Technical Report

NREL/TP-550-46314

March 2010

Technical Support Document: 

Development of the Advanced 

Energy Design Guide for Small 

Hospitals and Healthcare 

Facilities—30% Guide

Eric Bonnema, Ian Doebber, 

Shanti Pless, and Paul Torcellini
National Renewable Energy Laboratory

1617 Cole Boulevard, Golden, Colorado 80401-3393

303-275-3000 • www.nrel.gov

NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency and Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

Contract No. DE-AC36-08-GO28308

Technical Report

NREL/TP-550-46314

March 2010

Technical Support Document: 

Development of the Advanced 

Energy Design Guide for Small 

Hospitals and Healthcare 

Facilities—30% Guide

Eric Bonnema, Ian Doebber, 

Shanti Pless, Paul Torcellini

Prepared under Task No. BEC7.4001
NOTICE

This report was prepared as an account of work sponsored by an agency of the United States government. 

Neither the United States government nor any agency thereof, nor any of their employees, makes any 

warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or 

usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not 

infringe privately owned rights. Reference herein to any specific commercial product, process, or service by 

trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, 

recommendation, or favoring by the United States government or any agency thereof. The views and 

opinions of authors expressed herein do not necessarily state or reflect those of the United States 

government or any agency thereof.

Available electronically at http://www.osti.gov/bridge

Available for a processing fee to U.S. Department of Energy

and its contractors, in paper, from:

U.S. Department of Energy

Office of Scientific and Technical Information

P.O. Box 62

Oak Ridge, TN 37831-0062

phone: 865.576.8401

fax: 865.576.5728

email: mailto:reports@adonis.osti.gov

Available for sale to the public, in paper, from:

U.S. Department of Commerce

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22161

phone: 800.553.6847

fax: 703.605.6900

email: orders@ntis.fedworld.gov

online ordering: http://www.ntis.gov/ordering.htm

Printed on paper containing at least 50% wastepaper, including 20% postconsumer waste
iii

Acknowledgments

The authors would like to thank the U.S. Department of Energy (DOE) Office of Building 

Technologies, and Drury Crawley, Technology Development Manager for Commercial 

Buildings. We would also like to thank Pat Ledonne of the DOE Building Technologies

Program. This document was prepared by the National Renewable Energy Laboratory (NREL) 

Center for Electricity, Resources, and Building Systems Integration in the Commercial Building 

Statement of Work.

The authors would like to thank all the members of the Advanced Energy Design Guide (AEDG) 

project committee (PC) for their valuable input and willingness to share their expertise. Much 

work went into producing the lighting and daylighting recommendations; many types of heating, 

ventilation, and air-conditioning (HVAC) systems; and envelope considerations. Without the 

committee’s expertise and differing views and the support of the members’ employers, this 

document would not have been possible.

All the energy modeling analysis was based on two prototype facilities: a community hospital 

and a surgery center. The authors would like to thank the Community Hospital of Bremen, 

Indiana, and the architect The Troyer Group of Mishawaka, Indiana, as well as Cogdell Spencer 

ERDMAN of Middleton, Wisconsin, for providing the facility descriptions and energy use 

information to develop detailed energy models.

Additional thanks to Adam Hirsch, Feitau Kung, and Chad Lobato (all of NREL) who helped to 

edit and review the document. Finally, the authors greatly appreciate the assistance of Brent 

Griffith, Kyle Benne, Dan Macumber, Nicholas Long, and the rest of the NREL EnergyPlus 

analysis and modeling team. Their simulation development and support allowed us to evaluate 

the many variations of energy efficiency technologies.
iv

Executive Summary

Background

This Technical Support Document (TSD) describes the process and methodology for the 

development of the Advanced Energy Design Guide for Small Hospitals and Healthcare

Facilities (SHC-AEDG), which is intended to provide recommendations for achieving 30% 

whole-building energy savings in small hospitals and healthcare facilities over levels achieved by 

following the ANSI/ASHRAE/IESNA Standard 90.1-1999, Energy Standard for Buildings 

Except Low-Rise Residential Buildings. The SHC-AEDG was developed in collaboration with 

the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the 

American Institute of Architects (AIA), the American Society for Healthcare Engineering 

(ASHE), the Illuminating Engineering Society of North America (IESNA), the U.S. Green 

Building Council (USGBC), and DOE.

The 30% energy savings target is the first step toward achieving net-zero energy small hospitals 

and healthcare facilities. Net-zero energy facilities are buildings that draw from outside sources 

less or equal energy than they generate on site from renewable energy sources during a given 

year. Previous guides in this series include the Advanced Energy Design Guide for K-12 

Schools, Advanced Energy Design Guide for Small Office Buildings, the Advanced Energy 

Design Guide for Small Retail Buildings, and the Advanced Energy Design Guide for Small 

Warehouses and Self-Storage Buildings. Each provides user-friendly design assistance and 

recommendations to design, architectural, and engineering firms to achieve energy savings. The 

SHC-AEDG includes prescriptive recommendations by climate zone for designing the building 

envelope, fenestration lighting systems (including electrical lights and daylighting), HVAC 

systems, building automation and controls, outdoor air (OA) treatment, and service water heating

(SWH). Additional savings recommendations are also included, but are not necessary for 30%

savings. These are provided for exterior lighting; electricity distribution; plug, process, and 

phantom loads; renewable energy systems; combined heat and power; alternative HVAC 

systems; and other hot water systems. The SHC-AEDG contains recommendations only and is 

not a code or standard.

Our objectives in developing the 30% SHC-AEDG included:

• Document the process and schedule we used to develop the Guide.

• Develop baseline and low-energy EnergyPlus small hospital and healthcare facility 

models.

• Document the EnergyPlus modeling assumptions needed to verify 30% energy savings.

• Present the recommendations for 30% savings over ASHRAE 90.1-1999 for use in the 

SHC-AEDG.

• Present the recommendations for 30% savings over ASHRAE 90.1-2004.

• Demonstrate that the recommendations result in 30% or greater energy savings by 

climate zone.

Development Process

The SHC-AEDG was developed by a PC that represents a diverse group of professionals. 

Guidance and support were provided through collaboration between ASHRAE, AIA, ASHE,
v

IESNA, USGBC, and DOE. PC members came from these partner organizations, the ASHRAE 

Standing Standards Project Committee 90.1, and the ASHRAE Technical Committee on 

Healthcare Facilities. A steering committee (SC) made up of representatives of ASHRAE, AIA, 

IESNA, USGBC, and DOE issued a charge to the PC to develop the Guide. The charge included 

a timeline for the task, an energy savings goal, an intended target audience, space types to 

include, and desired design assistance characteristics.

The PC followed SC guidance to develop a one-year plan for completing the document. Key 

milestones were determined based on a final publication date such that it would be ready for the 

ASHRAE Winter Meeting in January 2010. The PC used a schedule similar to those developed 

for the previous guides to plan for two peer review periods that corresponded with a 65% 

completion draft (technical refinement review) and a 90% completion draft (final review for 

errors). A focus group reviewed the conceptual 35% draft. Six PC meetings were held at 

ASHRAE headquarters, at NREL, or at a PC member’s office building. Three conference calls 

with the full PC were also held.

Advanced Energy Design Guide Scope

This Guide applies to healthcare facilities up to 90,000 ft2 (8,360 m2

The small healthcare facilities included in the Guide are defined as:

), including acute care, 

outpatient surgical, and small critical access and inpatient community hospitals. These facilities 

typically include some or all of the following space types: patient rooms, surgery, emergency 

department, radiology, administration, dining and food preparation, postanesthesia care unit, and 

recovery, to name a few. The primary focus of this Guide is new construction, but 

recommendations may be applicable to facilities undergoing total renovation; and in part to 

many other healthcare renovation, addition, remodeling, and modernization projects (including 

changes to one or more systems in existing buildings).

• Small acute care hospitals

• Small inpatient community hospitals

• Critical access hospitals with 25 or fewer beds

• Outpatient surgical facilities

• Freestanding birthing centers (similar to outpatient surgical centers)

• Gastrointestinal endoscopy facilities (similar to outpatient surgical centers)

• Renal dialysis centers (similar to medical office buildings)

• Primary care outpatient centers

• Small primary (neighborhood) outpatient facilities

• Freestanding outpatient diagnostic and treatment facilities

• Freestanding urgent care facilities

• Medical office buildings (larger than 20,000 ft2 [1,860 m2

The Guide does not include all the components listed in Standard 90.1-1999. It focuses only on 

the primary energy systems within a building, so the underlying energy analysis presumes that 

all the other components are built according to the criteria in Standards 90.1 and ASHRAE 

Standard 170.

]).

Certain aspects of energy-efficient design, including steam heat, vehicle and other maintenance 

areas, and sewage disposal, are excluded. Significant energy efficiency opportunities may be 
vi

available in these areas; readers are encouraged to take advantage of these opportunities and treat 

them as “bonuses” beyond the 30% target.

The Guide is also not intended to substitute for rating systems or references that address the full 

range of sustainable issues in healthcare design, such as acoustics, productivity, indoor air 

quality, water efficiency, landscaping, and transportation, except as they relate to energy use. 

Nor is it a design text. The Guide assumes good design skills and expertise in healthcare and 

hospital design.

Guide Layout and Content

The introduction of the Guide contains information about its goal and scope as well as 

instructions for its use. The next section provides resources for those who want to understand 

and adopt an overall, integrated process for designing, constructing, and operating energyefficient small hospitals and healthcare facilities. The Guide presents an integrated process for 

achieving energy savings in these facilities and is valuable for designers and builders who want 

to augment and improve their practices so energy efficiency is deliberately considered at each 

stage of the development process from project conception through building operation. This 

section concludes by addressing the details of an integrated design process. It discusses the 

benefits and features of integrated design, specifics about the process, and step-by-step details 

about the four phases of the process: predesign, design, construction, and acceptance/occupancy/

operation.

The third section contains the climate-specific recommendation tables, a unique set of energy 

efficiency recommendations for each of the eight DOE climate zones in the United States. 

Efficiency recommendations are organized by several categories: envelope, electric lighting, 

daylighting, HVAC, and SWH. The recommendations are simply one path to reach the 30% 

energy savings target over ANSI/ASHRAE/IESNA Standard 90.1-1999. Other approaches may 

also save energy, but identifying all possible solutions is not in the scope of this Guide; 

assurance of the savings from other approaches is left to the user. To achieve 30% energy 

savings, this Guide assumes compliance with the more stringent of either the applicable edition 

of Standard 90.1 or the local code requirements in all areas not addressed in the climate-specific 

recommendation tables. Future editions of energy codes may have more stringent values. In 

these cases, the more stringent values are recommended.

The fourth section presents seven detailed case studies that illustrate techniques and methods 

discussed in the Guide. Energy numbers are provided to benchmark these buildings against 

future buildings. All these case studies use some of the recommendations in the tables, but 

predate the publication of the Guide and were not developed explicitly using those tables. 

Readers are encouraged to view more case studies at www.ashrae.org/aedg, and to submit their 

own. Case studies provide the motivation and the examples for others to follow.

The final section provides guidance about good practices for implementing the 

recommendations, as well as cautions to avoid known problems in energy-efficient construction. 

The section is divided into quality assurance and commissioning, envelope, lighting, daylighting, 

HVAC, SWH, and bonus savings. The bonus savings section includes areas for additional good 

practice items that, if implemented properly, should achieve savings beyond the 30% level.

The quality assurance and commissioning subsection contains specific details about 

commissioning and its importance in every step of the design process. The envelope section 

contains climate zone-specific information about explicit types of walls, roofs, floors, doors, 
vii

insulation, infiltration, and vertical fenestration. The lighting section details best practices for 

interior finishes, specific lamp and ballast types, lighting layouts, and control strategies for 

specific space types. The daylighting section provides tips on general principles, using 

daylighting analysis tools, daylighting space types and layouts, building shape and orientation 

with respect to daylighting, window-to-wall ratios, sidelighting, toplighting, skylight 

construction, shading devices, photosensor specification, and photocell placement.

The HVAC section includes best practices for multiple-zone VAV air-handling systems, watersource (including ground-source) heat pumps, dedicated OA systems, HVAC load calculations, 

equipment efficiencies, economizers, exhaust air energy recovery, ductwork design, duct 

insulation, duct sealing, exhaust air systems, system-level control strategies, filters, chilled water 

systems, heating water systems, and zone-level controls.

The bonus savings section includes good practices for lighting (exterior lighting, lamp types), 

process loads (medical equipment, high-performance kitchen and laundry equipment), renewable 

energy (photovoltaic and solar hot water systems, wind turbines), combined heat and power, 

additional HVAC systems (condenser water heat recovery, ground-source heat pumps, 

displacement ventilation, demand-controlled ventilation, thermal storage, desiccant-based 

dehumidification, evaporative condensing), and electrical distribution systems (transformer 

efficiencies, metering).

Evaluation Approach and Results

The purpose of our building energy simulation analysis is to assess and quantify the energy 

savings potential of our recommendations. The AEDG contains a set of energy efficiency 

recommendations for eight climate zones across the country. To provide prescriptive 30% 

recommendations, a specific quantitative energy savings goal must be measured against Standard 

90.1-1999, the “turn of the millennium” standard for each climate zone. The energy savings of 

the prescriptive recommendations are also determined against ASHRAE 90.1-2004. The Guide

contains a set of energy efficiency recommendations for each of the eight climate zones across 

the United States. The following steps describe how the energy savings potential of the Guide’s 

recommendations was determined:

1. Develop “typical” small hospital and small healthcare facility prototype

For building characteristics that are not specified by ASHRAE 90.1-1999, ASHRAE 90.1-2004, 

or ASHRAE 62, but that are needed to develop code-compliant baseline models, the PC chose 

two recently constructed buildings as references for prototypes: a community hospital and a 

surgery center. From these two buildings, a prototype small hospital and a prototype small 

surgery facility were developed (see Table ES-1).
viii

Table ES-1 SHC-AEDG Prototype Characteristics

Building Characteristic SHC-AEDG Prototype

Building type Community hospital Surgery center

Size 65,000 ft 41,000 ft 2

Number of floors

2

1 3

Number of occupants 675 414

Space types See Table 4-1 See Table 4-1

Constructions Steel-frame walls

Roof with insulation entirely above deck

Steel-frame walls

Roof with insulation entirely above deck

Window area 26% window-to-wall ratio 20% window-to-wall ratio

Occupancy Fully occupied during the day

Partially occupied at night

Fully occupied during the day

Vacant at night

Peak plug loads 2.1 W/ft 1.8 W/ft 2

Percent conditioned

2

Fully heated and cooled Fully heated and cooled

HVAC system types

Baseline: PVAV* with DX**

Low-energy: PVAV with DX, air-cooled 

chiller, and water-cooled chiller

Baseline: PVAV with DX

Low-energy: PVAV with DX, air-cooled 

chiller, and water-cooled chiller

* PVAV = package multizone direct expansion rooftop unit with variable-air volume

** DX = direct expansion

2. Create baseline models from the prototypes that are minimally code compliant 

for ASHRAE 90.1

The PC documented the baseline small hospital and healthcare facility energy modeling 

assumptions and methods, including the building form and floor plate, envelope characteristics, 

building internal loads and operating schedules, ventilation rates and schedules, HVAC 

equipment efficiency, operation, control and sizing, fan power assumptions, and SWH. The 

baseline models for the small hospital and healthcare facility were developed by applying the 

criteria in ASHRAE 90.1, the 2006 AIA Guidelines for Health Care, and ASHRAE 62 to the 

prototype characteristics. The criteria in these documents were used as the baselines to calculate 

energy savings for the SHC-AEDG recommendations. For the baselines needed to verify 30% 

savings for our DOE analysis, the SHC-AEDG baselines were updated to be minimally code 

compliant with ASHRAE 90.1-2004.

3. Create the low-energy models based on the recommended energy efficiency 

technologies

Our final recommendations were determined based on an iterative process using the PC’s 

expertise and results from modeling the recommendations. To quantify the potential energy 

savings from the final recommended energy efficiency measures (EEMs), we simulated the lowenergy building models by implementing the following energy efficiency technologies and 

documenting the EEMs and EnergyPlus modeling assumptions:

• Enhanced building opaque envelope insulation

• Enhanced window glazing with overhangs

• Reduced lighting power density and occupancy control

• Daylighting in staff areas (exam rooms, nurse stations, offices, corridors) and public 

spaces (waiting, reception)

• Higher efficiency HVAC equipment

• High-efficiency SWH.
ix

4. Verify 30% energy savings across HVAC system types over the 15 U.S. climate 

zones

Energy savings from our final recommendations are documented, along with the 

recommendations for 30% savings over ASHRAE 90.1-1999 and ASHRAE 90.1-2004. For each 

low-energy design, three cooling equipment types were modeled. The low-energy cooling 

equipment types included a packaged rooftop DX system, a packaged rooftop system with a 

central air-cooled chiller, and a packaged rooftop system with a central water-cooled chiller. The 

recommendations in the SHC-AEDG result in more than 30% savings over ASHRAE 90.1-1999 

in all climate zones, ranging from 32% to 45% savings depending on the climate zone. This was 

achieved for each prototype with a range of HVAC system types. Table ES-2 summarizes the 

percent savings for each prototype model in each climate zone.

Table ES-2 Percent Savings Over ASHRAE 90.1-1999

Climate

Zone Representative City

Community Hospital Surgery Center

Packaged

DX

AirCooled

Chiller

WaterCooled

Chiller

Packaged

DX

AirCooled

Chiller

WaterCooled

Chiller

1A Miami, Florida 38% 36% 36% 39% 36% 34%

2A Houston, Texas 40% 39% 38% 39% 38% 36%

2B Phoenix, Arizona 43% 43% 45% 44% 44% 45%

3A Memphis, Tennessee 39% 39% 37% 38% 38% 35%

3B El Paso, Texas 41% 43% 43% 44% 45% 45%

3C San Francisco, California 44% 45% 43% 45% 45% 42%

4A Baltimore, Maryland 40% 41% 39% 38% 39% 36%

4B Albuquerque, New Mexico 42% 44% 44% 44% 45% 45%

4C Seattle, Washington 41% 41% 40% 42% 42% 40%

5A Chicago, Illinois 41% 40% 40% 40% 40% 38%

5B Boise, Idaho 42% 43% 43% 43% 43% 43%

6A Burlington, Vermont 39% 40% 39% 38% 39% 38%

6B Helena, Montana 41% 42% 42% 41% 42% 42%

7A Duluth, Minnesota 39% 39% 39% 37% 37% 36%

8A Fairbanks, Alaska 33% 33% 33% 33% 33% 32%

For comparison of the low-energy models with ASHRAE 90.1-2004 baseline models, the 

recommendations are the same as those that are in the SHC-AEDG. However, 30% savings 

were not achieved for all climate zones over ASHRAE 90.1-2004; energy savings ranged from 

26% to 40%, depending on climate zone. The 2004 baseline models are better energy 

performers than their 1999 counterparts because the 2004 version of the Standard is more 

stringent than the 1999 version. For example, the allowable lighting power density in ASHRAE 

90.1-2004 is lower than that in ASHRAE 90.1-1999, resulting in lower energy use in the baseline 

models. This ultimately results in lower percent savings when the 2004 baseline models are 

compared to the low-energy models created using the SHC-AEDG recommendations.

Table ES-3 summarizes the percent savings for each prototype model in each climate zone (the 

specific model that did not reach 30% savings are indicated in red). The hot-humid climates 

zones (1A, 2A, 3A) and the extremely cold climates (8A) did not reach 30% savings over 

ASHRAE 90.1-2004.
x

Table ES-3 Percent Savings Over ASHRAE 90.1-2004

Climate

Zone Representative City

Community Hospital Surgery Center

Packaged

DX

AirCooled

Chiller

WaterCooled

Chiller

Packaged

DX

AirCooled

Chiller

WaterCooled

Chiller

1A Miami, Florida 33% 30% 30% 31% 28% 26%

2A Houston, Texas 35% 34% 33% 32% 31% 29%

2B Phoenix, Arizona 39% 38% 40% 38% 38% 39%

3A Memphis, Tennessee 34% 34% 32% 31% 32% 28%

3B El Paso, Texas 36% 38% 38% 36% 38% 38%

3C San Francisco, California 40% 40% 38% 39% 39% 36%

4A Baltimore, Maryland 35% 36% 34% 32% 33% 30%

4B Albuquerque, New Mexico 37% 39% 39% 37% 39% 38%

4C Seattle, Washington 36% 37% 35% 36% 36% 34%

5A Chicago, Illinois 36% 36% 35% 35% 34% 32%

5B Boise, Idaho 37% 38% 38% 36% 37% 37%

6A Burlington, Vermont 35% 36% 35% 33% 33% 32%

6B Helena, Montana 36% 37% 37% 34% 36% 35%

7A Duluth, Minnesota 34% 35% 34% 31% 31% 31%

8A Fairbanks, Alaska 29% 30% 29% 27% 28% 27%
xi

The flowchart in Figure ES-1 presents a visual representation of the evaluation approach.

