I'm assuming you've used the Contam3DExporter to generate your IDF file.
As indicated in the CONTAM documentation (quoted below), you must modify this IDF file to incorporate the energy related components of the building. This includes the design loads and other items that the CONTAM paradigm does not incorporate, e.g., "Design day information".
The Zone Infiltration is calculated by CONTAM during the co-simulation and will override any values set for the ZoneInfiltration:DesignFlowRate object.
EnergyPlus-CONTAM Coupling Process
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Modify IDF File The IDF file generated by CONTAM3DExport contains
the building geometry, surface
materials and constructions, air
loops, exhaust fans and partial
external interface objects as
described above. However, the file
will not include the HVAC components
associated with the generation or
removal of energy, e.g.,
heating/cooling coils, internal gains,
and thermostats. The IDF file can now
be edited using the IDF Editor or
other text-based editor to add the
desired HVAC system components. The
IDF file can also be viewed and edited
using tools such as SketchUp with the
OpenStudio plug-in [Gugliemetti 2011,
NREL 2015]. This is useful to modify
the rectangular elements that are
created by CONTAM3DExport, for example
to modify roofs to have sloped
surfaces and to add shading components
to the building.
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