CI-v5 WEc2: Enhanced Water Efficiency 1-8 points

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Intent

To reduce potable water consumption and the associated energy consumption and carbon emissions required to treat and distribute water and to reward the use of alternative water sources that preserve potable water resources.

Requirements

Implement a combination of the strategies below for a maximum of 8 points. Projects may either attempt Option 1 or any combination of Options 2 or 3 below.

Option 1. Whole-Project Water Use (1–8 points)
To pursue this pathway, project teams must develop a water use baseline and create a proposed use model. Points are achieved based on reductions from the baseline in Table 1.

Table 1. Points for Reducing Overall Project Water Use

OR

Option 2. Fixture and Fittings — Calculated Reduction (1–6 points)
Further reduce fixture and fitting water use from the calculated baseline in WEp1: Minimum Water Efficiency, Minimum Fixture and Fittings Efficiency, Option 2, Performance Path–Calculated Reduction. Some of these fittings and fixtures may be outside the tenant space. Additional potable water savings can be earned above the prerequisite level using alternative water sources. Points are awarded according to Table 2.

Table 2. Points for Reducing Indoor Water Use

AND/OR

Option 3. Appliance and Process Water (1–2 points)
Newly installed equipment within the tenant space must meet the minimum requirements in Tables 3, 4, and/or 5. 1 point is awarded for meeting all applicable requirements in any one table for a maximum of 2 points. All applicable, newly installed equipment listed in each table must meet the standard. Existing appliances and equipment can be excluded.

To use Table 3, the project must process at least 120,000 lbs. (57,606 kg.) of laundry per year.

Table 3. Compliant Commercial Washing Machines

_{*Based on equal quantities of heavily, medium, and lightly soiled laundry.}

To use Table 4, the project must serve at least 100 meals per day of operation.

Table 4. Standards for Compliant Commercial Kitchen Equipment

Table 5. Compliant Laboratory and Medical Equipment

AND/OR

Option 4. Optimize Process Water Use (1–2 points)
Include any associated base building water use that is necessary for equipment that serves the tenant space.

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 6.

Table 6. Maximum Concentrations for Parameters in Condenser

_{NOTE: ppm = parts per million
NOTE: 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 come in contact with the cooling tower water shall be of the type that can operate and be maintained within the cycles established in Table 7.

Table 7. Points for Cooling Tower Cycles

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 a 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 8.

Table 8. Points for Reducing Annual Water Use Compared to Water-Cooled Chiller System

Projects whose cooling is provided by district cooling systems are eligible to achieve Path 2 if the district cooling system complies with the above requirements.

OR

PATH 3. PROCESS WATER USE (1–2 POINTS)
Demonstrate that the project is using a minimum of 20% alternative water to meet the process water demand for 1 point or using a minimum of 30% alternative water to meet the process water demand for two points. Ensure that alternative water is of sufficient quality for its intended end use.

The minimum percentage of alternative water used should be based on water use during the month with the highest water demand.

Process water uses eligible for achievement of Path 3 must represent at least 10% of total building regulated water use and may not include water used for cooling.