Beneficios Torre de Resfriamento

CTI Sponsored Educational Program Benefits of Water Cooled vs Air Cooled Equipment in Air Conditioning Applications2011 AHR Expo – Las Vegas

January 31, 2011

Slide No.: 1

CTI Sponsored Educational Program

Presented By:Tim Facius

Baltimore Aircoil


January 31, 2011

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


January 31, 2011

Slide No.: 3

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.


January 31, 2011

Slide No.: 4

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.


January 31, 2011

Slide No.: 5

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).


January 31, 2011

Slide No.: 6

Please visit our website atwww.cti.org


January 31, 2011

Slide No.: 7

Publication and Presentation Disclaimer 2011

The information contained in the following publication, paper orpresentation 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.


January 31, 2011

Slide No.: 8

Benefits of Water Cooled vs Air Cooled Equipment

for Air-Conditioning Applications


January 31, 2011

Slide No.: 9

Overview

� Climate Change Background� US Response� Climate Change and HVAC� Benefits of Water Cooled Equipment� Water Usage� Energy Savings Tips

� EPA� Others


January 31, 2011

Slide No.: 10

U.S. Government commitment to reduce greenhouse gas emissions can have a significant impact on HVAC system design.


January 31, 2011

Slide No.: 11

Definition – Global Warming

Global warming is the average increase in the temperature of the atmosphere near the Earth's surface and in the troposphere, which can contribute to changes in global climate patterns.


January 31, 2011

Slide No.: 12

Definition – Global Warming

Global warming can occur from a variety of causes, both natural and human induced. In common usage, "global warming" often refers to the warming that can occur as a result of increased emissions of greenhouse gases from human activities.


January 31, 2011

Slide No.: 13

U.S. Commitment Reduce Global Warming

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.


January 31, 2011

Slide No.: 14


� The Recovery Act was signed into law on February 17, 2009 and has invested $80M 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


January 31, 2011

Slide No.: 15


� Leadership in Sustainability� President Obama signed an Executive Order on

Federal Sustainability, committing the Federal Government to lead by example and reduce greenhouse gas emissions by 28% by 2020, increase energy efficiency, and reduce fleet petroleum consumption.


January 31, 2011

Slide No.: 16


� Monitoring Emissions� For the first time, the U.S. will catalogue greenhouse

gas emissions from large emission sources – an important initial step toward measurable and transparent reductions.


January 31, 2011

Slide No.: 17

Global Warming

� Greenhouse gasses include:� Carbon Dioxide (CO2)� Methane (CH4)� Nitrous Acid (N20)� Hydrofluorocarbons (HFC’s)� Perflurocarbons (PFC’s)� Sulfur Hexafluorides (SF4)


January 31, 2011

Slide No.: 18

U.S. Greenhouse Gas Emissions by Component, 2001


January 31, 2011

Slide No.: 19

U.S. Greenhouse Gas Emissions

� Carbon Dioxide (CO2) emissions account for approximately 85% of the U.S. greenhouse gas emissions.� Transportation� Heavy Industry� Utilities


January 31, 2011

Slide No.: 20

Major CO2 Emission Sources Utility Industry

� Fossil Fuel Burning Power Plants� Produce 55% of U.S. electricity� Addition of exhaust gas scrubbers not economically

viable for most plants� Only 35% of Power Plants have exhaust scrubbers.

� Rather than upgrade the power plants, decision is to phase-out many of them.


January 31, 2011

Slide No.: 21

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


January 31, 2011

Slide No.: 22

Electricity and Air Conditioning

� About one-sixth of all the electricity generated in the U.S. is used to air-condition buildings.

� Air-conditioning systems drive many power plant peak loads and have been identified as an energy reduction opportunity.


January 31, 2011

Slide No.: 23

Basic Air-Conditioning System

� 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.


