Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
4

Zone within a zone

asked 2018-09-05 07:50:37 -0500

Siv gravatar image

updated 2018-09-05 08:13:11 -0500

I have thermal zone which is enclosed within another thermal zone. I have attached the picture below. The question is, when I create a zone within a zone the boundary conditions of the inner zone is Outdoor. However, this is a completely inner zone whose walls no contact with the outdoor conditions. You see, the outer zone is maintained at 25 C and inner is maintained at 18 C What should be boundary conditions of the inner zone ?!image description

edit retag flag offensive close merge delete

Comments

Just curious in this configuration, how is the outer zone floor surface represented in EnergyPlus? Its essentially a rectangle with a hole inside, 8 vertices in total. The surface is not simply connected anymore. How does SketchUp arrange the 8 vertices in a series to represent such a surface?

TiejunWu gravatar imageTiejunWu ( 2018-09-05 14:16:07 -0500 )edit

It is just a rectangle, it has no holes in it. Atleast, I have not created any holes in it. However, I am unsure how sketchup exports it.

Siv gravatar imageSiv ( 2018-09-06 01:58:50 -0500 )edit

3 Answers

Sort by ยป oldest newest most voted
4

answered 2018-09-05 10:22:11 -0500

You will get a severe or fatal error by having a space within a space in OpenStudio. This will create non-convex geometry, and EnergyPlus will have difficulty calculating the zone volume.

I recommend splitting the larger space into two spaces, setting the connecting surface as an air wall, and then assigning them under the same zone in OpenStudio. Your boundary conditions on the interior will be 'Surface' matched to the adjacent surface. The surface matching feature in OpenStudio should do this automatically.

edit flag offensive delete link more
1

answered 2018-09-05 08:21:07 -0500

Avi gravatar image

I believe that just like any other internal wall which divide two zones the condition should be the other side Surface.

edit flag offensive delete link more
0

answered 2018-09-05 08:20:33 -0500

The outside boundary condition for the wall surfaces of the inner zone is the outer zone (or rather the surfaces in the outer zone corresponding to the "other sides" of the inner-zone walls). Here is the documentation.

edit flag offensive delete link more

Comments

But there are no additional surfaces. Its just a singlular zone. It has no attachments with any other surfaces

Siv gravatar imageSiv ( 2018-09-05 08:36:11 -0500 )edit

Each interior wall in EnergyPlus is actually two surfaces, one for each face. Either way, you have a bigger problem on your hands as mentioned above.

__AmirRoth__ gravatar image__AmirRoth__ ( 2018-09-05 11:53:18 -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

2 followers

Stats

Asked: 2018-09-05 07:50:37 -0500

Seen: 118 times

Last updated: Sep 05 '18