CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 1
CTI Sponsored Educational Program
Presented By:Trevor Fontes - Baltimore Aircoil Company
Joe Vadder – Evapco, Inc.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 2
CTI Mission Statement
To advocate and promote the use of environmentally responsible Evaporative Heat Transfer Systems (EHTS) for the benefit of the
public by encouraging: Education Research Standards Development and Verification Government Relations Technical Information Exchange
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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CTI Objectives Maintain and expand a broad base membership of
individuals and organizations interested in Evaporative Heat Transfer Systems (EHTS). Owner/Operators Manufacturers Suppliers
Identify and address emerging and evolving issues concerning EHTS.
Encourage and support educational programs in various formats to enhance the capabilities and competence of the industry to realize the maximum benefit of EHTS.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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CTI Objectives Encourage and support cooperative research to improve
EHTS technology and efficiency for the long-term benefit of the environment.
Assure acceptable minimum quality levels and performance of EHTS and their components by establishing standard specifications, guidelines, and certification programs.
Establish standard testing and performance analysis systems and procedures for EHTS.
Communicate with and influence governmental entities regarding the environmentally responsible technologies, benefits, and issues associated with EHTS.
Encourage and support forums and methods for exchanging technical information on EHTS.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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CTI Certification Program
STD-201 The standard sets forth a program whereby the Cooling
Technology Institute will certify that all models of a line of evaporative heat rejection equipment offered for sale by a specific Manufacturer will perform thermally in accordance with the Manufacturer’s published ratings.
Applies to Mechanical Draft Evaporative Heat Rejection Equipment such as Cooling Towers, Closed Circuit Coolers (and Evaporative Refrigerant Condensers).
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Please visit our website atwww.cti.org
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Publication and Presentation Disclaimer 2012
The information contained in the following publication, paper or presentation is intended for education by the author or presenter, however information given is in no way an
endorsement of the Cooling Technology Institute. The publication, paper or presentation has been reviewed by the
CTI staff and program committee for commercial content, however there may be differing opinions regarding the
content of information. The Cooling Technology Institute accepts no liability for its content.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Benefits of Water-Cooled Systems vs. Air-Cooled Systems for Air Conditioning Applications
Trevor FontesProduct Marketing EngineerBaltimore Aircoil Company
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Overview
US Energy Policy Energy Comparison Codes and Standards Benefits of Water Cooled Equipment Energy Savings Tips
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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U.S. Government commitment to energy independence and reduced greenhouse gas emissions can have a significant impact on HVAC system design.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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U.S. Commitment to Energy Sustainability
For decades it has been clear that the way Americans produce and consume energy is not sustainable. Our addiction to foreign oil and fossil fuels puts our economy, our national security, and our environment at risk.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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The Recovery Act was signed into law on February 17, 2009 and has invested over $90B in the clean energy economy. Development of renewable energy and
clean technologies Smart electric grid and energy efficient
homes, offices, and appliances High speed rail and advanced car
batteries
U.S. Commitment to Energy Sustainability
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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U.S. Commitment to Energy Sustainability
Leadership in Sustainability President Obama signed Executive Order 13514 on
Federal Sustainability, committing the Federal Government, the largest user of energy in the country, to lead by example and reduce greenhouse gas emissions by 28% by 2020, increase energy efficiency, and reduce fleet petroleum consumption.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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U.S. Government Plan to Reduce CO2Emissions from Power Plants
Convert to less carbon intensive fuels or non-carbon fuels Taxation of carbon fuels Regulation of emissions for
new plants More research and funding
for renewable energy Reduce energy demand
New energy-saving technologies
Improve efficiency of equipment and systems
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Optimize Energy and Water Costs
Market trends suggest that the demand for energy resources will rise dramatically over the next 30 years: Global demand for all energy sources is forecast to grow
by nearly 56% from 2010 through 2040. U.S. demand for all types of energy is expected to
increase by 11% by 2040. The U.S. Commercial Sector is forecasted to increase by 24% by
2040
Sources: Annual Energy Outlook (DOE-er0383(2014)), International Energy Outlook 2013 (EIA-0484(2013)
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Air-Conditioning Energy Consumption
Air-conditioning systems, 13% of U.S. commercial electricity consumption1, drive many power plant peak loads and have been identified as an energy reduction opportunity.
