Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Unfortunately, it doesn't appear that there is a single object to assign to a zone for ideal hydronic heating/cooling. As you mentioned, the zone HVAC ideal loads air system is for fully-convective forced air heating/cooling.
As a work-around, you can define the demand side of the radiant heating/cooling system as normal (surfaces with internal source constructions, radiant panels assigned to those surfaces, etc.). For the supply side of this system, you can define a district heating and district cooling object with appropriate setpoint managers. When post-processing results, you would focus on the District Heating & District Cooling meters, just like for the ideal loads air system.
If you believe that this should be a new feature of EnergyPlus, you can add a new issue to their GitHub repository.