Figure ES-1 Evaluation approach flowchart
xii

Nomenclature

ACH air changes per hour

AEDG Advanced Energy Design Guide

AHU air handling unit

AIA American Institute of Architects

ARI Air-Conditioning and Refrigeration Institute

ASHE American Society for Healthcare Engineering

ASHRAE American Society of Heating, Refrigerating and AirConditioning Engineers

CAV constant air volume

CBECS Commercial Buildings Energy Consumption Survey

CHWS chilled water supply

COP coefficient of performance

CWS condenser water supply

DOE U.S. Department of Energy

DX direct expansion

EA exhaust air

Ec

EEM energy efficiency measure

combustion efficiency

EER energy efficiency ratio

EIR energy input ratio

Et

EF energy factor

thermal efficiency

FSEC Florida Solar Energy Center

HVAC heating, ventilation, and air conditioning

HHW heating hot water

HHWR heating hot water return

HHWS heating hot water supply

IESNA Illuminating Engineering Society of North America

IPLV integrated part-load value

LEED Leadership in Environmental and Energy Design

LPD lighting power density

MLPW mean lumens per watt

NEMA National Electrical Manufacturers Association

NREL National Renewable Energy Laboratory

OA outdoor air

PC project committee

PLF part-load factor

PLR part-load ratio

PVAV A package multi-zone DX rooftop with a VAV

RH relative humidity

SC steering committee

SHGC solar heat gain coefficient

SHC-AEDG Small Hospital and Healthcare Facility Advanced Energy Design 

Guide

SHR sensible heat ratio
xiii

SRI Solar Reflective Index

SWH service water heating

TSD Technical Support Document

USGBC U.S. Green Building Council

VAV variable air volume

VFD variable frequency drive

w.c. water column

WWR window-to-wall ratio
xiv

Contents

Acknowledgments........................................................................................................................................iii

Executive Summary ..................................................................................................................................... iv

Background.............................................................................................................................................. iv

Development Process .............................................................................................................................. iv

Advanced Energy Design Guide Scope.................................................................................................... v

Guide Layout and Content....................................................................................................................... vi

Evaluation Approach and Results...........................................................................................................vii

Nomenclature..............................................................................................................................................xii

1. Introduction .......................................................................................................................................... 1

1.1 Objectives ........................................................................................................................................ 2

1.2 Literature Review............................................................................................................................. 3

1.3 Scope of the SHC-AEDG and Technical Support Document.......................................................... 3

1.4 Report Organization......................................................................................................................... 4

2. Development Process........................................................................................................................... 5

2.1 Charge to the Project Committee..................................................................................................... 5

2.2 Inclusion of Economics and Cost .................................................................................................... 6

2.3 Approval Authority.......................................................................................................................... 6

2.4 Project Committee Organization and Membership.......................................................................... 6

2.5 Development Schedule and Process ................................................................................................ 7

2.6 Focus Group..................................................................................................................................... 9

3. Evaluation Approach.......................................................................................................................... 11

3.1 Determining 30% Savings ............................................................................................................. 11

4. Prototype Model Development Assumptions..................................................................................... 17

4.1 Prototype Model Summary ............................................................................................................ 17

4.2 Prototype Space Type Sizes and Layout........................................................................................ 18

5. Model Details..................................................................................................................................... 27

5.1 Model Development and Assumptions.......................................................................................... 27

5.2 Form and Floor Plate ..................................................................................................................... 28

5.3 Envelope ........................................................................................................................................ 34

5.4 Infiltration ...................................................................................................................................... 36

5.5 Air Flow Rates............................................................................................................................... 36

5.6 Internal Loads................................................................................................................................ 37

5.7 Schedules....................................................................................................................................... 42

5.8 Service Water Heating ................................................................................................................... 59

5.9 Air Handler Assignment ................................................................................................................ 59

6. HVAC Systems and Components...................................................................................................... 61

6.1 Sizing Programs Versus Whole-Building Simulation Programs................................................... 61

6.2 Airside System Type and Sizing.................................................................................................... 62

6.3 Fans................................................................................................................................................ 69

6.4 Pumps............................................................................................................................................. 78

6.5 Economizers................................................................................................................................... 80

6.6 Packaged Direct Expansion Systems............................................................................................. 81

6.7 Air-Cooled Chiller Systems........................................................................................................... 87

6.8 Water-Cooled Chiller Systems ...................................................................................................... 92

6.9 Cooling Tower Systems................................................................................................................. 95

6.10 Boilers........................................................................................................................................ 97

6.11 Service Water Heaters............................................................................................................. 101

6.12 Humidifiers.............................................................................................................................. 102

7. Model Validation.............................................................................................................................. 103
xv

7.1 Air Flow Verification................................................................................................................... 103

7.2 Utility Bill Comparisons.............................................................................................................. 105

8. Evaluation Results............................................................................................................................ 110

8.1 Recommendation Tables for 30% Savings.................................................................................. 110

8.2 Discussion of Recommendations................................................................................................. 121

8.3 Energy Savings Results................................................................................................................ 122

8.4 Bundled Energy Efficiency Measure Analysis............................................................................ 128

9. Conclusion........................................................................................................................................ 131

10. References........................................................................................................................................ 132

Appendix A Project Committee Meeting Agendas ................................................................................. 135

A.1 Meeting #1 Agenda ................................................................................................................. 135

A.2 Conference Call #1 Agenda..................................................................................................... 137

A.3 Meeting #2 Agenda ................................................................................................................. 138

A.4 Focus Group Agenda and Questions....................................................................................... 140

A.5 Meeting #3 Agenda ................................................................................................................. 142

A.6 Meeting #4 Agenda ................................................................................................................. 145

A.7 Meeting #5 Agenda ................................................................................................................. 147

A.8 Meeting #6 Agenda ................................................................................................................. 149

Appendix B Responses to 65% Draft Review Remarks.......................................................................... 151

Appendix C Community Hospital Baseline Scorecards.......................................................................... 155

Appendix D Surgery Center Baseline Scorecard..................................................................................... 164

Appendix E Determining Plug Loads for Small Healthcare Facilities.................................................... 173

Appendix F Energy Savings End Use Tables: ASHRAE 90.1-1999 Baseline ..................................... 177

Appendix G Energy Savings End Use Tables: ASHRAE 90.1-2004 Baseline ..................................... 181

Appendix H Fan Performance Characteristics......................................................................................... 185

H.1 Baseline and Low-Energy Equivalent Fan Summary.............................................................. 185

H.2 NEMA Motor Premium Efficiencies....................................................................................... 190

H.3 Fan Efficiency Charts.............................................................................................................. 191
xvi

Figures

Figure ES-1 Evaluation approach flowchart ............................................................................................. xi

Figure 3-1 Evaluation approach flowchart ............................................................................................ 12

Figure 3-2 DOE climate zones and representative cities....................................................................... 15

Figure 4-1 Community hospital prototype quadrant 1 layout................................................................ 20

Figure 4-2 Community hospital prototype quadrant 2 layout................................................................ 21

Figure 4-3 Community hospital prototype quadrant 3 layout................................................................ 22

Figure 4-4 Community hospital prototype quadrant 4 layout................................................................ 23

Figure 4-5 Surgery center prototype floor 1 layout ............................................................................... 24

Figure 4-6 Surgery center prototype floor 2 layout ............................................................................... 25

Figure 4-7 Surgery center prototype floor 3 layout ............................................................................... 26

Figure 5-1 Community hospital baseline model rendering: View from southwest .............................. 29

Figure 5-2 Surgery center baseline model rendering: View from southwest........................................ 30

Figure 5-3 Community hospital low-energy model rendering: View from southwest ......................... 32

Figure 5-4 Surgery center low-energy model rendering: View from southwest .................................. 33

Figure 5-5 Building lighting schedule ................................................................................................... 44

Figure 5-6 Administrative space set point schedule .............................................................................. 48

Figure 5-7 Critical space and operating room set point schedule .......................................................... 49

Figure 5-8 Building equipment schedule............................................................................................... 51

Figure 5-9 Building occupancy schedule............................................................................................... 53

Figure 5-10 Building SWH schedule....................................................................................................... 55

Figure 5-11 Building terminal box minimum flow fraction schedule ..................................................... 58

Figure 5-12 Community hospital air handling unit (AHU) map ............................................................. 60

Figure 6-1 Psychrometric chart showing space set points and supply air conditions............................ 66

Figure 6-2 Baseline supply fan selection............................................................................................... 73

Figure 6-3 Fan power PLF curves from ASHRAE 90.1-2004 and 0.5 in. w.c. static pressure reset 

curve .................................................................................................................................... 76

Figure 6-4 Transient sensible and latent capacity of a cooling coil over an operating cycle................. 84

Figure 6-5 Field data showing the net impact of part-load operation on SHR ...................................... 85

Figure 6-6 Scroll air-cooled chiller performance map with a constant 44°F CHWS ............................ 90

Figure 6-7 Screw air-cooled chiller performance map with a constant 44°F CHWS............................ 91

Figure 6-8 Screw water-cooled chiller performance map with a constant 44°F CHWS ....................... 94

Figure 6-9 Baseline boiler part load curves........................................................................................... 98

Figure 6-10 Low-energy model HHWS OA reset schedule .................................................................. 100

Figure 6-11 Baseline and low-energy boiler part-load curves............................................................... 101

Figure 7-1 Community hospital with patient room wing highlighted.................................................. 104

Figure 7-2 Community hospital patient room wing close up............................................................... 104

Figure 7-3 Community hospital electrical energy use ......................................................................... 107

Figure 7-4 Community hospital electrical demand.............................................................................. 108

Figure 7-5 Community hospital natural gas energy use ...................................................................... 109

Figure 8-1 Community hospital end uses: ASHRAE 90.1-1999 baseline .......................................... 124

Figure 8-2 Surgery center end uses: ASHRAE 90.1-1999 baseline ................................................... 125

Figure 8-3 Community hospital end uses: ASHRAE 90.1-2004 baseline .......................................... 126

Figure 8-4 Surgery center end uses: ASHRAE 90.1-2004 baseline ................................................... 127

Figure 8-5 Community hospital bundled EEM analysis results for climate zones 1A–8A ................. 129

Figure 8-6 Surgery center bundled EEM analysis results for climate zones 1A–8A........................... 130
xvii

Tables

Table ES-1 SHC-AEDG Prototype Characteristics...............................................................................viii

Table ES-2 Percent Savings Over ASHRAE 90.1-1999..........................................................................ix

Table ES-3 Percent Savings Over ASHRAE 90.1-2004........................................................................... x

Table 2-1 SHC-AEDG Project Committee Member Chart .................................................................... 7

Table 2-2 SHC-AEDG PC Development Schedule................................................................................ 8

Table 2-3 SHC-AEDG Focus Group Participants.................................................................................. 9

Table 4-1 SHC-AEDG Prototype Designs Space Types...................................................................... 17

Table 4-2 SHC-AEDG Prototype Characteristics................................................................................ 18

Table 4-3 Total Space Sizes Included in the AEDG Prototype............................................................ 19

Table 5-1 Selected Baseline Modeling Assumptions........................................................................... 28

Table 5-2 Ventilation and Exhaust Inputs............................................................................................ 37

Table 5-3 Internal Loads by Space Type.............................................................................................. 38

Table 5-4 Area-Weighted Average Internal Loads by Prototype......................................................... 38

Table 5-5 Space-by-Space AEDG LPD Versus ASHRAE 90.1-1999 ................................................. 39

Table 5-6 Whole-Building AEDG LPD Versus ASHRAE 90.1-1999................................................. 39

Table 5-7 Space-by-Space AEDG LPD Versus ASHRAE 90.1-2004 ................................................. 40

Table 5-8 Whole-Building AEDG LPD Versus ASHRAE 90.1-2004................................................. 40

Table 5-9 Space-by-Space AEDG LPD With Occupancy Sensors Versus ASHRAE 90.1-1999........ 41

Table 5-10 Whole-Building AEDG LPD With Occupancy Sensors Versus ASHRAE 90.1-1999........ 41

Table 5-11 Space-by-Space AEDG LPD With Occupancy Sensors Versus ASHRAE 90.1-2004........ 42

Table 5-12 Whole-Building AEDG LPD With Occupancy Sensors Versus ASHRAE 90.1-2004........ 42

Table 5-13 Building Lighting Schedule ................................................................................................. 43

Table 5-14 Building Heating Set Point Schedules ................................................................................. 45

Table 5-15 Building Cooling Set Point Schedules................................................................................. 46

Table 5-16 Operating Room Heating and Cooling Set Point Schedules................................................ 47

Table 5-17 Building Equipment Schedule.............................................................................................. 50

Table 5-18 Building Occupancy Schedule ............................................................................................. 52

Table 5-19 Building SWH Schedule ...................................................................................................... 54

Table 5-20 Infiltration and HVAC Operation Schedules....................................................................... 56

Table 5-21 Building Terminal Box Minimum Flow Fraction Schedule ................................................ 57

Table 6-1 Cooling Set Point and Cooling Supply Air Conditions........................................................ 65

Table 6-2 Heating Set Point and Heating Supply Air Conditions........................................................ 66

Table 6-3 Patient Room Geometry, Envelope Characteristics, and Internal Loads............................. 67

Table 6-4 Patient Room Envelope and Internal Heat Gains................................................................. 68

Table 6-5 Patient Room Envelope and Internal Heat Losses............................................................... 68

Table 6-6 CAV Terminal Unit Size for Example Patient Room.......................................................... 69

Table 6-7 Baseline and Low-Energy Supply Fan Internal Static Pressure Drop Breakdown .............. 70

Table 6-8 Baseline and Low-Energy Return Fan Internal Static Pressure Drop Breakdown............... 70

Table 6-9 Baseline and Low-Energy Supply Fan External Static Pressure Drop Breakdown ............. 70

Table 6-10 Baseline and Low-Energy Return Fan External Static Pressure Drop Breakdown.............. 71

Table 6-11 Baseline and Low-Energy Supply Fan Total Static Pressure Drop Breakdown .................. 71

Table 6-12 Baseline and Low-Energy Return Fan Total Static Pressure Drop Breakdown................... 71

Table 6-13 Baseline and Low-Energy Equivalent Fan Total Static Pressure......................................... 71

Table 6-14 Surgery Center Design Flow Rates...................................................................................... 72

Table 6-15 Baseline and Low-Energy Fan Static Efficiency ................................................................. 73

Table 6-16 Baseline Critical CAV System Supply and Return Fan Performance Characteristics......... 74

Table 6-17 Baseline and Low-Energy Equivalent Fan Total Static Pressure......................................... 75

Table 6-18 Fan Power PLF Curve Coefficients ..................................................................................... 76

Table 6-19 Fan Power Limitation Pressure Drop Adjustment (90.1-2007 Table 6.5.3.1.1B)................ 77
xviii

Table 6-20 ASHRAE 90.1-2007 Versus Baseline and Low-Energy Equivalent Fan Performance ....... 77

Table 6-21 Dedicated Exhaust Fan Baseline and Low-Energy Performance Characteristics................ 78

Table 6-22 Pump Performance Inputs.................................................................................................... 78

Table 6-23 Variable-Speed Pump Power PLF Curve Coefficients........................................................ 78

Table 6-24 HHW Pump Performance Characteristics............................................................................ 79

Table 6-25 Chilled Water Pump Performance Characteristics............................................................... 79

Table 6-26 Condenser Water Pump Performance Characteristics ......................................................... 80

Table 6-27 Domestic Hot Water Pump Performance Characteristics .................................................... 80

Table 6-28 Climates Modeled With Economizers.................................................................................. 81

Table 6-29 Critical CAV and Noncritical VAV Supply Dry Bulb Temperatures.................................. 81

Table 6-30 Packaged DX Rated Conditions Modifier Curves ............................................................... 83

Table 6-31 Packaged System Rated Full-Load Performance ................................................................. 87

Table 6-32 Packaged System Minimum EER and IPLV Performance for ASHRAE 90.1.................... 87

Table 6-33 Operational Characteristics of Air-Cooled Scroll and Screw Chillers................................. 88

Table 6-34 Scroll Air-Cooled Chiller Rated Conditions Modifier Curves............................................. 89

Table 6-35 Scroll Air-Cooled Chiller Performance at ARI Rated Conditions....................................... 89

Table 6-36 Screw Air-Cooled Chiller Performance at ARI Rated Conditions....................................... 90

Table 6-37 Screw Air-Cooled Chiller Rated Conditions Modifier Curves............................................ 91

Table 6-38 Air-Cooled Chiller Minimum EER and IPLV Performance for ASHRAE 90.1 ................. 91

Table 6-39 Size Range and Operational Characteristics Comparison of Water-Cooled Chillers .......... 92

Table 6-40 Screw Water-Cooled Chiller Rated Conditions Modifier Curves........................................ 93

Table 6-41 Screw Water-Cooled Chiller Performance at ARI Rated Conditions.................................. 93

Table 6-42 Water-Cooled Screw or Scroll Chiller Minimum EER and IPLV Performance.................. 94

Table 6-43 Water-Cooled Screw or Scroll Chiller Minimum EER and IPLV Performance for 

ASHRAE 90.1 ..................................................................................................................... 94

Table 6-44 Comparison of Cooling Tower Design and Operational Criteria......................................... 95

Table 6-45 Fan PLF Curve ..................................................................................................................... 97

Table 6-46 Baseline Boiler EnergyPlus Input Performance Curves....................................................... 98

Table 6-47 Baseline and Low-Energy Boiler EnergyPlus Input Performance Curves......................... 101

Table 6-48 Baseline Model Water Heater Characteristics ................................................................... 102

Table 6-49 Stand-Alone AHU Humidifier EnergyPlus Input .............................................................. 102

Table 7-1 AIA Total Air Flow Requirements .................................................................................... 103

Table 7-2 Community Hospital Patient Room Air Flow.................................................................... 105

Table 8-1 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 1–4.. 113

Table 8-2 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 5–8.. 117

Table 8-3 Energy Savings: ASHRAE 90.1-1999 Baseline ............................................................... 122

Table 8-4 Energy Savings: ASHRAE 90.1-2004 Baseline ............................................................... 123

Table 8-5 Energy Savings: Less Than 30% Over ASHRAE 90.1-2004 Baseline............................. 123

Table C-1 Community Hospital Baseline Scorecard: Climate Zones 1A–3B ..................................... 155

Table C-2 Community Hospital Baseline Scorecard: Climate Zones 3C–5A ..................................... 158

Table C-3 Community Hospital Baseline Scorecard: Climate Zones 5B–8A ..................................... 161

Table D-1 Surgery Center Baseline Scorecard: Climate Zones 1A–3B .............................................. 164

Table D-2 Surgery Center Scorecard: Climate Zones 3C–5A............................................................. 167

Table D-2 Surgery Center Baseline Scorecard: Climate Zones 3C–5A (con’t)................................. 168

Table D-3 Supply Center Baseline Scorecard: Climate Zones 5B–8A................................................ 170

Table E-1 Plug Loads for Small Healthcare Facilities.......................................................................... 174

Table F-1 Community Hospital End Uses: Climate Zones 1A–4A................................................... 177

Table F-2 Community Hospital End Uses: Climate Zones 4B–8A................................................... 178

Table F-3 Surgery Center End Uses: Climate Zones 1A–4A............................................................ 179

Table F-4 Surgery Center End Uses: Climate Zones 4B–8A ............................................................ 180

Table G-1 Community Hospital End Uses: Climate Zones 1A–4A................................................... 181
xix

Table G-2 Community Hospital End Uses: Climate Zones 4B–8A................................................... 182

Table G-3 Surgery Center End Uses: Climate Zones 1A–4A............................................................ 183

Table G-4 Surgery Center End Uses: Climate Zones 4B–8A ............................................................ 184
1

1. Introduction

The Advanced Energy Design Guide for Small Hospitals and Healthcare Facilities (SHCAEDG) (called the Guide or SHC-AEDG in this report) was written to help owners, designers, 

and builders of small- to medium-size acute care, outpatient, and inpatient buildings achieve site 

energy savings of at least 30% compared to the minimum requirements of ANSI/ASHRAE/

IESNA Standard 90.1-1999 (ASHRAE 1999), which serves as a baseline. The small healthcare

facilities included in the scope of the Guide are smaller than 90,000 ft2 (8,360 m2

• Small acute care hospitals

) and are 

defined as:

• Small inpatient community hospitals

• Critical access hospitals with 25 or fewer beds

• Outpatient surgical facilities

• Freestanding birthing centers (similar to outpatient surgical centers)

• Gastrointestinal endoscopy facilities (similar to outpatient surgical centers)

• Renal dialysis centers (similar to medical office buildings)

• Primary care outpatient centers

• Small primary (neighborhood) outpatient facilities

• Freestanding outpatient diagnostic and treatment facilities

• Freestanding urgent care facilities

• Medical office buildings (larger than 20,000 ft2 [1,860 m2

The Guide includes recommendations for the design of the building envelope; fenestration; 

lighting systems (including electrical lights and daylighting); heating, ventilation, and airconditioning (HVAC) systems; building automation and controls; outdoor air (OA) treatment; 

and service water heating (SWH). Additional savings recommendations are also included, but 

are not necessary for 30% savings. These are discussed in the bonus savings section and provide 

recommendations for process, plug, and phantom loads; renewable energy systems; alternative 

hot water systems; alternative HVAC systems; and electricity distribution. The Guide contains 

recommendations only and is not a code or standard.

]).

The Guide is intended to show that achieving the 30% target is not only possible, but easily 

achievable. Case studies show small healthcare facilities around the country that have achieved 

and surpassed the 30% energy savings target. Best practices and cautions are also provided to 

demonstrate how to implement the recommendations. The recommendation tables do not 

include all the components listed in ASHRAE 90.1-1999. Though the Guide focuses only on the 

primary energy systems in a building, the underlying energy analysis presumes that all the other 

components are built to the criteria in ASHRAE 90.1 (ASHRAE 2001) and ASHRAE 62.1 

(ASHRAE 2004c).

By specifying a target goal and identifying paths for each climate zone to achieve this goal, the 

Guide provides a way, but not the only way, to meet the 30% target and build small healthcare

facilities that use substantially less energy than those built to minimum energy code 

requirements. There may be other means of achieving the target goal, and we hope that the 

Guide generates ideas for innovation.
2

The 30% energy savings target is the first step toward achieving net-zero energy healthcare

facilities. Net-zero energy facilities are buildings that draw from outside energy sources an 

amount that is less than or equal to the energy that they generate on site from renewable energy 

sources in a given year. Other guides in this series include the Advanced Energy Design Guide 

for Small Office Buildings (ASHRAE 2004a), the Advanced Energy Design Guide for Small 

Retail Buildings (ASHRAE 2006), the Advanced Energy Design Guide for K-12 School 

Buildings (ASHRAE 2008a), the Advanced Energy Design Guide for Small Warehouses and 

Self-Storage Buildings (2008b), and the Advanced Energy Design Guide for Highway Lodging.

