This is some advanced stuff you’re doing here with EarthTubes and additional strings, @fn . When you say “get the results of a single room”, do you mean get a certain output after the simulation is run? Or do you need a certain variable as the simulation is running, which would be incorporated into an EMS program?
FYI, for a highly customized simulation of a few rooms like this, you may want to use the HB Set Identifier component to fix the EnergyPlus simulation name of the Room as a single value (instead of always having to get the uuid there).