Subdivide huge energyplus models into several files

asked 2021-03-26 11:12:54 -0500

updated 2021-04-02 12:18:21 -0500

Hello to everyone,

I'm modeling a skyscraper using OpenStudio 3.1. Because of the requirements of the job, I need to assign a thermal zone to every single space in the building. Therefore, once I ended modeling the geometry, I will have to deal with a huge energyplus file with more than 5k thermal zones and almost 100k surfaces. Needless to say, I'm experiencing always wider latencies in performing basic operations like creating spaces, selecting/subdiving surfaces, etc., which lead me to a very difficoult extimation of the time needed for creating the geometry.

Hoping that anyone in this forum has dealt with something similar in the past, here is my question: is it possible to split the final model into several files by adding a reduced number of thermal zones on each one and interconnecting them in a sort of master-slave relationship?

Thinking about this potential solution and assuming that I will make and extensive use of macroses where possible, the problems I foresee are:

  • assigning the constructions implemented in the master file to the surfaces available in the slave ones;
  • matching surfaces between master and slave zones;
  • implementing the HVAC system (unless the thermal zones subdivision is made in accordance with the loops available).

If such an implementation is actually possible, what should I do for making it work properly? Otherwise, are there other potential solution I could take into consideration?

Many thanks.

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To assist anyone wanting to help, could you confirm that resorting to zone lists/groups (i.e., multipliers) and/or internal mass approaches (i.e., spanners) are off the table for the "requirements of the job" in your case? If so, why? Both techniques can be challenging at first, but would trim down the size and complexity of your model.

Denis Bourgeois's avatar Denis Bourgeois  ( 2021-03-28 06:43:00 -0500 )edit

Unfortunately, those that you mentioned are not options as I need to have direct control on the specific thermal zone.

Angelo Martucci's avatar Angelo Martucci  ( 2021-03-28 15:41:03 -0500 )edit

... direct control of all 5000 thermal zones/spaces? And every floor in this skyscraper is unique i.e., no repetition in floor plan layout between floors? OK. I'd first validate your computing resources to accommodate 5K zones + 100K surfaces (e.g., an OpenStudio SDK script that automatically generates 5K zones + 20 surfaces each). If your RAM can take it, then I'd switch to an OpenStudio SDK parametric approach to generate building geometry and constructions (I wouldn't dare try this manually). You can visually validate the generated OSM in the App Geometry Tab.

Denis Bourgeois's avatar Denis Bourgeois  ( 2021-03-29 03:58:31 -0500 )edit

Well... I do work for a Company that uses calibrated energy models for optimizing indoor setpoint temperatures in real-time based on real-time data acquisition. Therefore yes... I do need to model almost every single space in the building. With reference to the building I'm dealing with at the moment, just the last 4 floors are missing. My question is still there: would it be possible to split huge models into several parts?

Angelo Martucci's avatar Angelo Martucci  ( 2021-03-29 04:52:25 -0500 )edit

I would suggest creating a separate model for each floor (or couple of floors if air systems serve more than one floor). You could set adiabatic surface conditions between floors since the temperature difference between floors should be small.

macumber's avatar macumber  ( 2021-04-15 00:03:20 -0500 )edit