Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
The first you mentioned if "ground" is your floor boundary condition. But these values simply will be what you put in monthly gound temperature object (so, these temperatures are your inputs).
This is the simpler way to model ground heat transfer, but really I do not know if this fit with your purposes. You may want to looking for some more detailed model
