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I'm trying to build a model for a HGHE embedded in a constructed wetland that will treat waste water.

My current objective is to understand how much cooling embedding a HGHE in a treatment wetland could provide, and therefore how much could be saved.

I'm new to EnergyPlus/OpenStudio, but have been trying to work with OS:GroundHeatExchanger:HorizontalTrench and the PondGroundHeatExchanger.idf example file though I'm struggling to understand how to use them to achieve the above objective.

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Importing GroundHeatExchanger:Pond in to OS

Firstly, I'm not sure how to use the PondGroundHeatExchanger in OpenStudio; I found out that OS doesn't import HVAC systems from IDF files, and I couldn't work out how to convert the IDF file to SDD unless I manually did it. I also can't see how to import a GroundHeatExchanger:Pond in to OS as it wasn't an option in my HVAC system library, as under GroundHeatExchanger there is only "Horizontal Ground HX" which is OS:GroundHeatExchanger:HorizontalTrench when implemented.

Question 1: Is there something I need to do in order to have access to a GroundHeatExchanger:Pond item in my library? Are there any resources detailing this process you could direct me towards?

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Adding an Undisturbed Ground Temperature Model to a GroundHeatExchanger:HorizontalTrench

So far I've brought in the GroundHeatExchanger to a same DOE model created using the Create DOE Prototype Building measure, and this runs successfully on it's own.

I've then gone in to the HVAC system design section, and edited the existing condensor water loop system to include a module GroundHeatExchanger:HorizontalTrench. Then I've edited the settings so it reflects saturated soil.

Now I'm stuck with the Undisturbed Ground Temperature Model section, as the drop down has an alert exclamation mark, but there are no options when I click the drop down and the simulation doesn't run due to this issue, the error being:

Assertion modelObject failed on line 152 of class openstudio::model::ModelObject __cdecl openstudio::model::detail::GroundHeatExchangerHorizontalTrench_Impl::undisturbedGroundTemperatureModel(void) const in file D:\OSN\Openstudio\src\model\GroundHeatExchangerHorizontalTrench.cpp.

After searching this, I've found there some options for the Undisturbed Ground Temp Model (UGTM), namely: https://bigladdersoftware.com/epx/docs/8-4/engineering-reference/undisturbed-ground-temperature-model-kusuda.html https://bigladdersoftware.com/epx/docs/8-7/engineering-reference/undisturbed-ground-temperature-model-xing.html

However, I'm unsure how to select or use these.

Within my OSM file, I also already have

OS:Site:GroundTemperature:Shallow,
  {f0a26f22-1412-41de-9fac-8456bd24dc0b}, !- Handle
  18.2,                                   !- January Surface Ground Temperature {C}
  16,                                     !- February Surface Ground Temperature {C}
  15.4,                                   !- March Surface Ground Temperature {C}
  15.9,                                   !- April Surface Ground Temperature {C}
  18.9,                                   !- May Surface Ground Temperature {C}
  22.2,                                   !- June Surface Ground Temperature {C}
  25.4,                                   !- July Surface Ground Temperature {C}
  27.7,                                   !- August Surface Ground Temperature {C}
  28.4,                                   !- September Surface Ground Temperature {C}
  27.3,                                   !- October Surface Ground Temperature {C}
  24.7,                                   !- November Surface Ground Temperature {C}
  21.4;                                   !- December Surface Ground Temperature {C}

OS:Site:GroundTemperature:Deep,
  {e2af9348-0bd6-41c8-b20d-194cf562ea01}, !- Handle
  21.5,                                   !- January Deep Ground Temperature {C}
  19.9,                                   !- February Deep Ground Temperature {C}
  18.9,                                   !- March Deep Ground Temperature {C}
  18.6,                                   !- April Deep Ground Temperature {C}
  19.1,                                   !- May Deep Ground Temperature {C}
  20.5,                                   !- June Deep Ground Temperature {C}
  22.1,                                   !- July Deep Ground Temperature {C}
  23.8,                                   !- August Deep Ground Temperature {C}
  24.9,                                   !- September Deep Ground Temperature {C}
  25.1,                                   !- October Deep Ground Temperature {C}
  24.5,                                   !- November Deep Ground Temperature {C}
  23.2;                                   !- December Deep Ground Temperature {C}

Which I saw can be used to calculate the values for the UGTM if included and the UGTM is left blank.

Line 152 is included within the OS:SpaceType description, so perhaps I should put something in there?

Question 2: How can I add an Undisturbed Ground Temperature Model to the GroundHeatExchanger:HorizontalTrench?

Question 3: Is there still no way to easily convert an IDF file to a SDD file, so I can import EnergyPlus HVAC systems into OS?

This is quite a long question as I've tried to provide all the details, thank you for reading and taking the time to reply!