The Guide was developed by a project committee (PC) that represents a diverse group of 

professionals. Guidance and support were provided through a collaboration between the 

American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the 

American Institute of Architects (AIA), the Illuminating Engineering Society of North America 

(IESNA), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy 

(DOE). PC members came from these partner organizations, the ASHRAE Standing Standards 

Project Committee 90.1, the ASHRAE Technical Committee on Healthcare Buildings (TC 9.6), 

and the American Society of Healthcare Engineers (ASHE).

1.1 Objectives

Our task in developing the 30% SHC-AEDG was to provide the analysis and modeling support 

to:

• Verify energy savings. The specific prescriptive recommendations that must, in 

aggregate, yield 30% savings beyond a benchmark building built to the Standard 90.1-

1999 for each climate region. The 30% is measured based on the total energy 

consumption, not just the regulated loads. It is not an average of the national energy 

savings. Cities used for testing in the Advanced Energy Design Guide for Small Office 

Buildings were also used for the SHC-AEDG (Jarnagin et al. 2006).

• Develop recommendations that meet a numeric goal value. The energy savings goal is a 

hard value as opposed to an approximate target. The 30% energy savings value was set 

to be as consistent as feasible with Leadership in Environmental and Energy Design 

(LEED) criteria (USGBC, 2006), given that LEED works from a cost basis and this 

document is based on energy savings. As in past AEDGs, this Guide can be used to 

obtain LEED Energy and Atmosphere credits.

• Identify methods to achieve the goal. The goal of the Guide is to save energy by

identifying packages of design measures and strategies combined with selecting state-ofthe-shelf building systems and design concepts (multiple suppliers of a given technology 

or system) that result in efficient and high-quality spaces.

Separate from the Guide, this Technical Support Document (TSD) was written to document the 

process used to develop the 30% SHC-AEDG and the analysis and modeling done to support that 

development. The specific objectives include:

• Document the process and schedule used for developing the Guide.

• Develop prototypical small healthcare facility characteristics.

• Document the EnergyPlus modeling assumptions needed to verify 30% energy savings.

• Develop the baseline and low-energy EnergyPlus small healthcare facility models.
3

• Present the recommendations for 30% savings over ASHRAE 90.1-1999 for use in the 

SHC-AEDG.

• Present the recommendations for 30% savings over ASHRAE 90.1-2004.

• Demonstrate that the recommendations result in 30% or greater energy savings by 

climate zone.

1.2 Literature Review

The first step in developing the 30% SHC-AEDG was to perform a literature review and 

summary of high-performance small hospital and healthcare facility guidelines. To ensure that 

the SHC-AEDG did not duplicate previous work in the relatively mature field of highperformance small healthcare facilities, we performed a literature review of the available design 

guides and rating systems for high-performance small healthcare facilities. Efforts focused on 

compiling a summary of the available high-performance small healthcare facilities guides 

available throughout the country. Based on this review, we concluded that the SHC-AEDG is

unique. None of the documents reviewed include prescriptive design guidance for targeted 

levels of energy savings based on climate. The SHC-AEDG should provide a needed resource 

and complement many available guides and criteria.

In addition to the vast selection of healthcare facility design guides, there are many datasets of 

physical healthcare facility characteristics and energy performance. The currently available data 

sources represent existing building stock as well as annual updates for new building construction. 

We surveyed these datasets to develop “typical” small healthcare facility characteristics and 

energy performance. Typical healthcare facility characteristics helped to inform our 

development of realistic prototypical models for the 30% AEDG analysis. Datasets that we 

evaluated include:

• The Commercial Building Energy Consumption Survey (CBECS) (EIA 2003)

• Additional datasets from the PC, including actual floor plates and space programming 

requirements for a small community hospital and a surgery center

• The DOE Buildings Database (DOE 2004)

• McGraw Hill Dodge construction data (McGraw Hill 2009)

• The Green Guide for Health Care (GGHC 2007)

• The DOE Commercial Buildings Benchmark Project (Torcellini et al. 2008).

1.3 Scope of the SHC-AEDG and Technical Support Document

Each guide in the AEDG series provides recommendations and user-friendly design assistance to 

designers, developers, and owners of commercial buildings that will encourage steady progress 

toward net-zero energy buildings. The SHC-AEDG provides prescriptive recommendation 

packages that can reach the energy savings target for each climate zone and ease the burden of 

designing and constructing energy-efficient small healthcare facilities.

Certain aspects of energy-efficient design, including steam heat, vehicle and other maintenance 

areas, and sewage disposal, are excluded. Significant energy efficiency opportunities may be 

available in these areas; readers are encouraged to take advantage of these opportunities and treat 

them as “bonuses” beyond the 30% target.
4

The Guide is also not intended to substitute for rating systems or references that address the full 

range of sustainable issues in healthcare design, such as acoustics, productivity, indoor air 

quality, water efficiency, landscaping, and transportation, except as they relate to energy use. 

Nor is it a design text. The Guide assumes good design skills and expertise in small hospital and 

healthcare facility design.

The guides in the AEDG series do not provide a detailed documentation for the development of 

the recommendations or the actual energy savings. This TSD describes the process and 

methodology for the development of the SHC-AEDG and provides the technical details for 

determining 30% energy savings, including model inputs and assumptions, the development of 

the 30% recommendations, and the energy savings.

1.4 Report Organization

This report is presented in four sections: Section 1 introduces the SHC-AEDG and the 

supporting background information; Section 2 describes the charge given to the PC for 

developing the Guide and outlines the process and development schedule; Section 3 provides the 

evaluation approach, including baseline and low-energy modeling methods and assumptions; and 

Section 4 documents the final recommendations and energy savings.

Additional information on the PC development process is included in Appendix A. Appendix B

includes the summary responses to the remarks received on the 65% review draft. Appendix C

and Appendix D summarize baseline model inputs. Appendix E summarizes the methodology 

behind determining the plug loads for small healthcare facilities. Appendix F and Appendix G

provide annual energy end use intensities for the primary end uses for the recommendations for 

30% savings over ASHRAE 90.1-1999 and for 30% savings over ASHRAE 90.1-2004. 

Appendix H contains HVAC fan details.
5

2. Development Process

The Guide was developed by a PC that represents a diverse group of professionals. Guidance 

and support were provided through collaboration between ASHRAE, AIA, IESNA, USGBC, and 

DOE. PC members came from these partner organizations, the ASHRAE Standing Standards 

Project Committee 90.1, the ASHRAE Technical Committee on Healthcare Buildings, and 

ASHE.

2.1 Charge to the Project Committee

A steering committee (SC) made up of representatives of the partner organizations issued a 

charge to the PC to develop the Guide. The charge included a timeline for the task, an energy 

savings goal, an intended target audience, and desired design assistance characteristics. These 

elements are listed here:

• Develop and document a process to achieve a savings of 30% progress toward a net-zero 

energy building for small healthcare facilities.

• Produce recommendations in a technically sound SHC-AEDG.

• Publish the Guide within a year.

• Constrain the scope and duration of the analysis effort to maintain the schedule. The PC 

should rely on current knowledge of energy-efficient building design, supplemented with 

energy design analysis that can be completed according to the schedule.

• Produce a document that is concise. Use the K-12 AEDG (ASHRAE 2008) to guide size 

and technical depth; the overall size is expected to be 100 to 200 published pages.

Additional guidance from the SC to the PC was provided in a Scope Document. Elements of the 

Scope Document are listed here:

• The baseline for energy use evaluation is annual site energy consumption.

• Address in a user friendly way the practical information needs of its intended users who 

are designers in medium to large firms, design/build contractors, and construction firms.

• The interaction of building components and systems will likely need to be considered 

rather than having all the savings come from individual parts (savings from integration of 

systems is encouraged). Accommodate, to the extent practical, some level of design 

flexibility through use of packages of energy efficiency measures (EEMs) that users may 

choose from.

• Adopt a prescriptive recommendation approach with packages of measures. This will 

include envelope, mechanical, lighting, and water heating measures. The document will 

be formatted for easy use, provide specific procedures, convey best practices, and avoid 

code language. The apparent complexity of the typical standard/guideline layout and 

format should be avoided to ease usability by the target audience.

• In addition to prescriptive EEMs, the Guide should contain “how to” guidance that will 

help the designer construct an energy-efficient small healthcare facility. In recognition of 

the constrained design fees available, the document should be presented in a very userfriendly manner to reduce design time. By focusing on user-friendly layouts and 

presentation as well as prescriptive design recommendations, the Guide should ease the 
6

burden for the designers and give small healthcare facility decision makers an overview 

of specific, easy-to-follow recommendations.

• The prescriptive recommendations presented should be sufficient to allow innovative 

firms to extend the design information that might be evaluated on performance-based 

criteria. That is, some additional allowance or flexibility should be provided for those 

accustomed to performance-based documents.

• Several case studies should be included to illustrate the energy efficiency components 

identified. These case studies can focus on the geographic regions (as in the K-12 

AEDG) or to illustrate particular items or techniques recommended.

2.2 Inclusion of Economics and Cost

The guidance provided in the SHC-AEDG should help designers design energy-efficient small 

healthcare facilities. The goal of 30% energy savings is to be considered its primary focus; i.e., 

the focus is on high-performance buildings and the energy savings related thereto, not on 

installations that have a payback less than some given number of years. Cost and payback are 

factors, but they are secondary to achieving buildings that use 30% less energy.

Therefore, energy use is to be considered the independent variable that is specified, and cost 

effectiveness (as measured by, for example, simple payback period) is the dependent (or 

resulting) variable. Although some of the products or recommendations may be considered 

premium, products of similar performance must be available from multiple manufacturers.

2.3 Approval Authority

The final approval for the Guide is the responsibility of the SC. SC members represent various 

interested parties and are responsible for reflecting the opinions of the group represented. This 

includes consulting with the groups, getting buy-in from them during the entire process, and 

providing the peer review. Efforts should be made to agree on the content, as was done, for 

example, for the ASHRAE Handbook: Fundamentals (ASHRAE 2009b); however, the Guide is 

not a consensus document.

2.4 Project Committee Organization and Membership

The Guide was developed by a PC administered under ASHRAE’s Special Project procedures. 

The SHC-AEDG PC was designated as ASHRAE Special Project 127 (SP-127), and included 

membership from each partner organization. Table 2-1 lists the PC members and their PC 

function.

The SC selected PC members with energy efficiency experience in small healthcare facilities. 

Each representative organization was given the chance to provide peer review input on the 

review drafts. In effect, these representatives were intended to be the interfaces to their 

respective organizations to ensure a large body of input into the development of the document.
7

Table 2-1 SHC-AEDG Project Committee Member Chart

Member PC Function

Shanti Pless Chairman

Merle McBride Vice-Chairman

Don Colliver SC Liaison

Walt Vernon USGBC Representative

John Gill IESNA Representative

Tom Myers IESNA Representative

Bernard Cole AIA Representative

Jeff Boldt ASHRAE Representative

John Murphy ASHRAE HVAC Representative

Dennis Wessel ASHRAE Technical Committee on Healthcare Buildings Representative

Michael Meteyer Member at Large

Bruce Hunn ASHRAE Staff Liaison

Lilas Pratt ASHRAE Staff Liaison

Ian Doebber Model Support (nonvoting consultant)

Eric Bonnema Model Support(nonvoting consultant)

2.5 Development Schedule and Process

Following the guidance from the SC, the SP-127 committee developed a one-year plan for 

completing the document. Key milestones were determined based on a final publication date in 

December 2009 (ready for the ASHRAE Winter Meeting in January 2010). The PC determined 

the time needed for the publication process and then determined the dates of review periods for 

the various completion stages for the draft document. The PC used a schedule similar to those

developed for the previous guides to plan for two peer review periods that corresponded with a 

65% completion draft (technical refinement review) and a 90% completion draft (final review for 

errors). A focus group reviewed the conceptual draft. Six PC meetings were held at ASHRAE 

Headquarters, at NREL, or at the office of a PC member. Three conference calls were also held. 

The schedule shown Table 2-2 outlines key dates in the development of the SHC-AEDG.
8

Table 2-2 SHC-AEDG PC Development Schedule

Date Event Description

September 4–5, 2008 Kick-off/PC meeting #1 Kick-off introduction meeting, first PC meeting

October 15, 2008 Conference call #1 Conference call to discuss concept draft

October 29–30, 2008 PC meeting #2 Discuss baseline modeling assumptions

December 10–11, 2008 PC meeting #3 Discuss progress of 65% draft

January 5, 2009 65% draft complete 65% draft complete

January 5–16, 2009 65% draft review 65% draft review

February 11–12, 2009 PC meeting #4 Review simulation results, address 65% 

review remarks

March 3, 2009 Conference Call #2 Review modeling results

April 27–28, 2009 PC meeting #5 Further develop 90% draft, finalize responses 

for 65% review remarks

May 11, 2009 90% draft complete 90% draft complete

May 11–29, 2009 90% draft review 90% draft review

June 4–5, 2009 PC meeting #6 Address 90% review remarks, finalize draft 

for 100%

July 8, 2009 Conference call #3 Finalize modeling results

August 21, 2009 SC approval Steering committee approval

August 14, 2009 Final 100% document to publications Final 100% document to publications

October 22, 2009 Document to printers Document to printers

November 10, 2009 Printed document complete Printed document complete

The development of the prototype, baseline, and low-energy models was an iterative process, 

with discussion of the model inputs and the current model results at every meeting and 

conference call. Results from the modeling, combined with input from the PC, led to the 

development of the final recommendations. The following steps show the modeling process 

used, from the initial prototype development to the final recommendations:

• Determine prototype models inputs from the PC, ASHRAE 90.1-1999 (ASHRAE 1999), 

ASHRAE 62 (ASHRAE 2001), and AIA 2006.

• Present preliminary baseline results for the prototype surgery center.

• Develop a consensus from the PC on the prototype model inputs.

• Develop initial recommendations and the corresponding low-energy models, including 

daylighting types, HVAC systems, and envelope recommendations.

• Present the low-energy modeling results and identify recommendations that do not result 

in 30% energy savings.

• Fine tune the recommendations to achieve at least 30% whole-building energy savings in 

all climate zones for the various HVAC options and building types.

• Determine final recommendations for the SHC-AEDG that achieve 30% savings.

The following sections of this TSD present the prototype development results from Step 3, the 

baseline model results from Step 4, and the final recommendations and energy savings results as 

determined in Step 8.

Because the document was developed under the ASHRAE special project procedures, and not 

the standards development procedures, the peer reviews were not considered true “public” 

reviews. However, review copies were made available to all partner organizations, and to the 

various bodies within ASHRAE represented by the PC membership. Interested members may 
9

download review copies from the ASHRAE Web site (www.ashrae.org). The responses to the 

remarks and suggestions received from the 65% review draft are summarized in Appendix B.

Further information about each meeting and conference call are included in the meeting agendas 

and conference call agendas (see Appendix A). These agendas were updated after each meeting 

or call to reflect the discussions and length of time spent on each item. After each conference 

call and meeting, the meeting notes, agenda, action items, future schedules, and other related 

documents were compiled into a meeting report. These were very useful for reference and 

organizational purposes during the development of the Guide.

2.6 Focus Group

To evaluate the concept of the SHC-AEDG, ASHRAE convened a focus group (see Table 2-3) 

of small healthcare facility administrators, designers, and energy management staff to review the 

conceptual draft. The focus group was brought to ASHRAE headquarters to discuss the concept 

of the SHC-AEDG.

Table 2-3 SHC-AEDG Focus Group Participants

Member Organization

Michael Harris Burrell Group

Tim Dudte Health Facilities Group

Ted Blosser Midwest Engineering Inc.

Jeff Blackwood Healthsouth

Wayne Carr Surgical Care Affiliates

David Lennon Nash Lipsey Burch, LLC

Before the meeting, the participants reviewed the concept draft, the scoping document, and 

examples of the recommendation tables and case studies from the previous guides. The 

questions asked of the focus group to stimulate discussion and solicit feedback are shown in

Appendix A.4. The highlights of the focus group feedback are shown below.

• Consider first cost compared to life cycle cost (need to make the business case)

• Provide a more detailed list of facility types the Guide does and does not cover

• Address different audiences: profit versus nonprofit, ownership model variation

• Refine message to healthcare providers (hospital board members, doctors, chief financial 

officers)

o Must reach doctors

o Want to appeal to the health ethic (improvement in care, specifically “patient 

days”)

• Keep it simple: Simple, passive systems should be first focus, rather than mechanical or 

control systems that require additional maintenance

• Reduce design time to evaluate the options—the Guide’s prescriptive nature would help 

with that 

• Provide some guidance on the life cycle analysis

• Commissioning is very important, at least at startup

• Mixed reaction to daylighting

• Would like to have these recommendations be required by code or have incentives built 

into the funding and reimbursement systems for hospitals

• Would like to have case studies in their geographical areas
10

• Technology case studies are a great idea

o Need to show what is doable in their area

o Need to show energy numbers, metrics, and use

o Want to see the economics (even percentages or orders of magnitude)

o Architects felt case studies would be helpful in selling the idea of energy 

efficiency.

In developing the SHC-AEDG, the PC attempted to include the results from the focus group by:

• Including time for discussion by the decision makers such as hospital board members and 

doctors

• Focusing on simpler systems

• Emphasizing operations and maintenance

• Addressing plug loads

• Addressing specialty spaces

• Providing a wider range of daylighting and HVAC recommendations

• Providing case studies with at least two years of measured energy performance as well as 

examples of cost-effective implementation of the Guide’s recommendations.
11

3. Evaluation Approach

This chapter describes the analysis methods used to support development of the SHC-AEDG. It 

presents how 30% energy savings were quantified, how prototype models were developed, and 

how the prototype models were converted into baseline and low-energy models.

3.1 Determining 30% Savings

The purpose of the building energy simulation analysis is to assess and quantify the energy 

savings potential of the Guide’s final recommendations. The AEDGs contain a set of energy 

efficiency recommendations for eight U.S. climate zones. To provide prescriptive 30% 

recommendations, a specific quantitative energy savings goal must be measured against a 

specific version of Standard 90.1. For the SHC-AEDG, this is 90.1-1999, the “turn of the 

millennium” standard (ASHRAE 1999). The energy savings of the prescriptive 

recommendations were also examined relative to ASHRAE 90.1-2004 (ASHRAE 2004).

The following steps were used to determine 30% savings:

• Develop “typical” small healthcare facility prototype characteristics.

• Create baseline models from the prototypes that are minimally code compliant for 

ASHRAE 90.1-1999 and ASHRAE 90.1-2004.

• Create the low-energy models based on the recommended energy-efficient technologies 

in the Guide.

• Verify 30% energy savings for the various HVAC system types across the 15 U.S. 

climate zones and subzones.

These steps are presented in a linear fashion but include some iteration. For example, certain 

baseline model inputs were determined by features included in the low-energy models, such as 

glass and skylight areas.

The flowchart in Figure 3-1 presents a visual representation of the evaluation approach.

3.1.1 Site Energy Use

The 30% energy savings goal of the AEDG series is based on site energy savings between a 

minimally code-compliant small healthcare facility and a low-energy small healthcare facility

that uses the recommendations in the Guide. Other metrics, such as energy cost savings, source 

energy savings, or carbon savings, could be used as alternative reference values for energy 

savings comparisons and accountability (Torcellini et al. 2006). Each metric has advantages and 

disadvantages from an implementation and calculation perspective, and each can favor different 

technologies and fuel types. The SHC-AEDG uses site energy savings, as directed by the SC, 

for the sake of consistency with the previous AEDGs.
12

Figure 3-1 Evaluation approach flowchart

3.1.2 Whole-Building Energy Savings

Historically, energy savings have been expressed in two ways: energy savings of regulated loads 

and energy savings of the whole building. The regulated loads energy savings indicate the 

savings when the unregulated loads are not included in the total loads. These typically include 

plug and some process loads. The whole-building energy savings indicate the savings when all 

the loads (regulated and unregulated) are included in the energy savings calculations. In general, 

for the same level of percent savings, whole-building savings are more challenging than 
13

regulated loads savings. In LEED 2.1 (USGBC 2006), plug loads are included in the required 

energy simulation (to capture proper heat loads), but not in the denominator of the energy 

savings calculation. In the case of Appendix G in ASHRAE 90.1-2004 (ASHRAE 2004b) and in 

LEED 2.2 (USGBC 2006), plug loads are included in the denominator, i.e., the whole-building 

method, which includes the unregulated loads for calculating energy savings. The SHC-AEDG

uses the whole-building method for determining 30% energy savings. (See Appendix E for more

information about determining the plug loads for small healthcare facilities.)

3.1.3 ASHRAE Baseline

The SHC-AEDG was written to help owners and designers of small hospitals and healthcare

facilities achieve energy savings of at least 30% compared to the minimum requirements of 

ANSI/ASHRAE/IESNA Standard 90.1-1999 (ASHRAE 1999), which serves as a baseline. The 

baseline level energy use was set for buildings built at the turn of the millennium, which are 

assumed to be based on Standard 90.1-1999. The selection of this standard for the baseline was 

also based on the fact that it was the most recent standard for which DOE had issued a formal 

determination of energy savings at the time the first AEDG was prepared.