1. U.S. Energy Information Administrationhttp://www.eia.gov/
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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National Weather Trends
Higher Ambient Temperatures1
2012 – Warmest year in US history National warming trend
1. National Oceanic and Atmospheric Administration, National Climatic Data Centerhttp://www.ncdc.noaa.gov/temp-and-precip/time-series/index.php
Rank Year Temperature1 2012 55.06°F2 1998 54.32°F3 2006 54.31°F4 1934 54.14°F5 1999 53.93°F6 1921 53.83°F7 2001 53.68°F8 2007 53.66°F9 2005 53.64°F
10 1931 53.60°F
Annual U.S. Temperatures
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Effects on Cooling Projects
Customer needs Expanded requirements for total capacity, first cost,
total cost, and reliability of equipment Policy
Increased standards regarding efficiency and capacity Incentives
Municipal and private programs offer rebates and financial incentives for certain types of equipment
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Equipment Selection
50%
60%
70%
80%
90%
100%
10 20 30 40 50 60 70 80 90
% o
f Des
ign
Valu
e
Wet Bulb (F)
Design Load vs. Wet Bulb (F)
Temperature increases affect the design load and subsequent equipment selection
The energy efficiency of the equipment is directly correlated to their owning and operating costs
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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ParameterWater Cooled
SystemAir Cooled
System
Chiller Efficiency [Full Load] (kW/ton)1 0.6 1.255
Chiller Efficiency [IPLV] (kW/ton)1 0.4 0.941
System Capacity (Ton) 500 500
Average Capacity (Ton) 290 290
Condenser Pump (HP) 30 --
Cooling Tower Fan (HP) 30 --Hours of Operation [Integrated Part Load Value] 4380 4380
1. Efficiencies based on ASHRAE 90.1-2013
500 Ton System Analysis Parameters
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Equations
IPLV = 0.01A+0.42B+0.45C+0.12D A = COP@100%, B = COP@75%, C = COP@50%, D =
COP@25% Chiller Energy Usage = IPLV Efficiency * Weighted Avg Capacity Peak Chiller Demand = Full Load Efficiency * System Capacity Fan Energy = Power (HP) * 0.24 * 0.7457 kW/HP Peak Fan Demand = Power (HP) * 0.7457 kW/HP Pump Energy = Power (HP) * 0.7457kW/HP
Annual Energy = Hours of Operation ∑ Energy Total Peak Demand = Peak Chiller Demand + Peak Fan Demand +
Pump Energy
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Energy Consumption
ParameterWater Cooled
SystemAir Cooled
SystemChiller Energy Usage (kW) 116 273Condenser Pump Energy Usage (kW) 22 -Fan Energy Usage (kW) 5 -Annual Energy Consumption (kWh for 4380 Hours of Operation) 629,937 1,195,258Peak Energy Demand (kW) 345 628
Water Cooled Advantage: Reduction in annual energy consumption by 47% Peak energy demand reduced by 45%
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Total Annual Cost
Water Cooled Advantage: Savings of $44,000 annually Approximately 33% savings on annual operating costs
ParameterWater Cooled
SystemAir Cooled
SystemEnergy Charge $ 64,883 $ 123,112Demand Charge $ 4,633 $ 8,434Total Annual Electricity Cost $ 69,517 $ 131,545Annual Water Cost (4 cycles of con) $ 9,186Annual Sewage Cost $ 4,047Annual Chemical Treatment Cost $ 4,060Annual Water Related Costs $ 18,332Total Annual Operating Costs $87,849 $131,545
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Total Cost Comparison
Payback Period of 1.2 years Approximating the life span of a water based cooling system
at 20 years, the total water cooled benefit is approximately $820,000
The water cooled system shows a clear financial advantage over the air cooled system
500 Ton SystemWater Cooled
SystemAir Cooled
System
Equipment and Installation Cost $ 242,033 $ 188,200
Total Annual Operating Cost $ 87,849 $ 131,545
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Other Comparative Examples A Comprehensive Comparison of Air- and
Water-Cooled Chillers Over a Range of Climates by Mark Hydeman, PE, FASHRAE1
Water-cooled chillers save significant energy in most climates.
