Start IDF Editor
IDF Editor should be located in the EnergyPlus\PreProcessor\IDFEditor directory where you
installed EnergyPlus. By double clicking on the IDF Editor icon you will get a screen similar
to the one shown above. This is the only screen that the IDF Editor uses. IDF Editor works
in conjunction with the current EnergyPlus Input Data Directory (IDD) file that resides in the
directory where EnergyPlus is installed. Another way to start the IDF Editor is from EPLaunch.
Creating or Selecting an Input Data File
Creating a new input data file or selecting an existing input data file can be accomplished
either through use of the File menu on the menu bar at the top of the screen or through use
of the New File icon button or Open File icon button on the tool bar.
Class List and Objects
The classes that can be used to make up an IDF file have been organized into groups as
shown in the ‘Class List’ portion of the screen. A class is made up of a group of objects.
Select a class from the list by clicking on and highlighting the class. The field to the left of the
selected class in the ‘Class List’ will either contain [------] to indicate that this class has no
objects in the IDF file or it will contain a number like [003] to indicate the number of times the
object currently appears in the IDF file. For example, for the SURFACE class selected in the
screen above under the ZONE group, there are 8 objects in the IDF file. The details for these
8 objects or any new object that is defined are displayed in columns within the grid. Each
object is made up of fields and can be used to further define the object. Any units attached to
each field are shown in the second column. You may need to scroll down the ‘field’ list or
maximize the application to see all of the fields. Likewise, you may need to scroll to the right
of the main grid to see other objects.
Changing Values
By clicking and highlighting a value within an object, several things happen:
1) Any user comments from the IDF file will be displayed in the ‘Comments from IDF’ portion
of the screen
2) Any notes contained in the IDD for this input field will be displayed in the ‘Explanation of
Keyword’ portion of the screen
3) The value can be edited. Depending on the field, a drop down list may display the default
value, maximum and minimum, or other keywords that can be used with the field.
4) Numeric fields that can be autosized will include "autosize" as a selection in the drop
down list.
5) Some numeric fields have a maximum and/or minimum value specified in the IDD. If the
value entered is outside this range, the cell will be highlighted in pale orange.
Working with Objects
To delete an object, first click on any value for the object and then click on the “Del Obj”
button. To add a new object, click on the “New Obj” button and a new object column with
fields set to blanks or zeros will be added to the far right of the grid. The “Dup Obj” button is
similar to “New Obj”, but copies the values of the fields of the currently selected object. (Also
see the Edit menu to perform these functions.)
File Menu
The File menu can be used for creating or selecting input files just like the buttons on the IDF
Editor screen (see the Creating or Selecting an Input File section above). In addition, the File
menu is used to save a file or exit the IDF Editor. More than one file can be opened at a
time.
Edit Menu
The Edit Menu offers options to create a new object, duplicate an object, and delete an
object. These same operations can also be accomplished by using the ‘New Obj’, ‘Dup Obj’
and ‘Del Obj’ buttons (see the Working with Objects section above). In addition, the "Next
Row after Enter" option can be toggled. When this option is on, the selection moves down
one row after pressing Enter. The copy and paste object commands allow a single object to
be copied within a file or between files. The pasted object appears as the last object in the
class. This capability makes it easier to utilize the data in the DataSets directory.
View Menu
The View menu offers options for units and column widths. The Narrow/Medium/Wide
Column options set the standard column width for items in the object grid. Individual columns
can also be resized by dragging the column separator. The displayed value is rounded
and/or expressed in scientific notation to fit within the column width.
EnergyPlus input files must always be in SI units, and the IDF Editor always opens in SI units
mode. Selecting "Inch-Pound" (IP) units in the View menu displays and edits values in IP
units. IP units are only partially supported:
1) Fields with no units specified are not converted. This includes all schedules and fluid
properties. If a field has no units displayed in the units column of the object grid, then no
conversion will be made.
Note that thermostat setpoints, people activity levels, and other dimensioned schedules must always be
entered in SI units, even when the IDF Editor is in Inch-Pound mode. These objects which have no units
field will not be converted.
2) The IP unit will be displayed in the units column of the object grid. Some SI units convert
to multiple IP units. For example, W becomes Btu/hr for heating and cooling capacity but
remains as W for lighting and electrical equipment.
3) All conversion factors used in the IDF editor are documented in a block of comments
near the top of the Energy+.IDD file.
Help Menu
The Help menu offers options to open the EnergyPlus documentation files.
Caveats
Remember to save any changes made before you create or edit another input file.
No “Run EnergyPlus” button is available. Save your IDF file and use EP-Launch to execute
an EnergyPlus run.
You cannot edit comments in the ‘Comments from IDF’ section of the screen.
All engineering units are in SI. IP units have not been implemented yet.
The use of point "." or comma "," as the decimal symbol is controlled by the windows system
settings. This setting is found in the Control Panel, Regional Options, Number tab, Decimal
Symbol field. IDF Editor will use the current decimal symbol to signify the start of the
fractional portion of the number and will ignore other symbols. The idf file is always written
using point "." as the decimal symbol.
Compact HVAC Objects
Beginning with the V1.2.2 release, “compact HVAC” objects are available. These are
intended to allow for several “usual” HVAC types to be expanded into EnergyPlus HVAC
inputs with minimal user entries. These are described in the “Input/Output Reference”
document under the Group “Compact HVAC” and the expansion process is described in the
Auxiliary Programs document under “ExpandObjects”.
Data Sets
EnergyPlus uses snippets of IDF files to create the library of data that may be useful for you.
Two folders are created upon installation: DataSets – which contains IDF snippets and
MacroDataSets – which also contain IDF