855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 193
Extracted Content
| Parameter | Maximum level |
|---|---|
| SiO2 | 150 ppm |
| Cl– | 300 ppm |
| Conductivity | 3300 μS/cm** |
*ppm = parts per million
**µS/cm = micro siemens per centimeter
Calculate the maximum number of cooling tower cycles by dividing the maximum allowed concentration level of each parameter by the actual concentration level of each parameter found in the potable makeup water analysis. Limit cooling tower cycles to avoid exceeding maximum values for any of these parameters.
The materials of construction for the water system that contact the cooling tower water must be of the type that can operate and be maintained within the cycles established in Table 9. Points are awarded according to Table 9.
Table 9. Points for cooling tower cycles
| Cooling tower cycles | Points |
|---|---|
| Maximum number of cycles achieved without exceeding any maximum concentration levels or affecting operation of condenser water system. | 1 |
| Meet the maximum calculated number of cycles to earn 1 point and increase the number of cycles by a minimum of 25% by increasing the level of treatment and/or maintenance in condenser or makeup water systems. OR Meet the maximum calculated number of cycles to earn 1 point and use a minimum 20% alternative water. | 2 |
Projects whose cooling is provided by district cooling systems are eligible to achieve Path 1 if the district cooling system complies with the above requirements.
OR
PATH 2. OPTIMIZE WATER USE FOR COOLING (1–2 POINTS)
To be eligible for Option 2, the baseline system designated for the building using ASHRAE 90.1- 2019 or 90.1-2022, Appendix G, Table G3.1.1-3, must include a cooling tower (systems 7, 8, 11, 12, and 13).
Achieve increasing levels of cooling tower water efficiency beyond a water-cooled chiller system with axial variable-speed fan cooling towers having a maximum drift of 0.002% of recirculated water volume and three cooling tower cycles. Points are awarded according to Table 10.
U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 183