ASHRAE TC 9.8 Seminar - Setty & Associates Final.pdf · ASHRAE 62n Positive Pressure ... Existing Classroom Unit Ventilators with Chilled Water Cooling Coils and Hot Water Heating

Moisture Migration ControlMoisture Migration Controlwith 100% Dedicatedwith 100% DedicatedOutdoor Air SystemsOutdoor Air Systems

ASHRAE 2005 Winter MeetingASHRAE 2005 Winter MeetingOrlando, FloridaOrlando, Florida

Presented byPresented byBoggarm S. Setty, P.E., FASHRAEBoggarm S. Setty, P.E., FASHRAE

Setty & Associates, Ltd.Setty & Associates, Ltd.

ASHRAE TC 9.8 SeminarASHRAE TC 9.8 Seminar

Moisture Migration Control with 100% Dedicated Outdoor Air SystemsMoisture Migration Control with 100% Dedicated Outdoor Air Systems

IntroductionIntroduction

Mold/Mildew Growth are Issues in SchoolsMold/Mildew Growth are Issues in Schools High Humidity Levels Encourage Fungi/Fungal GrowthHigh Humidity Levels Encourage Fungi/Fungal Growth Potential Health Effects Occur at Alarming RatePotential Health Effects Occur at Alarming Rate Claims and Litigation are CostlyClaims and Litigation are Costly Renew or Consider Property Insurance Policies Renew or Consider Property Insurance Policies Know How to Manage Mold Claims and LitigationKnow How to Manage Mold Claims and Litigation


Design ConsiderationsDesign Considerations

Control of Moisture PenetrationControl of Moisture Penetration EnvelopeEnvelope

100 % Dedicated Outside Air Unit System (DOAS)100 % Dedicated Outside Air Unit System (DOAS)


Design Considerations - EnvelopeDesign Considerations - Envelope

Heat Transfer CoefficientHeat Transfer Coefficient Permeability CoefficientPermeability Coefficient Envelope Dewpoint Design Envelope Dewpoint Design Outside Air Leakage ControlOutside Air Leakage Control Treat Exterior Water Penetration with Flashings and Treat Exterior Water Penetration with Flashings and

Weep HolesWeep Holes Design Windows, Doors, Roofing to Control Outside Air Design Windows, Doors, Roofing to Control Outside Air

LeakageLeakage


100% HVAC Dedicated System100% HVAC Dedicated System

Fresh Air to Every Breathing SpaceFresh Air to Every Breathing Space Discharge Air Temperature 50Discharge Air Temperature 50OOF DP and 70F DP and 70OOF DB – F DB –

ASHRAE 62nASHRAE 62n Positive Pressure up to 45Positive Pressure up to 45OOF DB Outside Air Temperature F DB Outside Air Temperature Neutral Pressure when Temperature falls below 45Neutral Pressure when Temperature falls below 45OOF DB.F DB. DOAS Units to Operate 24 hours, Positive PressureDOAS Units to Operate 24 hours, Positive Pressure DOAS Packaged Units or Builtup UnitsDOAS Packaged Units or Builtup Units


Liberty High School, Bealeton, Virginia Liberty High School, Bealeton, Virginia


Existing Envelope Conditions

Existing Air Handling UnitExisting Air Handling Unitand Zone Configurationand Zone Configuration


Existing Unit Ventilator ConfigurationExisting Unit Ventilator Configuration



Outside Air not Outside Air not Cooled to the Cooled to the Necessary Necessary DewpointDewpoint

Units Run Units Run ContinuouslyContinuously

Continuous 24 Continuous 24 Hour Draw of Hour Draw of Fresh Air Fresh Air

Potential Potential Condensation in Condensation in Ceiling and Ceiling and ClassroomsClassrooms

