Knowledgebase : General

EnergyPlus 8.2 to the current release are available at:

https://github.com/NREL/EnergyPlus/releases

EnergyPlus 7.0 to 8.1 are available at:

https://github.com/NREL/EnergyPlusRelease/releases

 

 

Question:  Is there a way to convert from idf to ifc?


According to the documentation, Simergy can import idf and it can export IFC. So, in theory, it could be used to convert from idf to ifc, but I cannot say that I have ever tried this. You may contact Simergy support if you have questions.

https://simergy.lbl.gov/

See pp. 40-42.

https://simergy.lbl.gov/resources/Simergy_Workspace%20Guide_v1.pdf

If you have a dxf file, then several of the EnergyPlus interfaces allow you to import the dxf drawing and trace over it to create EnergyPlus geometry.
As of February 2009, DesignBuilder, and OpenStudio (plugin for Google SketchUp) offer this capability, and possibly other interfaces.

If you have the full AutoCAD 3-D dwg model (more than just dxf), then you might be able to export to EnergyPlus using one of the availble utilities that work with AutoCAD, but only if the model was created in the correct way to support these tools.
As of February 2009, Green Building Studio and EnergyPlugged (a plugin to AutoCAD) supported export to EnergyPlus.

For more information about current tools which support EnergyPlus, please see
http://www.energyplus.gov/interfaces_tools.cfm
If you are familiar with building simulation already, you can use the 200+ example files that come with the program along with the Input Output Reference (which describes each input and output) to help you.

There are several youtube videos available:
Getting Started with EnergyPlus - EnergyPlus utilities, datasets, documentation and example files.
EnergyPlus Simulation Parameters - Overview of key objects in the simulation parameters group.
EnergyPlus Location and Climate - Overview of objects in the location and climate group.
EnergyPlus Building Envelope Overview - Overview of the basic object types required to describe the building envelope and internal gains.
EnergyPlus HVACTemplate Overview - Using HVACTemplate objects to add HVAC systems to a building model.

http://www.youtube.com/user/GARDAnalytics

These have been organized into an "EnergyPlus Basics" playlist:
http://www.youtube.com/watch?v=e-4xIRUmQVg&feature=list_related&playnext=1&list=SP83CB71B24D2650E9

If you are not familiar with building simulation, we suggest you start with the "Getting Started" document and work through the tutorial examples there.

If you want to bypass all that and just generate an example for your building that you can start using and learn that way, you can use the EnergyPlus Example File Generator application at:

http://apps1.eere.energy.gov/buildings/energyplus/cfm/inputs/

Each example file has a block of comments at the top which highlight the main features (view in a text editor to read these). There are also two xls files in the ExampleFiles folder which summarize the example files:

ExampleFiles.xls has one row per file summarizing key characteristics and at the far right, some sentences explaining the key feature of this example.


ExampleFiles-ObjectsLink.xls lists every EnergyPlus object type and the first five example files that contain that object.

For example, if you are interested in cross flow ventilation, look for RoomAirSettings:CrossVentilation, and there is one example file which uses that object type: CrossVent_1Zone_AirflowNetwork.idf

What is OpenStudio?
OpenStudio is a plugin for Google Sketchup (both free and Pro versions) that will readin or create IDF files for running EnergyPlus.

Where can I get help for OpenStudio?

Please send questions regarding OpenStudio registration, downloading, or installation, to openstudio@nrel.gov

For OpenStudio bug reports or other issues (not related to registration, download, or install), please post the questions on the OpenStudio user support list at openstudio-support@lists.sourceforge.net

Please visit <https://www.openstudio.net/> to join the OpenStudio user support mailing list, browse the list of known issues in the bug tracker, or post a new bug report.

Site energy refers to the total energy consumed by the building on site, and total source energy refers to the total energy input required to produce and deliver the energy to the site for use. The source energy is calculated from the site energy using the site to source conversion factor entered by user.

Please look the description of the FuelFactors object in the InputOutputReference documentation.

In general conversion factor includes the overall efficiency of the source energy conversion, transmission and distribution losses. This factor varies by fuel type as well, and whether the source is on-site (e.g. generator) or off-site (e.g. Utilities).

Please look at the Environmental Impacts subsection in the EngineeringReference documentation for conversion factor tables.