TRACE™ 700 Learning Series Module 3: Methodology ... 700 Learning Series Module 3: Methodology &...

TRACE™ 700 Learning SeriesModule 3: Methodology & Output Interpretation

Load Design Phase MethodologyTRACE PsychrometricsBalancing Airfl owsASHRAE 62.1Detailed Output Interpretation Module 3 Exercise

Learning Objectives

• Summarize load and design methodology

• Understand design weather and design schedules

• Explore inputs that impact load and design calculations

TRACE™ 700 Learning Series

©Trane a business of Ingersoll Rand Module 3: Methodology & Output l 1

Hourly Loads &Hourly Airflows

Peak LoadsLOAD PHASE

DESIGN PHASE

SYSTEMSIMULATION PHASE

EQUIPMENTSIMULATION PHASE

ECONOMICANALYSIS PHASE

Supply-Air Temp& Design Airflow

Energy Consumption & Demand

Economic Comparisonsof Alternatives

EquipmentPerformance

related entries calculations resultsdata

WeatherLibrarydesign

Utility Rate

BUILDINGlocation, envelope

design data

SYSTEMtype, economizerdedicated OA

phase

SYSTEM

EQUIPMENT

ECONOMICS

WeatherLibrary

typical

Load Design Phase

1

2

3

4

40

60

80

0 6 12 18 24

OA

DB

Tem

pera

ture

(°F

)

Design weather (cooling)

Time (hr)

July

Design weather (heating)

70

50

Design Weather



60

100

0 6 12 18 24

OA

DB

Tem

pera

ture

(°F

) Design weather (cooling)

Time (hr)

70

80

9088°F

92°F

Design Weather

• Day Types

• Cooling Design

• Weekday

• Saturday

• Sunday

• Heating Design

Sizing Equipment

Design day types are only used during the design calculationWeekday, Saturday, and Sunday day types used during all other calculations

All day types must be defined when creating a schedule

Day Types



Load Phaserelated entries calculations data

LOAD PHASEBUILDINGlocation, envelope

design data

WEATHER LIBRARYdesign

DETERMINE SPECIFIC ROOM MASSCREATE ROOMSconstruction typesroom mass average


DETERMINE SPECIFIC ROOM MASS

LOAD PHASE

calculations


design data

CREATE ROOMSconstruction typesroom mass average


DETERMINE CAPACITANCE OF ROOMCREATE ROOMSconstruction types

moisture capacitance





LOAD PHASE

calculations


design data



DETERMINE CAPACITANCE OF ROOM

CALCULATE ROOM HEAT GAINS

CREATE ROOMSconstruction types


CREATE ROOMSall inputs



LOAD PHASE

calculations


design data



DETERMINE CAPACITANCE OF ROOM

CALCULATE ROOM HEAT GAINS

CALCULATE ROOM LOADS(TETD, CLTD, DOE2, RP359, RTS)

CREATE ROOMSconstruction types


ACTIONSchange loadparameters

CREATE ROOMSall inputs

Peak Loads



Design Phaserelated entries calculations data

CALCULATE FAN HEAT

DESIGN PHASESYSTEMtype


Peak LoadsCREATE SYSTEMS

fans


CALCULATE FAN HEAT



Peak LoadsDETERMINE PLENUM & RETURN AIR CONDITIONCREATE SYSTEMS

advanced

CREATE SYSTEMSfans



Plenum/Return Air


CALCULATE FAN HEAT




advanced

CREATE SYSTEMSfans

DETERMINE VENTILATION LOADCREATE ROOMSairflow




CALCULATE FAN HEAT




advanced

CREATE SYSTEMSfans

DETERMINE VENTILATION LOAD

CALCULATE FAN & COIL LOAD COMPONENTSCREATE SYSTEMSFans and coils

CREATE ROOMSairflow


CALCULATE FAN HEAT




advanced

CREATE SYSTEMSfans

DETERMINE VENTILATION LOAD

CALCULATE FAN & COIL LOAD COMPONENTSCREATE SYSTEMSFans and coils

CREATE ROOMSairflow

PSYCHROMETRIC CALCULATIONCREATE SYSTEMSTemp. and humidity

Supply Air Temp. and Design Airflow



• Load phase determines the peak loads and design phase determines the supply temperature and airflows

• Thermal mass and load methodology impacts the time of peak

• Design schedules play important role in design load calculations

Conclusion



Learning Objectives• Explain psychrometric loop process

• Discuss implications of entering airflows and supply air temperatures

• Understand the over or undersizing load component



Initial Conditions:

•Starts with room dry bulb and relative humidity

•Determines CFM using leaving coil temp equal to room dew point

Psychrometrics



PsychrometricsBegins loop considering outside air and return air

1

1


Considers any return air heat gain

1

2

1 2





Determines mixed air conditions based on return air & outdoor air conditions

1

2

3

1 2

3




Follows generic coil curve to determineleaving cooling coil condition

1

2

3

4

1 2

3

4



4





Considers any supply air heat gain

1

2

3

4

51 2

3

5

4 1 2

3

5





Considers any supply air heat gain

Calculates SHR

If loop does not close, repeatsteps 2 through 6 up to 30 times

1

2

3

4

5

66



CFM = Q / [1.1 x (TROOM ‐ TSUPPLY)]

Specifying Design Conditions

TSUPPLY = TROOM ‐ Q / (1.1 x CFM)





