hermite spline interpolation, with option for monotone increasing (or decreasing) spline. 
The following existing components have been improved in a backward compatible way:
Buildings.Airflow.Multizone  
Buildings.Airflow.Multizone.BaseClasses.powerLaw  This function has been reimplemented to handle zero flow rate in a more robust and more efficient way. This change improves all components that model flow resistance in the package Buildings.Airflow.Multizone. 
Buildings.BoundaryConditions.WeatherData  
Buildings.BoundaryConditions.WeatherData.ReaderTMY3  This model has now the option of using a constant value, using the data from the weather file, or from an input connector for 7 variables, including atmospheric pressure, relative humidity, dry bulb temperature, global horizontal radiation, diffuse horizontal radiation, wind direction and wind speed. 
Buildings.Fluid  
Buildings.Fluid.Actuators.BaseClasses.PartialActuator Buildings.Fluid.Actuators.BaseClasses.PartialDamperExponential Buildings.Fluid.Actuators.BaseClasses.PartialTwoWayValve Buildings.Fluid.BaseClasses.PartialResistance Buildings.Fluid.BaseClasses.FlowModels.basicFlowFunction_dp Buildings.Fluid.BaseClasses.FlowModels.basicFlowFunction_m_flow Buildings.Fluid.Interfaces.StaticTwoPortHeatMassExchanger 
The computation of the linearized flow resistance has been moved from
the functions to the model, i.e., into an equation section.
If the linear implementation is in a function body, then a symbolic processor
may not invert the equation. This can lead to systems of coupled equations in
cases where an explicit solution is possible.
In addition, the handling of zero flow rate has been improved for the nonlinear
pressure drop model.
These improvements affect all models in Buildings.Fluid that compute
flow resistance. 
Buildings.Fluid.HeatExchangers  
Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed  This model can now be configured as a steadystate or dynamic model. 
Buildings.Fluid.HeatExchangers.DryCoilCounterFlow Buildings.Fluid.HeatExchangers.WetCoilCounterFlow Buildings.Fluid.HeatExchangers.DryCoilDiscretized Buildings.Fluid.HeatExchangers.WetCoilDiscretized 
The implementation for handling zero flow rate, if the models are used as steadystate models, have been improved. 
Buildings.Fluid.HeatExchangers.BaseClasses.ntu_epsilonZ  Changed implementation to use
Modelica.Media.Common.OneNonLinearEquation instead of
Buildings.Utilities.Math.BaseClasses.OneNonLinearEquation ,
which was removed for this version of the library.

Buildings.Fluid.HeatExchangers.CoolingTowers  
Buildings.Fluid.HeatExchangers.CoolingTowers.YorkCalc Buildings.Fluid.HeatExchangers.CoolingTowers.FixedApproach 
These models are now based on a new base class Buildings.Fluid.HeatExchangers.CoolingTowers.BaseClasses.CoolingTower .
This allows using the models as replaceable models without warning when checking the model.

Buildings.Fluid.HeatExchangers.CoolingTowers.YorkCalc  Changed implementation of performance curve to avoid division by zero. 
Buildings.Fluid.MassExchangers  
Buildings.Fluid.MassExchangers.HumidifierPrescribed  This model can now be configured as a steadystate or dynamic model. 
Buildings.Fluid.Sensors  
Buildings.Fluid.Sensors.*TwoPort  All sensors with two ports, except for the mass flow rate sensor, have been revised to add sensor dynamics. Adding sensor dynamics avoids numerical problems when mass flow rates are close to zero and the sensor is configured to allow flow reversal. See Buildings.Fluid.Sensors.UsersGuide for details. 
Buildings.Fluid.Storage  
Buildings.Fluid.Storage.Stratified Buildings.Fluid.Storage.StratifiedEnhanced 
Changed the implementation of the model Buoyancy
to make it differentiable in the temperatures. 
Buildings.Media  
Buildings.Media.Interfaces.PartialSimpleMedium Buildings.Media.Interfaces.PartialSimpleIdealGasMedium 
Moved the assignment of the stateSelect attribute for
the BaseProperties to the model
Buildings.Fluid.MixingVolumes.MixingVolume . This allows
to handle it differently for steadystate and dynamic models. 
Buildings.Utilities.Psychrometrics  
Buildings.Utilities.Psychrometrics.Functions.TDewPoi_pW  Changed implementation to use
Modelica.Media.Common.OneNonLinearEquation instead of
Buildings.Utilities.Math.BaseClasses.OneNonLinearEquation ,
which was removed for this version of the library.

