Revision history [back]

The coils are not required by EnergyPlus for cooling-only or heating-only mode. See the IDD too...

ZoneHVAC:TerminalUnit:VariableRefrigerantFlow,
...
  A11,  \field Cooling Coil Object Type
        \type choice
        \key Coil:Cooling:DX:VariableRefrigerantFlow
        \key Coil:Cooling:DX:VariableRefrigerantFlow:FluidTemperatureControl
        \note Cooling Coil Type must be Coil:Cooling:DX:VariableRefrigerantFlow
        \note if AirConditioner:VariableRefrigerantFlow is used
        \note to model VRF outdoor unit
        \note Cooling Coil Type must be
        \note Coil:Cooling:DX:VariableRefrigerantFlow:FluidTemperatureControl
        \note if AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl or
        \note if AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl:HR
        \note is used to model VRF outdoor unit
        \note This field may be left blank if heating-only mode is used
...
  A13,  \field Heating Coil Object Type
        \type choice
        \key Coil:Heating:DX:VariableRefrigerantFlow
        \key Coil:Heating:DX:VariableRefrigerantFlow:FluidTemperatureControl
        \note Heating Coil Type must be Coil:Heating:DX:VariableRefrigerantFlow
        \note if AirConditioner:VariableRefrigerantFlow is used
        \note to model VRF outdoor unit
        \note Heating Coil Type must be
        \note Coil:Heating:DX:VariableRefrigerantFlow:FluidTemperatureControl
        \note if AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl or
        \note if AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl:HR
        \note is used to model VRF outdoor unit
        \note This field may be left blank if cooling-only mode is used
...

The coils are not required by EnergyPlus for cooling-only or heating-only mode. See the IDD too...

ZoneHVAC:TerminalUnit:VariableRefrigerantFlow,
...
  A11,  \field Cooling Coil Object Type
        \type choice
        \key Coil:Cooling:DX:VariableRefrigerantFlow
        \key Coil:Cooling:DX:VariableRefrigerantFlow:FluidTemperatureControl
        \note Cooling Coil Type must be Coil:Cooling:DX:VariableRefrigerantFlow
        \note if AirConditioner:VariableRefrigerantFlow is used
        \note to model VRF outdoor unit
        \note Cooling Coil Type must be
        \note Coil:Cooling:DX:VariableRefrigerantFlow:FluidTemperatureControl
        \note if AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl or
        \note if AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl:HR
        \note is used to model VRF outdoor unit
        \note This field may be left blank if heating-only mode is used
...
  A13,  \field Heating Coil Object Type
        \type choice
        \key Coil:Heating:DX:VariableRefrigerantFlow
        \key Coil:Heating:DX:VariableRefrigerantFlow:FluidTemperatureControl
        \note Heating Coil Type must be Coil:Heating:DX:VariableRefrigerantFlow
        \note if AirConditioner:VariableRefrigerantFlow is used
        \note to model VRF outdoor unit
        \note Heating Coil Type must be
        \note Coil:Heating:DX:VariableRefrigerantFlow:FluidTemperatureControl
        \note if AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl or
        \note if AirConditioner:VariableRefrigerantFlow:FluidTemperatureControl:HR
        \note is used to model VRF outdoor unit
        \note This field may be left blank if cooling-only mode is used
...

PS - if you want to avoid casting optional objects to their specific class, you can use Julien's dirty method.