A question on series desiccant wheel modeling in E+

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Hi there,

I want to model a DOAS system in E+, of which the configuration is as follows. However, we have encountered some problems when trying to implement the series desiccant wheel (the orange one in the figure) in the air loop. I tried adding a heat exchanger to the existing air loop, but E+ seems to not allow an object to be referred to twice in an air loop. I tried different heat exchanger objects but none worked. Anyone knows a workaround for this?

I am attaching the proposed air loop branch and the error message below.

Much appreciated!

Branch,
DOAS Main Branch,        !- Name
,                        !- Pressure Drop Curve Name
AirLoopHVAC:OutdoorAirSystem,  !- Component 1 Object Type
DOAS OA System,          !- Component 1 Name
DOAS Air Loop Inlet,     !- Component 1 Inlet Node Name
DOAS Mixed Air Outlet,   !- Component 1 Outlet Node Name
HeatExchanger:AirToAir:SensibleAndLatent,  !- Component 2 Object Type
DOAS Heat Recovery,      !- Component 2 Name
DOAS Mixed Air Outlet,   !- Component 2 Inlet Node Name
DOAS Heat Recovery Supply Outlet,  !- Component 2 Outlet Node Name
Coil:Heating:Water,      !- Component 3 Object Type
DOAS Heating Coil,       !- Component 3 Name
DOAS Heat Recovery Supply Outlet,  !- Component 3 Inlet Node Name
DOAS Heating Coil Outlet,!- Component 3 Outlet Node Name
HeatExchanger:Desiccant:BalancedFlow,  !- Component 4 Object Type
Desiccant Wheel,                      !- Component 4 Name
DOAS Heating Coil Outlet,!- Component 4 Inlet Node Name
Desiccant Wheel Exchanger OA Outlet,  !- Component 4 Outlet Node Name
Coil:Cooling:Water,      !- Component 5 Object Type
DOAS Cooling Coil,       !- Component 5 Name
Desiccant Wheel Exchanger OA Outlet,  !- Component 5 Inlet Node Name
DOAS Cooling Coil Outlet,!- Component 5 Outlet Node Name
HeatExchanger:Desiccant:BalancedFlow,  !- Component 6 Object Type
Desiccant Wheel,                      !- Component 6 Name
DOAS Cooling Coil Outlet,!- Component 6 Inlet Node Name
Desiccant Wheel Exchanger Outlet,     !- Component 6 Outlet Node Name
Fan:VariableVolume,      !- Component 7 Object Type
DOAS Supply Fan,         !- Component 7 Name
Desiccant Wheel Exchanger Outlet,     !- Component 7 Inlet Node Name
DOAS Supply Fan Outlet;  !- Component 7 Outlet Node Name

** Severe  ** Same component name and type has differing Node Names.

**   ~~~   **    Component:    HEATEXCHANGER:DESICCANT:BALANCEDFLOW, name=Desiccant Wheel

**   ~~~   **    Nodes, inlet: DOAS HEATING COIL OUTLET, outlet: Desiccant Wheel EXCHANGER OA OUTLET

**   ~~~   **  & Nodes, inlet: DOAS COOLING COIL OUTLET, outlet: Desiccant Wheel EXCHANGER OUTLET

**   ~~~   **    Node Types:   UNDEFINED & Process Air Nodes