Exhaust Stack Discharge Velocity Reduction Study for Labs21 2009
-
Upload
cabbamonto -
Category
Documents
-
view
1.159 -
download
0
description
Transcript of Exhaust Stack Discharge Velocity Reduction Study for Labs21 2009
Safely Achievable Reductions Safely Achievable Reductions in Exhaust Fan Energy in in Exhaust Fan Energy in
Laboratory BuildingsLaboratory BuildingsChet Wisner, President, Ambient Air TechnologiesChet Wisner, President, Ambient Air Technologies
Jay Hayashi, P2S EngineeringJay Hayashi, P2S EngineeringMarc Gomez, Director, UCI EH&SMarc Gomez, Director, UCI EH&S
Fred Bockmiller, Principal Engineer, UCI FacilitiesFred Bockmiller, Principal Engineer, UCI FacilitiesChris Abbamonto, Energy Manager, UCI FacilitiesChris Abbamonto, Energy Manager, UCI Facilities
University of California, IrvineUniversity of California, Irvine
Large research universityLarge research university$16M annual utilities budget$16M annual utilities budget
Lab buildings consume 2/3 of campus energyLab buildings consume 2/3 of campus energyMany energy initiatives to reduce carbon footprintMany energy initiatives to reduce carbon footprint
Campus Energy $avings ChallengeCampus Energy $avings Challenge Recipe for SuccessRecipe for Success
SafetyManagement
Visionary & Supportive
UpperManagement
Engineers
FacilityManagersPatience
Team Synergy
Supportive Users/Researchers
AgendaAgenda
Smart Lab Overview Smart Lab Overview Lab Exhaust System ComponentsLab Exhaust System Components Study MethodologyStudy Methodology Wind Tunnel TestingWind Tunnel Testing Cost and Energy SavingsCost and Energy Savings SummarySummary
Can We BuildCan We Build“Smart Labs” “Smart Labs”
that Greatly Reduce that Greatly Reduce Energy Use?Energy Use?
Past PracticesPast Practices
Labs21 Best PracticesLabs21 Best Practices
Smart Lab Stretch Goal: Smart Lab Stretch Goal:
Outperform ASHRAE 90.1/CA Title 24 by 50%Outperform ASHRAE 90.1/CA Title 24 by 50%
Efficient Laboratory Design EvolutionEfficient Laboratory Design Evolution
Smart Laboratory ConceptSmart Laboratory ConceptBalancing Laboratory Safety and Climate SafetyBalancing Laboratory Safety and Climate Safety
Create lab buildings that out perform ASHRAE 90.1 / CA Title 24 by 40-50%. Combine energy initiatives such as centralized demand controlled ventilation (CDCV), low flow (high performance) fume hoods, reduced building exhaust stack airspeeds, and use of energy-efficient lighting.
Building Exhaust System
Labs w/CDCVreal time lab air monitoring4 ach occupied2 ach unoccupied
Energy efficientlighting
Labs with low flow fume hoods(as appropriate)
Centralized Demand Controlled Ventilation (CDCV)Centralized Demand Controlled Ventilation (CDCV)Utilizing real time lab air monitoring, reduce air changes in labs from approximately 6 ACH to 4 ACH while the lab is occupied and 2 ACH when lab is unoccupied.
Low Flow (High Performance) Fume HoodsLow Flow (High Performance) Fume HoodsUtilize fume hoods that are designed to operate safely at lower face velocities, i.e., 70 FPM rather than 100 FPM.
Exhaust plenum
Deeper work surface
Unique airfoil design
Advanced baffle design
Lab Area LPD from 1.1 to 0.55
Lab Prep LPD from 0.9 to 0.36
Prep Room LPD from 2.0 to 1.0
Corridor LPD from 0.6 to 0.3
Laboratory Lighting ControlsLaboratory Lighting ControlsReduce Power Density by 50%Reduce Power Density by 50%
- Daylight sensors for fixtures near windows- Occupancy sensing by lab bay
Lab Building Exhaust Fan Energy ReductionLab Building Exhaust Fan Energy Reduction
Building Exhaust System
Slightly higher stacks
Variable speed fans (wind responsive if necessary)
Air handler with fresh air intake
AgendaAgenda
Smart Lab OverviewSmart Lab Overview Lab Exhaust System ComponentsLab Exhaust System Components Study MethodologyStudy Methodology Wind Tunnel TestingWind Tunnel Testing Cost and Energy SavingsCost and Energy Savings SummarySummary
Can We Reduce Lab Building Can We Reduce Lab Building Exhaust Discharge RatesExhaust Discharge Rates
& Achieve Real Energy Savings & Achieve Real Energy Savings Without Compromising Safety?Without Compromising Safety?
