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

Deleting Design Days (DDY) from OpenStudio 1.9.0

asked 2015-11-11 13:38:08 -0600

NickC's avatar

updated 2015-11-11 14:31:50 -0600

I think I may have uncovered an OS bug and wanted to see if anyone else has observed the same issue.

My somewhat complex OS model seems to running fine with a number unimportant warnings and a few sizing errors. I WAS including 6 design days, but decided to remove them for computational time reasons.

Before removing DDYs image description

DropBox Link to *.err file

and after removing DDYs (using the checkboxes and red X delete button) image description

DropBox Link to *.err file

New errors are along the lines of

* Severe * IP: IDF line~37391 Object=CONTROLLER:MECHANICALVENTILATION, name=CONTROLLER MECHANICAL VENTILATION 3, Required Field=[Zone 1 Name] was blank.

and cause my model analysis to be...terminated image description

edit retag flag offensive close merge delete


Have you hard sized all your flow rates and equipment capacities? If you still have autosized values then the simulation will fail because no sizing was done during design day simulations. Nice photo thread BTW :-)

macumber's avatar macumber  ( 2015-11-11 14:07:43 -0600 )edit

That must be the problem; I thought everything was hard sized but must have missed some elements. Thanks! and hasta la vista

NickC's avatar NickC  ( 2015-11-11 14:16:28 -0600 )edit

@administrator, is it possible to vote up individual photos?

__AmirRoth__'s avatar __AmirRoth__  ( 2015-11-11 14:32:38 -0600 )edit

1 Answer

Sort by ยป oldest newest most voted

answered 2015-11-11 14:08:15 -0600

NickC's avatar

updated 2015-11-11 14:21:18 -0600

Thanks to some help from @macumber, I think I understand what was happening. I had an autosized piece of equipment, which needed design day information to determine how "big" the equipment should be in the model.

Removing all the design days caused the error...which was of the user variety. Main takeaway, you need those DDY files if you're gonna autosize. At this point, I'm not sure which DDYs are actually needed and which ones are overly extreme or redundant...

edit flag offensive delete link more


This is very odd, removing those objects from the GUI should have done exactly this. Can you diff the file you edited by hand with the one you edited in the GUI?

macumber's avatar macumber  ( 2015-11-11 14:17:19 -0600 )edit

Sorry for any confusion from my first answer post; I've updated it (hopefully correct now)

NickC's avatar NickC  ( 2015-11-11 14:25:12 -0600 )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: 2015-11-11 13:38:08 -0600

Seen: 332 times

Last updated: Nov 11 '15