The following existing components have been improved in a nonbackward compatible way:
Buildings.Airflow.Multizone  
Buildings.Airflow.Multizone.MediumColumnDynamic  The implementation has been changed to better handle mass flow rates
near zero flow.
This required the introduction of a new parameter m_flow_nominal
that is used for the regularization near zero mass flow rate. 
Buildings.Fluid  
Buildings.Fluid.Storage.Examples.Stratified Buildings.Fluid.MixingVolumes 
Removed the parameters use_T_start and h_start ,
as T_start is more convenient to use than h_start
for building simulation.

Buildings.Fluid.Boilers  
Buildings.Fluid.Boilers.BoilerPolynomial  The parameter dT_nominal has been removed
as it can be computed from the parameter m_flow_nominal .
This change was needed to avoid a nonliteral value for the nominal
attribute for the mass flow rate in the pressure drop model. 
Buildings.Fluid.MixingVolumes  
Buildings.Fluid.MixingVolumes.MixingVolume Buildings.Fluid.MixingVolumes.MixingVolumeDryAir Buildings.Fluid.MixingVolumes.MixingVolumeMoistAir 
The implementation has been changed to better handle mass flow rates
near zero flow if the components have exactly two fluid ports connected.
This required the introduction of a new parameter m_flow_nominal
that is used for the regularization near zero mass flow rate. 
Buildings.Fluid.Movers  
Buildings.Fluid.Movers.FlowMachine_y Buildings.Fluid.Movers.FlowMachine_Nrpm Buildings.Fluid.Movers.FlowMachine_dp Buildings.Fluid.Movers.FlowMachine_m_flow 
The performance data are now defined through records and not
through replaceable functions. The performance data now needs to be
declared in the formpressure(V_flow_nominal={0,V_flow_nominal,2*V_flow_nominal}, dp_nominal={2*dp_nominal,dp_nominal,0})where pressure is an instance of a record. A similar declaration is
used for power and efficiency.
The parameter m_flow_nominal has been removed from FlowMachine_y and FlowMachine_Nrpm. The parameter m_flow_max has been replaced by m_flow_nominal in FlowMachine_m_flow. The implementation of the pressure drop computation as a function of speed and volume flow rate has been revised to avoid a singularity near zero volume flow rate and zero speed. The implementation has also been simplified to avoid using two different flow paths if the models are configured for steadystate or dynamic simulation. 
Buildings.Fluid.Interfaces  
Buildings.Fluid.Interfaces.FourPortHeatMassExchanger Buildings.Fluid.Interfaces.PartialDynamicStaticFourPortHeatMassExchanger Buildings.Fluid.Interfaces.TwoPortHeatMassExchanger Buildings.Fluid.Interfaces.PartialDynamicStaticTwoPortHeatMassExchanger Buildings.Fluid.Interfaces.ConservationEquation 
The implementation has been changed to better handle mass flow rates near zero flow if the components have exactly two fluid ports connected. 
Buildings.Fluid.Sensors  
Buildings.Fluid.Sensors.TemperatureTwoPortDynamic  This model has been deleted since the sensor Buildings.Fluid.Sensors.TemperatureTwoPort has been revised and can now also be used as a dynamic model of a sensor. 
Buildings.Fluid.Interfaces  
Buildings.Fluid.Interfaces.PartialStaticTwoPortInterface  Renamed to Buildings.Fluid.Interfaces.PartialTwoPortInterface 
Buildings.Fluid.Interfaces.PartialStaticStaticTwoPortHeatMassExchanger  Renamed to Buildings.Fluid.Interfaces.StaticTwoPortHeatMassExchanger 
Buildings.Fluid.Interfaces.PartialTwoPortHeatMassExchanger  Renamed to Buildings.Fluid.Interfaces.TwoPortHeatMassExchanger 
Buildings.Fluid.Interfaces.PartialFourPort  Renamed to Buildings.Fluid.Interfaces.FourPort 
Buildings.Fluid.Interfaces.PartialStaticStaticFourPortHeatMassExchanger  Renamed to Buildings.Fluid.Interfaces.StaticFourPortHeatMassExchanger 
Buildings.Fluid.Interfaces.PartialStaticFourPortInterface  Renamed to Buildings.Fluid.Interfaces.PartialFourPortInterface 
Buildings.Fluid.Interfaces.PartialFourPortHeatMassExchanger  Renamed to Buildings.Fluid.Interfaces.FourPortHeatMassExchanger 
Buildings.Utilities.Math  
Buildings.Utilities.Math.BaseClasses.OneNonLinearEquation  This package has been removed, and all functions have been revised to use Modelica.Media.Common.OneNonLinearEquation. 
Buildings.Utilities.Reports  
Buildings.Utilities.Reports.Printer Buildings.Utilities.Reports.printRealArray 
Changed parameter precision to significantDigits and
minimumWidth to minimumLength
to use the same terminology as the Modelica Standard Library. 
The following critical errors have been fixed (i.e., errors that can lead to wrong simulation results):
Buildings.BoundaryConditions  
Buildings.BoundaryConditions.SkyTemperature.BlackBody  Fixed error in ifthen statement that led to
a selection of the wrong branch to compute the sky temperature. 
Buildings.Media  
Buildings.Media.PartialSimpleMedium Buildings.Media.GasesConstantDensity.SimpleAir 
Fixed error in assignment of singleState parameter.
This change can lead to different initial conditions if the density of
water is modeled as a function of pressure, or if the
medium model Buildings.Media.GasesConstantDensity.SimpleAir is used. 
Buildings.Media.GasesConstantDensity Buildings.Media.GasesConstantDensity.MoistAir Buildings.Media.GasesConstantDensity.MoistAirUnsaturated Buildings.Media.GasesConstantDensity.SimpleAir 
Fixed error in the function density which returned a nonconstant density,
and added a call to ModelicaError(...) in setState_dTX since this
function cannot assign the medium pressure based on the density (as density is a constant
in this model).

