Cooling Tower Water Savings - HMGh-m-g.com/T24/Cooling Tower... · 1 California Statewide Utility Codes and Standards Program Cooling Tower Water Savings Stakeholder Meeting #1 -DRAFT

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California Statewide Utility Codes and Standards Program

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Cooling Tower Water SavingsStakeholder Meeting #1 - DRAFT

Energy Solutions

August 25, 2010

8/25/2010CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

2CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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Cooling Tower Water Savings

Agenda

● 10:00 - 10:10 Introductions

● 10:10 - 10:20 Title 24 Background/Overview

● 10:20 – 11:45 Cooling Tower Water Savings

Presentation

● 11:45 – 12:00 Wrap Up



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IOU Support for 2011 Title 24

● The California Investor Owned Utilities (IOUs) are actively supporting the California Energy Commission (CEC) in developing the state’s building energy efficiency code (Title 24)

● Their joint intent is to achieve significant energy savings through the development of reasonable, responsible, and cost-effective code change proposals for the 2011 code update and beyond

● As part of the IOU effort, at the request of the CEC, we are hosting stakeholder meetings to get industry input and feedback on our code change proposals




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Code Change Activity

● 2011 T-24 Base Code (Part 6 of Title 24)

● 2011 Reach Standard (Part 11 of Title 24)

● Green Building Standard – i.e. CalGreen

● Voluntary standards that local governments can

adopt

● Future Codes

● 2014 T-24

● Future Reach Codes




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Requirements for a Successful Code Change

● To be included in the base code, a measure must:● Be cost-effective

● based on the standards-induced additional first cost, maintenance costs, measure life, and energy cost savings

● typically according to the Time Dependent Valuation (TDV) life-cycle costing methodology and weather data to be provided by the California Energy Commission

● Be possible to implement using equipment that is available from multiple providers or that is reasonably expected to be available following the code change




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Stakeholder Meetings Process

● Minimum of three meetings:

● First: present scope, request data

● Code change direction and possible options

● Methodology

● Best practices, market data

● Second: present findings

● Results of data collection and analysis

● Cost effectiveness

● “Strawman” proposed code language

● Third/final: present proposed code language

● All meetings can be attended remotely




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Submitting Comments

● Informal Comment Process

● Comments can be submitted to CASE authors,

substantive comments will be receive responses.

● Questions and responses will not be posted

online, but common or frequent questions will

be communicated as necessary between

stakeholders

● The team will work with stakeholders to resolve

issues as best we can.

● The CEC has a formal comment process during

later stages of the official rulemaking process




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Types of Code Change

● Mandatory Measure: The change would add or modify a mandatory measure● Mandatory measures must be satisfied whether the prescriptive or performance method is used to show compliance

● Prescriptive Requirement: The change would add or modify a prescriptive requirement that must be met when using prescriptive compliance approach● When using performance compliance (computer modeling), prescriptive requirements define a standard design (which sets the energy budget) and are not mandatory




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Types of Code Change – Ctd.

● Compliance Option: The change would add or modify a new measure to the list of existing compliance options for meeting the Standards using the performance approach.

● Modeling: The change would modify the calculation procedures or assumptions used in making performance calculations. ● This change would not add a compliance option or a new requirement, but would affect the way that trade-offs are made.




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Schedule: Key Dates

● Mar 2010 - Dec 2010● CEC develop foundation /methodology

● IOUs:● Conduct research, and cost effectiveness analysis

● Present results at stakeholder meetings

● Dec 2010● IOUs finalize code change proposals for submittal to CEC

● Feb 2011● CEC opens Rulemaking for Title 24, develop 45-day language

● June 15, 2011● Title 24 Adoption date

● Jan. 1, 2013● Title 24 Implementation date




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Meeting Protocols

● Please DO NOT place your phone on HOLD● Please mute your microphone, unless you want to speak

● Ask questions/comment by “chat” or by voice

● We want to hear your concerns● Opposing viewpoints are encouraged● We are seeking information, not resolution

● Time is limited● Raise your hand and be acknowledged by presenter● Clearly state your name and affiliation prior to speaking● Speak loudly for the people on the phone

