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How do I use advanced convection coefficient models in energyplus?

asked 2020-09-17 18:19:40 -0500

sajithwjay gravatar image

updated 2020-09-17 18:31:25 -0500

The drop-down menu shows TARP, SIMPLE, CeilingDiffuser, and AdaptiveCoenvectionAllgorithm for the SurfaceConvectionAlgorith Interior. But are there additional models available in EnergyPlus and can be used via IDF editor?

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answered 2020-09-17 18:32:48 -0500

updated 2020-09-18 11:08:29 -0500

The SurfaceConvectionAlgorithm:Inside object only has those four options. Is there a different algorithm that you would rather apply, or do you have specific convection coefficients that you want to apply each timestep?


You can set both inside and outside convection coefficients by timestep using the Energy Management System (EMS) feature of EnergyPlus. You would need to use the following EMS object:

See an example of these EMS objects below.

  Inside_Conv_Coeff_Act,     ! Name
  East Wall,                         ! Actuated Component Unique Name
  Surface,                           ! Actuated Component Type
  Interior Surface Convection Heat Transfer Coefficient;           ! Actuated Component Control Type

  Inside_Conv_Coeff_Sens,                      ! Name
  Convection Coefficient Schedule,         ! Output:Variable Index Key Name
  Schedule Value;                                   ! Output:Variable Name

  Inside_Conv_Coeff_Program,         ! Name
  SET Inside_Conv_Coeff_Act = Inside_Conv_Coeff_Sens;

  EMS Manager, ! Name
  BeginZoneTimestepAfterInitHeatBalance,       ! EnergyPlus Model Calling Point
  Inside_Conv_Coeff_Program;                 ! Program Name 1
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Thank you very much for your response. That was my observation too. But if I can input convection coefficient by timestep that would be useful for me for the current application I am thinking of.

sajithwjay gravatar image sajithwjay  ( 2020-09-17 19:15:55 -0500 )edit

Ah, I see. I've updated my solution to discuss how to set convection coefficients by timestep.

Aaron Boranian gravatar image Aaron Boranian  ( 2020-09-17 19:43:01 -0500 )edit

This is incredibly helpful. I will try to implement and post my feedback. Kind regards,

sajithwjay gravatar image sajithwjay  ( 2020-09-17 21:32:18 -0500 )edit

@sajithwjay Great! I forgot to mention one more EMS object that you will need, I've updated my answer accordingly.

Aaron Boranian gravatar image Aaron Boranian  ( 2020-09-18 11:06:58 -0500 )edit

Thank you! I tried few combinations and saw that after errors are sorted the coefficient value still wasn't captured by the output. I will try this.

sajithwjay gravatar image sajithwjay  ( 2020-09-18 14:53:27 -0500 )edit

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Asked: 2020-09-17 18:19:40 -0500

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Last updated: Sep 18 '20