Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question

CondenserEnteringReset via PythonPlugin

asked 2022-02-07 06:32:14 -0500

kem's avatar

updated 2022-02-18 17:01:52 -0500

I would like to reset the condenser water supply temperature via Python Plugin. I have experience with resetting following values: Schedule:Compact > Schedule Value; Pump > Pump Mass Flow Rate ; Fan > Fan Air Mass Flow Rate

What I did: I have found nice examples of condenser water reset in E+ Example folder (files CoolingTower_VariableSpeed_CondEntTempReset.idf CoolingTower_VariableSpeed_CondEntTempReset_MultipleTowers.idf CoolingTower_VariableSpeed_IdealCondEntTempSetpoint.idf CoolingTower_VariableSpeed_IdealCondEntTempSetpoint_MultipleTowers.idf

Problem: All these examples use SetpointManager:CondenserEnteringReset or SetpointManager:CondenserEnteringReset:Ideal object to reset the temperature. The issue is I don't know what E+ variable to use to be an actuator handle.

I tried to use OutputVariable as a handle but failed, "Output:Variable", "System Node Setpoint Temperature", "Condenser Tower", "Outlet Node")

returns -1 (=> it failed)

Could you help me to find right solution for resetting the condenser water temperature?

EDIT: Copying relevant sections from original file CoolingTower_VariableSpeed_IdealCondEntTempSetpoint.idf (see installation/ExampleFiles) where I want to reset the condenser tower outlet temperature.

  Condenser Water Loop Setpoint Manager,  !- Name
  Temperature,             !- Control Variable
  12,                      !- Minimum Lift {deltaC}
  32,                      !- Maximum Condenser Entering Water Temperature {C}
  Condenser Tower Outlet Node;  !- Setpoint Node or NodeList Name
  Central Tower,           !- Name
  Condenser Tower Inlet Node,  !- Water Inlet Node Name
  Condenser Tower Outlet Node,  !- Water Outlet Node Name
  YorkCalcUserDefined,     !- Model Type
Output:Variable,Condenser Tower Outlet Node,System Node Setpoint Temperature,Hourly;
edit retag flag offensive close merge delete


What about using a scheduled setpoint manager and then actuating the schedule?

bonnema's avatar bonnema  ( 2022-02-08 09:26:48 -0500 )edit

Thank you @bonnema for your suggestion. I am not the expert in idf language but it seems to me the SetpointManager has no relation to actuator definition via method. So it should be possible to setup it regardless the SP manager is SetpointManager:Scheduled or SetpointManager:CondenserEnteringReset. The problem is there are no examples of SetpointManager:CondenserEnteringReset with Python plugin. We will try to find direct solution first. Your suggesting is to change CondenserEnteringReset manager to Scheduled manager. This is definitely a good backup plan.

kem's avatar kem  ( 2022-02-08 10:15:07 -0500 )edit

You need to find an actuator within this section. You cannot just actuate anything you want. There must be a predefined actuator available. I am not seeing any actuator specific to the setpoint manager that you're using in the docs.

bonnema's avatar bonnema  ( 2022-02-08 10:23:59 -0500 )edit

You can change the setpoint manager, or try to actuate the schedule/curve fields within the setpoint manager that you're using to "back calculate" the result that you want. I think it is easier to change the setpoint manager, but it is hard to say without knowing exactly what you're trying to accomplish.

bonnema's avatar bonnema  ( 2022-02-08 10:24:32 -0500 )edit

1 Answer

Sort by ยป oldest newest most voted

answered 2022-02-23 05:24:27 -0500

kem's avatar

updated 2022-02-23 05:27:19 -0500

The solution we adopted: Configuration of Python Plugin:
     state, "System Node Setpoint", "Temperature Setpoint", "Condenser Tower Outlet Node")

Changes in the IDF: removed the Setpoint Manager


Result: It's working smoothly. We can change the setpoint via Plugin and the setpoint is followed.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Training Workshops


Question Tools



Asked: 2022-02-07 06:32:14 -0500

Seen: 167 times

Last updated: Feb 23 '22