This InitiativeThis Initiative
Lab Building Exhaust Stack Lab Building Exhaust Stack Discharge StudyDischarge Study
Prior to this study, we thought:Prior to this study, we thought:
Wind tunnel testing produces conservative designsWind tunnel testing produces conservative designs Field dispersion studies are not performed on new or Field dispersion studies are not performed on new or
renovated exhaust systemsrenovated exhaust systems Energy savings may be realizedEnergy savings may be realized Find a “one size fits all” solutionFind a “one size fits all” solution
Lab Exhaust Diagram AnimatedLab Exhaust Diagram Animated
Wind
Exhaust Fan Bypass Damper
Plenum
Fume Hood
Supply Fan Duct
Balcony
Re-Entrainment of Contaminated Air
AgendaAgenda
Smart Lab OverviewSmart Lab Overview Lab Exhaust System ComponentsLab Exhaust System Components Study MethodologyStudy Methodology Wind Tunnel TestingWind Tunnel Testing Cost and Energy SavingsCost and Energy Savings SummarySummary
Study MethodologyStudy Methodology
Selection of buildings – characteristics:Selection of buildings – characteristics:
Building size and age Building size and age Number of laboratoriesNumber of laboratories Fume hoods and hazardous contentsFume hoods and hazardous contents Types of fans – constant/variable fans, Types of fans – constant/variable fans,
induced airinduced air Exhaust stack parametersExhaust stack parameters Hazardous exhaust flowHazardous exhaust flow
Study MethodologyStudy Methodology
Final Three buildings:Final Three buildings:
Biological Sciences 3Biological Sciences 3 Natural Sciences 1Natural Sciences 1 Sprague HallSprague Hall
Study MethodologyStudy Methodology
Final three buildings were selected for the Final three buildings were selected for the following characteristics:following characteristics:
Representative of our campus environmentRepresentative of our campus environment Representative exhaust stack parametersRepresentative exhaust stack parameters Significant lab activitySignificant lab activity Induced-air fansInduced-air fans Curved metal roofsCurved metal roofs Manifolded exhaustsManifolded exhausts Modern design approachModern design approach
AgendaAgenda
Smart Lab OverviewSmart Lab Overview Lab Exhaust System ComponentsLab Exhaust System Components Study MethodologyStudy Methodology Wind Tunnel TestingWind Tunnel Testing Cost and Energy SavingsCost and Energy Savings SummarySummary
Wind Tunnel TestingWind Tunnel Testing
Wind Tunnel TestingWind Tunnel Testing
Removing Conservatism Requires Extra Removing Conservatism Requires Extra CareCare More comprehensive wind tunnel testingMore comprehensive wind tunnel testing Commissioning the renovated systemCommissioning the renovated system Educate lab usersEducate lab users
Wind Tunnel TestingWind Tunnel Testing
Build model of campusBuild model of campus
Wind Tunnel TestingWind Tunnel Testing
Build model of campusBuild model of campus Install model stacksInstall model stacks
Wind Tunnel TestingWind Tunnel Testing
Build model of campusBuild model of campus Install model stacksInstall model stacks Install air sampling Install air sampling
points (“receptors”)points (“receptors”)
Wind Tunnel Testing Wind Tunnel Testing MethodologyMethodology
Build model of campusBuild model of campus Install model stacksInstall model stacks Install air sampling Install air sampling
points (“receptors”)points (“receptors”) Ensure correct Ensure correct
approach flowapproach flow
Wind Tunnel Testing Wind Tunnel Testing MethodologyMethodology