The use of ASHRAE 90.1-1999 as a baseline for determining 30% energy savings for the SHCAEDG is also consistent with other AEDGs (Jarnagin et al. 2006; Liu et al. 2006). There has 

been considerable discussion between the SC and the SHC-AEDG PC about having the energy 

savings based on a percentage below a specific version of 90.1 (1999, 2001, 2004, 2007, etc.). 

The SC realized that a moving baseline would result if designers were always attempting to use 

the most current version of the standard. This would cause considerable confusion in the 

marketplace because recommendations would always be changing based on which version of 

90.1 was being used. Two very similar buildings could have different recommendations, solely 

because different baselines were being used. Therefore, the SC decided to look at the other end 

of the scale and describe the energy savings as the progress toward a net-zero energy building. 

The top end of the scale, or 0% progress, would be set as the energy used by a structure built to 

the energy standards at the turn of the millennium (90.1-1999). The bottom end of the scale, or 

100%, is the net-zero energy building.

For our analysis, the recommendations needed to achieve 30% savings over ASHRAE 90.1-2004 

have been determined as well. Recommendation tables and energy savings are provided for 30% 

savings over 90.1-1999 and 90.1-2004.

3.1.4 Modeling Methods

3.1.4.1 EnergyPlus

EnergyPlus Version 3.1 (DOE 2009) was used to complete the energy simulations. It was 

selected because it is the contemporary DOE tool that accounts for the complicated interactions 

between climate, internal gains, building form and fabric, HVAC systems, and renewable energy 

systems. The simulations are run with EnergyPlus Version 3.1 compiled to run on a 64-bit Linux 

cluster supercomputer at NREL. EnergyPlus is a heavily tested program with formal BESTEST 

validation efforts repeated for every release (Judkoff and Neymark 1995). All simulations were 

completed with the NREL analysis platform (called Opt-E-Plus) that manages inputs and outputs 

of the EnergyPlus simulations. Its core functionality is the user’s ability to pass high-level 

parameters of the building (building area, internal gains per zone, HVAC system configuration, 

etc.) to generate a fully parameterized input file for EnergyPlus. Such files are generated rapidly 

and can be easily changed to incorporate changes during the evolution of the model. The high-
14

level parameter file is a structured text file written in Extensible Markup. Modifying the highlevel parameters is preferred over modifying the EnergyPlus input file because it greatly 

simplifies the modeling input development process. Modifying EnergyPlus input files can be 

time intensive when the high-level parameters have a one-to-many relationship with the input 

objects in the low-level input file.

3.1.4.2 Simulation Details

3.1.4.2.1 Advanced Energy Design Guide Simulations

The AEDG simulations are used to evaluate the Guide recommendations. There are one baseline 

and three low-energy (three HVAC system types) models for each prototype (surgery center and 

community hospital) for a total of eight separate seed (starting point) energy models. The Opt-EPlus software then takes these eight seed models and “sweeps” them across the 15 cities 

representing all the climate zones in the United States. The Opt-E-Plus “sweep” takes the seed 

energy model files and creates 15 separate energy models while applying climate zone specific 

details such as weather data, utility rates, economizer use, and building envelope specifications 

from ASHRAE 90.1 (for the baseline model) or the AEDG (for the low-energy models). This 

results in 120 energy models for the AEDG simulations.

3.1.4.2.2 Bundled Energy Efficiency Measure Analysis

NREL researchers performed the bundled EEM analysis to better understand how each EEM 

from the AEDG affected energy performance. In the AEDG simulations, all AEDG EEMs are 

applied in a single operation; in the bundled EEM analysis, the AEDG EEMs are applied 

incrementally (and aggregately) to investigate how individual measures affect energy 

performance. (See Section 8.4 for more details about the bundled EEM analysis.) This analysis 

used the same “sweep” in Opt-E-Plus to apply climate zone-specific information, but it was 

performed for six steps in which individual AEDG EEMs were applied to the model. This 

analysis was performed for the surgery center and community hospital in the 15 cities 

representing all the U.S. climate zones, resulting in 180 energy models for the bundled EEM 

analysis.

3.1.4.2.3 Managing Simulations

Between the two separate analyses performed for the AEDG, 300 energy models required 

processing through the EnergyPlus engine. The 150 surgery center models averaged 

approximately 3 hours per simulation for a total of 450 simulation hours. The 150 community 

hospital models averaged about 5 hours per simulations for a total of 750 simulations hours. The 

prototypes together resulted in approximately 1200 simulation hours, equivalent to 50 days.

The development of the AEDG recommendations was an iterative process, and often modeling 

results were used to gauge the performance of a specific recommendation. To process all the 

simulations in a reasonable time, a Linux supercomputer (distributed computing) was used. OptE-Plus has a built-in run manager that was used create simulation queues and to submit 

simulations for processing to the supercomputer. For these simulations, 18, 8-core processors 

(for a total of 144) were dedicated to this project. Using the supercomputer allowed the 

simulations to be completed in about 12 hours. The increase was attributed to the overhead 

computing power needed to manage the simulations. The Linux supercomputer was essential to 

completing the AEDG in the required timeframe.
 15

3.1.4.3 Climate Zones 

The AEDGs contain a unique set of energy efficiency recommendations for a range of climate 

zones. The six AEDGs developed to date have standardized climate zones that the International 

Energy Conservation Code and ASHRAE have adopted for residential and commercial 

applications. The common set includes eight zones covering the entire United States (see Figure 

3-2). Climate zones are categorized by heating degree days and cooling degree days, and range 

from the very hot zone 1 to the very cold zone 8. Some climate zones are divided into subzones 

based on humidity levels. Humid subzones are “A” zones, dry subzones are “B” zones, and 

marine subzones are “C” zones. These climate zones may be mapped to other climate locations 

for international use (ASHRAE 2004b).

Figure 3-2 DOE climate zones and representative cities 

(Credit: American Society of Heating, Refrigerating and Air-Conditioning Engineers) 

When the climate zones were being developed, 15 specific climate locations (cities) were 

selected as being most representative of each (see Figure 3-2 and the following list). To 

determine energy savings, weather files for each zone were used to simulate the baseline and 

low-energy models. 

 
16

• Zone 1: Miami, Florida (hot, humid)

• Zone 2A: Houston, Texas (hot, humid)

• Zone 2B: Phoenix, Arizona (hot, dry)

• Zone 3A: Memphis, Tennessee (hot, humid)

• Zone 3B: El Paso, Texas (hot, dry)

• Zone 3C: San Francisco, California (marine)

• Zone 4A: Baltimore, Maryland (mild, humid)

• Zone 4B: Albuquerque, New Mexico (mild, dry)

• Zone 4C: Seattle, Washington (marine)

• Zone 5A: Chicago, Illinois (cold, humid)

• Zone 5B: Boise, Idaho (cold, dry)

• Zone 6A: Burlington, Vermont (cold, humid)

• Zone 6B: Helena, Montana (cold, dry)

• Zone 7: Duluth, Minnesota (very cold)

• Zone 8: Fairbanks, Alaska (extremely cold).
17

4. Prototype Model Development Assumptions

Similar to other principal commercial building types, there are not many datasets of small 

healthcare facility characteristics and performance data, so the PC provided complete drawings 

for two small healthcare buildings—a small community hospital and a surgery center. These 

drawings were used to develop the prototype model geometry, space layouts, space types, and 

sizes. The space types that are in the prototype models are shown in Table 4-1.

Table 4-1 SHC-AEDG Prototype Designs Space Types

Space Types Community Hospital Surgery Center

Emergency room X

Postanesthesia care unit/recovery X X

Exam/treatment X X

Nurse station X X

Pharmacy X X

Patient room X

Operating room X X

Nursery X

Staff work/supply X X

Physical therapy X X

Radiology/imaging X X

Laundry

Office/administration X X

Conference X X

Lobby X X

Lounge/waiting X X

Dining X

Food preparation X

Corridors/stairs X X

Storage X X

4.1 Prototype Model Summary

This section summarizes how the data for the surgery center and the community hospital were 

used to formulate the prototype models for the SHC-AEDG. For facility characteristics that are 

not specified by ASHRAE 90.1-1999, ASHRAE 90.1-2004, ASHRAE 62.1-2004, or AIA 

(2006), but that are necessary to develop code compliant baseline and low-energy models, we 

tried to document “typical” small healthcare facility practices, characteristics, and features to 

formulate the prototype SHC-AEDG models.

The first characteristic to establish was the facility type. Based on input from the PC, we 

determined that there was enough physical and operational variation over community hospitals 

and surgery centers to develop different prototypes for each. The actual SHC-AEDG model 

sizes, along with additional inputs and SHC-AEDG characteristics, are shown in Table 4-2.
 18

Table 4-2 SHC-AEDG Prototype Characteristics 

Building Characteristic Community Hospital Prototype Surgery Center Prototype

Form and 

Fabric 

Size 65,000-ft2

 community hospital 41,000-ft2

 surgery center 

Number of floors 1 3 

Number of occupants 675 414 

Space types See Table 4-1 See Table 4-1 

Constructions Steel-frame walls, insulation 

entirely above deck roof 

Steel-frame walls, insulation entirely 

above deck roof 

Window area 26% 20% 

Operations 

Occupancy Fully occupied during the day, 

partially occupied at night 

Fully occupied during the day, 

vacant at night 

Peak plug loads 2.1 W/ft2 1.8 W/ft2

Percent conditioned Fully heated and cooled Fully heated and cooled 

HVAC 

System types 

Baseline: PVAV* with DX** 

cooling 

Low energy: PVAV with DX 

cooling, air-cooled chiller, and 

water-cooled chiller 

Baseline: PVAV with DX cooling 

Low energy: PVAV with DX cooling, aircooled chiller, and water-cooled chiller 

* PVAV = package multizone DX rooftop unit with variable air volume 

** DX = direct expansion 

4.2 Prototype Space Type Sizes and Layout 

The drawings for a community hospital and surgery center were used to develop the prototype 

floor plans and space layouts. In general, the community hospital is divided into quadrants as 

follows: 

 Quadrant 1 contains critical care spaces such as operating rooms and radiology imaging 

centers. 

 Quadrant 2 contains office spaces and examination rooms. 

 Quadrant 3 contains patient rooms and nurse staff areas. 

 Quadrant 4 contains mechanical rooms and storage spaces. 

The first floor of the surgery center contains the critical care areas such as operating and 

recovery rooms; the second and third floors contain examination rooms, office spaces, and 

physical therapy areas. Total space sizes of the prototype models are shown in Table 4-3. The 

floor plans for the community hospital and surgery center prototypes are shown in Figure 4-1 

through Figure 4-7.
19

Table 4-3 Total Space Sizes Included in the AEDG Prototype

Space Type Community Hospital Surgery Center

Total Size (ft2) % of Total Total Size (ft2) % of Total

Anesthesia 72 0.1% 108 0.3%

Clean 1,354 2.1% 291 0.7%

Conference 1,137 1.8% 336 0.8%

Corridor 9,838 15.3% 8,475 20.7%

Dining 736 1.1% 420 1.0%

Examination room 3,669 5.7% 4,213 10.3%

Food preparation center 1,480 2.3% 0 0.0%

Laboratory 1,344 2.1% 0 0.0%

Lounge 1,494 2.3% 1,979 4.8%

Nurse station 2,422 3.8% 773 1.9%

Nursery 165 0.3% 0 0.0%

Office 11,799 18.3% 7,685 18.8%

Operating room 2,520 3.9% 1,416 3.5%

Patient corridor 2,752 4.3% 0 0.0%

Patient room 6,012 9.3% 527 1.3%

Physical therapy 1,584 2.5% 1,892 4.6%

Procedure room 656 1.0% 285 0.7%

Radiology 1,018 1.6% 1,508 3.7%

Reception area 2,380 3.7% 2,115 5.2%

Recovery room 1,440 2.2% 948 2.3%

Soiled 1,052 1.6% 362 0.9%

Storage 3,153 4.9% 6,284 15.3%

Toilet room 3,133 4.9% 790 1.9%

Trauma room 280 0.4% 0 0.0%

Triage 180 0.3% 0 0.0%

Utility 2,656 4.1% 539 1.3%
20

Figure 4-1 Community hospital prototype quadrant 1 layout
21

Figure 4-2 Community hospital prototype quadrant 2 layout
22

Figure 4-3 Community hospital prototype quadrant 3 layout
23

Figure 4-4 Community hospital prototype quadrant 4 layout
24

Figure 4-5 Surgery center prototype floor 1 layout
25

Figure 4-6 Surgery center prototype floor 2 layout
26

Figure 4-7 Surgery center prototype floor 3 layout
27

5. Model Details

This section contains a topic-by-topic description of the EnergyPlus model inputs for the 

baseline and low-energy building models. These inputs include the building form and floor 

plate; envelope characteristics; building internal loads and operating schedules; ventilation rates 

and schedules; HVAC equipment efficiency, operation, control, and sizing; fan power 

assumptions; and SWH.

5.1 Model Development and Assumptions

5.1.1 Baseline Model

The criteria in ASHRAE 90.1-1999 and ASHRAE 62-2004 were used for the baselines to 

calculate 30% savings for the SHC-AEDG recommendations. For the baselines needed to verify 

30% savings for our DOE analysis, the SHC-AEDG baselines were updated to be minimally 

code compliant with ASHRAE 90.1-2004. The ASHRAE 90.1-1999 community hospital

baseline inputs are summarized in a table in Appendix C and the surgery center ASHRAE 90.1-

1999 baseline input tables are summarized in Appendix D.

5.1.2 Low-Energy Model

The final recommendations were determined based on an iterative process using the PC’s 

expertise and results from modeling the recommendations. To quantify the potential energy 

savings from the final recommended EEMs in the Guide, the energy efficiency technologies 

listed below were implemented to simulate the low-energy building models. This section 

contains a topic-by-topic description of the low-energy building models and how the 

recommended EEMs were implemented into the low-energy modeling. The EEMs included in 

the 30% saving calculation are:

• Enhanced building opaque envelope insulation

• High-performance window glazing with overhangs

• Reduced lighting power density (LPD) and occupancy controls

• Daylighting in common areas (corridor, reception, dining) and permanently occupied 

staff areas (offices, nurse stations, exam rooms)

• Lower pressure ductwork design and higher efficiency fans

• Higher efficiency HVAC equipment

• High-efficiency SWH.

Plug load reductions are not credited to the calculated 30% energy savings, as these energy 

efficiency opportunities are not part of the prescriptive recommendations. They do, however, 

form a prominent part of the additional savings section.

5.1.3 Developing the Low-Energy Recommendations

The PC used the following guiding principles to develop the final recommendation for the SHCAEDG:

• Provide recommendations that represent responsible small healthcare design practices. If 

a recommendation generally represents good design practice, it is recommended for all 

climate zones, even if the resulting savings exceed 30%.
28

• Use off-the-shelf technologies that are available from multiple sources. The PC did not 

recommend technologies or techniques that are one of a kind or available from a single 

manufacturer.

• Provide recommendations that are at least as stringent as those in the forthcoming 

ASHRAE 90.1-2010. We did not want our recommendations to be less stringent than the 

most recent version of ASHRAE 90.1.

• Use the recommendations from the previous K-12 schools AEDG as a starting point for 

fine tuning the SHC-AEDG recommendations. Develop recommendations to address the 

focus group’s concerns about usability, operations and maintenance, simplicity, and 

flexibility.

• Verify 30% energy savings for the recommendations that represent the most typical small 

healthcare facility components, or for the components that are the least likely to result in 

30% savings.

5.2 Form and Floor Plate

5.2.1 Baseline Model

The prototype characteristics as documented in the previous section, combined with modeling 

assumptions, were used to generate the baseline models form and floor plate. The PC scrutinized 

the following form and floor plate modeling assumptions (see Table 5-1) to verify they were 

typical characteristics for small hospitals and healthcare facilities. The fenestration was equally 

applied over all exterior walls. No overhangs were included in the baseline model and no 

plenums were modeled.

Table 5-1 Selected Baseline Modeling Assumptions

Model Parameters

Value

Community Hospital Surgery Center

Ceiling height 9 ft 10 ft

Fraction of fenestration to gross wall area 26% 20%

Glazing sill height 4 ft 4 ft

Renderings of the community hospital and surgery center baseline models are shown in Figure 

5-1 and Figure 5-2, respectively. Each shows an isometric view from the southwest.
29

Figure 5-1 Community hospital baseline model rendering: View from southwest

Credit: Eric Bonnema/NREL
30

Figure 5-2 Surgery center baseline model rendering: View from southwest

Credit: Eric Bonnema/NREL
31

5.2.2 Low-Energy Model

The low-energy building models had conditioned floor area and exterior dimensions and 

orientations that were identical to those of the baseline buildings, except for the following 

components:

5.2.2.1 Overhangs

The Guide recommends overhangs with a projection factor of 0.5 on south-facing windows and 

clerestories in all climate zones. Therefore, low-energy models included fixed shading by 

assuming that the overhang starts just above the window and extends out from the façade half the 

window height to provide the projection factor of 0.5.

5.2.2.2 Skylights and Clerestories

The Guide recommends a 3% roof area maximum skylight distribution. Skylights were applied 

only in the surgery center prototype, as this part of the building is composed almost entirely of 

medical office building spaces. Skylights were not applied to the community hospital prototype. 

The PC felt skylights were not applicable to this type of building because of the potential direct 

solar beam radiation. Instead, clerestories were modeled in both the baseline and low-energy 

models to provide daylighting to certain spaces. These clerestories are visible in Figure 5-1 for 

the baseline model and Figure 5-3 for the low-energy model. The only difference between the 

clerestories in the baseline and low-energy models is that the low-energy models have overhangs 

(0.5 projection factor). The general approach to adding clerestory glass to the community 

hospital was to focus on adding north-facing clerestories to permanently occupied staff spaces 

(exam rooms, nurse stations, corridors, offices) and public spaces (waiting rooms, reception 

areas). South-facing clerestories were added when north-facing was not possible. The clerestory 

glazing is 3 ft (0.9 m) tall. Adding these clerestories results in approximately 22,550 ft2 (2,095 

m

2

Figure 5-3

) of building area with clerestories, representing 35% of the total building area. Renderings of 

the community hospital and surgery center low-energy models (with overhangs in both and 

skylights in the surgery center) are shown in and Figure 5-4, respectively. Each 

shows an isometric view from the southwest.
32

Figure 5-3 Community hospital low-energy model rendering: View from southwest

Credit: Eric Bonnema/NREL
33

Figure 5-4 Surgery center low-energy model rendering: View from southwest

Credit: Eric Bonnema/NREL
34

5.3 Envelope

5.3.1 Baseline Model

The PC assumed, based on the experience of those in the small hospital and healthcare facilities 

construction industry, that these facilities are typically constructed with steel-framed exterior 

walls, built-up roofs, and slab-on-grade floors. These constructions represent common practices. 

There is some regional variation, but the PC felt that steel-framed walls and built-up roofs were 

the most common techniques.

The baseline small healthcare facility envelope characteristics were developed to meet the 

prescriptive design option requirements in accordance with ASHRAE 90.1-1999 Section 5.3. 

For the ASHRAE 90.1-2004 baselines, the prescriptive building envelope option in Section 5.5 

was used. Layer-by-layer descriptions of the constructions of exterior surfaces were used to 

model the building thermal envelope in EnergyPlus.

5.3.2 Low-Energy Model

The low-energy building models had building envelope characteristics that were identical to 

those of the baseline buildings, except the exterior walls and roofs.

5.3.3 Exterior Walls and Roofs

5.3.3.1 Baseline Model

The baseline building exterior walls are modeled with steel-framed wall constructions. The 

layers consist of exterior sheathing, batt insulation between steel studs, and interior gypsum 

board. The U-factors of the insulation varied based on the applicable standard and were adjusted 

to account for the standard film coefficients. R-values for most of the layers were derived from 

Appendix A of ASHRAE 90.1-1999. Insulation R-values for continuous insulations were 

selected to meet the insulation minimum R-values required in Appendix B of ASHRAE 90.1-

1999, as defined by climate range. The baseline exterior wall U-factors are in Appendix C and

Appendix D of this report. Similar wall insulation values were modeled in the ASHRAE 90.1-

2004 baselines, as the steel-framed wall requirements did not change appreciably from ASHRAE 

90.1-1999 to ASHRAE 90.1-2004. The steel-framed wall layer details are as follows:

• Exterior air film (calculated by EnergyPlus)

• Nominally R-2 exterior sheathing

• Batt wall insulation (R-value varies by climate)

• 0.5-in. thick gypsum board

• Interior air film (calculated by EnergyPlus).

To calculate the thermal performance of the interior air films, the “detailed” algorithm in 

EnergyPlus for surface heat transfer film coefficients was used, and to calculate the thermal 

performance of the exterior air films, the “DOE-2” algorithm in EnergyPlus for surface heat 

transfer film coefficients was used. These are based on linearized radiation coefficients that are 

separate from the convection coefficients, as determined by surface roughness, wind speed, and 

terrain. However, standardized combined film coefficients are used to target assembly U-factors.

Built-up, rigid insulation above a structural metal deck roof was used in the baseline models. 

The layers consisted of the roof membrane, roof insulations, and metal decking. The U-factors 

varied based on the applicable standard and were adjusted to account for the standard film 
35

coefficients. Added insulation is continuous and uninterrupted by framing. Roof insulation Rvalues were also set to match the minimum roof insulation requirements in Appendix B of

ASHRAE 90.1-1999, by climate. The baseline roof U-factors are in Appendix C and Appendix 

D. Similar roof insulation values were modeled in the ASHRAE 90.1-2004 baselines, as the 

insulation above deck roof requirements did not change significantly from ASHRAE 90.1-1999 

to ASHRAE 90.1-2004.

Standard 90.1-1999 does not specify absorptance or other surface assumptions. The roof exterior 

finish was assumed to be a single-ply roof membrane with gray ethylene propylene diene 

terpolymer membrane in the baseline models. Therefore, a solar reflectance of 0.3, a thermal 

absorption of 0.9, and a visible absorption of 0.7 were assumed.

