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Chilled Chilled BeamsBeamsThe Energy Efficient Solution For SchoolsThe Energy Efficient Solution For Schools
Clint Schwartz, PEControlled Air, Inc.Controlled Air, [email protected]
Wh t A Chill d B ?Wh t A Chill d B ?What Are Chilled Beams?What Are Chilled Beams?
Passive Chilled BeamsPassive Chilled BeamsPassive Chilled BeamsPassive Chilled BeamsAirflow PatternAirflow Pattern
Concrete soffitConcrete soffit
Passive Chilled BeamsPassive Chilled BeamsPassive Chilled BeamsPassive Chilled BeamsAir Distribution Pattern w/ UFADAir Distribution Pattern w/ UFAD
Passive Chilled BeamsPassive Chilled BeamsPassive Chilled BeamsPassive Chilled BeamsTypical Installation Above CeilingTypical Installation Above Ceiling
Passive Chilled BeamsPassive Chilled BeamsPassive Chilled BeamsPassive Chilled BeamsTypical Installation Typical Installation –– Fidelity InvestmentsFidelity Investments
Active ChilledActive Chilled BeamsBeamsActive Chilled Active Chilled BeamsBeamsHow They WorkHow They Work
Sl b ffitPrimary
Slab or soffitair supply
Suspended Ceilingp g
Active Chilled BeamsActive Chilled BeamsActive Chilled BeamsActive Chilled BeamsTwoTwo--Way Way Distribution PatternDistribution Pattern
Active Chilled BeamsActive Chilled BeamsActive Chilled BeamsActive Chilled BeamsTypical InstallationTypical Installation
DesignDesignC id tiC id tiConsiderationsConsiderations
Design ConsiderationsDesign ConsiderationsDesign ConsiderationsDesign ConsiderationsThermal Output Test Thermal Output Test StandardsStandards
DesignDesign ConsiderationsConsiderationsDesign Design ConsiderationsConsiderationsWater Water Supply Supply vs. Room vs. Room DewpointDewpoint TemperatureTemperature
Extract From Extract From Independent ‘Independent ‘EnergieEnergie’ ’
Climatic CeilingsClimatic Ceilings
Passive° °
Climatic CeilingsClimatic Ceilings
+ 0.5 °C ( + 0.9 °F )
Active- 1.5 °C ( - 2.7 °F)
R l ti t i d i tRelative to room air dew point
Design ConsiderationsDesign Considerations
S D i t V til ti Ai
Design ConsiderationsDesign ConsiderationsOA OA DewpointDewpoint vs. Room vs. Room DewpointDewpoint –– 200 BTU/hr/person200 BTU/hr/person
Space Dewpoint vs. Ventilation Air
80.00
70.00
o F) 40 DP
Supply DP
60.00
Spac
e D
ewpo
int (
o 40 DP45 DP50 DP55 DP60 DPMax DP
50.00
40.005 10 15 20 25 30
Ventilation Air (cfm/person)
Design ConsiderationsDesign ConsiderationsDesign ConsiderationsDesign ConsiderationsPrimary/Secondary Chilled Water LoopsPrimary/Secondary Chilled Water Loops
Primary Chilled Water Supply
HEAT EXCHANGER
Primary Chilled Water Return
Supply Temperature
ControllerChill d
3-way Modulating
Valve T
Chilled Water Pump
Return Water BypassSecondary (Tempered)
Chilled Water Supply to B
2-way Chilled Water Valves (one per
BeamsSecondary Chilled Water
Return
To Chilled Beam Zones
Valves (one per zone)
Design ConsiderationsDesign ConsiderationsDesign ConsiderationsDesign ConsiderationsDedicated ChillerDedicated Chiller
3-way
Dedicated Chiller
TSupply
Temperature Controller
Chilled Water
yModulating
Valve
Return Water Bypass
Storage Vessel
Pumpyp
Chilled Water Supply to Beams
Chilled Water Return
To Chilled Beam Zones
Design ConsiderationsDesign ConsiderationsDesign ConsiderationsDesign ConsiderationsThermal ZoningThermal Zoning
Chilled water supply
Chilled water return
Isolation valveIsolation
valve
2 way control valve
Chill d b ithi i l th l
T Zone thermostat
Chilled beams within a single thermal zone
