Exporting IDF Files

You can use DesignBuilder to generate EnergyPlus idf files for use in external simulation environments such as EP-Launch. There are 4 alternative procedures for doing this:

 

  1. From the File | Export menu option (preferred method).
  2. By copying the intermediate in.idf file in the EnergyPlus folder.
  3. Tools | Display simulation input script from Simulation or Heating/Cooling design screens.
  4. Using the DOE executable EnergyPlus simulation option to open the EP-launch application before simulation.

 

Note that DesignBuilder will automatically generate compatible IDF files with the target version of EnergyPlus as set on the Program options dialog.

 

It is important to set the EnergyPlus version you intend to use before exporting the IDF data.

1. File > Export menu option (recommended)

  1. Open your DesignBuilder dsb model file.
  2. In the Program options dialog on the EnergyPlus tab, ensure that the recommended executable DOE version of the most current version of EnergyPlus available on the list is selected (e.g. "Version 7.0.0.036 (Recommended DOE)").
  3. Make sure that you have that version of EnergyPlus downloaded and installed from the DOE website.
  4. Make sure you are at building level or below.
  5. Click on the File > Export > Export EnergyPlus or DBSim input file > Simulation menu option.

2. Copy in.idf in the EnergyPlus folder

An alternative way to generate IDF files is to use the intermediate file in.idf in the EnergyPlus folder which is generated prior to each DesignBuilder EnergyPlus simulation. You should copy this file to a different filename/location before using it.

 

Important: You should not generally make any changes to in.idf itself because this file will get overwritten before the next DesignBuilder EnergyPlus simulation and your changes will then be lost.

3. Tools > Display menu option

You can view the input data script used to calculate these results by selecting the Tools > Display simulation input script menu option.  If you do not have the EnergyPlus IDF editor installed, then you should associate the .idf file extension with a text editor to make this option work.

 

Note: this shows the script stored with the model just before the simulation not the in.idf file stored in the EnergyPlus folder.

4. DOE executable EnergyPlus simulation option

In the Program options dialog you can select an executable EnergyPlus option and set the execution mode to 4-Executable (EP-Launch). This gives you some control over the IDF data before the simulation. Any changes made to the IDF data from within EP-Launch will be included in the simulation but will not be retained for future simulations. See Program options > EnergyPlus for more info on this.

Reading ESO results files back into DesignBuilder

Provided you haven't changed the zone and surface names in the IDF data you can read ESO results files generated from your modified data back into DesignBuilder for display and analysis.

Tip: If you are already familiar with the EnergyPlus data structure you may find it most convenient to edit DesignBuilder IDF data using a text editor as it shows more clearly the comments included to help reference IDF data back to the DesignBuilder model.