5.3.3.2 Low-Energy Model

The recommendations in the SHC-AEDG are all at least as stringent as the most recent version 

of ASHRAE 90.1 (ASHRAE 90.1-2010). (See Table 8-1 SHC-AEDG Recommendations for 

30% Savings Over 90.1-1999: Climate Zones 1–4 and Table 8-2 for the low-energy exterior 

wall and roof thermal characteristics.)

The SHC-AEDG recommends the use of high albedo roofs with a Solar Reflective Index (SRI) 

of 0.78 in climate zones 1 through 3. To model the high albedo roofs, we assumed the outer 

layer of the roof has a thermal absorption of 0.9, a solar reflectivity of 0.7, and a visible 

absorption of 0.3.

5.3.4 Slab-on-Grade Floors

5.3.4.1 Baseline Model

The baseline buildings were modeled with slab-on-grade floors. The layers consist of carpet pad 

over 8 in. (0.2 m) of heavyweight concrete. A separate program called slab.exe, which 

determines the temperature of the ground under the slab based on the area of the slab, the 

location of the building, and the type of insulation under or around the slab, was used to model 

the ground coupling (DOE, 2009). For the baseline models, slab.exe was used to run a simple 

building in each location with the slab insulation requirements in ASHRAE 90.1-1999. Slab.exe 

reports the perimeter ground monthly temperatures, the core ground monthly temperatures, and 

average monthly temperatures. For this analysis, the average monthly temperatures were used as 

the input for the ground temperatures under the floor slab in the EnergyPlus input files.

5.3.4.2 Low-Energy Model

The low-energy building slab-on-grade floors are the same as those in the baseline model, which 

is consistent with the Guide’s recommendation to comply with Standard 90.1.

5.3.5 Fenestration

5.3.5.1 Baseline Model

Fenestration systems in the baseline buildings were modeled at 26% fenestration to gross wall 

area for the community hospital and 20% fenestration to gross wall area for the surgery center. 

The fenestration on the community hospital includes the clerestory daylighting glass. Windows 

frames were not explicitly modeled to reduce complexity in the EnergyPlus models and make the 

simulations run faster. The window performance is modeled as representing the entire glazed 

area. U-factor and solar heat gain coefficient (SHGC) values were treated as representing the 

whole window assembly. Window U-factor and SHGC were set to match the fenestration 
36

performance criteria outlined in Appendix B of ASHRAE 90.1-1999, by climate zone. If the 

SHGC had no recommended value in ASHRAE 90.1 (1999 or 2004), it was set to the previous 

table’s value. Similar window U-factors and SHGCs were modeled in the ASHRAE 90.1-2004 

baselines, as the window requirements did not change significantly from ASHRAE 90.1-1999 to 

ASHRAE 90.1-2004.

Window fenestration U-factors and SHGC values are listed in Appendix C and Appendix D. 

These are the targets used in an iterative process to refine the material properties in the layer-bylayer descriptions to just match the assembly performance level. The multipliers from the visible 

light transmittance tables in ASHRAE 90.1-2004, Appendix C, Table C3.5 (ASHRAE 2004b) 

were used to calculate baseline visible light transmittance values for the windows.

The SHC-AEDG recommends daylighting in the public spaces (corridors, reception, waiting 

areas), exam rooms, and permanently occupied staff areas (nurse stations, offices, dining areas). 

The surgery center daylighting option includes skylights with an area of 5% of the floor area. 

The community hospital daylighting option includes clerestories. The baseline models also 

include the clerestories, but without daylighting controls, as recommended in Appendix G of 

ASHRAE 90.1-2004. Skylight and clerestory U-factor and SHGCs are set to match the 

fenestration performance criteria outlined in Appendix B of ASHRAE 90.1-1999, by climate 

zone.

5.3.5.2 Low-Energy Model

The vertical fenestration and skylight U-factors were modeled to meet the minimum 

requirements for each climate. (See Table 8-1 SHC-AEDG Recommendations for 30% 

Savings Over 90.1-1999: Climate Zones 1–4 and Table 8-2 for the low-energy fenestration 

thermal characteristics.) Horizontal overhangs with no offset and a projection factor of 0.5 were

added to the south-facing windows (including clerestories) in the low-energy models.

5.4 Infiltration

5.4.1 Baseline Model

Building air infiltration is addressed indirectly in the 90.1 Standard through the requirements in 

building envelope sealing, fenestration, and door air leakage. ASHRAE 90.1 does not specify 

the air infiltration rate. For this analysis (based on input from the PC), the infiltration rate was 

assumed to be a constant 0.2 cfm/ft2 (1.0 (L/s)/m2

) of exterior wall area. For equipment sizing 

simulations in EnergyPlus, the infiltration rate was assumed to be 0.4 cfm/ft2 (2.0 (L/s)/m2

5.4.2 Low-Energy Model

) of 

exterior wall area, applied only to perimeter zones.

The infiltration in the low-energy model is the same as in the baseline model.

5.5 Air Flow Rates

5.5.1 Baseline Model

Ventilation air requirements for specific spaces are addressed directly in AIA 2006. This was the 

primary reference used to determine ventilation air flow rates for specific zone types. If a 

specific zone type was not present in the AIA Guidelines, ASHRAE 62.1-2004 was used to 

determine the per-floor area and per-occupant ventilation air flow rates.

Exhaust air requirements for specific spaces are addressed directly in the AIA 2006. Not all 

spaces have exhaust requirements.
37

Total air requirements for specific spaces are addressed directly in AIA 2006. Not all spaces 

have exhaust requirements.

Table 5-2 shows the ventilation, exhaust, and total air flow rates used in the energy model.

Table 5-2 Ventilation and Exhaust Inputs

Space Type

AIA Guidelines 

Ventilation Air 

(ACH*)

62.1-2004 

Ventilation 

(cfm/occupant)

62.1-2004 

Ventilation 

(cfm/ft2

AIA Guidelines 

Exhaust

) (ACH)

AIA Guidelines 

Total Air

(ACH)

Anesthesia – – 0.12 8 8

Clean – – 0.12 – 4

Conference – 5 0.06 – –

Corridor – – 0.06 – –

Dining – 7.5 0.18 – –

Examination room – – 0.12 – 6

Food preparation 

center – – 0.12 625 CFM 10

Laboratory – – 0.12 – 6

Lounge – – 0.12 – –

Nurse station – – 0.12 – –

Nursery 2 – – – 6

Office – 5 0.06 – –

Operating room 3 – – – 20

Patient corridor – – 0.06 – 2

Patient room 2 – – – 6

Physical therapy – – 0.12 – 6

Procedure room 3 – – – 15

Radiology – – 0.12 12 –

Reception area – 5 0.06 – –

Recovery room 2 – – – 6

Soiled – – 0.12 10 10

Storage – – 0.12 – –

Toilet room – – 0.12 10 10

Trauma room 3 – – – 15

Triage 2 – – 12 12

Utility – – 0.12 – –

* Air changes per hour

** This value was changed from the 15 ACH that is listed in the AIA guidelines based on recommendations from the PC.

5.5.2 Low-Energy Model

The ventilation, exhaust, and total air flow rates in the low-energy model are the same as in the 

baseline model.

5.6 Internal Loads

5.6.1 Baseline Model

Internal loads include heat generated from occupants, lights, and appliances (plug loads such as 

computers, printers, and medical equipment and gas loads such as cooking equipment and 

medical sterilization equipment). For the occupancy loads, the load intensity refers to the 

maximum occupancy at the peak time of a typical day. Lighting, plug, and gas loads are 

represented by peak power density in watts per square foot. The assumed equipment load 

intensities are based on GGHC 2007. The equipment loads include all loads not associated with 

HVAC, SWH, and lighting. In addition to all loads that are plugged in, equipment loads include 

items such as elevators, distribution transformer losses, cooking appliances, and walk-in 

refrigerators.
38

The occupancy loads are based on the default occupant density from ASHRAE 62.1-2004 

(ASHRAE 2004c). The baseline interior LPD for each specific area is derived by using the 

space-by-space method described in Standard 90.1-1999. The baseline ASHRAE 90.1-1999 and 

ASHRAE 90.1-2004 LPDs, peak plug loads, and peak occupancy by space type are shown in 

Table 5-3. Table 5-4 shows area weighted averages of the ASHRAE 90.1-1999 and ASHRAE 

90.1-2004 LPDs, peak plug loads, and peak occupancy. Plug load, occupancy, and lighting 

schedules are documented in Section 5.7. The location of each space type can be found in Figure 

4-1 through Figure 4-7.

Table 5-3 Internal Loads by Space Type

Space Type

ASHRAE 

90.1-1999 LPD

(W/ft2

ASHRAE 

)

90.1-2004 LPD

(W/ft2

Peak Plug 

Load

) (W/ft

2

Peak Process 

Gas Load

) (W/ft2

Maximum 

Occupants 

(#/1000 ft ) 2

Anesthesia

)

2.9 0.9 2.0 – –

Clean 1.5 1.1 2.0 – 20

Conference 1.5 1.3 1.0 – 50

Corridor 1.6 1.0 0.4 – –

Dining 1.4 0.9 1.0 – 100

Examination room 1.6 1.5 1.1 – 20

Food preparation center 2.2 1.2 4.0 5 15

Laboratory 1.8 1.4 3.0 – 25

Lounge 1.4 0.8 3.0 – 15

Nurse station 1.8 1.0 2.0 – 20

Nursery 1.0 0.6 1.0 – 20

Office 1.5 1.1 1.1 – 5

Operating room 7.6 2.2 4.0 7 20

Patient corridor 1.6 1.0 0.4 – –

Patient room 1.2 0.7 2.0 – 10

Physical therapy 1.9 0.9 1.5 – 20

Procedure room 2.8 2.7 3.0 – 20

Radiology 0.4 0.4 10.0 – 20

Reception area 1.8 1.3 1.1 – 30

Recovery room 2.6 0.8 3.0 – 20

Soiled 1.5 1.1 2.0 – 20

Storage 2.9 0.9 0.1 – –

Toilet room 1.0 0.9 0.4 – –

Trauma room 1.6 1.5 2.0 – 20

Triage 2.8 2.7 2.0 – 20

Utility 1.3 1.5 5.0 – –

Table 5-4 Area-Weighted Average Internal Loads by Prototype

Prototype

ASHRAE 90.1-1999 

LPD 

(W/ft2

ASHRAE 90.1-2004 

LPD 

) (W/ft2

Peak Plug

)

Load

(W/ft2

Number of 

Occupants 

(#/1000 ft ) 2

Community hospital

)

1.9 1.1 2.1 10.5

Surgery center 1.8 1.1 1.8 10.1

5.6.2 Low-Energy Model

The internal loads for the low-energy model are the same as for the baseline building, except for 

the LPD and lighting controls.
39

5.6.2.1 Lighting Power Density

The SHC-AEDG provides recommendations for LPD by space type and an average LPD for the 

entire building. The baseline and SHC-AEDG LPD recommendations are shown in Table 5-5

for ASHRAE 90.1-1999 and in Table 5-7 for ASHRAE 90.1-2004. Whole-building values for 

ASHRAE 90.1-1999 are in Table 5-6 and whole building values for ASHRAE 90.1-2004 are in 

Table 5-8.

Table 5-5 Space-by-Space AEDG LPD Versus ASHRAE 90.1-1999

Space Type ASHRAE 90.1-1999 LPD 

(W/ft2 SHC-AEDG LPD) (W/ft2 ASHRAE 90.1-1999 ) Percent Reduction

Anesthesia 2.9 0.8 72%

Clean 1.5 0.9 40%

Conference 1.5 1.2 20%

Corridor 1.6 0.7 56%

Dining 1.4 0.9 36%

Examination room 1.6 1.2 25%

Food preparation center 2.2 1.2 45%

Laboratory 1.8 0.9 50%

Lounge 1.4 0.8 43%

Nurse station 1.8 1.0 44%

Nursery 1.0 0.6 40%

Office 1.5 0.9 40%

Operating room 7.6 2.0 74%

Patient corridor 1.6 0.7 56%

Patient room 1.2 0.7 42%

Physical therapy 1.9 0.9 53%

Procedure room 2.8 2.0 29%

Radiology 0.4 0.8 –

Reception area 1.8 0.9 50%

Recovery room 2.6 0.8 69%

Soiled 1.5 0.9 40%

Storage 2.9 0.8 72%

Toilet room 1.0 0.9 10%

Trauma room 1.6 1.2 25%

Triage 2.8 2.0 29%

Utility 1.3 0.9 31%

Table 5-6 Whole-Building AEDG LPD Versus ASHRAE 90.1-1999

Space Type ASHRAE 90.1-1999 LPD 

(W/ft2 SHC-AEDG LPD ) (W/ft2 ASHRAE 90.1-1999 ) Percent Reduction

Community hospital 1.85 0.92 50%

Surgery center 1.87 0.88 54%
40

Table 5-7 Space-by-Space AEDG LPD Versus ASHRAE 90.1-2004

Space Type ASHRAE 90.1-2004 LPD 

(W/ft2

SHC-AEDG LPD

) (W/ft2

ASHRAE 90.1-2004 

) Percent Reduction

Anesthesia 0.9 0.8 11%

Clean 1.1 0.9 18%

Conference 1.3 1.2 8%

Corridor 1.0 0.7 30%

Dining 0.9 0.9 0%

Examination room 1.5 1.2 20%

Food preparation center 1.2 1.2 0%

Laboratory 1.4 0.9 36%

Lounge 0.8 0.8 0%

Nurse station 1.0 1.0 0%

Nursery 0.6 0.6 0%

Office 1.1 0.9 18%

Operating room 2.2 2.0 9%

Patient corridor 1.0 0.7 30%

Patient room 0.7 0.7 0%

Physical therapy 0.9 0.9 0%

Procedure room 2.7 2.0 26%

Radiology 0.4 0.8 -

Reception area 1.3 0.9 31%

Recovery room 0.8 0.8 0%

Soiled 1.1 0.9 18%

Storage 0.9 0.8 11%

Toilet room 0.9 0.9 0%

Trauma room 1.5 1.2 20%

Triage 2.7 2.0 26%

Utility 1.5 0.9 40%

Table 5-8 Whole-Building AEDG LPD Versus ASHRAE 90.1-2004

Space Type ASHRAE 90.1-2004 LPD 

(W/ft2 SHC-AEDG LPD ) (W/ft2 ASHRAE 90.1-2004 ) Percent Reduction

Community hospital 1.11 0.92 17%

Surgery center 1.06 0.88 17%

5.6.2.2 Lighting Controls

The SHC-AEDG recommends daylighting controls in common areas (corridors, reception areas, 

dining areas) and permanently occupied staff spaces (nurse stations, offices, exam rooms). 

Continuous dimming daylighting controls that turn off when daylighting can meet the entire 

lighting load were modeled. Each daylight zone was modeled with one daylighting reference 

point controlling all lights in the zone. The daylighting control was not placed directly under a 

skylight or too near a window. The lights were controlled based on a daylighting set point of 40 

fc (400 lux). In the top floor of the surgery center with skylights, the daylighting control point 

was placed between the skylights to represent the lowest lighting level in the zone.

For the low-energy models, manual-on, auto-off occupancy sensors for certain zones are 

recommended. These include clean rooms, conference rooms, exam rooms, offices, soiled 

rooms, storage areas, restrooms, and utility (mechanical/electrical) rooms. Occupancy sensors 
41

were modeled by an additional 10% LPD reduction in the applicable zones. The baseline and 

SHC-AEDG LPD recommendations with a 10% reduction for occupancy sensors are shown in 

Table 5-9 for ASHRAE 90.1-1999 and Table 5-11 for ASHRAE 90.1-2004. Whole-building 

values for ASHRAE 90.1-1999 are in Table 5-10 whole-building values for ASHRAE 90.1-2004 

are in Table 5-12.

Table 5-9 Space-by-Space AEDG LPD With Occupancy Sensors Versus ASHRAE 90.1-1999

Space Type ASHRAE 90.1-1999 LPD

(W/ft2

SHC-AEDG LPD With 

Occupancy Sensors 

(W/ft ) 2

ASHRAE 90.1-1999 

Percent Reduction )

Anesthesia 2.9 0.8 72%

Clean 1.5 0.8 46%

Conference 1.5 1.1 28%

Corridor 1.6 0.7 56%

Dining 1.4 0.9 36%

Examination room 1.6 1.1 33%

Food preparation center 2.2 1.2 45%

Laboratory 1.8 0.9 50%

Lounge 1.4 0.8 43%

Nurse station 1.8 1.0 44%

Nursery 1.0 0.6 40%

Office 1.5 0.8 46%

Operating room 7.6 2.0 74%

Patient corridor 1.6 0.7 56%

Patient room 1.2 0.7 42%

Physical therapy 1.9 0.9 53%

Procedure room 2.8 2.0 29%

Radiology 0.4 0.8 –

Reception area 1.8 0.9 50%

Recovery room 2.6 0.8 69%

Soiled 1.5 0.8 46%

Storage 2.9 0.7 75%

Toilet room 1.0 0.8 19%

Trauma room 1.6 1.2 25%

Triage 2.8 2.0 29%

Utility 1.3 0.8 38%

Table 5-10 Whole-Building AEDG LPD With Occupancy Sensors Versus ASHRAE 90.1-1999

Space Type ASHRAE 90.1-1999 LPD

(W/ft2

SHC-AEDG LPD With 

Occupancy Sensors 

(W/ft ) 2

ASHRAE 90.1-1999 

Percent Reduction )

Community hospital 1.85 0.88 52%

Surgery center 1.87 0.83 56%
42

Table 5-11 Space-by-Space AEDG LPD With Occupancy Sensors Versus ASHRAE 90.1-2004

Space Type

ASHRAE 90.1-2004

LPD

(W/ft2

SHC-AEDG LPD

)

With Occupancy Sensors 

(W/ft2

ASHRAE 90.1-2004 

Percent Reduction

)

Anesthesia 0.9 0.8 11%

Clean 1.1 0.8 26%

Conference 1.3 1.1 17%

Corridor 1.0 0.7 30%

Dining 0.9 0.9 0%

Examination room 1.5 1.1 28%

Food preparation center 1.2 1.2 0%

Laboratory 1.4 0.9 36%

Lounge 0.8 0.8 0%

Nurse station 1.0 1.0 0%

Nursery 0.6 0.6 0%

Office 1.1 0.8 26%

Operating room 2.2 2.0 9%

Patient corridor 1.0 0.7 30%

Patient room 0.7 0.7 0%

Physical therapy 0.9 0.9 0%

Procedure room 2.7 2.0 26%

Radiology 0.4 0.8 –

Reception area 1.3 0.9 31%

Recovery room 0.8 0.8 0%

Soiled 1.1 0.8 26%

Storage 0.9 0.7 20%

Toilet room 0.9 0.8 10%

Trauma room 1.5 1.2 20%

Triage 2.7 2.0 26%

Utility 1.5 0.8 46%

Table 5-12 Whole-Building AEDG LPD With Occupancy Sensors Versus ASHRAE 90.1-2004

Space Type

ASHRAE 90.1-2004

LPD

(W/ft2

SHC-AEDG LPD With 

Occupancy Sensors

) (W/ft2

ASHRAE 90.1-2004 

Percent Reduction

)

Community hospital 1.11 0.88 21%

Surgery center 1.06 0.83 22%

5.7 Schedules

5.7.1 Baseline Model

The schedules were developed by modifying the standard healthcare building schedule sets 

available in ASHRAE 90.1-1989 (ASHRAE, 1989) based on input from each PC member. 

Schedules are presented as fractions of peak, unless otherwise noted. Administrative and critical 

schedules were created. The administrative schedules apply to quadrants 1 and 4 of the 

community hospital and to the entire surgery center. These spaces have schedules that are more 

typical of office buildings, with a near-vacant state at nights. The administrative schedules also 

have different schedules for weekdays, Saturdays, and all other days (Sundays and holidays), 

whereas the critical schedules are the same every day. The critical schedules applied to 

quadrants 2 and 3 of the community hospital, where there is 24-hour access. Each respective 

administrative and critical schedule follows the same time patterns; nighttime reduction is greater 
43

in the administrative schedules. Table 5-13 shows the administrative and critical lighting 

schedules; Figure 5-5 represents the same data graphically.

Table 5-13 Building Lighting Schedule

Hour Critical All 

Days

Administrative 

Weekday

Administrative 

Saturday

Administrative All 

Other Days

1 0.5 0.1 0.1 0.05

2 0.5 0.1 0.1 0.05

3 0.5 0.1 0.1 0.05

4 0.5 0.3 0.1 0.05

5 0.7 0.3 0.1 0.05

6 0.7 0.6 0.1 0.05

7 0.9 0.9 0.1 0.05

8 0.9 0.9 0.3 0.05

9 0.9 0.9 0.3 0.1

10 0.9 0.9 0.4 0.1

11 0.9 0.9 0.4 0.1

12 0.9 0.9 0.4 0.1

13 0.9 0.9 0.4 0.1

14 0.9 0.9 0.4 0.1

15 0.9 0.9 0.4 0.1

16 0.9 0.9 0.3 0.1

17 0.9 0.9 0.3 0.1

18 0.9 0.9 0.3 0.05

19 0.7 0.6 0.3 0.05

20 0.7 0.6 0.3 0.05

21 0.7 0.3 0.1 0.05

22 0.7 0.3 0.1 0.05

23 0.5 0.1 0.1 0.05

24 0.5 0.1 0.1 0.05

Each zone in the baseline models used the same thermostat set point schedules (see Table 5-14

and Table 5-15, except for the operating rooms, which used the thermostat set point schedule in 

Table 5-16. The HVAC systems are controlled with dual thermostatic control based on dry bulb 

temperature in the zones. Zone thermostat set points are generally 70oF (21oC) for heating and 

72oF (22oC) for cooling. Thermostat setup to 77oF (25oC) and setback to 65oF (18oC) were 

included in the models. A visual representation of the thermostat set point schedules can be seen 

in Figure 5-6 and Figure 5-7.

