.Buildings.Examples.VAVReheat.BaseClasses.PartialHVAC

Information

This partial model consist of an HVAC system that serves multiple thermal zones.

The HVAC system is a variable air volume (VAV) flow system with economizer and a heating and cooling coil in the air handler unit. There is also a reheat coil and an air damper in each of the zone inlet branches. The figure below shows the schematic diagram of an HVAC system that supplies 5 zones:

The control sequences for this HVAC system are added in the two models that extend this model, namely Buildings.Examples.VAVReheat.ASHRAE2006 and Buildings.Examples.VAVReheat.Guideline36.

Contents

Name	Description
MediumA	Medium model for air
MediumW	Medium model for water

Revisions

• February 7, 2023, by Jianjun Hu:
  Set the value of parameter transferHeat to true for the mixed air temperature sensor.
• February 6, 2023, by Jianjun Hu:
  Added junction to mix the return and outdoor air.
  This is for issue #3230.
• August 22, 2022, by Hongxiang Fu:
  Replaced fan and pump models with preconfigured mover models. This is for issue #2668.
• April 26, 2022, by Michael Wetter:
  Changed fan efficiency calculation to use Euler number.
  This is for #2668.
• November 9, 2021, by Baptiste Ravache:
  Vectorized the terminal boxes to be expanded to any number of zones.
  This is for issue #2735.
• October 4, 2021, by Michael Wetter:
  Refactored Buildings.Examples.VAVReheat and its base classes to separate building from HVAC model.
  This is for issue #2652.
• September 3, 2021, by Michael Wetter:
  Updated documentation.
  This is for issue #2600.
• August 24, 2021, by Michael Wetter:
  Changed model to include the hydraulic configurations of the cooling coil, heating coil and VAV terminal box.
  This is for issue #2594.
• June 30, 2021, by Antoine Gautier:
  Changed cooling coil model. This is for issue #2549.
• May 6, 2021, by David Blum:
  Change to from_dp=false for all mixing box dampers.
  This is for issue #2485.
• April 30, 2021, by Michael Wetter:
  Reformulated replaceable class and introduced floor areas in base class to avoid access of components that are not in the constraining type.
  This is for issue #2471.
• April 16, 2021, by Michael Wetter:
  Refactored model to implement the economizer dampers directly in Buildings.Examples.VAVReheat.BaseClasses.PartialHVAC rather than through the model of a mixing box. Since the version of the Guideline 36 model has no exhaust air damper, this leads to simpler equations.
  This is for issue #2454.
• March 11, 2021, by Michael Wetter:
  Set parameter in weather data reader to avoid computation of wet bulb temperature which is need needed for this model.
• February 03, 2021, by Baptiste Ravache:
  Refactored the sizing of the heating coil in the VAVBranch (renamed VAVReheatBox) class.
  This is for #2024.
• July 10, 2020, by Antoine Gautier:
  Added design parameters for outdoor air flow.
  This is for #2019
• November 25, 2019, by Milica Grahovac:
  Declared the floor model as replaceable.
• September 26, 2017, by Michael Wetter:
  Separated physical model from control to facilitate implementation of alternate control sequences.
• May 19, 2016, by Michael Wetter:
  Changed chilled water supply temperature to 6°C. This is for #509.
• April 26, 2016, by Michael Wetter:
  Changed controller for freeze protection as the old implementation closed the outdoor air damper during summer. This is for #511.
• January 22, 2016, by Michael Wetter:
  Corrected type declaration of pressure difference. This is for #404.
• September 24, 2015 by Michael Wetter:
  Set default temperature for medium to avoid conflicting start values for alias variables of the temperature of the building and the ambient air. This is for issue 426.