Responsible Condenser Responsible Condenser Cooling Water SystemsCooling Water Systems

We all have a role to play in…We all have a role to play in…

• Designing• Designing• Selling• Selling• Building • Building • Owning• Owning• Maintaining• Maintaining

System ContaminationSystem ContaminationA typical 200 ton cooling tower A typical 200 ton cooling tower "scrubs" airborne contaminants (dust "scrubs" airborne contaminants (dust & pollen) from the atmosphere and & pollen) from the atmosphere and deposits as much as 600 pounds of deposits as much as 600 pounds of particulate matter into the condenser particulate matter into the condenser cooling water system each year.cooling water system each year.

Ref: Clive Broadbent, ASHRAE Report 1992 & ASHRAE Handbook 1996Ref: Clive Broadbent, ASHRAE Report 1992 & ASHRAE Handbook 1996

Cooling Tower = Air ScrubberCooling Tower = Air Scrubber

Shut Down for Expensive System Shut Down for Expensive System CleaningCleaning

Sources of ContaminantsSources of Contaminants

• System Water Make• System Water Make--Up (silt and soil)Up (silt and soil)• Airborne Particulate (dust and pollen)• Airborne Particulate (dust and pollen)• Corrosion Products (iron oxides)• Corrosion Products (iron oxides)• Mineral Precipitate (calcium buildup)• Mineral Precipitate (calcium buildup)• Microbiological Colonies (bacteria)• Microbiological Colonies (bacteria)

Effects of ContaminantsEffects of Contaminants

• Decreases Heat Transfer• Decreases Heat Transfer• Decreases System Flow• Decreases System Flow• Increases Energy Costs• Increases Energy Costs• Increases Maintenance Costs• Increases Maintenance Costs• Increases Chemical Treatment• Increases Chemical Treatment• Decreases Equipment Life• Decreases Equipment Life• Increases Liability Exposure• Increases Liability Exposure

Decreased heat transfer Decreased heat transfer efficiencies and reduced flow efficiencies and reduced flow rates rates

resulting from layers of resulting from layers of contaminant contaminant buildup in:buildup in:

• System Piping • System Piping • Cooling Tower (fill & basins)• Cooling Tower (fill & basins)• Heat Exchanger (tubes, plates)• Heat Exchanger (tubes, plates)

Fouling FactorFouling Factor

Increased Energy CostIncreased Energy Cost

Notice that each .001” increase in fouling results in 1.1% increase in power.

New chillers are designed to operate with a fouling factor of .0001” to .00025”

[Ref: ASHRAE Standards 550-98]

0

44.00.048.00433.00.036.00322.00.024.00211.00.012.0015.50.006.00051.10.001.0001

00Power IncreaseScale ThicknessClean

0

44.00.048.00433.00.036.00322.00.024.00211.00.012.0015.50.006.00051.10.001.0001

00Power IncreaseScale ThicknessClean

•• Drexel University Drexel University –– Dr. Y.I. Cho Dr. Y.I. Cho

• DuPont Corporation• DuPont Corporation

Independent Case StudiesIndependent Case Studies

Without antiWithout anti--fouling technology and filtration, the systems heat transfer fouling technology and filtration, the systems heat transfer coefficient decreased 29% from peak initial performance. coefficient decreased 29% from peak initial performance.

When using a nominal 5 micron filter the system experienced a deWhen using a nominal 5 micron filter the system experienced a decrease of crease of only 19%.only 19%.

This translates to a 33% reduction in system fouling simply by uThis translates to a 33% reduction in system fouling simply by using filtration sing filtration alone, resulting in a alone, resulting in a 10% savings in energy cost10% savings in energy cost..

The study concludes that peak performance can be maintained withThe study concludes that peak performance can be maintained with the the combination of a properly monitored chemical treatment program acombination of a properly monitored chemical treatment program along with long with filters and antifilters and anti--fouling technologies such as UV light sterilization.fouling technologies such as UV light sterilization.

Ref: Use of electronic antiRef: Use of electronic anti--fouling technology with filtration to prevent fouling in a heat fouling technology with filtration to prevent fouling in a heat exchanger. International Journal of Heat and Mass Transfer 41 (exchanger. International Journal of Heat and Mass Transfer 41 (1998) 29611998) 2961--2966.2966.

Drexel University Drexel University -- Dr. ChoDr. Cho

The formula listed below can be used to calculate the energy cosThe formula listed below can be used to calculate the energy cost per t per year for a water cooled condenser system:year for a water cooled condenser system:

AC TR x Design Average of 0.65 Kw/TR x Load factor x Hours of AC TR x Design Average of 0.65 Kw/TR x Load factor x Hours of Operation per Year x Cost/KwhOperation per Year x Cost/KwhFor Example: 400 TR x 0.65 Kw/TR x 0.7 load factor x 2500 operaFor Example: 400 TR x 0.65 Kw/TR x 0.7 load factor x 2500 operating ting hours x 0.08/Kwh = US $ 36,400 Energy Cost per year.hours x 0.08/Kwh = US $ 36,400 Energy Cost per year.