Buildings.Media.Interfaces.PartialSimpleIdealGasMedium  Updated package with a new copy from the Modelica Standard Library, since the Modelica Standard Library fixed a bug in computing the internal energy of the medium. This bug led to very fast temperature transients at the start of the simulation. 
Buildings.Media.Interfaces.PartialSimpleMedium  Fixed bug in function density, which always returned d_const ,
regardless of the value of constantDensity .

Buildings.Media.GasesPTDecoupled  Fixed bug in u=hR*T , which is only valid for ideal gases.
For this medium, the function is u=hpStd/dStp .

Buildings.Media.GasesConstantDensity  Fixed bug in u=hR*T , which is only valid for ideal gases.
For this medium, the function is u=hp/dStp .

Buildings.Rooms  
Buildings.Rooms.MixedAir Buildings.Rooms.BaseClasses.ExteriorBoundaryConditions 
Fixed bug (ticket 35) that leads to the wrong solar heat gain for roofs and for floors. Prior to this bug fix, the outside facing surface of a ceiling received solar irradiation as if it were a floor and vice versa. 
Buildings.Rooms.MixedAir Buildings.Rooms.BaseClasses.ExteriorBoundaryConditionsWithWindow 
Fixed bug (ticket 36) that leads to too high a surface temperature of the window frame when it receives solar radiation. The previous version did not compute the infrared radiation exchange between the window frame and the sky. 
The following uncritical errors have been fixed (i.e., errors that do not lead to wrong simulation results, but, e.g., units are wrong or errors in documentation):
Buildings.BoundaryConditions  
Buildings.BoundaryConditions.WeatherData.BaseClasses.ConvertRadiation  Corrected wrong unit label. 
The following trac tickets have been fixed:
Buildings.BoundaryConditions  
#8  Add switches for new data. 
#19  Shift the time for the radiation data 30 min forth and output the local civil time in the data reader. 
#41  Using whenthen sentences to reduce CPU time. 
#43  Add a ConvertRadiation to convert the unit of radiation from TMY3. 
Buildings.Fluid  
#28  Move scripts to Buildings\Resources\Scripts\Dymola. 
Buildings.HeatTransfer  
#18  Add a smooth interpolation function to avoid the event. 
Buildings.Media  
#30  Removed nonrequired structurally incomplete annotation. 
Buildings.Rooms  
#35  Wrong surface tilt for radiation at exterior surfaces of floors and ceilings. 
#36  High window frame temperatures. 
Note:
x.y
and a build number. The first official
release of each version has the build number 1
. For each released bug fix,
the build number is incremented.
See
Modelica.UsersGuide.ReleaseNotes.VersionManagement for details.
Buildings/Resources/Scripts/Dymola
and the annotation that
generates the entry in the Command
pull down menu has been changed to
__Dymola_Commands(file=...
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Note: The packages whose name ends with Beta
are still being validated.
Buildings.Rooms  
Buildings.Rooms.BaseClasses.InfraredRadiationExchange  The model Buildings.Rooms.BaseClasses.InfraredRadiationExchange
had an error in the view factor approximation.
The error caused too much radiosity to flow from large to small surfaces because the law of reciprocity
for view factors was not satisfied. This led to low surface temperatures if a surface had a large area
compared to other surfaces.
The bug has been fixed by rewriting the view factor calculation.