January 31, 2011

Slide No.: 24

Condenser

Evaporator

AHU - 1

AHU - 2

AHU - 3

Pump

Pump

Cooling Tower


January 31, 2011

Slide No.: 25

Benefits of Water Cooled Systems

� Water-cooled systems� More energy-efficient than air-cooled systems –

approximately 35%� Reduced plan area� Reduced sound� Independently certified performance

� AHRI for chillers� CTI for cooling towers


January 31, 2011

Slide No.: 26

Challenges of Water Cooled Systems

� Water-cooled systems� Higher installation cost� Water use

� Consider the water use at the cooling tower� Consider the water used at power plant to create energy

� Water treatment


January 31, 2011

Slide No.: 27

Water Usage

� Water cooled systems recycle 95% of the total water.� The remaining 5% is lost to evaporation & bleed.� NO water is destroyed.� A small portion of the water is bled from the system to

control the build-up of impurities.

Bleed Rate = Evaporation RateCycles of Concentration -1

� Water use is proportional to load and time of day.� Trend toward using grey water for make up.


January 31, 2011

Slide No.: 28

Water Quality and Control Cost Considerations

� Water-cooled systems require treatment to control scale/corrosion and biological growths.� Chemical or NCD

� Water and chemical costs must be included in a cost analysis of water-cooled and air-cooled systems.


January 31, 2011

Slide No.: 29

Cooling Tower Industry Answer

� Hybrid technology� Optimizes water use and

energy use based on load, water availability

� Materials of Construction� Increase cycles of

concentration� Use grey water


January 31, 2011

Slide No.: 30

Optimize Energy and Water Costs

� Market trends suggest that the demand for energy resources will rise dramatically over the next 25 years:� Global demand for all energy sources is forecast to grow

by 57% over the next 25 years. � U.S. demand for all types of energy is expected to

increase by 31% within 25 years. � By 2030, 56% of the world’s energy use will be in Asia. � Electricity demand in the U.S. will grow by at least 40% by

2032.

� Sources: Annual Energy Outlook (DOE/EIA-0383(2007)), International Energy Outlook 2007 (DOE/EIA-0484(2007), Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2005 (April 2007) (EPA 430-R-07-002)


January 31, 2011

Slide No.: 31

U.S. Actions Impacting HVAC Systems and Equipment

� ASHRAE Standard 90.1 as basis for energy efficiency for commercial buildings

� New ASHRAE Standard 189� California Title 24


January 31, 2011

Slide No.: 32

ASHRAE Standard 90.1

� Basis of energy efficiency for commercial buildings� Fan speed control on heat rejection equipment� Performance requirement

� Axial fan towers = 38.2 gpm/hp*� Centrifugal fan towers = 20.0 gpm/hp*� Axial fan closed circuit cooling towers = 14.0 gpm/hp*� Centrifugal fan closed circuit cooling towers = 7.0

gpm/hp*� Air cooled condensers = 176,000 BTU/h•hp

•Based on 95/85/75 for towers, and 102/90/75 for closed circuit cooling towers, and 125/190/15/95 for air cooled condensers


January 31, 2011

Slide No.: 33

ASHRAE Standard 189

� Performance requirement� Increased from 4-14% above ASHRAE 90.1

requirements� Air Cooled condenser requirement removed and is

dependent on tonnage


January 31, 2011

Slide No.: 34

ASHRAE Standard 189

� Once through cooling with potable water is prohibited.

� Cooling towers and evaporative condensers shall be equipped with make-up and blow down meters, conductivity controllers, and overflow alarms.

� Cooling towers shall be equipped with efficient drift eliminators:� 0.002% of recirculated water for counterflow� 0.005% of recirculated water for crossflow


January 31, 2011

Slide No.: 35

California Title 24

� Basis for energy efficiency for commercial buildings� Same as ASHRAE 90.1� Flow turndown up to 33%�Updated to make the flow turndown 50%


January 31, 2011

Slide No.: 36

California Title 24

� Limitations� Centrifugal Fan Towers

� 900 gpm or higher must meet efficiency requirements of axial fans

� Air Cooled Chillers� More than 300 tons of total capacity� Only 100 tons provided by air cooled


January 31, 2011

Slide No.: 37

Energy Saving System Designs….


January 31, 2011

Slide No.: 38

EPA Climate Wise Program – Wise Rules to Energy Efficiency

� Process Cooling Wise Rule 1. Installing energy efficient chillers and refrigeration systems can save 1.2% of a facility’s total energy use with an average simple payback of 23 months.


