In general, the Construction object in EnergyPlus is a list of Material objects defined somewhere else in the IDF input file to represent the layers from outside to inside. The Construction:InternalSource object is similar, but one layer is an internal source of heating or cooling within the construction assembly (e.g. radiant floor with pipes throughout concrete). The severe error is saying that for the Construction object named "GBXML HEMCRETE - CBM1-0.075_0.07" has an internal heating or cooling source or sink, so it is specifically a Construction:InternalSource object. To fix the severe error, you have two options:
- You ARE NOT trying to model a thermally active assembly. If so, then use the "normal" Construction object
- You ARE trying to model a thermally active assembly. If so, then the assembly must have at least one material layer according to the end of the severe error message. This is because the heating or cooling source is placed in a boundary between material layers (refer to the Source Present After Layer Number input field of the Construction:InternalSource object). If there isn't another material layer in the real assembly you're trying to model, then make the inputs for the new material layer:
- same roughness as the original HEMCRETE layer
- very thin
- highly conductive
- low density
- low specific heat
- same absorptance as the original HEMCRETE layer
These settings will minimize the new layer's impact on the heat transfer and storage for the thermally active construction assembly.