According to AIA 2006, the relative humidity (RH) of the critical spaces needs to be maintained 

between 30% and 60%. Dedicated steam humidifiers are included in air handlers serving critical 

zones and have a humidistat set point of 40% as good design practice. Dehumidification is 

addressed indirectly by controlling air handler deck temperature. Set points for the supply air 

temperature in the baseline and low-energy models are 52oF (11oC) for air handlers serving 

critical zones and 55oF (13oC) for air handlers serving administrative zones.
44

Figure 5-5 Building lighting schedule
45

Table 5-14 Building Heating Set Point Schedules

Hour

Critical

All Days

(oF)

Administrative 

Weekday

(oF)

Administrative 

Saturday

(oF)

Administrative

All Other Days

(oF)

1 70 65 65 65

2 70 65 65 65

3 70 65 65 65

4 70 65 65 65

5 70 65 65 65

6 70 70 65 65

7 70 70 65 65

8 70 70 70 65

9 70 70 70 65

10 70 70 70 65

11 70 70 70 65

12 70 70 70 65

13 70 70 70 65

14 70 70 70 65

15 70 70 70 65

16 70 70 65 65

17 70 70 65 65

18 70 70 65 65

19 70 65 65 65

20 70 65 65 65

21 70 65 65 65

22 70 65 65 65

23 70 65 65 65

24 70 65 65 65
46

Table 5-15 Building Cooling Set Point Schedules

Hour

Critical

All Days

(oF)

Administrative 

Weekday

(oF)

Administrative 

Saturday

(oF)

Administrative

All Other Days

(oF)

1 72 77 77 77

2 72 77 77 77

3 72 77 77 77

4 72 77 77 77

5 72 77 77 77

6 72 72 77 77

7 72 72 77 77

8 72 72 72 77

9 72 72 72 77

10 72 72 72 77

11 72 72 72 77

12 72 72 72 77

13 72 72 72 77

14 72 72 72 77

15 72 72 72 77

16 72 72 77 77

17 72 72 77 77

18 72 72 77 77

19 72 77 77 77

20 72 77 77 77

21 72 77 77 77

22 72 77 77 77

23 72 77 77 77

24 72 77 77 77
47

Table 5-16 Operating Room Heating and Cooling Set Point Schedules

Hour Heating

(oF)

Cooling

(oF)

1 65 72

2 65 72

3 65 72

4 65 72

5 65 72

6 65 72

7 65 65

8 65 65

9 65 65

10 65 65

11 65 65

12 65 65

13 65 65

14 65 65

15 65 65

16 65 65

17 65 65

18 65 72

19 65 72

20 65 72

21 65 72

22 65 72

23 65 72

24 65 72
48

Figure 5-6 Administrative space set point schedule
49

Figure 5-7 Critical space and operating room set point schedule
50

Each zone in the baseline models used the same equipment schedules (see Table 5-17 and Figure 

5-8).

Table 5-17 Building Equipment Schedule

Hour Critical All 

Days

Administrative 

Weekday

Administrative 

Saturday

Administrative All 

Other Days

1 0.5 0.3 0.3 0.3

2 0.5 0.3 0.3 0.3

3 0.5 0.3 0.3 0.3

4 0.5 0.3 0.3 0.3

5 0.8 0.5 0.3 0.3

6 0.8 0.5 0.3 0.3

7 1.0 1.0 0.3 0.3

8 1.0 1.0 0.5 0.3

9 1.0 1.0 0.5 0.5

10 1.0 1.0 0.8 0.5

11 1.0 1.0 0.8 0.5

12 1.0 1.0 0.8 0.5

13 1.0 1.0 0.8 0.5

14 1.0 1.0 0.8 0.5

15 1.0 1.0 0.8 0.5

16 1.0 1.0 0.5 0.5

17 1.0 1.0 0.5 0.5

18 1.0 1.0 0.5 0.3

19 0.8 0.5 0.5 0.3

20 0.8 0.5 0.5 0.3

21 0.5 0.3 0.3 0.3

22 0.5 0.3 0.3 0.3

23 0.5 0.3 0.3 0.3

24 0.5 0.3 0.3 0.3
51

Figure 5-8 Building equipment schedule
52

Each zone in the baseline models used the same occupancy schedules (see Table 5-18 and Figure 

5-9).

Table 5-18 Building Occupancy Schedule

Hour Critical All 

Days

Administrative 

Weekday

Administrative 

Saturday

Administrative All 

Other Days

1 0.4 0.05 0.05 0.0

2 0.4 0.05 0.05 0.0

3 0.4 0.05 0.05 0.0

4 0.4 0.05 0.05 0.0

5 0.65 0.2 0.05 0.0

6 0.65 0.2 0.05 0.0

7 0.9 0.5 0.05 0.0

8 0.9 0.9 0.2 0.0

9 0.9 0.9 0.2 0.05

10 0.9 0.9 0.3 0.05

11 0.9 0.9 0.3 0.05

12 0.9 0.9 0.3 0.05

13 0.9 0.9 0.3 0.05

14 0.9 0.9 0.3 0.05

15 0.9 0.9 0.3 0.05

16 0.9 0.9 0.2 0.05

17 0.9 0.9 0.2 0.05

18 0.9 0.9 0.2 0.0

19 0.65 0.5 0.2 0.0

20 0.65 0.5 0.2 0.0

21 0.65 0.2 0.05 0.0

22 0.65 0.2 0.05 0.0

23 0.4 0.05 0.05 0.0

24 0.4 0.05 0.05 0.0
53

Figure 5-9 Building occupancy schedule
54

The building SWH schedules are shown in Table 5-19 and Figure 5-10.

Table 5-19 Building SWH Schedule

Hour Weekday Saturday All Other Days

1 0.01 0.01 0.01

2 0.01 0.01 0.01

3 0.01 0.01 0.01

4 0.01 0.01 0.01

5 0.01 0.01 0.01

6 0.01 0.01 0.01

7 0.01 0.01 0.01

8 0.17 0.01 0.01

9 0.58 0.20 0.01

10 0.66 0.28 0.01

11 0.78 0.30 0.01

12 0.82 0.30 0.01

13 0.71 0.24 0.01

14 0.82 0.24 0.01

15 0.78 0.23 0.01

16 0.74 0.23 0.01

17 0.63 0.23 0.01

18 0.41 0.10 0.01

19 0.18 0.01 0.01

20 0.18 0.01 0.01

21 0.18 0.01 0.01

22 0.10 0.01 0.01

23 0.01 0.01 0.01

24 0.01 0.01 0.01
55

Figure 5-10 Building SWH schedule
56

The infiltration schedules and HVAC operational schedules are shown in Table 5-20. The OA 

and fan schedules are the same as the HVAC operational schedules. There are two HVAC 

operation schedules: one for 24-hour critical access areas and another for administrative areas. 

During off hours, the HVAC system is shut off and cycles on only when the setback thermostat 

control calls for heating or cooling to maintain the setback temperature. During unoccupied 

hours, the OA is turned off with motorized dampers. Therefore, no OA is available when the 

system night cycles.

Table 5-20 Infiltration and HVAC Operation Schedules

Hour Infiltration Critical HVAC Operation Administrative HVAC Operation

1 1.0 1.0 0.0

2 1.0 1.0 0.0

3 1.0 1.0 0.0

4 1.0 1.0 0.0

5 1.0 1.0 0.0

6 1.0 1.0 0.0

7 1.0 1.0 1.0

8 1.0 1.0 1.0

9 1.0 1.0 1.0

10 1.0 1.0 1.0

11 1.0 1.0 1.0

12 1.0 1.0 1.0

13 1.0 1.0 1.0

14 1.0 1.0 1.0

15 1.0 1.0 1.0

16 1.0 1.0 1.0

17 1.0 1.0 1.0

18 1.0 1.0 1.0

19 1.0 1.0 0.0

20 1.0 1.0 0.0

21 1.0 1.0 0.0

22 1.0 1.0 0.0

23 1.0 1.0 0.0

24 1.0 1.0 0.0

5.7.2 Low-Energy Model

The schedules used in the low-energy models were the same as the baseline schedules, except 

when schedules were added to model a specific recommendation. One recommendation in the 

AEDG is to schedule the terminal box minimum flow fraction to be 1 during occupied hours (to 

mimic a constant volume box and meet AIA guidelines) and to reduce the minimum flow 

fraction during unoccupied hours of critical spaces to save HVAC energy. These are not critical 

spaces with 24-hour requirements (patient rooms, for example); rather, they are critical spaces 

that have predictable occupied and unoccupied times (such as operating rooms). Two terminal 

box schedules were used: one for humid climate zones and one for the other climate zones. The 

minimum flow fraction for the humid climates is larger than that of the other climates to better 

dehumidify the spaces during unoccupied hours. Climate zones 1A, 1B, 2A, 3A, and 4A use the 

schedule with larger minimum flow fraction values during unoccupied hours.
57

Table 5-21 Building Terminal Box Minimum Flow Fraction Schedule

Hour Humid Locations All Other Locations

1 0.5 0.3

2 0.5 0.3

3 0.5 0.3

4 0.5 0.3

5 0.5 0.3

6 0.5 0.3

7 1.0 1.0

8 1.0 1.0

9 1.0 1.0

10 1.0 1.0

11 1.0 1.0

12 1.0 1.0

13 1.0 1.0

14 1.0 1.0

15 1.0 1.0

16 1.0 1.0

17 1.0 1.0

18 1.0 1.0

19 0.5 0.3

20 0.5 0.3

21 0.5 0.3

22 0.5 0.3

23 0.5 0.3

24 0.5 0.3
58

Figure 5-11 Building terminal box minimum flow fraction schedule
59

5.8 Service Water Heating

5.8.1 Baseline Model

The PC defined the baseline SWH system for the small hospitals and healthcare facilities as a 

gas-fired storage water heater that meets the minimum requirement for medium-sized water 

heaters under Standard 90.1-1999. Gas water heaters were chosen for the baseline to be 

consistent with the use of gas for heating in the baseline prototype buildings. The thermal 

efficiency (Et

The hot water consumption rates were determined as documented in the DOE Benchmark 

Hospital, one of the buildings in the DOE benchmark buildings set (Torcellini et al. 2008). The 

hot water was assumed to be used at 104oF (40oC). The set point of the water heater was 140oF 

(60oC). For reporting purposes in Section 

) of the baseline water heaters is 80% for both ASHRAE 90.1-1999 and ASHRAE 

90.1-2004.

7, the gas use for SWH is stated as “Water Systems.”

5.8.2 Low-Energy Model

The SHC-AEDG provides recommendations for gas-fired storage and electric instantaneous and 

storage service water heaters. The recommendations were based on the K-12 AEDG SWH

recommendations. For our analysis to verify 30% savings, the low-energy models included 90% 

efficient gas storage service water heaters.

5.9 Air Handler Assignment

Air handlers were assigned in the energy model according to the as-built drawings of the 

prototypes provided by the PC. The air handler assignment was consistent for the baseline and 

low-energy models.

The two total air handlers in the surgery center are assigned by floor. A constant air volume 

(CAV) air handler serves the first floor, where the critical healthcare functions are conducted. A 

variable air volume (VAV) system serves the second and third floors, where less critical 

healthcare functions are conducted.

Air handlers in the community hospital (single story) were assigned according to building 

quadrant. Figure 5-12 shows each of the four quadrants in a different color. The red areas are 

administrative spaces and are served by a VAV air handler. The yellow areas are 

mechanical/electrical rooms and storage spaces and are served by a VAV air handler. The blue 

areas contain patient rooms and are served by a CAV air handler without a night air flow setback 

(see Section 5.7.2). The green areas are critical healthcare spaces and are served by a CAV air 

handler with a night air flow setback.
60

Figure 5-12 Community hospital air handling unit (AHU) map

Credit: Eric Bonnema/NREL
61

6. HVAC Systems and Components

Before reviewing the modeling procedure of the HVAC systems and components, Sections 6.1

and 6.2 focus on the importance of sizing equipment to improve the accuracy of simulations and

how the proper sizing routine can be used to streamline whole-building modeling during the 

design process. Section 6.1 defines sizing programs versus whole-building simulation programs 

and why merging their strengths is integral to improving the design process. Section 6.2 reviews 

in depth the comprehensive sizing strategy applied to EnergyPlus to ensure the proper sizing of 

the terminal units serving each zone and the air handling unit (AHU) serving them. The sizing of 

the airside system is the initial—and thus the most crucial—step in sizing an entire HVAC 

system. Section 6.2 shows that when a whole-building simulation program such as EnergyPlus 

is used correctly, it can be used to size the HVAC system and to conduct annual simulations.

These sections review the modeling inputs for the HVAC systems and components, which 

include:

• Section 6.3: Fans

• Section 6.4: Pumps

• Section 6.5: Economizers

• Section 6.6: Packaged Direct Expansion Systems

• Section 6.7: Air-Cooled Chiller Systems

• Section 6.8: Water-Cooled Chiller Systems

• Section 6.9: Cooling Tower Systems

• Section 6.10: Boilers

• Section 6.11: Service Water Heaters

• Section 6.11: Humidifiers.

6.1 Sizing Programs Versus Whole-Building Simulation Programs

The HVAC design industry currently distrusts whole-building simulation programs to size 

HVAC systems. For this document, these programs will be referenced as whole-building 

simulation programs. This distrust stems from two main issues:

• Whole-building simulation programs focus primarily on annual simulation and only 

secondarily on system sizing.

• Whole-building simulation programs do not clearly output the equipment size or provide 

established engineering checks such as cfm/ton, which designers refer to when evaluating 

the legitimacy of the equipment size.

Instead, design engineers use programs that are almost exclusively developed by HVAC 

manufacturers to size HVAC equipment. For this document, these programs will be referenced 

as sizing programs. HVAC engineers trust sizing program due to the following two main issues:

• Sizing programs are dedicated to sizing equipment, and only secondarily to annual 

simulation.
62

• Sizing programs tend to be conservative and typically oversize equipment. This gives the 

designer confidence that the installed equipment will be able to meet peak heating or 

cooling loads.

However, oversizing can provide a false sense of security. For example, oversizing direct 

expansion (DX) rooftop equipment prevents the system from meeting dehumidification load 

under design and part-load conditions. 

On the other hand, the HVAC design community typically does not consider sizing programs to 

be reliable for annual simulation. A great deal of this uncertainty stems from the lack of detailed 

outputs that prevent the user from verifying that the simulation program is functioning properly. 

From an annual simulation perspective, sizing programs typically behave as “black boxes,” and 

the user has limited exposure to the program’s internal calculations.

Some whole-building simulation programs, used correctly, are as accurate as sizing programs. 

Fortunately, EnergyPlus implements robust sizing routines that will size HVAC systems to the 

same level of confidence and conservatism (if deemed by the engineer) as industry-accepted 

sizing programs. Also, ensuring the proper sizing in EnergyPlus is integral to modeling accuracy 

and to integrating whole-building simulation into the standard design process.

From a modeling perspective, the accuracy of the whole-building simulation is contingent on 

correctly sizing and simulating the operating conditions of HVAC equipment. The energy 

performance of such equipment is extremely sensitive to part-load performance. Primary 

equipment—chillers and boilers in particular—experience a wide range of energy performance, 

depending on their part-load operation (see Sections 6.7, 6.8, and 6.10). All too often, capturing 

the part-load performance of primary equipment is emphasized and the validity of the equipment 

size is rarely checked. An accurate model is realized only when both tasks are completed.

From a design perspective, whole-building simulation will become streamlined in a standard 

design process only if design engineers can use it to confidently size their HVAC equipment and 

run annual simulations. Ideally, whole-building simulation and sizing programs can be merged 

into a single program. The whole-building simulation will save time and better reflect the actual 

performance of the system, because the installed equipment sizes will be used in the model. All 

too often, the equipment sizes calculated from the sizing program are not reconciled with the 

sizing calculated by the whole-building simulation program. Consequently, the whole-building 

simulations are based on equipment sizes that differ substantially from the installed ones. 

Streamlining the process of sizing and annual simulation into a single program would alleviate 

this problem.

6.2 Airside System Type and Sizing

The following sections step through the process of calculating the total and ventilation air flow 

rates to maintain comfort and meet the requirements established by AIA 2006 and ASHRAE 

62.1-2004 (ASHRAE 2004c). The procedure begins with sizing the terminal units and then 

sizing the AHU based on the units it serves.

6.2.1 Constant Air Volume, Variable Air Volume, and Exhaust Air Systems

The community hospital and surgery center models consisted of three types of air systems:

• The CAV system maintains a constant air flow rate. The CAV system served air loops 

dominated by critical space types that required stringent air-change and pressurization 
63

requirements, according to AIA 2006. Each zone has its own CAV terminal box that 

modulates a damper based on static pressure fluctuations to ensure a constant flow rate is 

delivered to the zone. Even noncritical spaces served by the CAV system were supplied 

a constant air flow. This design strategy represents HVAC best practices to ensure that 

the positive or negative pressurization requirements of certain critical spaces are not 

compromised. More specifically, VAV terminal units on the same air loop may cause 

rapid static pressure fluctuations such that the CAV dampers would be unable to maintain 

the constant air flow rate necessary to meet the pressurization requirements.

• The VAV system modulates the air flow rate between a peak design and a minimum flow 

rate. The air flow rate varies by modulating the fan speed using a variable frequency 

drive (VFD) attached to the electric motor. In the case of healthcare facilities, the VAV 

system serves air loops with predominantly noncritical spaces (no stringent air change or 

pressurization requirements, based on AIA 2006). VAV systems often serve air loops 

that contain critical spaces, as long they are far fewer than the number of noncritical 

spaces. The critical spaces are still served by CAV terminal boxes and those typically 

allowed to be on a VAV air system do not have pressurization requirements. 

Each zone was served by a VAV terminal box that modulates its damper position, based 

on the zone thermostat to vary flow between a maximum and a minimum flow rate. 

Although the damper position can also be controlled by the space RH or carbon dioxide 

concentration, this additionally sophisticated control is not typically implemented 

because of the RH/carbon dioxide sensor reliability issues and the correct implementation 

of the control based on three inputs instead of one. The main supply fan modulates its 

speed to maintain a constant static pressure at a sensor as far downstream from the AHU 

as possible. The minimum flow rate is typically 30% of the maximum to maintain 

sufficient flow across the fan motor to prevent overheating.

• The exhaust air (EA) system included dedicated exhaust fans serving a critical zone 

required by AIA 2006 to exhaust all the supply air to the outdoors. To prevent crosscontamination, each critical zone requiring exhaust had its own dedicated exhaust fan and 

ductwork.

6.2.2 Terminal Box Sizing

The HVAC sizing methodology begins with calculating the terminal unit size, which is based 

solely on its air flow rate. For the CAV terminal unit, this rate remains constant. For the VAV 

terminal unit, this is the maximum rate. The VAV terminal unit can modulate the air flow rate 

down to a specified minimum air flow rate based on temperature control, reviewed in detail in 

6.2.1. Equation 6-1 summarizes the sizing algorithm.

6-1

Where:

The variable represents the total air flow rate at the design cooling supply air 

condition necessary to offset the design cooling load. The calculation focuses on the sensible 

heat gain of the space; hence the subscript sensible. (See Section 6.2.2.2 for more detail behind 

the calculation procedure.)
64

The variable represents the total air flow rate at the design heating supply air 

condition necessary to offset the design heating load. The calculation focuses on the sensible 

heat loss of the space, hence the subscript sensible. See Section 6.2.2.3 for more detail behind 

the calculation procedure.

The variable represents the total air flow rate mandated by Table 2.1-2 of AIA 2006.

The variable represents the total air flow rate that needs to be supplied onto the space 

to offset the dedicated EA flow rate mandated by Table 2.1-2 of AIA 2006.

The variable represents the total air flow rate necessary to satisfy the ventilation 

requirements of the zone(s) being served. The variable is NOT the ventilation flow rate but 

rather the total air flow rate necessary to ensure that the necessary ventilation air flow rate is 

provided. This is addressed by accounting for the design OA fraction of the AHU serving that 

space. The ventilation requirements are based on Table 2.1-2 of AIA 2006 or the ventilation rate 

procedure specified in ASHRAE 62.1-2004. The calculation procedure is different for CAV 

versus VAV systems. See Section 6.2.2.4 for more detail.

The total air flow and EA flow calculations are straightforward, simply converting the air change 

requirement in Table 2.1-2 of AIA 2006 into a flow rate. The other calculations are more 

involved. Therefore, Sections 6.2.2.1 and 6.2.2.4 include more detail behind the calculation 

procedure for the variables sensible cooling/heating, and OA flow rates, respectively. Section 

6.2.2.5 steps through the calculation of all the air flow rates for a north-facing patient room in 

Chicago to ultimately determine the CAV terminal unit size.

6.2.2.1 Calculating Sensible Air Flow Rates

Sensible air flow rates are calculated based on a guarantee that a comfortable space, dry bulb 

temperature dead band is maintained during peak load conditions. The calculation procedure is 

the same for both flow rate requirements. The two main parameters needed are the space peak 

cooling or heating load and the dry bulb temperature difference between the set point and the

supply air condition.

The rest of the section specifies the set points and supply air conditions used in sizing the 

terminal boxes for the AEDG modeling process and the reasoning behind these design values.

