Hello! I am playing around with a simple building model in Open Studio. The simulation ran with no errors until I tried to add an HVAC system. I added a PTHP (Packaged Terminal Heat Pump) system to Thermal Zone 1. Ideal air loads are thus turned off for this zone. The remaining four thermal zones operate with ideal air loads only.

I get the following severe error which causes the simulation to fail:

* Severe * For autosizing of ZoneHVAC:PackagedTerminalHeatPump PTHP, a zone sizing run must be done. * ~~~ * No "Sizing:Zone" objects were entered.

What I have tried, per other thread posts: Under Simulation Settings --> Simulation Control, I have turned on "Do Zone Sizing Calculation", "Do System Sizing Calculation", and "Do Plant Sizing Calculation"

Any idea how I can add a zone sizing object/fix this error?