● Minutes and presentation material will be available online – we will distribute link


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California Statewide Utility Codes and Standards Program

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Cooling Tower Water SavingsMeasure Slides

Erika Walther

[email protected]

Energy Solutions

August 25, 2010




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● Cooling tower overview

● Cooling tower water use

● Measure scope

● Summary of current code requirements

● Typical practice

● Summary of potential code change

proposals

● Data Request




Cooling Tower Overview

● Use evaporative cooling to remove heat from water-

cooled A/C systems and from industrial processes

that produce heat

● Water Balance: M = E + B + D





Cooling Tower Water Use

● Typical cooling tower circulates ~3 gpm per ton of cooling; loses 1-2% to evaporation, blowdown and drift

● Typical water balance for 1,000 ton cooling tower with 10°F range (water entering and leaving condenser):

● Evaporation – 1%

● Blowdown – 0.5%

● Assumed equivalent full load cooling hours = 1,500

● E + B = 45 gpm, or 4,050,000 gpy

● Less frequent blowdown/increased cycles → water savings

● Maximum cycles is limited by TDS in makeup water and effectiveness of treatment of tower water





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Measure Scope

● New construction, major renovation, and

replacement of existing cooling towers

● Commercial/ Industrial/ Institutional

● Evaporative Cooling Towers

● Cost-effectiveness may determine a minimum

size




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Existing Code Requirements

● ASHRAE 189.1 P, Standard for the Design of High Performance Green Buildings, Section 6: Water Use Efficiency● A/C systems only

● 6.3.2.3.b. Mandatory requirement that cooling towers and evaporative coolers shall be equipped with makeup and blowdown meters, conductivity controllers, and overflow alarms if cooling tower flow through is over 500 gpm; and shall be equipped with efficient drift eliminators that achieve drift reduction to 0.002% of the circulated water volume for counterflow towers and 0.005% for cross-flow towers.

● 6.4.2.1 Prescriptive option that cooling towers with makeup waters having less than 200 ppm (mg/L) of total hardness (calcium carbonate) achieve 5 cycles of concentration; and for makeup waters having more than 200 ppm (mg/L), 3.5 cycles of concentration● Exception where TDS concentration of discharge water exceeds 1,500 ppm (1,500 mg/L), or silica exceeds 150 ppm (150 mg/L) measured as silicon dioxide before the above CoC are met





● IAPMO Green Plumbing and Mechanical Code Supplement, 2010● 410.2 Cooling Towers and Evaporative Coolers

● Cooling towers and evaporative coolers shall be equipped with makeup water and blow down meters, conductivity controllers and overflow alarms. Cooling towers shall be equipped with efficiency drift eliminators that achieve drift reduction to 0.002% of the circulated water volume for counterflow towers and 0.005% for cross-flow towers.

● 410.3 Cooling Tower Makeup Water● Not less than 5 cycles of concentration is required for air-conditioning cooling tower makeup water having a total hardness of less than 11 gr/gal (188 mg/L) expressed as calcium carbonate. Not less than 3.5 cycles of concentration is required for air-conditioning cooling tower makeup water having a total hardness equal to or exceeding 11 gr/gal (188 mg/L) expressed as calcium carbonate.– Exception: Air-conditioning cooling tower makeup water having discharge conductivity range not less than 7 gr/gal (120 mg/L) to 9 gr/gal (154 mg/L) of silica measured as silicon dioxide.






● IAPMO Green Plumbing and Mechanical Code

Supplement, 2010

● 410.4 Use of Reclaimed (Recycled) and On-Site Treated Non-

Potable Water for Cooling

● Where approved for use by the water/ wastewater utility and the

Authority Having Jurisdiction, reclaimed (recycled) or on-site treated

non-potable water shall be permitted to be used for industrial and

commercial cooling or air-conditioning

– 410.4.1 Drift Eliminator. A drift eliminator shall be utilized in a cooling

system, utilizing alternate sources of water, where the aerosolized water

may come in contact with employees or members of the public

– 410.4.3 Disinfection. A biocide shall be used to treat the cooling system

recirculation water where the recycled water may come in contact with

employees or members of the public.






