.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

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.