I'm trying to model a VRF system (exceptional calc from model generated in CBECC-Com) using the default objects. Form what I can see, there are only two: the system itself and the terminal units. It seems like the default settings are good for a test run, so I ran everything as it is, but set the control zone to one of the zones in each system and turned heat recovery on. The errors I'm getting from it are all about unassinged airflow nodes. For example:
* Severe * IP: IDF line~55232 Error detected in Object=ZONEHVAC:TERMINALUNIT:VARIABLEREFRIGERANTFLOW, name=VRF ZONE TERMINAL 8 * ~~~ * Field [Terminal Unit Air Inlet Node Name] is required but was blank *** IDF Context for following error/warning message: *** Note -- lines truncated at 300 characters, if necessary... *** 55229 ZoneHVAC:TerminalUnit:VariableRefrigerantFlow, *** indicated Name=VRF Zone Terminal 8 *** Only last 4 lines before error line shown..... *** 55230 VRF Zone Terminal 8, !- Zone Terminal Unit Name *** 55231 Always On Discrete 1, !- Terminal Unit Availability Schedule *** 55232 , !- Terminal Unit Air Inlet Node Name *** 55233 , !- Terminal Unit Air Outlet Node Name * Severe * IP: IDF line~55233 Error detected in Object=ZONEHVAC:TERMINALUNIT:VARIABLEREFRIGERANTFLOW, name=VRF ZONE TERMINAL 8 * ~~~ * Field [Terminal Unit Air Outlet Node Name] is required but was blank *** IDF Context for following error/warning message: *** Note -- lines truncated at 300 characters, if necessary... *** 55255 Fan:OnOff, *** indicated Name=VRF Zone Terminal Fan 8 *** Only last 9 lines before error line shown..... *** 55256 VRF Zone Terminal Fan 8, !- Name *** 55257 Always On Discrete 15, !- Availability Schedule Name *** 55258 0.6, !- Fan Total Efficiency *** 55259 300, !- Pressure Rise {Pa} *** 55260 Autosize, !- Maximum Flow Rate {m3/s} *** 55261 0.8, !- Motor Efficiency *** 55262 1, !- Motor In Airstream Fraction *** 55263 VRF Zone Terminal 8 Heating Coil Outlet Node, !- Air Inlet Node Name *** 55264 , !- Air Outlet Node Name * Severe * IP: IDF line~55264 Error detected in Object=FAN:ONOFF, name=VRF ZONE TERMINAL FAN 8 * ~~~ * Field [Air Outlet Node Name] is required but was blank *** IDF Context for following error/warning message: *** Note -- lines truncated at 300 characters, if necessary... *** 55286 OutdoorAir:Mixer, *** indicated Name=VRF Zone Terminal 8 OA Mixer *** Only last 5 lines before error line shown..... *** 55287 VRF Zone Terminal 8 OA Mixer, !- Name *** 55288 VRF Zone Terminal 8 Mixer Outlet Node, !- Mixed Air Node Name *** 55289 VRF Zone Terminal 8 Outdoor Air Node, !- Outdoor Air Stream Node Name *** 55290 VRF Zone Terminal 8 Relief Node Name, !- Relief Air Stream Node Name *** 55291 ; !- Return Air Stream Node Name
But I'm not really sure where I'm supposed to set these nodes. It seems like something that OpenStudio would know by default because each system is assigned to a zone and this is purely zonal recirculation (DOAS defined elsewhere). Is there a place I'm missing to put the terminals on an air loop?
Thanks, Ben