● Title 24, Part 6 (Energy Code)● Section 112 – Mandatory Requirements for Space-conditioning Equipment. Table 112-G: Requires minimum gpm/ hp (max flow rate of the tower/ fan nameplate rated motor power)

● Section 144 – Prescriptive Requirements for Space Conditioning Systems.● Part (h) Heat Rejection Systems: Fan Speed Control, Tower Flow Turndown, Limitation on Centrifugal Fan Cooling Towers

● Part (i) Limitation of Air-Cooled Chillers: Chilled water plants with more than 300 tons total capacity shall not have more than 100 tons provided by air-cooled chillers.– Exception for water quality at the building site that fails to meet manufacturer’s specification for the use of water-cooled equipment.

● Title 24, Part 2 (Building Code)● Codes regarding use of non-combustible materials

● Cooling Technology Institute’s Acceptance Test Code for Water Cooling Towers● Provides procedures for testing and evaluation of thermal capability of cooling towers. May have procedures applicable to water conservation tests.





In-progress Code Requirements

● International Code Council, 2009/10 code development cycle

● International Energy Conservation Code Table 503.2.3(8) - same as T24, Part 6 Table 112-G

● ASHRAE 191P, “Standard for the Efficient Use of Water in Building, Site and Mechanical Systems”

● TBD: Draft Standard not yet released, but cooling towers will be addressed





Typical Practice

● Cooling tower system water chemistry is managed to control:● Scale

● Corrosion

● Biological fouling

● Water chemistry and frequency of blowdown is managed by a third party

● Cooling tower facility manager may not be aware of what cycles of concentration is being achieved, or losses that may be occurring





Typical Practice

● Cycles range from 1 (constant bleed) to 5+

● Cycles average 3-4, across the state

● Koeller and Company – PBMP report for CUWCC (2006) - 3 cycles

● PG&E Cooling Tower code change proposal, references Chem-Aqua as source (2002) – 4 cycles

● Similar for nationwide

● USDOE FEMP BMP (2010) – 2 to 4 cycles

● North Carolina DENR Water Efficiency Manual (2009) –2 to 3 cycles

● Constant bleed is a water chemistry management strategy used in some (smaller?) cooling towers





Potential Code Change Proposals

1) Mandatory requirement for controls

2) Mandatory requirement for Cycles of Concentration (based on water quality)

3) Voluntary requirement for water re-use

● Potential Code Change

● Feasibility and Challenges

● Cost Estimating

● Planned Data Collection and Analysis

● Data Request





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Potential Code Change Proposal

● Mandatory Requirement for Controls

● Install flowmeters on bleed and makeup water

lines, overflow alarm, and conductivity

controller.

● Equip cooling towers with efficient drift

eliminators that achieve drift reduction to a

maximum of 0.002% of the re-circulated water

volume for counterflow towers and 0.005% of

the re-circulated flow for cross-flow towers.

● Drift eliminators more appropriate for Part 11?

● Affects all buildings covered under T24, Part 6




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● Mandatory Requirement (if enforcement can be addressed…)● Achieve a minimum of 5 cycles in regions with makeup water having less than 200 ppm of total hardness expressed as calcium carbonate.

● Achieve a minimum of 3.5 cycles in regions with makeup water having more than 200 ppm of total hardness expressed as calcium carbonate.● Exception: Where TDS concentration of discharge water exceeds 1,500 ppm, or the silica exceeds 150 ppm measured as silicon dioxide, before the above cycles requirements are reached.

● Affects all buildings covered under T24, Part 6





● Mandatory requirement re: placement of

makeup water line and blowdown line

● Purpose is to prevent unnecessary losses

when makeup water enters sump too

close to blowdown valve and exits sump

w/o circulating





Feasibility and Challenges

● Measures accepted by range of stakeholders under ASHRAE 189.1P

● Cost-effectiveness yet to be determined

● Want to avoid shift to less expensive, less efficient air-cooled equipment

● Performance verification/enforceability of cycles of concentration requirement

● Documentation of water quality

● Documentation of cycles achieved





Cost Estimating

● Installed costs of the following for new construction, major retrofit and replacement markets:

● Conductivity controllers

● Flow meters

● Overflow alarm

● Drift eliminators

● Maintenance costs – i.e., will use of controls decrease or increase maintenance costs?