In some climates source water usage equal
1. Seminar #48, Salt Lake City Conference, ASHRAE, 2008
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Other Comparative Examples
PG&E study simulating three sizes of chiller plants in three climatic zones.1 Recommended chilled water plants greater than 300
Tons shall employ water-cooled chillers Resulted in air-cooled equipment restrictions in
California Title 24
1) PG&E Codes and Standards Enhancement Report: Code Change Proposal for Cooling Towers, http://www.energy.ca.gov/title24/2005standards/archive/documents/2002-04-23_workshop/2002-04-11_COOL_TOWERS.PDF
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Standards Impacting HVAC Systems and Equipment
ASHRAE Standard 90.1 Energy Standards for Building Except Low-Rise
Residential Buildings ASHRAE Standard 189.1
Standard for Design of High-Performance, Green Buildings
California Title 24 California’s Energy Standards for Residential and
Nonresidential Buildings Only 100 tons provided by air cooled equipment for
applications with more than 300 tons of total capacity
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Air-Conditioning System Selection
Large Buildings (> 300 tons) Water cooled systems provide clear-cut economic
and environmental justification. Mid-size Buildings (100-300 tons)
Air cooled systems may offer first cost incentive to sacrifice energy efficiencies of water cooled systems.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Benefits of Water-Cooled Systems
More energy efficient than air-cooled systems Approximately 47%
Reduced plan area Reduced sound Independently certified performance
Water-CooledAHRI for chillers up to 3,000 tonsCTI for cooling towers
Air-CooledAHRI for chillers up to 600 tons
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Water Cooled Considerations
Installation cost Offset by energy savings
Cooling tower water use Water use at tower is offset by water use at power
plant to create energy 2 gal/kWh1 on average 4.42 gal/kWh1 in the west
Sustainability based projects should evaluate total water usage, including the power plant impact
1. Consumptive Water Use for U.S. Power Production (NREL/TP-550-33905)
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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While occupying a total smaller footprint, water-cooled systems require a larger equipment room
Water-cooled systems require treatment to control scale/corrosion and biological growths
Water and chemical costs must be included in a cost analysis of water-cooled and air-cooled systems Water cooled systems recycle 95% of the
total water The remaining 5% is lost to evaporation & bleed
Water Cooled Considerations
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Cooling Tower Water Usage
Water use is proportional to load, time of day, and weather.
7
8
9
10
11
12
13
14
15
16
10 20 30 40 50 60 70 80 90
Evap
orat
ion
(USG
PM)
Wet Bulb (F)
Evaporation (USGPM) versus Wet Bulb (F)
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Options to Reduce Water Usage Increase cycles of
concentration Alternate materials of
construction
Use of non-potable sources, such as grey water, recycled water, or condensate collection
Hybrid technology Optimizes water use and
energy use based on load, water availability
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Leveraging Water Cooled Solutions Wet Bulb Depression: Utilize the lowest possible
temperature when cooling. The wet bulb temperature is on average 7°F lower than the dry bulb temperature Lower design conditions
Condenser Water Reset: Supply lower temperature condenser water. For each 1°F decrease, until optimal water temperature is reached, there is a decrease in chiller energy use by up to 3.5%.
