There are a few options for running a simulation for a single space. There are a few issues involved. The first is how to have OpenStudio only simulate the space you want. The second part is handling HVAC systems that should be ignored that don't participate in conditioning of the space you are modeling. As far as spaces, what do you want to happen to the surfaces for your space if you don't have adjacent zones. Presumably you don't want them to revert to being exposed to the outside environment. A simple option is to mimic behavior where adjacent zones have the same temperature as your space. Using an adiabatic boundary condition can do this. OpenStudio has just added support for OtherSideCoeficent objects, which would allow you to associate temperature schedules with adjacent surfaces; initially this will just be available in the API and not the GUI. The adiabatic solution you can do today in the GUI. On the HVAC side you can remove Air and Plant loops that don't directly support this space. A measure that fully automates this would be great, I'm not aware of one yet, but I have seen others do this with large models to allow quick testing of specific parts of their model. Below are a few options you could take. In any of these work in a copy of your model.
- The OpenStudio application will ignore spaces that are not part of a thermal zone. So if you remove the thermal zones from all but the clean room forward translation will just pass that space to the IDF file. You will have to manually change the surface boundary conditions to adiabatic or you will get an error about missing adjacent surface. You also want to make sure you don't leave any other zones in the model, otherwise they will go to EnergyPlus and you will hit an error about not having any geometry. Then you need to clean up the HVAC by hand.
- The SketchUp Plugin has a user script to Export Selected Spaces to a New Model. This will just export the space, not other parts of the model. Similar to Option 1 you would have to open that copy and change the surfaces to adiabatic and hard assign constructions (there is a user script to do that). You would also need to re-assign the space type and build up an HVAC system.
There is nothing in particular that is tricky about writing a measure to automate all of this, but just takes a lot of thought about how it should behave. Ideally it could use adjacent zone setpoint temperatures to create schedules for use with OtherSideCoefficients, and it could automatically remove necessary spaces and HVAC components and loops. Anything that was not autosized in the system should probably be autosized? We also sometimes just put in district heating and cooling on the plant when we are just modeling a single zone. of a larger building.