The following improvements and additions have been made:
homotopy
operator.
k
as an algebraic variable.
This increases robustness.
enthalpyOfCondensingGas
and saturationPressure
in single substance media
to allow use of the room model with media that do not contain water vapor.
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Note: The packages whose name ends with Beta
are still being validated.
port_b
was multiplied with the mass flow rate at
port_a
. The old implementation led to small errors that were proportional
to the amount of moisture change. For example, if the moisture added by the component
was 0.005 kg/kg
, then the error was 0.5%
.
Also, the results for forward flow and reverse flow differed by this amount.
With the new implementation, the energy and moisture balance is exact.
Advanced.OutputModelicaCodeWithJacobians=true/false;
in the model
Buildings.Examples.HydronicHeating.
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
mC
to avoid wrong trajectory
when concentration is around 1E7.
See also
https://trac.modelica.org/Modelica/ticket/393.
assert(dp_in >= 0, ...)
to assert(dp_in >= 0.1, ...)
.
The former implementation triggered the assert if dp_in
was solved for
in a nonlinear equation since the solution can be slightly negative while still being
within the solver tolerance.
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
The following critical error has been fixed (i.e. error that can lead to wrong simulation results):
Buildings.Fluid.Storage.  
Buildings.Fluid.Storage.StratifiedEnhanced  The model Buildings.Fluid.Storage.BaseClasses.Stratifier
had a sign error that lead to a wrong energy balance.
The model that was affected by this error is
Buildings.Fluid.Storage.StratifiedEnhanced.
The model
Buildings.Fluid.Storage.Stratified was not affected.The bug has been fixed by using the newly introduced model Buildings.Fluid.Storage.BaseClasses.ThirdOrderStratifier. This model uses a thirdorder upwind scheme to reduce the numerical dissipation instead of the correction term that was used in Buildings.Fluid.Storage.BaseClasses.Stratifier .
The model Buildings.Fluid.Storage.BaseClasses.Stratifier has been removed since it
also led to significant overshoot in temperatures when the stratification was pronounced.

Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
epsilonNTU
relations to compute the heat transfer.
y
, then
the flow is equal to zero if y=0
. This change required rewriting
the package to avoid division by the rotational speed.
dp_nominal
is set to zero,
then the pressure drop equation is removed. This allows, for example,
to model a heating and a cooling coil in series, and lump there pressure drops
into a single element, thereby reducing the dimension of the nonlinear system
of equations.
T
in closed form assuming no saturation. Then, a check is done to determine
whether the state is in the fog region. If the state is in the fog region,
then Internal.solve
is called. This new implementation
can lead to significantly shorter computing
time in models that frequently call T_phX
.
A
to avoid compilation error
if the parameter is disabled but not specified.
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Medium.BaseProperties
the initialization
X(start=X_start[1:Medium.nX])
. Previously, the initialization
was only done for Xi
but not for X
, which caused the
medium to be initialized to reference_X
, ignoring the value of X_start
.
Buildings.Media.PerfectGases.MoistAirNonSaturated
to
Buildings.Media.PerfectGases.MoistAirUnsaturated
and Buildings.Media.GasesPTDecoupled.MoistAirNoLiquid
to
Buildings.Media.GasesPTDecoupled.MoistAirUnsaturated,
and added assert
statements if saturation occurs.
enthalpyOfNonCondensingGas
and its derivative.
eOn
.
Fixed error by introducing parameter Td
,
which used to be hardwired in the PID controller.
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
RealInput
ports, which are obsolete
in Modelica 3.0.
Buildings.Fluid.HeatExchangers.HeaterCoolerIdeal
to
Buildings.Fluid.HeatExchangers.HeaterCoolerPrescribed
to have the same nomenclatures as is used for
Buildings.Fluid.MassExchangers.HumidifierPrescribed
d m_flow/d p
near the origin that is not too steep for a Newtonbased solver.
dp
in
Buildings.Fluid.BaseClasses.PartialResistance and in its
child classes.
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Kv
or Cv
can
be used as the flow coefficient (in [m3/h] or [USG/min]).
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
Buildings
library is upgraded to
to Modelica 3.0.0, it should be safe to remove this bug fix.
0
and 1
. This was in earlier versions restricted.
In the same model, a bug was fixed that caused the flow to be largest for y=0
, i.e., when the damper is closed.
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
New in this version are models for two and three way valves.
In addition, the Fluids
package has been slightly revised.
The package Fluid.BaseClasses
has been added because in
the previous version, partial models for fixed resistances
where part of the Actuator
package.
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).
First release of the library.
This version contains basic models for modeling building HVAC systems. It also contains new medium models in the package Buildings.Media. These medium models have simpler property functions than the ones from Modelica.Media. For example, there is medium model with constant heat capacity which is often sufficiently accurate for building HVAC simulation, in contrast to the more detailed models from Modelica.Media that are valid in a larger temperature range, at the expense of introducing nonlinearities due to the medium properties.
Extends from Modelica.Icons.ReleaseNotes (Icon for release notes in documentation).