● Water costs





Planned Data Collection and Analysis

● Determine baseline water use and savings● Market data from manufacturers, distributors, industry groups

● Number and size of cooling towers in CII sector

● New construction estimates (sqft) provided by Energy Commission● Assume # and size of CT installed per sq foot of new construction in applicable sectors

● Typical practices of newly installed cooling towers with regard to controls● What percentage of newly installed CTs are installed without controls? If n/a, use existing cooling tower practices as proxy.

● Of those that are installed with controls, which controls are installed?

● Statewide average cycles - is 3, 4 or other value an accurate baseline?

● For controls measure, assume achieved cycles and calculate water savings

● Cooling tower water use by climate zone, accounting for variation in evaporation rate






● Equipment cost data

● Manufacturers and distributors

● MEANS data

● Water cost projections

● DOE Appliances and Commercial Equipment Standards data (2010)

● Black & Veatch Water Charge Survey, 2006 (to be updated in 2010)

● Develop a population-weighted average by climate zone if feasible

● Embedded energy – 9,977 kWh/MG

● Population-weighted for Northern and Southern California using data from an Energy Commission PIER study (2006)




Data Request

● Survey information to be requested from cooling tower water quality management companies and cooling tower maintenance companies● Prevalence of conductivity controls, flow meters, overflow alarms, and drift eliminators by size category (e.g., <100 tons, 100 – 499 tons; 500 tons or greater)

● Typical practices by size category● Conductivity setpoints for blowdown

● Cycles achieved

● Prevalence of constant bleed

● Survey information to be requested from cooling tower manufacturers● Market share of system sizes by market sector





Additional Potential Code Change Proposal

● T24, Part 11 - Green Code (voluntary)

Requirement for Water Re-use

● Minimum of 5% of make-up water must be

from on-site or off-site non-potable water

source






● Many possible sources

● Rainwater and stormwater

● A/C or steam condensate

● Filter and membrane reject water

● Foundation drain water

● Cooling tower/ boiler blowdown

● On-site treated graywater and wastewater

● Reclaimed water from wastewater tx plant






● Sources are of varying quality

● May contain impurities such as salts, metals, organics

● Can have more or less TDS than municipal freshwater

● High COD (organic compounds), ammonia and phosphate leading to biological fouling

● Determination of conservative ratio of non-potable to potable appropriate for range of makeup waters

● Any source will likely require on-site treatment for reuse in cooling tower

● Treatment can create problems● E.g., chlorine-based agents → chloride-induced pitting

● Retrofitting plant piping can be complex and expensive

● Energy penalty

● Options and cost-effectiveness will vary from site to site

● Enforcement





Cost Estimating

● Offsets increasing costs of freshwater and wastewater

● On-site treatment may remove regulated substances from source discharge water and associated penalties

● Capture and on-site treatment

● Effects on cooling tower water chemistry and maintenance






● Case studies/ feasibility studies

● Water quality for various sources of

reused water

● Onsite treatment options and costs





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Specific Stakeholder Requests

● We are requesting input from manufacturers, distributors and industry groups regarding● Installed costs of flow meters, conductivity controllers, overflow alarms and drift eliminators

● Cooling tower market data: Tonnage and distribution across sectors

● We are requesting input from cooling tower managers and water quality management companies regarding● Typical practices – e.g., # of cycles, conductivity setpoints, incidences of constant bleed

● Prevalence of currently installed flow meters, conductivity controllers, overflow alarms and drift eliminators

● Applications of water reuse in cooling towers




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Cooling Tower Water SavingsStakeholder Meeting #1

QUESTIONS & COMMENTS

Erika [email protected]

(510) 482-4420 x224

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Documents

Cooling Tower Water Savings - HMGh-m-g.com/T24/Cooling Tower... · 1 California Statewide Utility Codes and Standards Program Cooling Tower Water Savings Stakeholder Meeting #1 -DRAFT