Design ConsiderationsDesign ConsiderationsDesign ConsiderationsDesign ConsiderationsWater Piping Condensation SensorWater Piping Condensation Sensor
Design ConsiderationsDesign ConsiderationsDesign ConsiderationsDesign ConsiderationsThermal Comfort Thermal Comfort -- DiffuserDiffuser
What does a diffuser do?• Delivers fast cold (or hot) air to the space• It directs the discharge
M k f th C dă ff t
What does a diffuser do?• Delivers fast cold (or hot) air to the space• It directs the discharge
M k f th C dă ff t
The primary air•Provides fresh air requirementC t l t t• Makes use of the Coandă effect
• Reduced velocity by mixing• Changes temperature by mixing
• Makes use of the Coandă effect• Reduced velocity by mixing• Changes temperature by mixing
•Controls temperature•Controls humidity
Design ConsiderationsDesign ConsiderationsDesign ConsiderationsDesign ConsiderationsThermal Comfort Thermal Comfort -- Chilled BeamChilled Beam
Beam vs. diffuser• Increases volume, Example: assume 60% water 40% airBeam vs. diffuser• Increases volume, Example: assume 60% water 40% air
• 100 cfm by diffuser, 40 cfm @ beam but with induction ratio of say 5:1, = total air discharged is 40 x 5 = 200 cfm
• If we work on 1cfm/SF and room Height of 10’
• 100 cfm by diffuser, 40 cfm @ beam but with induction ratio of say 5:1, = total air discharged is 40 x 5 = 200 cfm
• If we work on 1cfm/SF and room Height of 10’• If we work on 1cfm/SF and room Height of 10• 100 cfm = 6 ac/hr, 200 cfm = 12 ac/hr (room air movement)
• The increased discharge temperature helps but the higher volume throws further
• If we work on 1cfm/SF and room Height of 10• 100 cfm = 6 ac/hr, 200 cfm = 12 ac/hr (room air movement)
• The increased discharge temperature helps but the higher volume throws further
Where Does The Energy Where Does The Energy S i C F ?S i C F ?Savings Come From?Savings Come From?
Energy SavingsEnergy SavingsEnergy SavingsEnergy SavingsWater vs. AirWater vs. Air
• Water weighs 800 times more than water– 1 lb. of CHW (6°∆T) transports 25% more
cooling energy than 1 lb. of air (20°∆T)• On a volumetric basis:
– 1 FT³ of CHW (6°∆T) transfers 1000 times more cooling energy vs. 1 FT³ of air (20°∆T)
Space SavingsSpace SavingsSpace SavingsSpace SavingsWater vs. AirWater vs. Air
Flo Cross Section Ratio
1 : 327
Flow Cross Section Ratio
18“ x 18“
Air Duct
1“ diameter Water Pipe
Energy SavingsEnergy SavingsEnergy SavingsEnergy SavingsChilled BeamsChilled Beams
Airflow requirement reduced by 60 to 70%Airflow requirement
reduced by 60 to 70%
60 to 70% of sensible heat60 to 70% of sensible heat removed by chilled water
Energy SavingsEnergy SavingsEnergy SavingsEnergy SavingsDOE Report DOE Report –– Energy Savings PotentialEnergy Savings Potential
Energy SavingsEnergy SavingsEnergy SavingsEnergy SavingsDOE Report DOE Report –– 15 Technologies Investigated15 Technologies Investigated
Energy SavingsEnergy SavingsEnergy SavingsEnergy SavingsDOE Report DOE Report –– Simple PaybackSimple Payback
Energy SavingsEnergy SavingsEnergy SavingsEnergy SavingsLEED Analysis LEED Analysis –– Constitution Center, Washington DCConstitution Center, Washington DC
22.4% Cost
Baseline Building Constitution Center E U
Cost Savings
Energy Usage Energy Usage
Energy SavingsEnergy SavingsEnergy SavingsEnergy Savings
• No motor to cool• Reduced airflow
Transportation of a ton– Transportation of a ton of cooling by air requires 7 to 10 times more energy than by chilledenergy than by chilled water.