Free Cooling: Use a cooling tower to supplement or bypass the chiller during cold weather operation. Reduce cooling system energy use by as much as 40%.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Energy Saving Tips – Wise Rules to Energy Efficiency
ASHRAE 0.4% Wet Bulb TemperaturesLocation Wet Bulb CWT
Baltimore, MD 78°F 85°FNew York, NY 76°F 83.5°FBoston, MA 75°F 82.7°FLos Angeles, CA 70°F 80.5°FSeattle, WA 66°F 76.0°FDenver, CO 65°F 75.0°F
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Energy Saving Tips – Wise Rules to Energy Efficiency
ASHRAE 0.4% Wet Bulb TemperaturesLocation Wet Bulb CWT Energy
Baltimore, MD 78°F 85°F 0.57 kW/TRNew York, NY 76°F 83.5°F 0.55 kW/TRBoston, MA 75°F 82.7°F 0.54 kW/TRLos Angeles, CA 70°F 80.5°F 0.53 kW/TRSeattle, WA 66°F 76.0°F 0.49 kW/TRDenver, CO 65°F 75.0°F 0.48 kW/TR
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Energy Saving Tips – Wise Rules to Energy Efficiency
ASHRAE 0.4% Wet Bulb TemperaturesLocation Wet Bulb CWT Energy Savings
Baltimore, MD 78°F 85°F 0.57 kW/TR Base
New York, NY 76°F 83.5°F 0.55 kW/TR $2K
Boston, MA 75°F 82.7°F 0.54 kW/TR $3K
Los Angeles, CA 70°F 80.5°F 0.53 kW/TR $4K
Seattle, WA 66°F 76.0°F 0.49 kW/TR $6K
Denver, CO 65°F 75.0°F 0.48 kW/TR $9KSavings are based on 500 ton cooling tower with 10°F Range.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Conclusion
Cooling system evaluations should take the pending impact of energy regulation into consideration.
Water cooled systems provide the most energy efficient systems and can help protect building owners and operators from uncertainties in electricity pricing.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 39
Water-Energy Nexus
Joe VadderEvapco, Inc.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Critical Natural Resources
• Water and Energy are both Critical Resources
• Water and Energy Production are Interrelated– Water is needed to produce Energy– Energy is needed to store and
transport Water
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Water Energy Relationship
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Resource Relationship: Water in Energy
• 2003 National Renewable Energy Lab report:
On average 2 gallons of water consumed per 1 kWh electricity generated in the US
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Power Grid Interconnects
Western = 4.42 gal/kWh
Nat’l Avg. = 2 gal/kWh
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Resource Interrelationship: Energy in Water
• 2005 California Energy Commission study:
On average 5 kWh required to produce 1,000 gallons of water
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Water-Energy Nexus?The conflict created by trying to conserve both resources at the
same time
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Water-Energy Nexus
Proposal: Develop a Metric to Evaluate Water-
Energy Tradeoff
Proposal: Develop a Metric to Evaluate Water-
Energy Tradeoff
How does this apply to the Cooling Industry?
Dry Cooling vs. Wet Cooling
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Traditional Supply and Demand
Demand Curve: Price Goes Up Demand Goes Down
Supply Curve: Price Goes Up Supply Goes Up
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Demand Curve for a Critical Natural Resource
Relatively Abundant Natural Capital Elastic Demand
Vulnerable Natural Capital Inelastic Dem
Demand decreases little with increase in price.
Regulation becomes necessary.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Energy Regulation• ASHRAE Std. 90.1 sets minimum energy
efficiencies for building equipment
Continental US at Night
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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• AHSRAE 90.1 Energy Regulation:
Evaporative Cooling is sometimes considered the “green” solution
Energy Regulation
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Energy Regulation & Wet Cooling
• Less energy required- lower fan Hp and lower
condensing temperatures
• Less indirect water used in energy generation
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Water Regulation
Aral Sea –4th Largest Inland Sea
• ASHRAE Std. 191 will set baseline water use for building equipment
1989 2009
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Water Shortages at Lakes Powell
Lake Powell 1999 and 2013
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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• Water Regulation:Dry Cooling is sometimes considered the “green” solution
• Uses no water directly
Water Regulation
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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• However:– More Energy required
(higher condensing temperatures, more fan power)
– More Indirect Water used in Energy generation
Water Regulation & Dry Cooling
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 56
Regulations Must Consider Multiple Concepts
ASHRAE 90.1
ASHRAE 191
Energy Restrictions
Water Restrictions
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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The Problem?