OV/UNDR SIZING= 1.1 x CFM x (TROOM ‐ TSUPPLY) ‐ Q

Conclusion

• Psychrometrics are used to solve for design supply temperature

• Airflow is calculated using the sensible heat equation

• Over or undersizing loads can occur by specifying supply temperatures and/or airflows



Learning Objectives

• Defining balancing airflows

• Explain how transferring airflow relates to balanced airflow

• Implement transfer airflow in the program



room

Airflow Balance+ System Exhaust = Ventilation + InfiltrationRoom Exhaust

system exhaust

ventilation

infiltration

room exhaust

supply air

return air

ACU

150 cfmInfiltration (25 cfm)Ventilation (125 cfm)

75 cfmSystem Exhaust

75 cfmRoom Exhaust

Restroom

Airflow Balance



Lab B

Lab A


75 cfmRoom Exhaust

150 cfmRoom ExhaustC

orridor

Airflow Balance

Lab B

Lab A


50 cfmRoom Exhaust

100 cfmRoom ExhaustC

orridor

100 cfmTransfer Air

150 cfm requested

50 cfmTransfer Air

75 cfm requested

Airflow Balance



Airflow BalanceLesson 2: Program Methodology

SCREENCAST

Conclusion

• Program will not model over or under pressurized spaces

• Adjacent air transfer and room exhaust inputs allow for modeling of transfer air



Learning Objectives

• Defining the standard

• Describe the calculation process

• Implementation of ASHRAE Standard 62.1



• Purpose“…specify minimum ventilation rates and indoor air quality that will be acceptable to human occupants…”

• Methods Ventilation Rate Procedure (VRP)

Indoor Air Quality Procedure (IAQP)

ASHRAE Standard 62.1

• Zone Calculations Determine area/occupancy rates

Table 6-1 Determine Zone Air Distribution Effectiveness (Ez)

Table 6-2 Calculate Breathing Zone Outdoor Airflow (Vbz)

Vbz = RpPz + RaAz

Calculate Zone Outdoor Airflow (Voz)Voz = Vbz / Ez




• Multi-Zone Calculation Determine Zone Primary OA Fraction (Zp)

Zp = Voz / Zone Primary Airflow (Vpz) TRACE assumes minimum stop airflow for both

cooling and heating Determine Occupant Diversity (D) (not required)

D = Ps / Σall zonesPz

Determine Uncorrected OA Intake (Vou)Vou = D Σall zones Rp Pz + Σall zones Ra Az


• Multi-Zone Calculation Determine System Ventilation Efficiency (Ev)

Table 6-3 or Appendix A

Calculate Outdoor Air IntakeVot = Vou / Ev




ASHRAE Standard 62.1Lesson 2: Program Methodology

• TRACE and ASHRAE Standard 62.1 Setup

• Create Rooms• Create Systems

Analysis• ASHRAE 62.1 Report• Determine Critical Space(s)

Additional Steps• Understand Critical Space(s)• Adjust Minimum Stops

• Airflows tab• Max Vent (Z) Ratio Allowed

SCREENCAST

ASHRAE Standard 62.1Lesson 2: Program Methodology

ASHRAE Standard 62.1 Report

1.System Ventilation Parameters Average Outdoor Air Fraction (Xs) System Ventilation Efficiency (Ev) Outdoor Intake Flow (Vot)

2.Zone Ventilation Parameters Breathing Zone Outdoor Airflow (Vbz) Zone Outdoor Fraction (Voz)

3.Zone Ventilation Calculations Cooling design and heating design Zone outdoor air fraction (Zd) Critical zone identified with *Asterisk*

SCREENCAST



ASHRAE Standard 62.1Lesson 2: Program Methodology100% OA

Max Zd = 75%

SCREENCAST

Conclusion• Program uses the Ventilation Rate Procedure

• Use the Standard 62.1 report for zone level and system level calculation outputs

• 100% OA scenarios can be corrected using the max Zd input



Learning Objectives

• Comparison of design outputs for various system types VAV with reheat

Single zone constant volume

VRF with DOAS

• Discuss the design load values on the reports



SCREENCAST

SCREENCAST



SCREENCAST

SCREENCASTSCREENCAST



SCREENCAST

SCREENCAST



Conclusion• Before viewing checksum reports, look at the

System Component Selection report for coil and fan locations

• TRACE™ sizes coils for worst case scenarios• Differences in time of coil peak and space peak lead

to different component loads and airflows on checksums report

• Psychrometric report values are elevation specific



Purpose:• Practice basic inputs and navigation.Procedure:• Enter the weather location, building parameters,

and system information as described.• Calculate the file.• Review questions.Payoff:• Familiarity with the program navigation from start

to finish.• Understanding of the basic entries required

by the program.

Exercise:

Bringing It All Together

Note:Create a new project. Do not change any default values unless noted



Purpose:Practice basic inputs and navigation

Methodology:CLTD (cooling), UATD (heating)You can change this through the Actionsmenu and select Change Load Parameters.

Location: Tampa, Florida Note:Use default values unless otherwise noted

Exercise:

Bringing It All Together

phone I 608.787.3926

fax I 608.787.3005

email I [email protected]

Web I www.tranecds.com

contact us



TRACE™ 700 Learning Series Module 3: Methodology ... 700 Learning Series Module 3: Methodology &...

Documents

Transcript of TRACE™ 700 Learning Series Module 3: Methodology ... 700 Learning Series Module 3: Methodology &...