modelGuideline36Winter

Variable air volume flow system with terminal reheat and five thermal zones controlled using an ASHRAE G36 controller

Extends from Modelica.Icons.Example, Buildings.Examples.VAVReheat.BaseClasses.HVACBuilding.

Information

This model consist of an HVAC system, a building envelope model and a model for air flow through building leakage and through open doors.

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 five zone inlet branches.

See the model Buildings.Examples.VAVReheat.BaseClasses.PartialHVAC for a description of the HVAC system, and see the model Buildings.ThermalZones.EnergyPlus_24_2_0.Examples.SmallOffice.BaseClasses.Floor for a description of the building envelope.

The control is based on ASHRAE Guideline 36, and implemented using the sequences from the library Buildings.Controls.OBC.ASHRAE.G36 for multi-zone VAV systems with economizer. The schematic diagram of the HVAC and control sequence is shown in the figure below.

image

A similar model but with a different control sequence can be found in Buildings.ThermalZones.EnergyPlus_24_2_0.Examples.SmallOffice.ASHRAE2006Winter.. Note that this model, because of the frequent time sampling, has longer computing time than Buildings.Examples.VAVReheat.ASHRAE2006. The reason is that the time integrator cannot make large steps because it needs to set a time step each time the control samples its input.

Parameters

TypeNameDefaultDescription
RealACHCor4Design air change per hour core
RealACHSou4Design air change per hour south
RealACHEas6Design air change per hour east
RealACHNor4Design air change per hour north
RealACHWes6Design air change per hour west

Revisions

  • December 20, 2021, by Michael Wetter:
    Changed parameter declarations and added optimal start up. This is for issue #2829.
  • 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.
  • November 25, 2019, by Milica Grahovac:
    Impementation of Buildings.Examples.VAVReheat.Guideline36 model with an EnergyPlus thermal zone instance.