6.2.2.2 Calculating Sensible Cooling Air Flow Rates

The cooling supply air condition is dictated by dehumidification needs. The supply air needs to 

have a low moisture content to ensure the space never exceeds a design peak RH. Although 

ASHRAE 62.1-2004 specifies the peak RH to be 65%, the PC specified that 60% should be used 

based on design best practices. The design community has established approximately 52° to 

55°F (11° to 13°C) dry bulb supply off the cooling coil as a rule of thumb, because its associated 

moisture content (approximately 50 gr/lb [7.2 g/kg]) is low enough to offset the latent gains from 

occupants, process loads, and infiltration of moist air.

The PC specified different supply air conditions for CAV than for VAV systems as an 

established best practice (see Table 6-1). The CAV supply dry bulb temperature and humidity 

ratio are lower as added safety factors to guarantee that these spaces, which fall under the critical 

care category, will be sufficiently cooled and dehumidified. Figure 6-1 plots the cooling set 

point and cooling design supply conditions on the psychrometric chart.
65

Table 6-1 Cooling Set Point and Cooling Supply Air Conditions

Dry Bulb Temperature* Humidity Ratio

Cooling set point 72°F 71 g/lb

CAV cooling supply 52°F 49 g/lb

VAV cooling supply 55°F 55 g/lb

* Includes the sensible heat gain across the fan.

6.2.2.3 Calculating Sensible Heating Air Flow Rates

Unlike the cooling supply air condition, the heating supply air condition does not need to take 

into account the latent needs of the space. The humidifier, if one is needed, will ensure the 

supply air has adequate moisture to maintain a minimum design RH. (See Section 6.12 for more 

detail about the AHU humidifier.) Instead, the heating supply air condition is based on the 

performance limitation of the reheat coil to ensure the ventilation air supplied to the space 

reaches the breathing zone. Reheat performance and ventilation effectiveness are based on the 

design heating supply dry bulb temperature.

Whether in heating, cooling, or economizing mode, the supply air leaving the AHU is 

maintained at a constant 52°F (11°C) dry bulb temperature for a CAV and 55°F (13°C) dry bulb 

temperature for a VAV system. It depends on the reheat coil, whether electric resistance or 

heating hot water (HHW), to heat the air to the design heating supply dry bulb temperature. The 

higher that temperature, the greater the heating rate the reheat coil needs to provide. For an 

electric resistance reheat coil, this may mean an unrealistically large power draw. For an HHW 

reheat coil, this may mean higher hot water supply and return temperatures, which degrade boiler 

performance, increase HHW pump power, and may require two row coils that add an 

unnecessary pressure drop to the supply fan.

Hot design heating supply temperatures will compromise the ability of the supply ventilation air 

to reach the breathing zone. Because of buoyancy, the hotter the incoming air relative to the 

space temperature, the greater percentage of the supply air remains at the ceiling, where it short 

circuits via the return grill without entering the breathing zone. ASHRAE 62.1-2004 quantifies 

this behavior by assigning a ventilation effectiveness for a given supply and return grill 

configuration (ceiling supply and return) and temperature difference between the supply air and 

the space set point. Based on Table 6-2 in ASHRAE 62.1-2004, the “ceiling supply of warm air 

15°F (8°C) or more above the space temperature and ceiling return” has a ventilation 

effectiveness of 0.8 (ASHRAE 2004c). As a result, this Standard stipulates ventilation flow rate 

based on the per-occupant and per-area requirements would need to be increased by 20% to 

account for a ventilation effectiveness of 0.8. To achieve a ventilation effectiveness of unity 

under ASHRAE 62.1-2004, the design heating supply air temperature should be lower than 85°F 

(29°C) with a 70°F (21°C) heating set point.

However, healthcare design practitioners do not typically increase ventilation levels to account 

for ventilation effectiveness based on design heating supply temperatures of 85°F (29°C) or 

higher. Healthcare spaces are internal load driven and mitigate infiltration through 

pressurization, so terminal units need heating for short durations only. Furthermore, during these 

brief heating episodes, the supply temperature will rarely be above 85°F (29°C). The PC 

therefore recommended the design heat supply temperature be set to 95°F (35°C) as established 

best practice. Table 6-2 shows the heating set point and design supply air conditions. Figure 6-1

plots the heating set point and heating design supply conditions on the psychrometric chart.
66

Table 6-2 Heating Set Point and Heating Supply Air Conditions

Dry Bulb Temperature*

Heating set point 70°F

CAV–VAV heating supply 95°F

* Includes sensible heat gain across the fan.

Figure 6-1 Psychrometric chart showing space set points and supply air conditions

6.2.2.4 Calculating Outdoor Air Flow Rate

The calculation of the OA flow rate guarantees that the space served by the terminal unit is 

provided the required ventilation flow rate, based on Table 2.1-2 of AIA 2006 or the ventilation 

rate procedure of ASHRAE 62.1-2004. The OA flow rate is not the ventilation flow rate but the 

total air flow rate of the terminal unit. The following sections discuss the difference in the 

calculation procedure between CAV and VAV systems.

6.2.2.4.1 Constant Air Volume System

The calculation of the OA flow rate for a CAV system is straightforward because the OA 

fraction remains constant. The AHU OA fraction is specified by the mechanical engineer and 

typically ranges from 0.25 to 0.35. The CAV AHUs on the surgery center and community

hospital models used a constant 0.33 OA ratio, which is based on the patient room OA ratio of 2 

air changes of ventilation for every 6 air changes of total air flow (from Table 2.1-2 of AIA 

2006). Therefore, the ventilation air flow requirements are simply divided by the OA ratio, 0.33 

in the AEDG models case, to determine the total air flow necessary to ensure proper ventilation.
67

6.2.2.4.2 Variable Air Volume System

The calculation of the OA flow rate for a VAV system is more complicated, because neither the 

OA fraction nor the air flow rates through the VAV terminal units remain constant. First, the 

OA requirements for each space must be calculated based on Table 2.1-2 of AIA 2006 or the 

ventilation rate procedure of ASHRAE 62.1-2004. The ASHRAE 62.1-2004 ventilation rate 

procedure for multizone systems outlines in detail how to compile these individual space 

ventilation flow rate requirements into the OA flow rates required of the AHU. (Refer to the 

ASHRAE 62.1-2004 ventilation rate procedure and ASHRAE 62.1-2004 users’ manual for 

explicit step-by-step instructions and examples for properly calculating the system’s OA fraction 

and VAV terminal box minimum flow fraction.) Based on the experience of the PC, VAV 

systems typically have a 0.25 OA fraction.

6.2.2.5 Example Patient Room Constant Air Volume Terminal Unit Calculation

The following illustrates the sizing of a terminal unit serving a north-facing patient room in 

Chicago. Table 6-3 provides a high-level overview of the information necessary for calculating 

the air flow rates for the patient room.

Table 6-3 Patient Room Geometry, Envelope Characteristics, and Internal Loads

Category Value

Floor area 225 ft

Floor-to-ceiling height

2

10 ft

Room volume 2,250 ft

Glazing geometry

3

4 ft × 5 ft punched window

Opaque wall R-value = 15 h·ft2

Glazing properties

·°F/Btu

SHGC = 0.25/U-factor = 0.5 Btu/h·ft2

Occupant density

·°F

7 occupants /1000 ft

Lighting power density

2

1.2 W/ft

Process power density

2

2.0 W/ft

Design infiltration rate

2

0.2 cfm/ft2-external wall

Before diving into the calculations, the type of terminal unit (CAV or VAV) serving the patient 

room must be determined. According to Table 2.1.1 of AIA 2006, the patient room must have 6

air changes per hour (ACH) total flow rate and 2 ACH ventilation flow rate. These required total 

and ventilation constant air flow rates mean that a CAV terminal unit will serve the patient room. 

The next step is to determine whether the CAV terminal unit is served by a CAV or VAV AHU. 

Patient rooms are typically grouped into patient wings along with other spaces served by CAV 

terminal units, so the patient room in this example will be served by a CAV AHU. Section 6.2.1

explains in more detail the methodology behind specifying a CAV or VAV system.

6.2.2.5.1 Total Air Flow Rate

Based on Table 2.1.1 of AIA 2006, the patient room must have 6 ACH total flow rate, which 

equates to 225 cfm (106 L/s).

6.2.2.5.2 Exhaust Air Flow Rate

Based on Table 2.1.1 of AIA 2006, the patient room has no exhaust requirements.
68

6.2.2.5.3 Sensible Cooling Air Flow Rate

The calculation procedure first requires the space peak cooling load. Table 6-4 summarizes the 

patient room peak cooling load breakdown. The cooling set point and cooling supply air dry 

bulb temperatures are based on Table 6-1. Equation 6-2 shows the calculation procedure to 

determine the sensible cooling air flow rate.

Table 6-4 Patient Room Envelope and Internal Heat Gains

Category Cooling Load

Wall conduction 164 Btu/h

Window conduction 190 Btu/h

Window solar 315 Btu/h

Infiltration sensible 615 Btu/h

Occupant 400 Btu/h

Lighting 922 Btu/h

Process 1,536 Btu/h

Total heat gain 4,142 Btu/h

6-2

6-3

6-4

6.2.2.5.4 Sensible Heating Air Flow Rate

The calculation of the space peak heating load is summarized in Table 6-5. The heating set point 

and heating supply air dry bulb temperatures are based on Table 6-2. Equation 6-5 shows the 

calculation procedure to determine the sensible heating air flow rate.

Table 6-5 Patient Room Envelope and Internal Heat Losses

Category Heating Load

Wall conduction –692 Btu/h

Window conduction –760 Btu/h

Window solar –

Infiltration sensible –2,462 Btu/h

Occupant 400 Btu/h

Lighting –

Process –

Total heat gain –3,514 Btu/h

6-5

6-6

6-7
69

6.2.2.5.5 Outdoor Air Flow Rate

Based on Table 2.1.1 of AIA 2006, the patient room must have 2 ACH ventilation flow rate. 

This equates to 74 cfm (35 L/s). An OA fraction of 0.33 is specified by the mechanical engineer.

6-8

6.2.2.5.6 Terminal Unit Size

Table 6-6 compiles the air flow requirements based on the different sizing criteria. As shown, 

the total air flow and OA flow criteria are the largest; thus, the CAV terminal unit serving the 

patient room is sized to 225 cfm (106 L/s).

Table 6-6 CAV Terminal Unit Size for Example Patient Room

Requirement Air Flow Rate Description

 192 cfm Meeting peak cooling load

 130 cfm Meeting peak heating load

 225 cfm 6 ACH total flow per AIA 2006, Table 2.1-2

 – No requirement per AIA 2006, Table 2.1-2

 225 cfm 2 ACH ventilation flow per AIA 2006,

Table 2.1-2 and 0.33 OA fraction

6.2.3 Air Handing Unit Sizing

The AHU size is defined by its peak flow rate and is a summation of the terminal unit air flows it 

serves. There are two methods to sum the air flows: coincident and noncoincident. The 

coincident method sizes the AHU air flow rate based on the sum of the coincident zone air flows. 

Noncoincident sizes the AHU air flow rate based on the sum of the noncoincident zone air flows. 

The CAV systems used noncoincident sizing; the VAV systems used coincident sizing.

6.3 Fans

EnergyPlus requires three inputs to define the performance characteristics of a fan:

• Total static pressure drop across the fan at the design flow rate

• Fan, motor, and belt drive combined efficiency at the static pressure and flow rate

• Fan power part-load factor (PLF) curve that defines the power draw of a variable-speed 

fan as it ramps down from its full load condition.

6.3.1 Static Pressure Drop

The total static pressure drop across the fan is the summation of the internal and external 

pressure drops. The internal pressure drop is the pressure force the fan needs to exert to 

overcome the friction imposed on the air flow by the AHU’s internal components, such as the 

heating and cooling coils and filters. Table 6-7 provides the PC-recommended breakdown of the 

component pressure drops. The critical CAV system experiences an additional 1.5 in. w.c. (375 

Pa) because a MERV 14 or greater filter is required, per AIA 2006. The PC recommended that 

the low-energy model experience lower internal pressure drops by increasing the heating and 

cooling coils’ cross-sectional area to reduce face velocity and therefore pressure drop.
70

Table 6-8 reviews the internal pressure drop associated with the return fan. The noncritical VAV 

system low-energy cooling coil pressure drop was supposed to decrease to 0.75 in. w.c. (187 Pa) 

like the critical CAV system low-energy cooling coil.

Table 6-7 Baseline and Low-Energy Supply Fan Internal Static Pressure Drop Breakdown

Device

Critical CAV System Noncritical VAV System

Baseline Low-Energy Baseline Low-Energy

Heating coil 0.5 in. w.c. 0.25 in. w.c. 0.5 in. w.c. 0.25 in. w.c.

Cooling coil 1.0 in. w.c. 0.75 in. w.c. 1.0 in. w.c. 1.0 in. w.c.

25% filter 0.5 in. w.c. 0.5 in. w.c. 0.5 in. w.c. 0.5 in. w.c.

95% filter 1.5 in. w.c. 1.5 in. w.c. – –

Total 3.5 in. w.c. 3.0 in. w.c. 2.0 in. w.c. 1.75 in. w.c.

* Average of clean and dirty filters.

Table 6-8 Baseline and Low-Energy Return Fan Internal Static Pressure Drop Breakdown

Device

Critical CAV System Noncritical VAV System

Baseline Low-Energy Baseline Low-Energy

Motorized damper 0.25 in. w.c. 0.25 in. w.c. 0.25 in. w.c. 0.25 in. w.c.

Total 0.25 in. w.c. 0.25 in. w.c. 0.25 in. w.c. 0.25 in. w.c.

The external pressure drop is the pressure force the fan needs to exert to overcome the friction 

imposed by components, namely ductwork, external to the AHU. Table 6-9 shows the external 

pressure drop breakdown recommended by the PC. Guidance for reducing this drop is provided 

in the SHC-AEDG. The low-energy model experiences 0.5 in. w.c. (125 Pa) less pressure drop 

through a better engineered outlet transition with turning vanes and larger ductwork.

Table 6-9 Baseline and Low-Energy Supply Fan External Static Pressure Drop Breakdown

Device

Critical CAV System and Noncritical VAV System

Baseline Low-Energy

Inlet transition 0.1 in. w.c. 0.1 in. w.c.

Outlet transition 0.4 in. w.c. 0.2 in. w.c.

Duct mains 1.0 in. w.c. 0.8 in. w.c.

Duct branches 0.5 in. w.c. 0.4 in. w.c.

Terminal box 0.5 in. w.c. 0.5 in. w.c.

Total 2.5 in. w.c. 2.0 in. w.c.

* Includes sound attenuation and electric or hot water coil.
71

Table 6-10 Baseline and Low-Energy Return Fan External Static Pressure Drop Breakdown

Device

Critical CAV System Noncritical VAV System

Baseline Low-Energy Baseline Low-Energy

Plenum/duct mains 1.5 in. w.c. 1.5 in. w.c. 1.5 in. w.c. 1.5 in. w.c.

Total 1.5 in. w.c. 1.5 in. w.c. 1.5 in. w.c. 1.5 in. w.c.

Table 6-11 and Table 6-12 show the combined internal and external pressure drops for the 

supply and return fans, respectively. The low-energy model realizes a 1.0 in. w.c. (250 Pa) 

reduction for the CAV System and 0.75 in. w.c. reduction for the VAV system. As previously 

stated, the VAV system low-energy cooling coil pressure drop was supposed to decrease to 0.75 

in. w.c. (187 Pa) such that the low-energy model realized a 1.0 in. w.c. (250 Pa) total static 

pressure drop reduction.

Table 6-11 Baseline and Low-Energy Supply Fan Total Static Pressure Drop Breakdown

Device Critical CAV System Noncritical VAV System

Baseline Low-Energy Baseline Low-Energy

Internal pressure drop 3.5 in. w.c. 3.0 in. w.c. 2.0 in. w.c. 1.75 in. w.c.

External pressure drop 2.5 in. w.c. 2.0 in. w.c. 2.5 in. w.c. 2.0 in. w.c.

Total static pressure drop 6.0 in. w.c. 5.0 in. w.c. 4.5 in. w.c. 3.75 in. w.c.

Table 6-12 Baseline and Low-Energy Return Fan Total Static Pressure Drop Breakdown

Device

Critical CAV System Noncritical VAV System

Baseline Low-Energy Baseline Low-Energy

Internal pressure drop 0.25 in. w.c. 0.25 in. w.c. 0.25 in. w.c. 0.25 in. w.c.

External pressure drop 1.5 in. w.c. 1.5 in. w.c. 1.5 in. w.c. 1.5 in. w.c.

Total static pressure drop 1.75 in. w.c. 1.75 in. w.c. 1.75 in. w.c. 1.75 in. w.c.

EnergyPlus cannot model a supply and a return fan separately. Therefore, with the approval of 

the PC, the EnergyPlus models used an “equivalent fan” that represented the combined 

performance of the supply and return fans. The equivalent fan was assigned a total static 

pressure drop equal to summation of the supply and return fan total static pressure drop shown in

Table 6-13. Yet to capture the performance of the supply and return fans, a special calculation 

procedure was needed to determine the equivalent fan combined fan-motor-belt efficiency based 

on the performance characteristics of the supply and return fans. Section 6.3.3 provides an 

example of the equivalent fan combined efficiency calculation procedure.

Table 6-13 Baseline and Low-Energy Equivalent Fan Total Static Pressure

Device Critical CAV System Noncritical VAV System

Baseline Low-Energy Baseline Low-Energy

Total static pressure drop 7.75 in. w.c. 6.75 in. w.c. 6.25 in. w.c. 5.50 in. w.c.

6.3.2 Motor-Belt-Fan Efficiency

The combined efficiency is defined by the delivered power to the motor relative to the delivered 

power to the air and is a function of the motor efficiency, belt-drive efficiency, and fan 

efficiency. Multiplying all these efficiencies together provides a combined efficiency. The fan 
72

performance requirements in ASHRAE 90.1 are stringent, so both the baseline and the lowenergy fans had National Electric Manufacturers Association (NEMA) premium efficiency 

motors. Appendix H.2 shows the NEMA premium efficiency based on the motor size.

The belt-drive losses can be significant, and depend on the type of belt used. A standard V-belt 

has a wide efficiency range of 90% to 97%. A cogged belt has a tighter efficiency range of 94%

to 98%. Fortunately, direct drive motors, even in larger sizes, are becoming more common in 

healthcare design. Again, because of the stringent requirements of ASHRAE 90.1, the baseline 

and low-energy fans were modeled as direct drive such that no belt-drive losses were incurred.

The fan efficiencies depend mainly on the fan type and configuration. The PC recommended 

single-width, single-inlet centrifugal airfoil plenum fans for the supply and return fans. The 

Loren Cook Compute-A-Fan program (Loren Cook 2009) was used to calculate the supply and 

return fan static efficiency based on the total static pressure drops in Table 6-11 and Table 6-12.

The design flow rates based on the surgery center model are shown in Table 6-14. The surgery 

center design flow rates were chosen as a typical ratio of supply, return, and dedicated exhaust 

air flow rate for critical and noncritical systems.

Table 6-14 Surgery Center Design Flow Rates

Device

Critical CAV System Noncritical VAV System

Supply Return Exhaust Supply Return Exhaust

Flow rates 25,000 cfm 20,000 cfm 5,000 cfm 20,000 cfm 17,000 cfm 3,000 cfm

Static pressure efficiency was chosen over total pressure efficiency. Space in healthcare 

mechanical rooms is so limited that an insufficient length of straight duct is provided at the 

discharge of the fan. Consequently, the velocity pressure does not have sufficient straight duct 

length to convert to static pressure, also known as static regain. To be on the conservative side, 

the velocity pressure is assumed to dissipate to heat. This is the reason for using plenum fans, 

which are designed to maximize static pressure at the fan discharge with minimal velocity 

pressure. As is typical of programs from most fan manufacturers, the fan selection program 

provides only the static efficiency, labeled SE in Figure 6-2.

Because ASHRAE 90.1 fan performance requirements are so stringent, the same high static 

efficiencies were specified for the baseline and low-energy fans (see Table 6-15). Therefore, the 

low-energy model would realize fan energy savings only through the lower total static pressure 

drops shown in Table 6-13.
73

Figure 6-2 Baseline supply fan selection

Credit: Ian Doebber/NREL

Table 6-15 Baseline and Low-Energy Fan Static Efficiency

Device

Critical CAV System Noncritical VAV System

Supply Return Supply Return

Fan static efficiency 76% 70% 76% 74%

With the total static pressure drops and motor-belt-fan efficiencies known for the supply and 

return fans, a combined efficiency was calculated for the equivalent fan. The best way to review 

the calculation procedure is through an example in Section 6.3.3.

6.3.3 Equivalent Fan Combined Efficiency Example Calculation

Table 6-16 shows an example calculation of the combined efficiency for the surgery center 

baseline critical CAV system based on the supply and return fan performance characteristics.
74

Table 6-16 Baseline Critical CAV System Supply and Return Fan Performance Characteristics

Device

Critical CAV System

Supply Return

Design flow rate 25,000 cfm 20,000 cfm

Total static pressure drop 6.0 in. w.c. 1.75 in. w.c.

Fan static efficiency 76% 70%

Motor efficiency 93.6% 91.7%

Belt efficiency 100% 100%

The supply fan performance characteristics in Table 6-16 are used to calculate its power draw

(Rabi and Kreider 1994).

6-9

The return fan performance characteristics in Table 6-16 are used to calculate its power draw.

6-10

The supply and return fan power draws are summed.

6-11

The supply and return fan total static pressures are summed.

6-12

Using the 25,000 cfm (11,800 L/s) supply flow rate, the total power draw, and the total static 

pressure of the equivalent fan, the combined efficiency can be calculated.

