Openstudio crashes when trying to access thermal zones

[dmeist]

Hello,

I'm experiencing consistent crashes in OpenStudio whenever I try to access the thermal zones tab. This issue started happening after I tried to change the air terminal from "OS:AirTerminal:SingleDuct:ConstantVolume:NoReheat" to "OS:AirTerminal:VAV:NoReheat". The HVAC system is a Packaged Rooftop Heat Pump and the building is a 2 story Outpatient facility. I tried deleting the heat pump system entirely from the HVAC tab, but the issue still persists. I can provide the file if needed, and I attached the HVAC loop and building geometry for reference.

Steps to Reproduce

1. Added the Package Rooftop Heat Pump template using the green + button.
2. Dragged & dropped all the thermal zones to the "drag from library" box, then it automatically sets the air terminal to diffuser.
3. Clicked "x" next to all the diffusers to delete them and added the VAV air terminal.
4. Tried adding more thermal zones but kept crashing, and I noticed I can't access the thermal zones tab at all.

Environment

• Platform (Operating system, version): Windows 11
• Version of OpenStudioApplication : 3.8.0

[macumber]

Hi @dmeist can you please upload the file to this issue if you are able? Just rename the OSM with a .txt extension and upload it to the issue.

[dmeist]

Hi @macumber, here is the file to this issue.
outpatient.txt

[macumber]

The OS:ZoneHVAC:EquipmentList related to some of the zones have become invalid, for example the equipment list for TZ-Hall:

 OS:ZoneHVAC:EquipmentList,
  {f0549ec1-dcbf-4b2c-a191-bc4d1baf0267}, !- Handle
  Zone HVAC Equipment List 2,             !- Name
  {ca0fd7af-15b9-4367-b39b-3f1ada1a5859}, !- Thermal Zone
  ,                                       !- Load Distribution Scheme
  ,                                       !- Zone Equipment 1
  1,                                      !- Zone Equipment Cooling Sequence 1
  1,                                      !- Zone Equipment Heating or No-Load Sequence 1
  ,                                       !- Zone Equipment Sequential Cooling Fraction Schedule Name 1
  ;                                       !- Zone Equipment Sequential Heating Fraction Schedule Name 1

The field for Zone Equipment 1 is empty. The other affected zones are TZ-Exam2-1 and TZ-Exam2-2. Were these zones on the loop you were modifying? It seems like these zones are not assigned to an air loop.

[macumber]

@jmarrec do you think this is related to NREL/OpenStudio#5121 ?

[macumber]

I used the following code to update the OSM to remove the three zones with bad equipment lists:

require 'openstudio'

m = OpenStudio::Model::Model::load('outpatient.osm').get
m.getThermalZones.each do |z|
  if ['TZ-Hall', 'TZ-Exam2-1', 'TZ-Exam2-2'].include?(z.nameString)
    z.remove
  end
end
m.save('outpatient.osm', true)

Uploaded the file here, fixed_outpatient.osm.txt

@dmeist I was not able to reproduce the issue following your steps. If you are able to provide exact steps that reproduce the issue from an empty model that will really help us figure out how your model became corrupted.

[jmarrec]

@jmarrec do you think this is related to NREL/OpenStudio#5121 ?

No clue unless we get steps from @dmeist to reproduce the issue from scratch.

Then it'd be easy to test: if we can repro the crash with latest official OSApp that uses OS SDK 3.8.0, and we cannot reproduce it with 1.9.0-rc1 (which uses OS SDK 3.9.0), then probably related yes.