LEED v5 BD+C Rating System_November 2025_clean - Page 073

Extracted Content

Option 5. Optimize Process Water Use (1–2 points)

PATH 1. LIMIT COOLING TOWER CYCLES (1–2 POINTS)

For cooling towers and evaporative condensers, conduct a one-time potable water analysis, measuring at least the five control parameters listed in Table 8.

Table 8. Maximum Concentrations for Parameters in Condenser Water

Parameter	Maximum Level
Ca (as CaCO3)	600 ppm
Total alkalinity	500 ppm
SiO2	150 ppm
Cl−	300 ppm
Conductivity	3,300 μS/cm

Note: 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 preceding requirements.

OR

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, November 2025 Edition 66