What is the best metric to evaluate the tradeoff between
Water and Energy use for a building cooling system?
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 58
Regulation Options
• Presently the only tool available to regulators is cooling tonnage- Current energy restrictions restrict dry cooling by
tonnage- New water regulations could restrict wet cooling by
tonnage
• This does not interrelate local availability of water and energy
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Water Shortages are Regional
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Let’s Create a BETTER Tool !!
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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A New Option: Proposed Water-Energy Nexus Ratio
• Simple ratio allowing simultaneous evaluation of two critical natural resources.
Ratio of Water-Energy Nexus (RWEN) =
kWh (returned) / Mgal (invested)
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Water-Energy Nexus:Proposed Ratio
Ratio of Water-Energy Nexus (RWEN) =
kWh (returned) / Mgal (invested)
• kWh = energy saved by using wet cooling instead of dry
• Mgal = total water used in the wet cooling process
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Proposed Minimum RWEN
Low RWEN where Water is Plentiful
High RWEN where Water is scarce
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Proposed Minimum RWEN Alternate scale where Energy is also scarce
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Water-Energy Nexus: Price Basis
• Price Basis
– If the price of Water is $6.00/Mgal– If the price of Energy is $0.10/kWh– $6.00/$.10=60
• RWEN>60 = operating savings with wet cooling
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Minimum RWEN: Price BasisRWEN>60 = operating savings with wet cooling
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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RWEN In Use: CTI Example
• Evaporative Cooling per CTI:400-ton tower operated 1800 full load equivalent hours per year
– 1,728 Mgal water used– 393,588 kWh saved
• RWEN = 393,588 / 1,728 = 227
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 68
RWEN In Use: CTI Example
RWEN= 227 in CTI example
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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RWEN In Use: Wet/Dry Hybrid
+
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Wet/Dry Hybrid
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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RWEN In Use: Wet/Dry Hybrid Example
• 400-ton Wet/Dry unit operated 1800 full load equivalent hours per year
– 50% more fan energy:393,588 kWh saved is reduced to 376,803 kWh saved
– 60% less water used:1,728 Mgal used is reduced to 691 Mgal water used
• RWEN = 376,803 / 691 = 545
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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RWEN In Use: Hybrid Example
RWEN= 545 in Hybrid example
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 73
RWEN In Use: Hybrid Example
Hybrid Range is flexible
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 76
Tool for Regulators
City Baseline RWEN
% Water Reduction
Minimum RWEN
Atlanta ? ? ?Phoenix ? ? ?Los Angeles ? ? ?Denver ? ? ?Houston ? ? ?Bridgeport ? ? ?
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
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Opportunity
• Tool for Regulators - Ratio of Water-Energy Nexus (RWEN) could be used by regional regulators to analyze the water-energy usetrade off of a process.
This value could be easily changed depending on the temporary climate conditions.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 78
Opportunity
• Tool for Design Engineers - Ratio of Water-Energy Nexus (RWEN) could be used by design engineers to understand alternative cooling methods and the need for flexibility.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 79
Opportunity
• Flexibility – Hybrid systems could be programmed to use evaporative cooling only when the Ratio of Water-Energy Nexus (RWEN) is greater than a specific value.
This value could be easily changed depending on the temporary climate conditions.
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 80
Summary
Ratio of Water-Energy Nexus (RWEN) =
kWh (returned) / Mgal (invested)
• RWEN - Simple ratio allows simultaneous evaluation of both water and energy for a truly GREEN solution
• RWEN Index – Flexible to account for local conditions and costs
CTI Sponsored Educational Program Air Cooled & Water Cooled Systems2014 AHR Expo – New York City
January 21, 2014
Slide No.: 81
QUESTIONS?
Top Related