Excessive Air Excessive Air LeakageLeakage

Existing Typical Classroom Unit Ventilator

Existing Unit Ventilator Schematic Diagram


Existing Typical Classroom System

Existing Passive Relief Air System


Air Leakage Unconditioned Air Passive Outside Air

Exhaust Gravity Ventilators Natural Flow through the Ceiling

During Unoccupied Hours

Typical Roof Exhauster


Existing DX Hot Water AHU Flow Diagram


Serves Administration AreaServes Administration Area Units Contain other DX SystemUnits Contain other DX System Not Capable of Cooling Supply Ducts Down Not Capable of Cooling Supply Ducts Down

to 50to 5000F DewpointF Dewpoint

Existing DX Hot Water AHU ConfigurationExisting DX Hot Water AHU Configuration


OptionsOptions

C-1C-1: Convert Existing Classroom Unit with Chilled Water and : Convert Existing Classroom Unit with Chilled Water and Electric Heating CoilElectric Heating Coil C-2C-2: Existing Unit Ventilator Chilled and Hot Water Coil: Existing Unit Ventilator Chilled and Hot Water Coil C-3C-3: Existing Unit Ventilator with Chilled Water and Electric: Existing Unit Ventilator with Chilled Water and Electric Heating Coil with DOA UnitHeating Coil with DOA Unit C-4C-4: Convert to Four-Pipe Fan Coil Units with a Separate DOAS: Convert to Four-Pipe Fan Coil Units with a Separate DOAS UnitUnit C-5C-5: New Four-Pipe Fan Coil Units with a Separate DOAS Unit: New Four-Pipe Fan Coil Units with a Separate DOAS Unit C-6C-6: New Four-Pipe Chilled and Hot Water Coil with Electric: New Four-Pipe Chilled and Hot Water Coil with Electric Heating Coil with DOAS UnitsHeating Coil with DOAS Units


Option C-1Option C-1

Existing Classroom Unit VentilatorExisting Classroom Unit Ventilator Convert to Two PipeConvert to Two Pipe

Chilled Water Coil/Chilled Water Coil/Electric Heating CoilElectric Heating Coil

New Duct to be Extended New Duct to be Extended for Proper Circulationfor Proper Circulation

Dehumidification Up toDehumidification Up to505000F Dewpoint not F Dewpoint not FeasibleFeasible



Existing Classroom Unit Ventilators withExisting Classroom Unit Ventilators withChilled Water Cooling Coils and Hot Water Chilled Water Cooling Coils and Hot Water Heating CoilsHeating Coils Convert Existing Two PipeConvert Existing Two Pipe

System to Chilled/Hot Water Coils System to Chilled/Hot Water Coils Keep the Unit Ventilation in PlaceKeep the Unit Ventilation in Place Modify DuctworkModify Ductwork Hot Water Coil Instead of Electric Hot Water Coil Instead of Electric

Heating Coil Heating Coil



Existing Classroom UnitExisting Classroom UnitVentilators with Chilled WaterVentilators with Chilled WaterCooling/Electric Heating CoilsCooling/Electric Heating Coils Fresh Air is Supplied throughFresh Air is Supplied through

Dedicated Unit - DOASDedicated Unit - DOAS Dehumidified and Heated to Dehumidified and Heated to

707000F and 50F and 5000F Dewpoint F Dewpoint Existing Fresh Air is Shut DownExisting Fresh Air is Shut Down Passive Air is Disconnected Passive Air is Disconnected



Existing Classroom UnitExisting Classroom UnitVentilators With ChilledVentilators With ChilledWater Cooling Coils andWater Cooling Coils andHot Water Heating CoilsHot Water Heating Coils

Difference: Hot Water Coil Difference: Hot Water Coil Instead of Electric CoilInstead of Electric Coil

Four-Pipe SystemFour-Pipe System


Option C-5Option C-5New Fan Coil Units withNew Fan Coil Units withChilled Water CoolingChilled Water CoolingCoils and Hot Water Coils and Hot Water Heating CoilsHeating Coils

Hot Water Coil Provides Hot Water Coil Provides Necessary ReheatNecessary Reheat

Ducted Air DistributionDucted Air Distribution DOAS Fresh Air SupplyDOAS Fresh Air Supply


