session h2: successful use of energy modeling to inform design

Session H2: Successful Use of Energy Modeling to Inform DesignOctober 23, 2019

Michael J. Walsh, PE

I2SL 2019

Learning Objectives

• Learn how successful energy modeling in early concept

phases can inform system selection;

• Understand the engineering tasks necessary to produce data

needed by energy modeling consultants to perform

calculations reflecting design intent;

• Learn how continuous energy modeling informs and optimizes

systems to be installed; and

• Case study of actual building performance matching energy

model results.

I2SL 2019

Agenda

Engineering Design Criteria for Energy Modeling01

Conceptual System Development for Energy Modeling02

Continuous Energy Modeling To Enhance Performance03

04 Case Study

05 Takeaways

I2SL 2019

Section 01

Engineering Design Criteria &

Operational Schedules for Energy Model

I2SL 2019

Design Criteria for Energy Modeling

section 01

Minimum Energy Model Inputs

• Thermal Zone Type: Lab, Lab Support, Office, High Occupancy, Vivarium and Other

• Thermal Zone Area: Square Feet Each Zone Type

• Lab Zone Breakdown: Constant Load or Variable Load

• Space Cooling/Heating Temperature/Humidity Occupied and Setback

• Occupancy

• Occupancy Schedule

• Lighting Loads

• Lighting Diversity Schedules

• Internal Process/Plug Loads for Design

• Internal Process/Plug Load Diversity Schedules

• Occupied Minimum Ventilation (Exhaust Rate)

• Unoccupied Ventilation (Exhaust Rate)

• Ventilation Operational Schedule

• Exhaust Devices Airflow (Hoods/BSCs/Vented Cages)

• Exhaust Device Operational Schedules

• Minimum Unoccupied Supply Air Setback (50%)

I2SL 2019


Space Temperature Criteria

Sta

nd

ard

Th

erm

al C

om

fort

section 01

I2SL 2019


section 01

Space Humidity Criteria

I2SL 2019


section 01

Specialty Temperature and Humidity

Criteria

• Vivarium

• BSL-3/ABSL-3

I2SL 2019


Internal Loads:

Occupant Density Lighting Process/Plug Load

Include Discussion of Future Flexibility Criteria and Safety Factors

section 01

I2SL 2019


Ventilation Criteria

section 01

I2SL 2019


Ventilation Criteria

New ASHRAE Guide:

Classification of Lab Ventilation Design Levels

section 01

I2SL 2019


Exhausted Equipment Criteria

Types of Exhaust:

• Chemical Fume Hoods

• Biosafety Cabinets

• Snorkel Exhaust

• Vented Cabinets

• Ventilated Cage Racks

Need Estimated Quantity of Each,

Airflow Maximum and Minimum

Plus Static Pressure Drop for Each

(Affects Fan Power Estimate)

FT

03

FCD

03

To Exhaust

System

AO

AI

Stand Alone

Fume Hood

Controller

AI

HOODZT

01HS

03

AI

FITA

01

ZT

02

FAHFAL

AI

DI

Hybrid VAV Sash

Position Control Plus

Through The Wall

Sensor Feedback

Control with Local FH

Face Velocity Alarm

and DDC System

Analog Alarm Point

TYPICAL FOR EACH FUME HOOD

HORIZ/

COMBO

SASH ONLY

Fume Hood

AI

YS

03

Presence

Sensor

section 01

I2SL 2019


Operational Diversity Schedules and Equipment Efficiencies

section 01

I2SL 2019


Operational Schedules Developed By

Labs21/I2SL Included in ASHRAE 90.1

User’s Manual

section 01

90% 10%

Lab Breakdown

I2SL 2019

Section 02

Concept Systems For Energy Modeling

I2SL 2019

Air Side Systems

section 02

Air Systems Studied

Code Baseline Systems

Combined Lab/Non-Lab System – Cascade Air

Combined System with Supplemental Cooling

Combined System with Supplemental Cooling & Heat Pipe Recovery

Combined System With Enthalpy Recovery, Separate FH Exhaust

Separate Lab Office Systems Enthalpy Recovery, Separate FH Exhaust

Combined System With Heat Pipe Recovery Manifold GE and FH Exhaust

Office System With Enthalpy Recovery, Lab System with Heat Pipe

Office System With Heat Pipe, Labs with Glycol Recovery

Combined Lab/Non-Lab System With Heat Pipe – 100% OA Owner Request

Combined System with FCU Cooling All Lab/Lab Support & Heat Pipe Recovery

Combined System With CHB/FCU Cooling Labs Only and Heat Pipe

Combined System With Supplemental Cooling Lab Support Only and Heat Pipe Labs 21 BPG

I2SL 2019

ASHRAE 90.1 Baseline Air Systems

ASHRAE Baseline Based on

Building Size/Floors

Return Air

VFD

VFD

Outside

Air

Econo.

