Are you using the ZoneHVAC:RefrigerationChillerSet to model this? This should be doable if that's the case.this?

If you're using a Refrigeration:CompressorRack to model the compressors you You may be able to use the Refrigeration:TransferLoadList to connect the thermal storage to the walk-ins do this but I have not personally attempted this.

I would recommend using That being said, you may want to just create separate compressor(s) that serve the ZoneHVAC:RefrigerationChillerSet approach HVAC to simplify things. You won't lose much accuracy by doing this because EnergyPlus doesn't really account for the part-load performance of Refrigeration:CompressorRack's refrigeration compressor racks to begin with :( Compressor rack performance is solely dependant on the discharge and suction temperatures.

You may be able to use the Refrigeration:TransferLoadList to do this but I have not personally attempted this.

That being said, you may want to just create separate compressor(s) that serve the HVAC to simplify things. You won't lose much accuracy by doing this because EnergyPlus doesn't really account for the part-load performance of refrigeration compressor racks to begin with :( Compressor rack performance is solely dependant on the discharge and suction temperatures.