Chilled Chilled BeamsBeamsThe Energy Efficient Solution For SchoolsThe Energy Efficient Solution For Schools

Clint Schwartz, PEControlled Air, Inc.Controlled Air, Inc.clint@controlled-air.com

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!