• Elevated CHWSHi h hill COP– Higher chiller COP
– Longer free cooling (water-cooled chiller)
Energy SavingsEnergy SavingsEnergy SavingsEnergy SavingsCompressor Efficiency Compressor Efficiency -- ChillersChillers
Energy SavingsEnergy SavingsEnergy SavingsEnergy SavingsLower Humidity, Raise TemperatureLower Humidity, Raise Temperature
• Save energy by having higher db, lower rh– Higher comfort perceivedHigher comfort perceived
at 78/45% vs. 75/50%– Less temp difference
between inside and outsidebetween inside and outside– 3 To 5% energy cost
reduction for each ºF thermostat is raisedthermostat is raised
Energy SavingsEnergy SavingsEnergy SavingsEnergy SavingsReduced Outdoor Air vs. VAVReduced Outdoor Air vs. VAV
• Multiple space equation in ASHRAE 62.1 can add up to 70%7 to required outdoor air in VAV
DOASvs. DOASProject: Reynolds and Reynolds- 4th Floor
Zone Box Max. Cfm Min Pos Min. Cfm OA Reg. % OA Room Nos. Zone Type1 7045 30% 2114 620 29% n/a Exterior Office Space2 21240 30% 6372 4620 73% n/a Interior Office Space ASHRAE 62 METHOD MULTIPLE SPACES2 21240 30% 6372 4620 73% n/a Interior Office Space ASHRAE 62 METHOD, MULTIPLE SPACES
3 220 100% 220 0 0% 402,404 Restrooms4 455 30% 137 100 73% n/a Round Stairwell Y = X/(1+X-Z)
5 1765 30% 530 275 52% 406,420 Copy/Coffee/Corr X = OA rate for all branches on sys tem / Total supply airf low
6 1455 30% 437 325 74% 408 Break Rm/Stairwell Z = OA rate for c ritical space / Total supply air in critical space
7 350 100% 350 0 0% 414,416 Electrical/SER Y = Corrected fraction of OA / Total suppy airf low
8 285 50% 143 120 84% 422,424 Huddle Rooms9 935 70% 655 520 79% 426 Staff Team Room X = 0.63
10 C f10 515 80% 412 340 83% 428 Conference Z = 0.87
11 650 50% 325 260 80% 432,434,436,438 Huddle Rooms Zone No. 12
12 415 100% 415 360 87% 480 Conference Y = 0.83
13 505 50% 253 205 81% 460,464,468,470 Huddle/Storage14 895 40% 358 260 73% 472 Diagnostics Lab Corrected Fraction of Outdoor air = Y (Total supply airf low)
15 485 100% 485 420 87% 474 Conference16 445 100% 445 380 85% 482 War Room OA = 13125 cfm
17 2680 30% 804 600 75% 484 Break/Coffee Rm17 2680 30% 804 600 75% 484 Break/Coffee Rm18 1100 30% 330 180 55% 486,488 Mail/Corr/Copy/Stairwell19 350 100% 350 0 0% 490,492 SER/Electrical20 255 100% 255 0 0% 496,498 SW Rest21 845 60% 507 400 79% 476, 478 Video Conf/AV
Totals 42890 15894 9985
Oth A f S iOth A f S iOther Areas of SavingsOther Areas of Savings
Chilled Beam BenefitsChilled Beam BenefitsChilled Beam BenefitsChilled Beam BenefitsStructural Height SavingsStructural Height Savings
600mm2’6”
12’6” 11’
9”6 9’6”
f.f.l.8” 6”
Active Chilled BeamsActive Chilled BeamsActive Chilled BeamsActive Chilled BeamsStructural Height Savings Structural Height Savings -- Constitution CenterConstitution Center
12” Ceiling Plenum
’-0
”’-
0”
12 Ceiling Plenum
2’
2’
8’–
4”
Chilled Beam BenefitsChilled Beam BenefitsChilled Beam BenefitsChilled Beam BenefitsMaintenance SavingsMaintenance Savings
• No Moving Parts– No Fans– No MotorsNo Motors– No Power Requirements
• No Filter• No Condensate
Pump/Drain• 4 Year Inspection &• 4 Year Inspection &
Vacuum• Simple Controls
Active Chilled BeamsActive Chilled BeamsActive Chilled BeamsActive Chilled BeamsAstraZeneca AstraZeneca –– Waltham, MassachusettsWaltham, Massachusetts
“Our first Waltham building using chilled beams was opened in 2000 Wh l d f ilit i 2003 i t ith2000. When we enlarged our facility in 2003, we again went with chilled beams. Our new buildings under construction will also be using chilled beam technology”.
