Export to gbxml changing space id

[CodyMorganVBFA]

When exporting to gbxml for import to energy modeling or HVAC load software the initial run through works great, but after updating the model to add or remove spaces and trying to export again, the spaceid numbers have been modified. This causes the other software to believe that existing spaces are now new spaces and they are added to the project rather than the original space being modified. Has anyone else had this problem and is there a solution for it? What causes those space id numbers to change when the space was not modified? Is there a way to prevent it? Currently I am using Revit 2018 and trying to import into Elite CHVAC version 8.

Thanks for your help.

[christian.riley]

@CodyMorganVBFA - 

Just to clarify, after you have updated the floor plan and exported a new gbxml, the load calc software sees all of the rooms as new rooms instead of updating the existing rooms? Does the software keep the existing rooms and duplicate those with the "new" rooms? Have you tried this with any other load calculation software?

[CodyMorganVBFA]

The results seem to vary. All of the rooms are not necessarily duplicated. With further testing I found the following. Some of them may stay as they were, some may be overwritten by other rooms and still others will be duplicated as new rooms. For example, when I exported a gbxml file then deleted a space on level 1 and added a space on level 3 the re-exported and compared the two files. I noticed that room 101 had the space id of aim0099 in both files and was updated in the loads file, room 103 was identified with the space id aim0212 in the first file, but was then assigned aim0217 causing it to stay in the loads file as the original room and then be duplicated as a new room. Now, here is where we get real problems. Room 202 was assigned the space id aim0399 on the first run, and then aim0351 on the second run and room 203 was assigned aim0447 on the first run and then aim0399 on the second run which caused it to overwrite room 202 in the loads file.
I have not tried it with any other loads software. I am working with Revit 2018 and using Elite CHVAC version 8.02.29
Thank you for looking into this.

[christian.riley]

@CodyMorganVBFA

Ok, thank you for that information. I will continue investigating this.

[christian.riley]

@CodyMorganVBFA -

For clarity. When you're working with the files you export the GBXML, you then delete a room/space in Revit then re-export that? And that is when you are seeing the issue? Or are you exporting the GBXML then deleting the room within the load calc software?

Thank you

[CodyMorganVBFA]

The issue occurs after I have deleted/added spaces in Revit then re-export the gbxml.
Thank you,

[christian.riley]

@CodyMorganVBFA -

I was able to speak to the development team regarding this. In your load calculation software are you able to map to a different parameter? The id parameter you are speaking of may be an internal unique identifier that is not persistent within model sessions. 

We would definitely recommend mapping to a room name, number, or combination of the two if at all possible.

If my post answers your question, please click the "Accept as Solution" button. This helps everyone find answers more quickly!

[CodyMorganVBFA]

Christian,
I don't really have any choice over what data the loads file uses for mapping. If you notice in the screen shot below, the only items I can modify on import are "include" (true/false), "Air Handler number for space", and " Group number for space". Everything else is automatically set by what is in the gbxml file. Also, I would anticipate a lot of problems with using room names and numbers to coordinate, because names and numbers change many times throughout a project. When I receive an updated model from an architect and the rooms have all moved around and been renumbered the space is not associated with a room that moved, it is associated with an area in the model surrounded by bounding elements. It would make sense to me that the space would need some sort of an ID number that stays consistent throughout the project no matter what the users choose to name the space. Otherwise we will constantly be duplicating spaces in the loads file as the names change. I assume that is why the loads software uses the Space ID parameter to "ID" the spaces. When it sees a number it has seen before, it updates the room data and when it sees a new number it creates a new room. Let me know if you do have a way to change that data.
[cid:image001.png@01D40320.59A29110]
Thank you,

[christian.riley]

@CodyMorganVBFA -

Thank you for that information, I am working with the development team. Thank you for your patience in this issue.

[christian.riley]

@CodyMorganVBFA -

I am currently waiting to hear back from the development team.

Thank you for your patience with this issue.

[CodyMorganVBFA]

Thanks for pursuing this. Let me know if you come up with a solution.

[christian.riley]

@CodyMorganVBFA - 

I am still waiting to hear back on this issue. I just wanted to check in and let you know that I have not forgotten about this issue. As soon as I hear from the team I will update you.

Thank you for your patience!

[christian.riley]

@CodyMorganVBFA
Could you please attach the orginal xml file as well as an updated xml? Can we see if the Space ID updates between these two instances?

[CodyMorganVBFA]

Here they are. Hopefully they will help. You'll see that in file test9 room 202 has number aim0399 then changes to aim 0351 in test10 and room 203 goes from number aim0447 to aim0399 to overwrite room 202. Other numbers were also changed, but that should give you a place to start.

Thanks for keeping on this issue.

[christian.riley]

@CodyMorganVBFA -

I just wanted to check in and let you know that I am still working on this. Thank you for your patience

[christian.riley]

@CodyMorganVBFA

Is there any way you could post the project? The development team would like to use it for testing this issue.

[CodyMorganVBFA]

The two attached files are what I am using. The file labeled arch is a linked in architectural model where the rooms exist. The spaces in the mechanical model are named based on the rooms in the architectural model. The gbxml file is being exported from the mechanical model.

Let me know if you find anything.

Thank you,

[christian.riley]

@CodyMorganVBFA - 
Thank you for those files. I have passed them to our development team and will keep you posted as any information arises.

[christian.riley]

@CodyMorganVBFA - 

I just wanted to check in and provide you with an update. The development has logged this issue and is currently investigating it. I will post an article here within the next couple of days that will update once there is a solution. Thank you for your patience in all of this.