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How to change value of an EPlus variable using EMS

asked 2016-02-11 21:14:41 -0500

Rehan Khalid's avatar

updated 2016-02-11 21:18:03 -0500


I am trying to modify the "Server exit air temperature" as calculated by EnergyPlus. Basically EnergyPlus uses a steady-state equation to compute this temperature and I am trying to incorporate a transient scheme using EMS. The variable that I am trying to map for this purpose is "ITE Outlet Dry-Bulb Temperature". I have declared this as an EMS Sensor object and created the variable Taex for this purpose. However, no matter what I do, I cannot access this variable and modify its value using my code. I tried to use an EMS actuator but cannot find a suitable one that will control temperature. How can I accomplish this. Any help would be greatly appreciated.

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answered 2016-02-12 08:13:23 -0500

Archmage's avatar

I am afraid that if there is not already a suitable EMS actuator which provides a hook into the model's calculations, then EMS cannot really be used to alter an existing model. EMS can create new output variables but it can only modify the results showing in an existing output variable if there are suitable actuators that can override the program’s calculations.

You could make a user-voice request that the specific actuator you want be added to ElectricEquipment:ITE:AirCooled. (Or take advantage of the open-source code and add the EMS actuator yourself.)

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Thank you for that answer, I appreciate it. Can you give me any guidelines on how to access the source code and make changes (to add an actuator). I would like to work with the source code from v8.4, which is available in C++. Thanks.

Rehan Khalid's avatar Rehan Khalid  ( 2016-02-27 14:24:47 -0500 )edit

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Asked: 2016-02-11 21:14:41 -0500

Seen: 260 times

Last updated: Feb 12 '16