“The beams at our facility have not required any maintenance or cleaning. The facility does not have rugs, and the chilled beams are supplied by the same air handlers that serve laboratories.”
“The three principal advantages that I see for chilled beams over a VAV system are (i) the level of quiet operations, (ii) the energy efficiency, and (iii) the virtual freedom from maintenance.”
Bruce MacGregorSystem Specialist
S i lt Chill d BS i lt Chill d BSpecialty Chilled BeamsSpecialty Chilled Beams
FourFour Way BlowWay BlowFourFour--Way BlowWay Blow
• Available in 2 x 2 and 2 x 4 sizes– Primarily for
partitioned office applicationspp
Displacement VentilationDisplacement VentilationDisplacement VentilationDisplacement VentilationTroxTrox QLCIQLCI
• Induction Nozzles– Primary air delivered at 50 to 55ºF– Mixing within terminal elevates supply
air to appropriate temperature
• Integral Heat Transfer Coil• Integral Heat Transfer Coil– Room air induced through coil– Supplements space cooling– Eliminates separate heating systemEliminates separate heating system
Displacement VentilationDisplacement VentilationDisplacement VentilationDisplacement VentilationHow Does it Work?How Does it Work?
Return @ 80Return @ 80--8585ooFF
Convective Heat SourceConvective Heat Source
Displacement VentilationDisplacement VentilationDisplacement VentilationDisplacement Ventilation
Displacement VentilationDisplacement VentilationDisplacement VentilationDisplacement VentilationVentilation EffectivenessVentilation Effectiveness
Displacement SystemDisplacement System Mixed Air SystemMixed Air System
VEFF = CRETURN - CSUPPLY
CROOM - CSUPPLY≤ 1VEFF =
CRETURN - CSUPPLY
CROOM - CSUPPLY≥ 1
Displacement SystemDisplacement System Mixed Air SystemMixed Air System
CROOM ≈ CRETURN
CFLOOR ≤ CROOM ≤ CCEILING
Ele
vatio
n
Occupied Z
T50Occupied
Zone
Ele
vatio
n
Local CO Concentration
Zone
Local CO Concentration Local CO2 ConcentrationLocal CO2 Concentration
Trox QLCITrox QLCITrox QLCITrox QLCICOCO22 Comparison with Unit VentComparison with Unit Vent
1600
• Identical classrooms
• Tests conducted over two eek period
Minnesota Elementary School
tion
(PPM
)
1000
1200
1400 Mixed Air System (UV) week period
• CO2 concentration at six foot level monitored
2C
once
ntra
t
600
800
1000 level monitored– Mixed system: 1100 PPM– DV System: 400 PPM
• 20% reduction in CO2 levels
CO
2
400
Displacement System20% reduction in CO2 levels produced 15% improvement in student performance
Time Source: Technical University of Denmark (Indoor Air 2005)
Active Chilled BeamsActive Chilled BeamsActive Chilled BeamsActive Chilled BeamsDisplacement Conditioning Displacement Conditioning –– Cooling OperationCooling Operation
Return Air 450 CFM
(82 to 85ºF)
100% Exhausted 450 CFM
Primary Airflow 450 CFM
(50 to 55ºF)
Room Air 900 CFM
(75 to 78ºF)Chilled Water
Supply Airflow 1350 CFM
(62 to 68ºF)
Active Chilled BeamsActive Chilled BeamsActive Chilled BeamsActive Chilled BeamsDisplacement Conditioning Displacement Conditioning –– Heating OperationHeating Operation
Return Air 450 CFM
100% Exhausted 450 CFM
Optional Heat Recovery
Primary Airflow 450 CFM
(50 to 60ºF)
Room Air 900 CFM
Hot Water
(50 to 60ºF)
Supply Airflow
(70 to 72ºF)
y1350 CFM
(82 to 85ºF)
Active Chilled BeamsActive Chilled BeamsActive Chilled BeamsActive Chilled BeamsDisplacement Conditioning Displacement Conditioning –– Staggered OperationStaggered Operation
68˚F 68˚F90˚F 90˚F68 F 68 F90 F 90 F
TroxTrox QLCIQLCITroxTrox QLCIQLCIInstallation Example Installation Example –– Ocean City Community College, NJOcean City Community College, NJ
MultiMulti Sevice Chilled BeamsSevice Chilled BeamsMultiMulti--Sevice Chilled BeamsSevice Chilled Beams
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsCustomized DesignCustomized Design
B C tBeam Costs
Cooling & Heating 40%
Other services 10%
Lighting 30% Aesthetics 20 %Aesthetics 20 %
~ + 25% of aesthetics = + 5% of total price
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsRoyal Bank of ScotlandRoyal Bank of Scotland
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsAirbus, UK: Pearce, Carillion Airbus, UK: Pearce, Carillion
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsBow Call CenterBow Call Center