Relief

C

PH

VFD

CRH

C

C

General

Exhaust

General

Exhaust

Office/Conference/Non-Lab Spaces

Air Handling Unit

CRH

Ventilation Air Relief

Determine ASHRAE 90.1

Appendix G Baseline

VFD

Outside

Air

C

PH

VFD

CRH

C

C

General

Exhaust

General

Exhaust

100% OA Air Handling Unit

CRH

100% OA

Spaces

Separate ASHRAE Baseline 100%

OA System – Typical for Vivarium

& Human Anatomy

General

Exhaust

Return Air

VFD

VFD

Outside

Air

Econo.

Relief

C

PH

VFD

CRH

C

C

General

Exhaust

Fume Hood

Exhaust

General

Exhaust

Laboratories

Air Handling Unit

Difference Between

Cooling Supply and

Required Exhaust – For

Baseline Energy

Modeling Purposes Only

CRH

Combined Code

Ventilation/Fume Hood/

General Exhaust

Separate Baseline Laboratory

System – ASHRAE Appendix G

S = 340,300 cfm

E = 112,350 cfm

R = 227,950 cfm

S = 390,010 cfm

E = 246,990 cfm

R = 143,020 cfm

Vivarium

S = 125,000 cfm

E = 125,000 cfm

Anatomy

S = 50,500

E = 50,500

section 02

I2SL 2019

Proposed Air Systems

Proposed System – Supplemental Cooling

section 02

Supply Air

Return Air

CRH

VFD

VFD

Outside

Air

Econo.

Relief

C

PH

VFD

CRHCRH CRH CRH

C

C

General

Exhaust

Fume Hood

Exhaust

General

Exhaust

Low Load Labs All Air Labs High Load Labs

Fan Coil Unit

Offices All Air High

Occupancy

(Conference/

Classroom/

Auditorium)

Chilled Beam Chilled Beam

Office Air Handling Unit

System

C

C

Combined Code


General Exhaust

VFD

Outside

Air

C

PH

C

C

Lab Air Handling Unit System S = 320,570 cfm

E = 112,350 cfm

R = 208,220 cfm

S = 249,800 cfm

E = 249,800 cfm

R = 0 cfm

FCU = 108,000 cfm

I2SL 2019


Proposed System – Combined Lab/Office Supplemental Cooling

Supply Air

Return Air

CRH

VFD

VFD

Outside

Air

Econo.

Relief

C

PH

VFD

CRHCRH CRH CRH

C

C

General

Exhaust

Fume Hood

Exhaust

General

Exhaust


Fan Coil Unit


Occupancy

(Conference/

Classroom/

Auditorium)

Chilled Beam Chilled Beam

Manifold Air Handling Unit System

C

C

Combined Code


General Exhaust

S = 570,320 cfm

E = 359,335 cfm

R = 210,985 cfm

FCU = 108,000 cfm

section 02

I2SL 2019


Proposed System – Combined, Sup. Clg, Separate FH, Enthalpy Wheel

S = 570,320 cfm

GE = 305,565 cfm

FH = 53,770 cfm

R = 210,985 cfm

FCU = 108,000 cfm

section 02

Return Air

Fume Hood

Exhaust

VFD

VFD

Outside

Air

Econo.

Relief

C

PH

VFD

VFD

C

C

General

Exhaust

Fume Hood

Exhaust

General

Exhaust

Manifold Air Handling Unit System

C

HR

CHR

Enthalpy

Wheel

Supply Air

CRHCRHCRH CRH CRH


Fan Coil Unit


Occupancy

(Conference/

Classroom/

Auditorium)

Chilled Beam Chilled BeamC

C

I2SL 2019


Return Air

VFD

VFD

Outside

Air

Econo.

Relief

C

PH

VFD

CRH

C

C

General

Exhaust

Fume Hood

Exhaust

General

Exhaust

Laboratories

Air Handling Unit

Difference Between Cooling Supply

and Ventilation Relief

CRH

Combined Code


General Exhaust

Office/ Conference/

Non-Lab Spaces

C

HRHeat Pipe

CRH

High Load Labs

Fan Coil Unit

C

C

General

Exhaust

Proposed System – Combined System Heat Pipe Recovery

S = 642,000 cfm

GE = 410,400 cfm

R = 230,720 cfm

FCU = 108,000 cfm

section 02

I2SL 2019

Additional Data for Energy Model

Code Baseline Fan Power Allowance (Peak kW/cfm)

Proposed System Fan Power Estimate – Each System (Peak kW/cfm)