Build model of campusBuild model of campus Install model stacksInstall model stacks Install air sampling points Install air sampling points
(“receptors”)(“receptors”) Ensure correct approach Ensure correct approach
flowflow Wind tunnel testingWind tunnel testing Data analysisData analysis
Establish Appropriate Design Establish Appropriate Design CriteriaCriteria
ASHRAE Recommendation for Labs isASHRAE Recommendation for Labs is 400 (µg m 400 (µg m-3-3)/(g s)/(g s-1-1))
ANSI Z9.5 Recommendation for Labs isANSI Z9.5 Recommendation for Labs is 750 (µg m 750 (µg m-3-3)/(g s)/(g s-1-1))
Adjust up or down based on specific Adjust up or down based on specific materials and activities in the labmaterials and activities in the lab
AgendaAgenda
Smart Lab OverviewSmart Lab Overview Lab Exhaust System ComponentsLab Exhaust System Components Study MethodologyStudy Methodology Wind Tunnel TestingWind Tunnel Testing Cost and Energy SavingsCost and Energy Savings SummarySummary
Typical Timeline of Exit Typical Timeline of Exit Velocity RequirementsVelocity Requirements
0102030405060708090
1 3 5 7 9 11 13 15 17 19 21 23
Time
CF
M x
100
0
Typical Design
1% Design
Required by Dispersion
Required by High Air Change Rate
Required by Low AirChange Rate
Energy & Cost SavingsEnergy & Cost SavingsBiological Sciences 3Biological Sciences 3
(based on $0.11/kWh)(based on $0.11/kWh)
ActionsActions SavingsSavings Payback Payback PeriodPeriod
General LaboratoryGeneral LaboratoryIncrease stacks (5 feet)Increase stacks (5 feet)Reduce flow (13,000 cfm/stack)Reduce flow (13,000 cfm/stack)
Up to 58 kWUp to 58 kW
$61K/year$61K/year
1.6 years1.6 years
BSL 3 LaboratoryBSL 3 LaboratoryIncrease stacks (4 feet)Increase stacks (4 feet)Reduce flow (270 cfm/stack)Reduce flow (270 cfm/stack)
Up to 5.6 kWUp to 5.6 kW
$6K/Year$6K/Year
5.1 years5.1 years
Energy & Cost SavingsEnergy & Cost SavingsNatural Sciences 1Natural Sciences 1 (based on $0.11/kWh)(based on $0.11/kWh)
ActionsActions SavingsSavings Payback Payback PeriodPeriod
Safety and Energy SavingsSafety and Energy SavingsIncrease stacks on Nat Sci 1 Increase stacks on Nat Sci 1
(4 feet)(4 feet)Install variable frequency drivesInstall variable frequency drivesInstall wind responsive Install wind responsive
equipmentequipmentReduce exhaust fan flows Reduce exhaust fan flows
Up to 39 kWUp to 39 kW
$41K/year$41K/year
3.7 to 5.3 3.7 to 5.3 yearsyears
Energy & Cost SavingsEnergy & Cost SavingsSprague HallSprague Hall
(based on $0.11/kWh)(based on $0.11/kWh)
ActionsActions SavingsSavings Payback Payback PeriodPeriod
Do not modify exhaust stack heightsDo not modify exhaust stack heights Install Variable Frequency Drives on Install Variable Frequency Drives on
each faneach fanDisable or remove the existing Disable or remove the existing
bypass dampersbypass dampersSet the minimum exhaust flow to Set the minimum exhaust flow to
25,000 cfm (6 air changes)25,000 cfm (6 air changes)
Up to 46 kWUp to 46 kW
$48K/year$48K/year
1.7 years1.7 years
AgendaAgenda
Smart Lab OverviewSmart Lab Overview Lab Exhaust System ComponentsLab Exhaust System Components Study MethodologyStudy Methodology Wind Tunnel TestingWind Tunnel Testing Cost and Energy SavingsCost and Energy Savings SummarySummary
QuestionQuestion
Can We Reduce Laboratory Can We Reduce Laboratory Building Exhaust Stack Building Exhaust Stack
Discharge RatesDischarge Rates& Save Energy & Save Energy
Without Compromising Safety?Without Compromising Safety?