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsChamber of Commerce, LuxembourgChamber of Commerce, Luxembourg
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsIndirect LightingIndirect Lighting
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsInnovative LightingInnovative Lighting
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsInnovative LightingInnovative Lighting
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsInnovative LightingInnovative Lighting
MultiMulti--Service Chilled BeamsService Chilled Beams
Multi Purpose Chilled Beams are
MultiMulti Service Chilled BeamsService Chilled BeamsCapital CostCapital Cost
Multi-Purpose Chilled Beams are delivered to the job ready to install as one unit.
All ti i k l
$ Cost Neutral
All connections are quick couple type.
Pre-assemble units average up to g p12 ft in length.
Cost data courtesy of
MultiMulti--Service Chilled BeamsService Chilled BeamsMultiMulti Service Chilled BeamsService Chilled BeamsAccelerated Construction Schedule Accelerated Construction Schedule –– MSCB vs. FCUMSCB vs. FCU
AHU L t O tiAHU L t O tiAHU Layout OptionsAHU Layout Options
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Traditional Traditional -- DX Cooling w/ Hot Gas ReheatDX Cooling w/ Hot Gas Reheat
R d d ffi i• Reduced efficiency• Requires multiple
compressor stages– Compressor cycling issues
require capacity modulation at part load
– Recommend at least four,Recommend at least four, but preferably six
• Requires modulating hot-gas reheat to maintain gspace comfort– Limited at part load as
reheat requirements can exceed coolingexceed cooling
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Cooling w/ Reheat Cooling w/ Reheat PsychrometricsPsychrometrics
123
1
223
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Energy Recovery Energy Recovery –– Heatpipe (Plate HX Alternative)Heatpipe (Plate HX Alternative)
• Sensible only energy transfer– More beneficial in
heating• Still need HGRH• Still need HGRH• Need frost prevention
strategystrategy– Preheat frost control– Face and bypassyp
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design HeatpipeHeatpipe PsychrometricsPsychrometrics -- CoolingCooling
1356
12
4
3
2 4
5 65 6
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Energy Recovery Energy Recovery –– Passive Desiccant (Enthalpy) WheelPassive Desiccant (Enthalpy) Wheel
S ibl d l• Sensible and latent energy recovered
• Wheel must be maintained– Motor and bearings– Potential for clogginggg g
• Still need HGRH• Need frost prevention
strategystrategy– Modulating wheel– Preheat frost control
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Passive Wheel Passive Wheel PsychrometricsPsychrometrics -- CoolingCooling
65 3 1
14
4
2
2
3
5 65 6
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design “Wringer”“Wringer”
E i h• Energy recovery with no exhaust air– Provides free pre-cool p
and reheat based on the temperature difference between
td i d ioutdoor air and air leaving the cooling coil
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Wringer PsychrometricsWringer Psychrometrics
45
3
2112
3 43 4
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Active Desiccant Wheel (Condenser Heat Regeneration)Active Desiccant Wheel (Condenser Heat Regeneration)
• Reduced mechanical cooling requirement
• Wheel converts latent• Wheel converts latent to sensible energy
• Slow rotational speedp– As low as 1/10 RPM
• Increased COP
Active Desiccant ProcessActive Desiccant ProcessActive Desiccant ProcessActive Desiccant ProcessHow It WorksHow It Works
• Moisture transfer based on difference in RH• Moisture transfers from high RH to low• The greater the difference in RH, the greater the
mechanism for moisture transfer• Conversion of latent heat to sensible
– Evaporative cooling in regeneration airstream and it i l ( ) i topposite in supply (process) airstream
– Heat increase is ≈ heat of vaporization of water• 1050 BTU per lb of water1050 BTU per lb of water
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Active Wheel PsychrometricsActive Wheel Psychrometrics
A
C
B
C
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Which System Uses Least Which System Uses Least DehumidificationDehumidification Energy?Energy?
