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Example file runs only on two design days. Why?

asked 2021-12-22 18:24:02 -0600

halimgur gravatar image

updated 2021-12-22 20:22:57 -0600

Ammar De gravatar image

I am running one of the example files: AirflowWindowsAndBetweenGlassShades.idf. The simulation produces results only for the two design days specified in the IDF file. The file has no _SimulationControl_ object. I also could not see any object in it that controls the simulation parameters in another way.

I specify the outputs as

  Output:Variable,*,Zone Mean Air Temperature,Hourly;
  Output:Variable,*,Site Outdoor Air Drybulb Temperature,Hourly;

The outputs in the CSV file are only for the two design days (48 rows). I provide a full weather file that I use with my other simulations with no problem. What could it be in this example IDF file that instructs the simulation to run only for design days. I repeat, it is an EP example file. I only changed the output list.

I run the simulation using the python API and this is the output I get in spyder:

EnergyPlus Starting
EnergyPlus, Version 9.5.0-de239b2e5f, YMD=2021.12.23 09:56
Adjusting Air System Sizing
Adjusting Standard 62.1 Ventilation Sizing
Initializing Simulation
Reporting Surfaces
Beginning Primary Simulation
Initializing New Environment Parameters
Warming up {1}
Warming up {2}
Warming up {3}
Warming up {4}
Warming up {5}
Warming up {6}
Starting Simulation at 01/21 for CHICAGO_IL_USA ANNUAL HEATING 99% DESIGN CONDITIONS DB
Initializing New Environment Parameters
Warming up {1}
Warming up {2}
Warming up {3}
Warming up {4}
Warming up {5}
Warming up {6}
Starting Simulation at 07/21 for CHICAGO_IL_USA ANNUAL COOLING 1% DESIGN CONDITIONS DB/MCWB
EnergyPlus Run Time=00hr 00min  0.54sec
EnergyPlus Completed Successfully.

Would anyone be able to tell me why EP does not do an annual simulation for this IDF example file?

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answered 2021-12-22 20:21:29 -0600

Ammar De gravatar image

Since the IDF file you are referring to doesn't have a RunPeriod object, EnergyPlus runs the simulation for only the two design days as specified by default in the SimulationControl object. You should add the RunPeriod object and select the desired simulation period. If the IDF has no specific objects, like RunPeriod or SimulationControl, you can actually add them yourself and modify the parameters as desired.

If you are using EP-Launch, you can search for the object you want from the Class List and click on New Obj, you will be able to add/modify the fields.

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I understand. Thank you for the clear and categorical answer.

halimgur gravatar image halimgur  ( 2021-12-22 21:49:47 -0600 )edit

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Asked: 2021-12-22 18:24:02 -0600

Seen: 90 times

Last updated: Dec 22 '21