AnswerAnswer
Yes.Yes. Establish design criteria/performance Establish design criteria/performance
guidelinesguidelines Wind tunnel screening studyWind tunnel screening study Audit new and renovated designsAudit new and renovated designs Conduct field commissioning studiesConduct field commissioning studies Sufficient wind tunnel receptorsSufficient wind tunnel receptors
Study SummaryStudy Summary
What we learned:What we learned:
Wind tunnel testing, as it is used in design, is Wind tunnel testing, as it is used in design, is conservativeconservative
Field dispersion studies are not performed on new or Field dispersion studies are not performed on new or renovated exhaust systemsrenovated exhaust systems
Energy savings can be realizedEnergy savings can be realized Didn’t find a “one size fits all” solutionDidn’t find a “one size fits all” solution
Thank You!Thank You!
Review Existing Exhaust Review Existing Exhaust SystemSystem
Review as-built hazardous exhaust Review as-built hazardous exhaust mechanical systemsmechanical systems
Examine system configuration, fan type, Examine system configuration, fan type, redundancy, sequence of operation, etc.redundancy, sequence of operation, etc.
Review exhaust fan curves Review exhaust fan curves CRITICALCRITICAL
Variable volume vs. constant volumeVariable volume vs. constant volume
Smart Labs & Energy $avings Smart Labs & Energy $avings ChallengeChallenge
Balance energy savings & safetyBalance energy savings & safety
Maximize
Energy
Savings
Createa SaferLab
Identify & Test Alternative Identify & Test Alternative Renovation DesignsRenovation Designs
Identify exhaust system renovations which can Identify exhaust system renovations which can be economically implementedbe economically implementedto reduce exit velocitiesto reduce exit velocities
Install VFDsInstall VFDs Stack extensionsStack extensions Manifolding & clusteringManifolding & clustering Re-Sequencing multipleRe-Sequencing multiple
fan setsfan sets
23 = 8a
Energy Proportional to Velocity Cubed
Identify & Test Alternative Identify & Test Alternative Renovation DesignsRenovation Designs
Identify exhaust system renovations which can Identify exhaust system renovations which can be economically implementedbe economically implementedto reduce exit velocitiesto reduce exit velocities
Install VFDsInstall VFDs Stack extensionsStack extensions Manifolding & clusteringManifolding & clustering Re-Sequencing multipleRe-Sequencing multiple
fan setsfan sets
Test the design alternatives in the wind tunnel to Test the design alternatives in the wind tunnel to determine safety of personnel and research determine safety of personnel and research animalsanimals
Commission TestingCommission Testingof Exhaust Dispersionof Exhaust Dispersion
Field tracer gas studyField tracer gas study
Overall check on entire exhaust system Overall check on entire exhaust system including plume dispersionincluding plume dispersion
Ensures margin of safety is actually Ensures margin of safety is actually achievedachieved
AgendaAgenda
Lab Exhaust System ComponentsLab Exhaust System Components Study MethodologyStudy Methodology Wind Tunnel TestingWind Tunnel Testing Cost and Energy SavingsCost and Energy Savings Saving Energy for Your Lab BuildingSaving Energy for Your Lab Building Saving Energy for Your CampusSaving Energy for Your Campus SummarySummary
BYPASSBYPASS
NOT MANIFOLDEDNOT MANIFOLDED
MANIFOLDEDMANIFOLDED
Study MethodologyStudy Methodology
Buildings considered:Buildings considered:
Biological Sciences Biological Sciences Natural Sciences 1Natural Sciences 1 Natural Sciences 2Natural Sciences 2 Croul HallCroul Hall Hewitt HallHewitt Hall Sprague HallSprague Hall Cal-IT2Cal-IT2 Engineering Lab FacilityEngineering Lab Facility Engineering GatewayEngineering Gateway
Wind Tunnel Testing Wind Tunnel Testing MethodologyMethodology
Build model of campusBuild model of campus Install model stacksInstall model stacks Install air sampling points Install air sampling points
(“receptors”)(“receptors”) Ensure correct approach Ensure correct approach
flowflow Wind tunnel testingWind tunnel testing