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LEED v4
New Construction
Water Efficiency

Cooling tower water use

LEED CREDIT

NC-v4 WEc3: Cooling tower water use 1-2 points

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Requirements

For cooling towers and evaporative condensers, conduct a one-time potable water analysis, in order to optimize cooling tower cycles. Measure at least the five control parameters listed in Table 1.

Table 1. Maximum concentrations for parameters in condenser water
Parameter Maximum level
Ca (as CaCO3) 1,000 ppm
Total alkalinity 1,000 ppm
SiO2 100 ppm
Cl- 250 ppm
Conductivity 2000 µS/cm
ppm = parts per million µS/cm = micro siemens per centimeter Calculate the 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. Limit cooling tower cycles to avoid exceeding maximum values for any of these parameters.
Table 2. Points for cooling tower cycles
Cooling tower cycles Points
Maximum number of cycles achieved without exceeding any filtration levels or affecting operation of condenser water system (up to maximum of 10 cycles) 1
Achieve a minimum 10 cycles by increasing the level of treatment in condenser or make-up water
OR
Achieve the number of cycles for 1 point and use a minimum 20% recycled nonpotable water
2
Pilot Alternative Compliance Path available
A pilot alternative compliance path is available for this credit to certain project types without cooling towers. For more information, please visit the Pilot Credit Library Pilot ACPs: No Cooling Tower - alternative compliance path (BD+C) No Cooling Tower - alternative compliance path (O+M) No Cooling Tower - alternative compliance path (O+M: Data Centers)
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Cost estimates for this credit

On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.

Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.

This information is also available in a full PDF download in The Cost of LEED v4 report.

Learn more about The Cost of LEED v4 »

Frequently asked questions

What if my building doesn’t use a cooling tower?

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LEEDuser expert

Maeve Donohue

LEED AP BD+C, WELL AP, LFA, Fitwel Ambassador

Introba
Consultant

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USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Requirements

For cooling towers and evaporative condensers, conduct a one-time potable water analysis, in order to optimize cooling tower cycles. Measure at least the five control parameters listed in Table 1.

Table 1. Maximum concentrations for parameters in condenser water
Parameter Maximum level
Ca (as CaCO3) 1,000 ppm
Total alkalinity 1,000 ppm
SiO2 100 ppm
Cl- 250 ppm
Conductivity 2000 µS/cm
ppm = parts per million µS/cm = micro siemens per centimeter Calculate the 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. Limit cooling tower cycles to avoid exceeding maximum values for any of these parameters.
Table 2. Points for cooling tower cycles
Cooling tower cycles Points
Maximum number of cycles achieved without exceeding any filtration levels or affecting operation of condenser water system (up to maximum of 10 cycles) 1
Achieve a minimum 10 cycles by increasing the level of treatment in condenser or make-up water
OR
Achieve the number of cycles for 1 point and use a minimum 20% recycled nonpotable water
2
Pilot Alternative Compliance Path available
A pilot alternative compliance path is available for this credit to certain project types without cooling towers. For more information, please visit the Pilot Credit Library Pilot ACPs: No Cooling Tower - alternative compliance path (BD+C) No Cooling Tower - alternative compliance path (O+M) No Cooling Tower - alternative compliance path (O+M: Data Centers)

Cost estimates for this credit

On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.

Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.

This information is also available in a full PDF download in The Cost of LEED v4 report.

Learn more about The Cost of LEED v4 »

In the end, LEED is all about documentation. LEEDuser’s Documentation Toolkit, for premium members only, saves you time and helps you avoid mistakes with:

  • Calculators to help assess credit compliance.
  • Tracking spreadsheets for materials purchases.
  • Spreadsheets and forms to give to subs and other team members.
  • Guidance documents on arcane LEED issues.
  • Sample templates to help guide your narratives and LEED Online submissions.
  • Examples of actual submissions from certified LEED projects.

What if my building doesn’t use a cooling tower?

The answer to this question is available to LEEDuser premium members. Start a free trial »

(If you're already a premium member, log in here.)

LEEDuser expert

Maeve Donohue

LEED AP BD+C, WELL AP, LFA, Fitwel Ambassador

Introba
Consultant

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