January 31, 2011

Slide No.: 39


� Process Cooling Wise Rule 2. Free cooling with cooling tower water can reduce a facility's total energy use by about 1% with an average simple pay back of 14 months.� Using cooling tower water in place of the chiller when the

outside temperature is low� Cooling tower is sized for winter capacity


January 31, 2011

Slide No.: 40


� Process Cooling Wise Rule 3. Free cooling can reduce cooling system energy use by as much as 40% depending on location and load profile.

� Process Cooling Wise Rule 4. Increasing chilled water temperature by 1°F reduces chiller energy use by 0.6% to 2.5%.


January 31, 2011

Slide No.: 41


� Process Cooling Wise Rule 5. Reducing condenser pressure by 10 psi can decrease refrigeration system energy use per ton of refrigeration by about 6%.

� Process Cooling Wise Rule 6. For each 1°F degree decrease in condenser cooling water temperature, until optimal water temperature is reached, there is a decrease in chiller energy use by up to 3.5%.


January 31, 2011

Slide No.: 42

Energy Saving Tip

� Installing VFDs in place of constant speed systems can reduce cooling system energy use by 30% to 50%, depending on load profile.� Cooling tower fans� Chiller compressor


January 31, 2011

Slide No.: 43

Single Speed BHP & VFD BHP Versus Wet Bulb

0

10

20

30

40

50

60

35404550556065707580

Wet Bulb

BH

P

VFD

Single Speed Motor

Assumes constant load with varying wet bulb temperatures


January 31, 2011

Slide No.: 44

Energy Saving Tip

• Take advantage of ambient wet bulb temperatures


January 31, 2011

Slide No.: 45

ASHRAE 0.4% Wet Bulb Temperatures

65°FDenver, CO

66°FSeattle, WA

70°FLos Angeles, CA

75°FBoston, MA

76°FNew York, NY

78°FBaltimore, MD

Wet BulbLocation


January 31, 2011

Slide No.: 46


75.0°F

76.0°F

80.5°F

82.7°F

83.5°F

85°F

CWT

65°F

66°F

70°F

75°F

76°F

78°F

Wet Bulb

Denver, CO

Seattle, WA

Los Angeles, CA

Boston, MA

New York, NY

Baltimore, MD

Location


January 31, 2011

Slide No.: 47


75.0°F

76.0°F

80.5°F

82.7°F

83.5°F

85°F

CWT

0.48 kW/TR

0.49 kW/TR

0.53 kW/TR

0.54 kW/TR

0.55 kW/TR

0.57 kW/TR

Energy

65°F

66°F

70°F

75°F

76°F

78°F

Wet Bulb

Denver, CO

Seattle, WA

Los Angeles, CA

Boston, MA

New York, NY

Baltimore, MD

Location


January 31, 2011

Slide No.: 48


0.48 kW/TR

0.49 kW/TR

0.53 kW/TR

0.54 kW/TR

0.55 kW/TR

0.57 kW/TR

Energy

$9K

$6K

$4K

$3K

$2K

Base

Savings

75.0°F

76.0°F

80.5°F

82.7°F

83.5°F

85°F

CWT

65°F

66°F

70°F

75°F

76°F

78°F

Wet Bulb

Denver, CO

Seattle, WA

Los Angeles, CA

Boston, MA

New York, NY

Baltimore, MD

Location

Savings are based on 500 ton cooling tower with 10°F Range.


January 31, 2011

Slide No.: 49

Energy Saving Tips

� Tip #1 – Install energy efficient equipment.� Tip #2 – Evaluate additional free cooling hours.� Tip #3 – Increase chilled water temperature.� Tip #4 – Reduce condenser pressure.� Tip #5 – Lower the design condenser water

temperature.� Tip #6 – Install VFDs on constant speed fan

systems.� Tip #7 – Take advantage of low ambient wet

bulb temperatures.


January 31, 2011

Slide No.: 50

Conclusion

� Air-conditioning system evaluations should take the pending impact of environmental issues into consideration.

� Water cooled systems provide the most energy efficient systems and can help protect building owners and operators from uncertainties in electricity pricing.

Beneficios Torre de Resfriamento

Documents

vs air cooled equipment

educational programs

educational programpresented

cti certification program

performance of ehts

ehts technology

cti objectives

performance analysis