Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
I'm not sure why it cannot be saved, but note that Continuous Insulation Nominal R-value is total R, not R/in, so your entry should be 20 not 5. The Whole Wall R-20 XPS is probably your best bet. As for ceiling spacing values, those are so that it can calculate how much of the rim joist is thermal bridging to the floor versus exposed/insulated.
| | 2 | No.2 Revision |
I'm not sure why it cannot be saved, but note that Continuous Insulation Nominal R-value is total R, not R/in, so your entry should be 20 not 5. The Whole Wall R-20 XPS is probably your best bet. As for ceiling spacing values, those are so that it can calculate how much of the rim joist is thermal bridging to the floor versus exposed/insulated.
BEopt's Slab entries are for slab-on grade. Since the ground's temperature below the frost-line/in a basement is relatively constant compared to the ambient temperature, the software simplifies inputs and ignores under-slab insulation. This is a fairly reasonable simplification unless you have radiant heating in the slab, which BEopt itself does not explicitly handle anyhow.