HCU
Single HX Energy Use Comparison
Wringer
HCU
Heatpipe
Enthalpy Wheel
$0 $2,000 $4,000 $6,000 $8,000 $10,000 $12,000 $14,000 $16,000 $18,000
Brute Force
Dehumidification Heating Frost Control Fan Penaltyg y
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Hybrid System Hybrid System -- Two Two HeatpipesHeatpipes or Plates or Plates
• Increases recovered energy while utilizing maintenance friendlymaintenance friendly heat exchangers
• Provides free reheatProvides free reheat• Need to have frost
prevention strategyprevention strategy– Preheat coil in OA or
EA positions
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Two Two HeatpipeHeatpipe PsychrometricsPsychrometrics
135 135
7
12
4
6
3
2
6
5 46
5
7
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Hybrid System Hybrid System –– Passive Wheel and Passive Wheel and HeatpipeHeatpipe or Plateor Plate
• Increases energy recovered
• Provides free reheat
• Need to have frost prevention strategy– Preheat coil in OA
or EA
DOAS System DesignDOAS System DesignDOAS System DesignDOAS System DesignPassive Wheel and Passive Wheel and HeatpipeHeatpipe
135 135
7
24
6
1
66
25 4
3 6
5
7
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Passive Wheel and Wringer CyclePassive Wheel and Wringer Cycle
• Combines energy recovery with dehumidification
• Need frost prevention strategy– Prefer modulating wheel with vfd
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Passive Wheel and Wringer CyclePassive Wheel and Wringer Cycle
1 3
24 5
6
7
1 3 6
14
2
35
6
7
6
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Passive Wheel and Active WheelPassive Wheel and Active Wheel
C bi h• Combines heat recovery and dehumidification
• Exhaust air stream is the P C l Supply SideGasF Side Return Air
condensing air stream– No separate condensing
unit
Pre -CoolDX Coil
SupplyFan
SideSupply
GasAfterheat
ED
F
B C
Side Return AirBottom Deck
Whe
el
• Need frost prevention for enthalpy wheel– Modulating enthalpy
h l / VFD R t C ilSide Makup Air
G
Top Exhaust
H I
Enthalpy Wheel
DH
W
C d C il
J
Con
trol -
Can
Com
pres
sors
wheel w/ VFD React CoilSide Makup AirTop Deck A
Top ExhaustCond Coil
DOAS System DesignDOAS System DesignDOAS System Design DOAS System Design Passive Wheel and Active WheelPassive Wheel and Active Wheel
AG
F
BC
D
DOAS OptionsDOAS OptionsDOAS OptionsDOAS OptionsEnergy Usage ComparisonEnergy Usage Comparison
Drycool ERV
DOAU Operational Cost Comparison
Enthalp Wheel
Two Sens HX
Enthalpy Wheel/Sens HX
Enthalpy Wheel/Wringer
Heatpipe
Wringer
HCU
Enthalpy Wheel
$0 $2,000 $4,000 $6,000 $8,000 $10,000 $12,000 $14,000 $16,000 $18,000
Brute Force
Dehumidification Heating Frost Control Fan Penaltyg y
Th k F Li t i !Th k F Li t i !Thanks For Listening!Thanks For Listening!