I am getting the following error while trying to model a low temp radiant system: Program Version,EnergyPlus-Windows-64 8.1.0.009, YMD=2014.11.14 10:36,IDD_Version 8.1.0.009 * Severe * IP: IDF line~572 Object=ZONEHVAC:LOWTEMPERATURERADIANT:SURFACEGROUP, name=LOW TEMP RADIANT VAR FLOWCEILINGS, Required Field=[Surface 1 Name] was blank. * Severe * IP: IDF line~572 Object=ZONEHVAC:LOWTEMPERATURERADIANT:SURFACEGROUP, name=LOW TEMP RADIANT VAR FLOWCEILINGS, Required Field=[Flow Fraction for Surface 1] was blank. * Warning * IP: Note -- Some missing fields have been filled with defaults. See the audit output file for details.
The idf looks like this: ZoneHVAC:LowTemperatureRadiant:SurfaceGroup, Low Temp Radiant Var FlowCeilings; !- Name
and nothing else follows after this, so the surface names and flow fractions are missing (below is cut and pasted from EP input output ref):
ZoneHVAC:LowTemperatureRadiant:SurfaceGroup, Zone 1 Radiant Surfaces, !- name of surface list Zn001:Flr001, !- Surface name 1 0.75, !- Flow fraction for surface 1 Zn001:Roof001, !- Surface name 2 0.25; !- Flow fraction for surface 2