section 02

I2SL 2019

Heating/Cooling Plants Modeled

Plant Options Studied

Code Baseline Systems

High Efficiency Chillers, Code Efficiency Boilers

High Efficiency Chillers, Separate Supplemental Cooling Loop, Standard Boilers

High Efficiency Chillers, Low Temperature Reheat Loop with Heat Shift Chiller,

Standard Boilers

High Efficiency Chillers, Low Temperature Reheat Loop with Heat Shift Chiller,

High Efficiency Condensing Boilers

High Efficiency Chillers, Low Temperature Reheat Loop, Heat Shift Chiller

Serving Only Limited Supplemental Cooling, High Efficiency Condensing Boilers

High Efficiency Chillers, Heat Shift Chiller Serving Only Limited Supplemental

Cooling, Standard Boilers

section 02

I2SL 2019

Baseline Plant Systems for Comparison

section 02

C

RH

C

PH

C

PH

C

PH

Base Building, Lab

Anatomy & Vivarium

Preheat Coils

Re

heat C

oils

C

RH

C

RH

C

C

C

C

C

C

Base Building, Lab,

Anatomy & Vivarium

Cooling Coils

Cooling

Tower

C

C

Sup

ple

menta

l

Co

olin

g C

oils

CONDENSER

EVAPORATOR

C

C

C

C

CONDENSER

EVAPORATOR

C

PH

Perimeter

Heat

Perimeter

Heat

Perimeter

Heat

C

C

Free Cooling Heat

Exchanger

BO

ILE

R

BO

ILE

R

ASHRAE 90.1

Appendix G –

Baseline Plants

I2SL 2019

Proposed Plant Systems

Proposed Plants

section 02

CONDENSER

EVAPORATOR

Heat Shift

Chiller

C

RH

C

PH

C

PH

C

PH

Base Building, Lab

Anatomy & Vivarium

Preheat Coils

Reh

ea

t C

oils

C

RH

C

RH

C

C

C

C

C

C

Base Building, Lab,

Anatomy & Vivarium

Cooling Coils

Cooling

Tower

C

C

Su

pp

lem

en

tal

Coo

ling

Co

ils

CONDENSER

EVAPORATOR

C

C

C

C

CONDENSER

EVAPORATOR

C

PH

Perimeter

Heat

Perimeter

Heat

Perimeter

Heat

C

C

Free Cooling Heat

Exchanger

BO

ILE

R

BO

ILE

R

Sep

ara

te L

ow

Te

mp

era

ture

Reh

eat

Lo

op

Hig

he

r T

em

pe

ratu

re P

eri

mete

r &

Pre

he

at

Lo

op

I2SL 2019

Design Data for Each Plant Option

Plant Data Required Code Baseline Proposed System

Chiller Capacity 3,800 tons 3,800 tons

Chiller COP/IPLV 6.10/6.40 5.47/7.68

CHW Prim Pump Flow/Power 7,600 gpm/7.7 watts/gpm 6,080 gpm/20.3 watts/gpm

CHW Sec Pump Flow/Power 7,600 gpm/14.3 watts/gpm 5,600 gpm/19.0 watts/gpm

Condenser Pump Flow/Power 11,400 gpm/19.0 watts/gpm 7,600 gpm/28.3 watts/gpm

Cooling Tower Power 38.2 gpm/ Fan HP 38.2 gpm/ Fan HP

Boiler Capacity 46,630 MBH 46,630 MBH

Boiler Efficiency 80% 90%

HW Prim Pump Flow/Power 1,865 gpm/19 watts/gpm 4,660 gpm/15.79 watts/gpm

HW Sec Pump Flow/Power N/A 4,660 gpm/23.2 watts/gpm

Heat Shift Chiller Capacity N/A 140 tons

CHW Pump Flow/Power N/A 670 gpm/29.0 w/gpm

HW Pump Flow/Power N/A 420 gpm/11.6 w/gpm

section 02

I2SL 2019

Section 03

Modeling Results

I2SL 2019

Concept Phase Modeling for System Selection

section 03

Atelier Ten

I2SL 2019

Final Design Energy Model

0.00

50.00

100.00

150.00

200.00

250.00

Baseline (kBTU/GSF-yr) Proposed (kBTU/GSF-yr)

LEED Model Results

Lights Exterior Lights Misc. Equipment Space Heating Space Cooling

Heat Rejection Pumps & Aux Ventilation & Fans Domestic Hot Water

Final LEED Model Results: 40% Energy Reduction vs. Concept 31%

EUI=140 kBTU/GSF-yr

section 03

EUI=233 kBTU/GSF-yr

I2SL 2019

Section 04

Actual Energy Use Case Study

Jacobs School of Medicine & Biomedical Sciences

HOK HOK

I2SL 2019

Actual vs. Model Energy Performance

section 04

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

1 2 3 4 5 6 7 8 9 10 11 12

Electric (kWh)

Model Actual ASHRAE Baseline

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

1 2 3 4 5 6 7 8 9 10 11 12

Gas (Therm)

Model Actual ASHRAE Baseline

ASHRAE 90.1 Baseline:

EUI = 233 kBTU/gsf-yr

Proposed System:


Actual 2018 Performance:


Model vs. Proposed

Difference: 4.3%

I2SL 2019

RESULTS

section 04

I2SL 2019

Section 05

Takeaways

I2SL 2019

Takeaways

section 05

• Defining program criteria for energy modeling is critical to

making informed decisions based on energy model results.

• Preliminary engineering is required to define energy model

inputs.

• Use of operational diversity profiles from I2SL/Labs21 in

conjunction with defined program criteria is recommended.

• Energy modeling consistent with intended system operation

can provide results similar to actual building usage.

I2SL 2019

Questions??

Questions???

session h2: successful use of energy modeling to inform design

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