Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
The boundary conditions for slab and basement were meant for when you are using the ground pre-processor. You can find documentation on that here. http://nrel.github.io/EnergyPlus/AuxiliaryPrograms/AuxiliaryPrograms/#ground-heat-transfer-in-energyplus
If you are just making a basic model and not calculating ground temperatures then you would typically use "Ground" as the boundary condition. But that is of course not as accurate as calculating them on your own. EnergyPlus now as the ability to calculate ground temperatures during the main simulation vs. only as a pre-processor. With the built in method I believe you would generally end up with a boundary condition of "OtherSideCoefficients" then you would have to create an object to use as the Outside Boundary Condition Object.
