855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 205
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Projects with alternative water sources Projects using alternative water sources do not require a one-time water analysis. Using a minimum of 20% alternative water can help projects earn two points, as long as the maximum calculated number of cycles is also met.
Projects in a campus environment Projects in a campus environment, or those supplied by a district cooling system, may comply with Path 1 if the district system conducts a potable water analysis and limits the cycles of concentration for its system. Projects can determine compliance at the district level by working with the utility provider.
PATH 2. OPTIMIZE WATER USE FOR COOLING
Path 2 has minimum eligibility requirements. Using ASHRAE Standard 90.1–2019 (or later), Appendix G. Performance Rating Method, Table G3.1.1–2, confirm that the project’s baseline case includes chilled water for cooling and cooling towers in the baseline design. Table 21 outlines the eligible baseline systems from Appendix G.
Projects pursuing this path do not require an Appendix G energy model. Other tools can help perform water-use calculations.
Table 21. ASHRAE Standard 90.1–2019, Appendix G Compliant Baseline Systems
| System number | System description |
|---|---|
| 7 | VAV with reheat |
| 8 | VAV with parallel fan-powered boxes and reheat. |
| 11 | Single-zone VAV system with water-cooled chillers |
| 12 | Single-zone constant volume system with water-cooled chillers and a hot-water fossil-fuel boiler |
| 13 | Single-zone constant volume system with water-cooled chillers and electric resistance heat. |
Projects can demonstrate a 100% reduction from baseline if the Appendix G baseline includes a cooling tower and the final design eliminates the need for a cooling tower.
Projects may benefit from a combination of strategies to reduce water consumption for the cooling system. Strategies include maximizing cycles of concentration, increased levels of chemical treatment, smart controls for monitoring and optimization, drift eliminators, flow meters, and water-level controls.
U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 195