.Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Controller

Information

Controller for terminal box of VAV system with reheat according to ASHRAE Guideline 36, Part 5.E. It outputs damper position yDam, hot water valve position yVal, AHU cooling supply temperature setpoint reset request yZonTemResReq, and static pressure setpoint reset request yZonPreResReq.

The sequence consists of four subsequences.

a. Heating and cooling control loop

The subsequence is implementd according to Part 5.B.5. The measured zone temperature TZon, zone setpoints temperatures TZonHeaSet and TZonCooSet are inputs to the block conHeaLoo and conCooLoo to generate the control loop signal.

b. Active airflow setpoint calculation

This sequence sets the active maximum and minimum airflow according to Part 5.E.3-5. Depending on operation modes uOpeMod, it sets the airflow rate limits for cooling and heating supply. See Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Reheat.SetPoints.ActiveAirFlow.

c. Damper and valve control

This sequence sets the damper and valve position for VAV reheat terminal unit. The implementation is according to Part 5.E.6. According to heating and cooling control loop signal, it calculates the discharge air temperature setpoint TDisHeaSet. Along with the defined maximum and minimum airflow, measured zone temperature, the sequence outputs yDam, yVal, TDisHeaSet and discharge airflow rate setpoint VDisSet_flow. See Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Reheat.DamperValves.

d. System reset requests generation

According to Part 5.E.9, this sequence outputs the system reset requests, i.e. cooling supply air temperature reset requests yZonTemResReq, static pressure reset requests yZonPreResReq, hot water reset requests yHeaValResReq, and the boiler plant reset requests yHeaPlaReq. See Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits.Reheat.SystemRequests.

Revisions

• November 5, 2021 by Karthik Devaprasad:
  Added missing outputs yHeaValResReq and yHeaPlaReq for requests to heating plant.
• October 9, 2020, by Jianjun Hu:
  Changed the default heating maximum airflow setpoint to 30% of the zone nominal airflow.
  This is for issue 2172.
• April 18, 2020, by Jianjun Hu:
  Added actual VAV damper position as the input for generating system request.
  This is for issue 1873.
• March 06, 2020, by Jianjun Hu:
  Added default component name.
  This is for issue 1809.
• November 15, 2017, by Michael Wetter:
  Added integrator reset.
• October 27, 2017, by Jianjun Hu:
  Moved it from example package.
• September 25, 2017, by Michael Wetter:
  First implementation.