Option C-6Option C-6New Fan Coil Units withNew Fan Coil Units withChilled Water Cooling Coils Chilled Water Cooling Coils and Electric Heating Coilsand Electric Heating Coils Existing Piping will be Existing Piping will be

Converted into Two-Pipe Converted into Two-Pipe Chilled Water and Electric Chilled Water and Electric Reheat CoilReheat Coil

Ducted Air DistributionDucted Air Distribution DOAS Fresh Air SupplyDOAS Fresh Air Supply


New Chilled/Hot Water AHU ConfigurationNew Chilled/Hot Water AHU Configuration


New DX and Hot Water Reheat AHUNew DX and Hot Water Reheat AHU


New 100% Dedicated Outdoor Air System (DOAS) Options

Option 1:

Variable Speed Makeup Air Handling Unit DX Coil, Hot Water Reheat Coil

Option 2:

Constant Volume Air Handling Unit Chilled Water and Hot Water Heating Coils Desiccant Wheels for Dehumidification Units


DOAS – Option 1DOAS – Option 1

100% Fresh Air Heat Reclaim Make-Up Air Handling Units


DOAS - Option 2DOAS - Option 2

100% Fresh Air New Desiccant Dehumidification – DOAS Unit


New 100% Dedicated Outside Air Units LocationsNew 100% Dedicated Outside Air Units Locations


New Integrated DOAS and FCU SystemsNew Integrated DOAS and FCU Systems

New Fan Coil Units Toilet Exhaust System

DOA Units New Reheat Coil


New DX and Hot Water Reheat AHU ConfigurationNew DX and Hot Water Reheat AHU Configuration


XXX (1)Unit Ventilators, Dual Temp

Second Floor ClassroomsUnit Ventilators19

XAHU: DX, HWGymnasium, WestAHU-1818

XAHU: DX, HWGymnasium, CenterAHU-1717

XAHU: Dual TempTeam RoomsAHU-1616

XAHU: DX, HWBoys Lockers, Wrestling, Weights

AHU-1515

XAHU: DX, HWGymnasium, EastAHU-1414

XAHU: Dual TempGirls Lockers/Aux GymAHU-1313

XAHU: Dual TempGirls LockersAHU-1212

XAHU: Dual TempMusicAHU-1111

XAHU: Dual TempArtAHU-1010

XAHU: DX, HWStageAHU-99

XAHU: DX, HWAuditoriumAHU-7, 8 & 198

XAHU: Dual TempHealth, Athletic OfficesAHU-67

XAHU: DX, HWDining/KitchenAHU-56

XAHU: DX, HWLibraryAHU-45

XAHU: DX, HWOffice/AdminAHU-34

XAHU: DX, HWOffice/AdminAHU-23

XAHU: Dual TempSupport, VocationalAHU-12

XXX (1)Unit Ventilators, Dual Temp

First Floor ClassroomsUnit Ventilators1

Add New Make-up Air Units

Convert DT Coil To Chilled

Water

Add Reheat Coil

RecommendationsSystem TypeSpace TypeSystemZone No

Options SummaryOptions Summary


SummarySummary

MU-1CH-1DX-1C-6

MU-1CH-1DX-1C-5

MU-1CH-1DX-1C-4

MU-1CH-1DX-1C-3

--CH-1DX-1C-2

--CH-1DX-1C-1

Makeup Air Unit Option

AHU Heating/Cooling

Option

ClassroomOption

RecommendationsRecommendations

Two-Pipe Fancoil Unit with Electric Heating Coil with DOAS.Two-Pipe Fancoil Unit with Electric Heating Coil with DOAS.

MU-1CH-1DX-1

C-6


Makeup Air Unit Option

AHU Heating/Cooling

Option

ClassroomOption

Documents

ASHRAE TC 9.8 Seminar - Setty & Associates Final.pdf · ASHRAE 62n Positive Pressure ... Existing Classroom Unit Ventilators with Chilled Water Cooling Coils and Hot Water Heating