This would not work because OpenStudio's "reverse translator" translation" (importing an IDF) does not work for HVAC objects so the resulting OSM would be incomplete. See the documentation.

Import and Export Options

• IDF import (geometry, constructions, loads, thermal zones, and schedules only)
• IDF export (full model including HVAC)
• gbXML import (geometry, constructions, thermal zones, and schedules only)
• gbXML export (geometry, constructions, and thermal zones only)
• SDD import (simulation format - full model including HVAC)
• SDD export (input format - geometry, constructions, and thermal zones only)
• IFC import (geometry only)

This I don't think this would not work because OpenStudio's "reverse translation" (importing an IDF) does not work for HVAC objects so the resulting OSM would be incomplete. See the documentation.

Import and Export Options

• IDF import (geometry, constructions, loads, thermal zones, and schedules only)
• IDF export (full model including HVAC)
• gbXML import (geometry, constructions, thermal zones, and schedules only)
• gbXML export (geometry, constructions, and thermal zones only)
• SDD import (simulation format - full model including HVAC)
• SDD export (input format - geometry, constructions, and thermal zones only)
• IFC import (geometry only)

I don't think this would work because OpenStudio's "reverse translation" (importing an IDF) does not work for HVAC objects so the resulting OSM would be incomplete. See the documentation.