From the above example, each .001 inch of fouling in a 400 TR chFrom the above example, each .001 inch of fouling in a 400 TR chiller iller operating 2500 hours a year at US $ 0.08/Kwh will result in an operating 2500 hours a year at US $ 0.08/Kwh will result in an additional $ 3,640 energy cost per year to operate.additional $ 3,640 energy cost per year to operate.

10% Energy Savings10% Energy Savings

DuPont Case StudyDuPont Case Study

DuPont Case StudyDuPont Case Study

DuPont Case StudyDuPont Case Study

DuPont Case StudyDuPont Case Study

2525%% 25%25%

COPCOPREFRIGERATIONREFRIGERATION

CAPACITYCAPACITY HEATHEAT EXCHANGER LIFEEXCHANGER LIFE

DISCHARGEDISCHARGE TEMPERATURETEMPERATURE

SIDE STREAM FILTRATIONSIDE STREAM FILTRATION

ENERGYENERGY CONSUMPTIONCONSUMPTION

10%10% 1010%%

Realistic Returns on InvestmentRealistic Returns on Investment• 10% Savings in Energy Costs• 10% Savings in Energy Costs• 20% Savings in Chemical Costs• 20% Savings in Chemical Costs• 50% Savings in Maintenance Costs• 50% Savings in Maintenance Costs• Increased Equipment Life• Increased Equipment Life• Reduced Liability Exposure• Reduced Liability Exposure

Cooling Water Filters Add Cooling Water Filters Add Bottom Line PerformanceBottom Line Performance

Legionella BacteriaLegionella BacteriaLe·gion·naires' diseaseLe·gion·naires' disease (l(l¶”¶”jj……-- nârznârz““)) n.n. An acute, sometimes fatal An acute, sometimes fatal respiratory disease caused by a respiratory disease caused by a bacterium of the genus bacterium of the genus Legionella,Legionella, especially especially L. pneumophila,L. pneumophila, and and characterized by severe pneumonia, characterized by severe pneumonia, headache, and a dry cough. [So called headache, and a dry cough. [So called because it was first recognized when an because it was first recognized when an outbreak occurred during an American outbreak occurred during an American Legion Convention in Philadelphia in Legion Convention in Philadelphia in 1976.]1976.]

Due DiligenceDue Diligence

•• Carrier CorporationCarrier Corporation

• Blue Cross Blue Shield• Blue Cross Blue Shield

• USAA Insurance Company• USAA Insurance Company

• CDC• CDC--Center Disease ControlCenter Disease Control

Contaminant Dictates Contaminant Dictates The MeansThe Means

Use the right tool for the job...Use the right tool for the job...• Granular Media• Granular Media

Sand FiltersSand Filters• Centrifugal Separators• Centrifugal Separators• Bag Filter Systems• Bag Filter Systems• Cartridge Filters Systems• Cartridge Filters Systems

Sand FilterSand Filter(Granular Media)(Granular Media)IMF Media FilterIMF Media Filter

CentrifugalCentrifugal(particle size and specific

gravity dependent)

Bag FilterBag Filter

Cartridge FilterCartridge Filter

StrainerStrainer

Microns 0.01 0.5 1 5 10 100

Filtration MethodsFiltration Methods

A Micron is one millionth of a meter. A Micron is one millionth of a meter. (Table Salt = 100um : Red Blood Cell = 2um)(Table Salt = 100um : Red Blood Cell = 2um)

Granular Media FiltersGranular Media Filters

•• Self Cleaning (Auto or Manual)Self Cleaning (Auto or Manual)• Side Stream or Full Flow• Side Stream or Full Flow• Maximum Particle Removal• Maximum Particle Removal• Multi• Multi--Media FlexibilityMedia Flexibility• Minimum Maintenance• Minimum Maintenance

Centrifugal SeparatorsCentrifugal Separators

•• Self Cleaning (Auto or Manual)Self Cleaning (Auto or Manual)• Side Stream or Full Flow• Side Stream or Full Flow• Limited Particle Removal• Limited Particle Removal• Minimum Maintenance• Minimum Maintenance

Bag Filter SystemsBag Filter Systems

•• Manual CleaningManual Cleaning• Side Stream or Full Flow• Side Stream or Full Flow• Maximum Particle Removal• Maximum Particle Removal• Disposable Media Flexibility• Disposable Media Flexibility• High Maintenance• High Maintenance

Cartridge FiltersCartridge Filters

•• Manual CleaningManual Cleaning• Side Stream or Full Flow• Side Stream or Full Flow• Maximum Particle Removal• Maximum Particle Removal• Disposable Media Flexibility• Disposable Media Flexibility• High Maintenance• High Maintenance

Side Stream FiltrationSide Stream Filtration

Sweeper Jets NozzlesSweeper Jets Nozzles

www.pepfilters.comwww.pepfilters.com

FILTERS