IDF files generated by DesignBuilder don't run in EP-Launch
Posted by Andy Tindale on 16-Nov-10 03:39 PM
This advice refers to EnergyPlus v5 and earlier (DesignBuilder v.2.2 and earlier) - it should not be relevant to EnergyPlus v6 (DesignBuilder v2.3) and later which have fully extensible data.

In some cases DOE versions of EnergyPlus cannot simulate the IDF file generated by DesignBuilder using EP-Launch because DesignBuilder uses a special extended version of the EnergyPlus data description file: Energy+.idd. 
DesignBuilder automatically generates compatible IDF files with the target version of EnergyPlus as set on the Program options dialog but if you attempt to use a file intended for an internal DesignBuilder version of EnergyPlus in a DOE installation you may get some surface or HVAC data errors related to the changes listed below.  By default, DesignBuilder uses an internal version of EnergyPlus which has a slightly extended IDD file to allow:
  1. Surfaces of up to 330 vertices.
  2. Shading surfaces of up to 33 vertices.
  3. Up to 400 zones in compact HVAC systems.
To avoid such E+ version incompatibilities you should either:
  1. Explicitly target your DOE EnergyPlus installation by making the appropriate setting on the Program options dialog (preferred option), or
  2. Carry the DesignBuilder IDD extensions over to your standalone version of EnergyPlus by copying Energy+.idd from the DesignBuilder EnergyPlus folder (use the File > Folder > EnergyPlus folder menu command) to your standalone EnergyPlus folder (e.g. C:\EnergyPlusV1-4-0).

Note that DesignBuilder generates code appropriate to the target version of EnergyPlus.

See also Exporting IDF files.