ENERGY STAR Update: Update U-factor for floors over multifamily buffer space in ES MFNC Rev. 05

[bpark1327]

Pull Request Description

Address language update for floors -- added multifamily buffer space:

Checklist

Not all may apply:

• OS-HPXML git subtree has been pulled
• 301validator.xml has been updated (reference EPvalidator.xml)
• Sample files have been added/updated (openstudio tasks.rb update_hpxmls)
• Tests have been added/updated (e.g., rulesets\tests and/or workflow/tests/*_test.rb)
• Documentation has been updated
• Changelog has been updated
• openstudio tasks.rb update_measures has been run
• No unexpected changes to simulation results on CI

[shorowit]

Let's also double-check the results for 1.2 vs 1.3 for the MFNCv13_CZ6_VT_elec_middle_interior.xml test case.

[bpark1327]

Let's also double-check the results for 1.2 vs 1.3 for the MFNCv13_CZ6_VT_elec_middle_interior.xml test case.

We observed an unexpected ERI discrepancy when using different mechanical ventilation system types (HRV for MFNC v1.3 and exhaust-only for MFNC v1.2). OS-ERI showed that the ventilation system type had a much greater impact on the rated home’s ERI than we expected. This difference seems to stem primarily from variations in the Rated Home's infiltration rates.
To clarify whether our modeling approach aligns with the intended ANSI 301 methodology, we reached out to Philip and Brian via email on 3/27/2025.

[bpark1327]

Let's also double-check the results for 1.2 vs 1.3 for the MFNCv13_CZ6_VT_elec_middle_interior.xml test case.

We observed an unexpected ERI discrepancy when using different mechanical ventilation system types (HRV for MFNC v1.3 and exhaust-only for MFNC v1.2). OS-ERI showed that the ventilation system type had a much greater impact on the rated home’s ERI than we expected. This difference seems to stem primarily from variations in the Rated Home's infiltration rates. To clarify whether our modeling approach aligns with the intended ANSI 301 methodology, we reached out to Philip and Brian via email on 3/27/2025.

It is addressed in #774

[shorowit]

Looks good, just two minor requests.

[shorowit]

Looks good. Assuming the CI passes and results look reasonable, I'll merge this in. Thanks!