Hello,
We are working on a LEED v4.1 BD+C project where the proposed design uses both District Hot Water (Purchased Heat) and District Chilled Water (Purchased Cooling).
The baseline system is System 7 (VAV with Reheat).
Based on our review of ASHRAE 90.1-2016 Appendix G:
- G3.1.1.1 states that when purchased hot water is used, the heating source shall be modeled as purchased hot water in both the proposed and baseline models.
- G3.1.3.2 states that the boiler plant shall use the same fuel as the proposed design.
- G3.1.3.7 states that electric chillers shall be used in the baseline building design regardless of the cooling energy source.
Therefore, our interpretation is:
- Proposed: District Hot Water / District Chilled Water
- Baseline: District Hot Water / Electric Chiller
Is this the correct interpretation for LEED v4.1 and ASHRAE 90.1-2016 Appendix G?
Or should both heating and cooling remain as purchased energy in the baseline model?
In addition, if purchased heating and cooling must be used in the baseline model, what supply water temperatures should be assumed for the purchased hot water and chilled water?
Any guidance or reviewer precedents would be greatly appreciated.
Thank you.