Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question

Defining internal objects in EnergyPlus

asked 2017-03-07 10:31:47 -0500

Dear All!

I intend to define an internal object (solid material) inside the building to evaluate the impact of thermal inertia for different materials, but Sketchup and EnergyPlus only allow me to define specific types of surfaces (roof, floor, wall) or subsurfaces (windows, doors, etc.). Would you please help me with that? Thanks a lot!

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted

answered 2017-03-07 11:25:00 -0500

updated 2017-03-07 11:25:55 -0500

You can add Internal Mass objects with an IDF editor. If you are using the Legacy OpenStuido SketchUp plugin, it doesn't have access to this, however Interior Partitions in OSM files are translated to EnergyPlus Internal mass objects by default. But keep in mind, their position in space doesn't mater for the internal mass object since it just has an area and a construction and not a specific position in space. The position on interior partitions is for the benefit Radiance analysis.

image description

Here is a view of the Internal Mass objet in the OpenStudio application which looks similar to the EnergyPlus fields, but also offers option to normalize internal mass area per person or floor area.

image description

edit flag offensive delete link more


Thanks a lot David! but there should be a difference if the material is next to the window or the other side of room where it doesn't receive much sunlight, no?

Pouya gravatar imagePouya ( 2017-03-08 03:19:00 -0500 )edit

Yes, it will affect daylighting levels and solar gain in the room.

David Goldwasser gravatar imageDavid Goldwasser ( 2017-03-08 08:35:05 -0500 )edit

Depending on what you are trying to analyze, you may want to consider the Solar Distribution setting and how it may impact your results.

Lyle K gravatar imageLyle K ( 2017-03-08 17:06:34 -0500 )edit

Thanks for the hint Lyle, I intend to evaluate the influence of internal objects near the windows and how they can contribute to thermal performance of the building.

Pouya gravatar imagePouya ( 2017-03-09 02:55:04 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer


Question Tools

1 follower


Asked: 2017-03-07 10:31:47 -0500

Seen: 725 times

Last updated: Mar 07 '17