Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
EnergyPlus constrains a given zone to only one AirLoopHVAC system through the ZoneHVACEquipmentConnections object, which allows only a single "Zone Return Air Node" as opposed to a list of nodes. A zone is added to the AirLoopHVAC based system through the "Zone Air Inlet Node" (of which there can be many) and the "Zone Return Air Node" (of which there can only be one). @rraustad might be able to give more detail about why EnergyPlus is structured this way.
Zone equipment connects to a zone through the "Zone Air Inlet Node" and the "Zone Air Exhaust Node" (defined in ZoneHVACEquipmentConnections) both of which are extensible through a node list. Because of this you can have as many zone hvac components as you want.