6-13

6-14

Therefore, the equivalent fan modeled with performance characteristics of 25,000 cfm (11,800 

L/s), 7.75 in. w.c. (1930 Pa), and 73% combined efficiency will consume the same amount of 

power as if the supply and return fans were modeled separately. Table 6-17 shows the total static 

pressure drop and combined efficiency for the equivalent fans used in the baseline and lowenergy models.
75

Table 6-17 Baseline and Low-Energy Equivalent Fan Total Static Pressure

Device

Critical CAV System Noncritical VAV System

Baseline Low-Energy Baseline Low-Energy

Total static pressure drop 7.75 in. w.c. 6.75 in. w.c. 6.25 in. w.c. 5.50 in. w.c.

Fan-motor-belt combined efficiency 73% 73% 73% 73%

6.3.4 Fan Power Part-Load Factor Curve

EnergyPlus does not model a system curve and fan curve to determine the power consumption 

by the fan at each time step. Instead, it combines the two curves into a single one defined as the 

PLF curve. This provides a relationship between the fraction of full flow at which a fan operates 

and the associated fraction of peak power consumption at full flow. This curve is needed for 

VAV system only, where the flow rate can modulate. CAV systems always maintain maximum 

flow at maximum power draw.

Although ASHRAE 90.1-2004 specifies a fan power PLF curve in Table G3.1.3.15, a fan power 

PLF curve based on a 0.5 in. w.c. (125 Pa) static pressure reset was used instead. The PLF curve 

was obtained from Energy Design Resources (2007). The static pressure reset in ASHRAE 90.1-

2004 6.5.3.2.3 stipulates that the static pressure set point will be reset based on the zone 

requiring the most pressure. In other words, the static pressure is set downward until one 

terminal box damper is fully open. Figure 6-3 compares the fan power PLF curves, indicating 

that the 0.5 in. w.c. (125 Pa) static pressure reset curve will provide greater fan savings when the 

fan operates at 20% to 100% of its flow.

The PLF curve methodology indicates the importance of not having the design flow rate 

incorrectly oversized (see Table 6-18). For example, assume a VAV AHU is incorrectly sized 

for a maximum flow rate of 30,000 cfm (14,160 L/s), based on standard sizing methodology. 

Correctly sized, the maximum design flow rate should have been 27,000 cfm (12,740 L/s); 90% 

of 30,000 cfm (14,160 L/s). The fan flow fraction at each time step will be artificially low, 

which in turn will artificially reduce the fan power fraction. Therefore, the fan power at each 

time step will be artificially low.
76

Figure 6-3 Fan power PLF curves

Credit: Ian Doebber/NREL

Table 6-18 Fan Power PLF Curve Coefficients

Coefficients 90.1-2004 Appendix G Table G3.1.3.15

Method 2

Stein/Hydeman “Good SP Reset”

(0.5 in. w.c.)

C1 0.0013 0.0408

C2 0.1470 0.0880

C3 0.9506 –0.0729

C4 –0.0998 0.9437

6.3.5 ASHRAE 90.1-2007 Fan Performance

ASHRAE 90.1 fan performance requirements are extremely stringent for healthcare facilities, 

where fans need to overcome large internal pressure drops from required high efficiency filters. 

Although ASHRAE 90.1 provides pressure credits for air systems requiring high levels of 

filtration, the performance requirements still mandate that the mechanical designer reduce 

internal pressure drop through lower face velocities, reduce external pressure drop through 

improved duct design, and install high-efficiency motors, belts, and fans. Although the baseline 

for the AEDG is ASHRAE 90.1-1999, the fan power limitations shown in Table 6-19 are based 

on ASHRAE 90.1-2007 calculations based on recommendation by the PC. (The AEDG 

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Fan Flow Fraction

Fan Power Fraction

90.1-2004 Table G3.1.3.15

Energy Design Resources 2007
77

recommendation tables reference the ASHRAE 90.1-2007 (ASHRAE 2007) calculations for fan 

performance.)

Table 6-19 provides the pressure drop adjustments for the two types of air systems. Then 

Equations 6-15 through 6-20 calculate the minimum fan performance in bhp per 1000 cfm (470 

L/s) using the ASHRAE 90.1-2007 procedure specified in Table 6.5.3.1.1A and the pressure 

credits from Table 6-19. As shown, the minimum performance requirements are much more 

stringent for the CAV system than for the VAV system. Table 6-20 compares ASHRAE 90.1-

2007 fan performance requirements to those used for the baseline and low-energy systems.

Table 6-19 Fan Power Limitation Pressure Drop Adjustment (90.1-2007 Table 6.5.3.1.1B)

Device Critical CAV System Noncritical VAV System

Ducted return credit 0.50 in. w.c. 0.50 in. w.c.

Return dampers credit 0.50 in. w.c. –

Filter credit 0.90 in. w.c.* 0.50 in. w.c.**

Sound attenuator 0.15 in. w.c. 0.15 in. w.c.

Total 2.05 in. w.c. 1.15 in. w.c.

* Critical care system requires 95% filtration

** Noncritical care system requires 85% filtration

Table 6-20 ASHRAE 90.1-2007 Versus Baseline and Low-Energy Equivalent Fan Performance

Device

Critical CAV System Noncritical VAV System

90.1-2007 Baseline Low-Energy 90.1-2007 Baseline Low-Energy

bhp/1000 cfm 

performance 1.4 1.7 1.4 1.6 1.4 1.2

6.3.5.1.1 Constant Air Volume—Critical Care Fan Power Limitation

bhp ≤ cfm · 0.00094 + A 6-15

bhp ≤ 1000 cfm · 0. 00094 + (2.05*1000 cfm/4,131) 6-16

≤ 1.4 bhp/1000 cfm 6-17

6.3.5.1.2 Variable Air Volume—Noncritical Care Fan Power Limitation

bhp ≤ cfm · 0.0013 + A 6-18

bhp ≤ 1000 cfm · 0.0013 + (1.15*1000 cfm/4,131) 6-19

≤ 1.6 bhp/1000 cfm 6-20

6.3.6 Dedicated Exhaust Fan Performance

The dedicated exhaust fan performance characteristics are shown in Table 6-21. The PC 

recommended a belt-driven, down-blast centrifugal fan as the standard fan type. Like the supply 

and return fans, the static pressure efficiency was used. The low-energy fan achieves a higher 

static efficiency because it operates at a more efficient point on its fan curve (see Appendix H.1). 

There are no efficiency standards for the motors serving these exhaust fans, as they are smaller 

than 1 hp (745 kW). The baseline motor efficiency was based on the minimum efficiency for a 

1-hp motor prior to the Energy Policy Act of 2005. The low-energy motor efficiency was based 

on the NEMA premium efficiency for a 1-hp (745 kW) motor. The baseline belt efficiency 

represented a high drive loss; the low-energy belt efficiency represented a low drive loss.
78

Table 6-21 Dedicated Exhaust Fan Baseline and Low-Energy Performance Characteristics

Performance Characteristics Baseline Low-Energy

Total static pressure drop 1.0 in. w.c. 1.0 in. w.c.

Fan static efficiency 47% 60%

Motor efficiency 76.7% 85.5%

Belt efficiency 85% 89%

Combined efficiency 31% 46%

6.4 Pumps

The constant and variable-speed pumps in the baseline and low-energy models were modeled 

with the performance characteristics in Table 6-22. Brief descriptions about each of these 

performance characteristics follow.

• Intermittent pump operation means that the pump operates only when there is a load 

on the plant loop.

• The design pump flow rate is autosized based on the plant loop peak load calculated 

during the EnergyPlus design day sizing run and the design loop temperature 

difference, which are stated in Table 6-24 through Table 6-27.

• The rated pump power is autosized based on the design pump flow rate, rated pump 

head, motor efficiencies, and pump efficiencies stated in Table 6-24 through Table 

6-27.

• The minimum pump flow rate is used for variable-speed pumps only.

• The percentage of motor heat transferred to the fluid was specified as 0%, meaning 

that none of the motor heat affected the fluid temperature leaving the pump.

Table 6-22 Pump Performance Inputs

Performance Characteristics Baseline and Low-Energy

Pump operation Intermittent

Design pump flow rate autosized

Rated pump power autosized

Minimum pump flow rate 0 gpm

Percentage of motor heat to fluid 0%

The pump power PLF curve in Table 6-23 applies to variable-speed pumps only. The 

coefficients dictate that the pump motor power varies linearly from 0 to design pump power 

based on a plant loop flow rate varying from 0 to design pump flow rate.

Table 6-23 Variable-Speed Pump Power PLF Curve Coefficients

Coefficients Baseline and Low-Energy

C1 0

C2 1

C3 0

C4 0
79

The following sections specify the pump performance characteristics specific to each loop. The 

motor efficiency derives from an approximation of a NEMA premium efficiency motor based on 

an estimation of the motor size.

6.4.1 Heating Hot Water Pumps

In accordance with the specification for facilities smaller than 120,000 ft2 (11,150 m2

Table 6-24

) in 

ASHRAE 90.1-2004, Appendix G3.1.3.5, the heating hot water (HHW) system comprises a 

primary only loop with constant speed pumps. reviews the HHW pump performance 

characteristics. The pump is constant speed, so the heating hot water return (HHWR)

temperature will float based on the heating demand on the loop.

Table 6-24 HHW Pump Performance Characteristics

Performance Characteristics Baseline and Low-Energy

Capacity modulation Constant speed

Rated pump head 60 ft w.c.

Motor efficiency 90%

Pump efficiency 100%

Design leaving temperature 180°F

Design return temperature 160°F

Design loop temperature difference 20°F

The low-energy model incorporates a heating hot water supply (HHWS) temperature OA reset 

schedule (see Figure 6-10). Even though the supply temperature changes, the HHW pump still 

maintains a constant flow rate. A variable-speed pump would have modulated the flow rate to 

maintain the constant design loop temperature difference.

6.4.2 Chilled Water Pumps

ASHRAE 90.1-2004, Appendix G3.1.3.10 stipulates that the chilled water system comprise a 

primary and a secondary loop (see Table 6-25). The PC found that for chilled water plants in the 

size range for small hospital and healthcare facilities, the design community is shifting toward 

primary loop only. Therefore, the PC recommended a primary loop only configuration. The 

primary/secondary loop stipulation has become antiquated, as chiller manufacturers no longer 

dictate that the chiller water through the chiller evaporator maintain a constant flow rate. Typical 

minimum flow rate is 40% for a centrifugal chiller and 50% for a scroll or screw chiller. A more 

aggressive minimum flow rate is possible, but can have negative impacts on chiller operation and 

maintenance. The design leaving temperature and design return temperature are based on AirConditioning and Refrigeration Institute (ARI) Standard 550-590. The variable-speed pump 

modulates the flow rate to maintain the constant design loop temperature difference.

Table 6-25 Chilled Water Pump Performance Characteristics

Performance Characteristics Baseline and Low-Energy

Capacity modulation Variable speed

Rated pump head 60 ft w.c.

Motor efficiency 90%

Pump efficiency 100%

Design leaving temperature 44°F

Design return temperature 56°F

Design loop temperature difference 12°F
80

6.4.3 Condenser Water Pumps

The capacity modulation of the condenser water pump is not specifically stated in ASHRAE 

90.1-2004, Appendix G3.1.3.11. The PC stated that variable-speed condenser pumps are by far 

the exception because of fears about the control of a cooling tower variable-speed fan and 

variable-speed condenser pump. Improved chilled water plant controls are now being 

implemented in conjunction with variable-speed cooling tower fans and condenser pumps that 

have shown energy savings without controllability or maintenance issues. Despite this proven 

capability, the PC recommended constant-speed condenser pumps because they are the typical 

design (see Table 6-26).

Table 6-26 Condenser Water Pump Performance Characteristics

Performance Characteristics Baseline and Low-Energy

Capacity modulation Constant speed

Rated pump head 60 ft w.c.

Motor efficiency 87%

Pump efficiency 100%

Design leaving temperature 85°F

Design return temperature 100°F

Design loop temperature difference 15°F

The PC also recommended a 15°F (8°C) condenser design loop temperature difference as the 

standard design practice for chilled water plants, instead of the 10°F (6°C) condenser loop 

temperature difference specified in ASHRAE 90.1-2004 Appendix G3.1.3.11. The intent is to 

reduce the condenser flow rate to reduce the condenser pump power draw, which can be 

substantial with at least 60 ft (18 m) of head pressure. With a constant-speed pump, all the 

condenser heat rejection is modulated by the cooling tower variable-speed fan. Section 6.9

reviews the design and operation of the cooling tower fan and condenser pump in further detail.

6.4.4 Domestic Hot Water Pumps

The domestic hot water loop is a primary-only loop served by a VFD pump. Table 6-27 reviews 

the performance characteristics of the domestic hot water pump. The motor efficiency derives 

from an approximation of a NEMA premium efficiency motor based on an estimation of the 

motor size.

Table 6-27 Domestic Hot Water Pump Performance Characteristics

Performance Characteristics Baseline and Low-Energy

Capacity modulation Variable speed

Rated pump head 60 ft w.c.

Motor efficiency 90%

Pump efficiency 100%

Design leaving temperature 140°F

Design return temperature 131°F

Design loop temperature difference 9°F

6.5 Economizers

Although ASHRAE 90.1 does not require economizers for systems that include nonparticulate 

air treatment, the PC recommended that small hospital and healthcare facilities typically 

incorporate them. Therefore, economizers were included in all climate zones (except those that 
81

are exempt in 90.1 because of extremely hot or humid conditions). ASHRAE 90.1-2007, Table 

6.5.1 states that climate zones 1A, 1B, 2A, 3A, and 4A are not required to have economizers. 

Table 6-28 indicates which of the 15 climates included economizers for the critical CAV and 

noncritical VAV systems. Both the baseline and low-energy models had economizers, climate 

permitting, with identical control configurations.

Table 6-28 Climates Modeled With Economizers

Location Climate Zone Economizer

Miami, Florida 1A –

Houston, Texas 1A –

Phoenix, Arizona 2B Yes

Memphis, Tennessee 3A –

El Paso, Texas 3B Yes

San Francisco, California 3C Yes

Baltimore, Maryland 4A –

Albuquerque, New Mexico 4B Yes

Seattle, Washington 4C Yes

Chicago, Illinois 5A Yes

Boise, Idaho 5B Yes

Burlington, Vermont 6A Yes

Helena, Montana 6B Yes

Duluth, Minnesota 7A Yes

Fairbanks, Alaska 8A Yes

The PC recommended that a fixed dry bulb economizer be used with a 65°F (18°C) change over 

temperature. Therefore, if the ambient dry bulb temperature exceeds 65°F (18°C), the OA flow 

rate modulates to the minimum set point. Although the ambient dry bulb temperature is less than 

or equal to 65°F (18°C), the OA damper will modulate between minimum and full open to try to 

meet the post-fan supply dry bulb temperatures specified in Table 6-29 before turning on the 

chilled water or DX cooling coil.

Table 6-29 Critical CAV and Noncritical VAV Supply Dry Bulb Temperatures

Dry Bulb Temperature

Critical CAV supply 52°F

Noncritical VAV supply 55°F

6.6 Packaged Direct Expansion Systems

The small hospital and healthcare facilities addressed in the AEDG are typically ideal for 

packaged DX systems because their relatively small overall building sizes and expansive rooftop 

spaces provide a great deal of flexibility for locating the units. Packaged DX systems are 

commercially available in a large size range from single-compressor 5-ton (17.6 kW) units to 

multicompressor units reaching 500 tons (1,760 kW). More common units range from 70 to 150 

tons (246 to 528 kW), coinciding with typical peak cooling demand for AHUs serving small 

hospital and healthcare facilities. This is true even in hot, humid climates such as Miami. 

Packaged DX units are typically installed in these facilities and therefore represent the baseline 

for the AEDG. Section 6.6.1 reviews the inputs that define the baseline and low-energy package 

DX units.
82

Unlike chilled water systems, which use water as a secondary heat transfer medium, packaged 

DX systems condition the air directly with an evaporator coil. The term direct expansion refers 

to the absence of a secondary medium. A packaged DX system increases its cooling capacity by 

adding DX circuits in parallel. Each DX circuit consists of one or more compressors, an 

evaporator coil in the supply air stream, and a condenser coil that rejects the heat to the ambient 

environment. Each DX circuit is its own closed loop. The individual evaporator coils are 

configured in interwoven or stacked arrangements in the supply air stream. Standard packaged 

DX systems modulate their cooling capacity by cycling on and off compressors depending on the 

cooling demand. However, improved capacity modulation technologies such as digital 

compressors—which may provide much greater control over the cooling provided—are 

beginning to enter the marketplace.

6.6.1 Packaged Direct Expansion Rated Performance Inputs

The packaged DX model in EnergyPlus uses full-load performance information at rated 

conditions based on ARI Standard 340-360, which specifies the rating conditions for packaged 

DX equipment up to 250 MBH (73 kW). However, there is no standard for units larger than 250 

MBH (73 kW), so ARI Standard 340-360 has become the de facto standard for any packaged DX 

unit of 65 MBH (19 kW) or larger.

The full load performance information includes the total cooling capacity, sensible heat ratio 

(SHR), coefficient of performance (COP), and air volume flow rate. The rating conditions are 

80°F (27°C) dry bulb and 67°F (19°C) wet bulb air entering the evaporator coil, 95°F (35°C) dry 

bulb air entering the condenser coil, and an air volume flow rate across the evaporator coil based 

on 350 cfm per ton (47 L/s per kW) of rated total cooling capacity. The rated air volume flow 

rate based on ARI Standard 340-360 can range from 300 to 450 cfm/ton (47 (L/s)/kW to 60

(L/s)/kW).

The rated COP is the only performance input that is hard entered into the model. Section 6.6.4

reviews the procedure to determine the rated COP; Section 6.6.5 reviews the rated COP specified 

in the baseline and low-energy models. The rated total cooling capacity and the air volume flow 

rate are autosized. The rated SHR is autocalculated based on the user-specified supply air 

conditions and the ARI Standard 340-360 rated inlet dry bulb and wet bulb temperature 

conditions.

6.6.2 Packaged Direct Expansion Modifier Curves

Modifier curves are empirical curves, based on manufacturer data, that capture performance at 

nonrated conditions. Five modifier curves are used to model packaged DX systems in 

EnergyPlus; the first four provide the actual total cooling capacity and COP based on the air 

temperature conditions, and air flow rates on the evaporator and condenser coil at each time step. 

These four curves account for the steady-state performance; a fifth accounts for the transient 

performance. EnergyPlus models the packages’ DX system as having a variable-speed 

compressor with infinitely variable capacity. In reality, the system cycles on and off a discrete 

number of compressors to meet the cooling demand. Although EnergyPlus does not capture the 

over- and undercooling that occurs with cycling compressors to meet a partial load, the last 

modifier curve attempts to capture the degradation of system performance caused by compressor 

cycling.

The five curves are:
83

• The total cooling capacity modifier curve as a function of the wet bulb temperature of the 

air entering the evaporator coil and the dry bulb temperature of the air entering the 

condenser coil. The output is multiplied by the rated total cooling capacity to provide the 

total cooling capacity at the specific evaporator and condenser coil conditions.

• The total cooling capacity modifier curve as a function of the ratio of actual air flow 

across the evaporator coil to the rated air flow. The output of this curve is multiplied by 

the rated total cooling capacity to provide the total cooling capacity at the specific air 

flow rate across the evaporator coil.

• The energy input ratio (EIR, inverse of COP) modifier curve as a function of the wet bulb 

temperature of the air entering the evaporator coil and the dry bulb temperature of the air 

entering the condenser coil. The output of this curve is multiplied by the rated EIR to 

provide the EIR at the specific evaporator and condenser coil conditions.

• The EIR modifier curve as a function of the ratio of actual air flow across the evaporator 

coil to the rated air flow. The output of this curve is multiplied by the rated EIR to 

provide the EIR at the specific air flow rate across the evaporator coil.

• The EIR modifier curve as a function of the part-load ratio (PLR) (sensible cooling load 

divided by the steady-state sensible cooling capacity). The output of this curve is 

multiplied by the rated EIR to provide the EIR at the specific part-load condition to 

account for efficiency losses caused by compressor cycling.

Table 6-30 specifies the coefficients for these five modifier curves. These performance 

coefficients were fit from manufacturer data for a 2-compressor, 10-ton (35-kW) packaged 

rooftop unit. Although the packaged DX systems installed on small hospital and healthcare 

facilities are much larger built-up units—easily exceeding 70 tons (246 kW) with at least 4 DX 

circuits—the detailed manufacturer data necessary to create the empirical curves were not 

available.

Table 6-30 Packaged DX Rated Conditions Modifier Curves

Coefficients Cooling Capacity 

f(Twb1*,Tdb2**)

Cooling Capacity

f(FF3***)

EIR

f(Twb1,Tdb2)

EIR 

f(FF3)

PLF 

f(PLR4****)

Constant 0.42415 0.77136 1.23649 1.20550 0.77100

x 0.04426 0.34053 –0.02431 –0.32953 0.22900

x –0.00042 2 –0.11088 0.00057 0.12308

y 0.00333 – –0.01434 –

y –0.00008 2 – 0.00063 –

xy –0.00021 – –0.00063 –

Min x 17.0 0.75918 17.0 0.75918 0

Max x 22.0 1.13877 22.0 1.13877 1

Min y 13.0 – 13.0 – –

Max y 46.0 – 46.0 – –

* Twb1 is the wet bulb temperature of the air entering the evaporator coil

** Tdb2 is the dry bulb temperature of the air entering the condenser coil

*** FF3 is the ratio of the actual air flow rate across the evaporator coil to the rated air flow rate (flow fraction)

**** PLR represents the part-load ratio (sensible cooling load/steady state sensible cooling capacity)

6.6.3 Degradation of Latent Cooling Capacity

Extensive small packaged DX testing at the Florida Solar Energy Center (FSEC) reveals that 

moisture removed from the air while a compressor is on will cling to the evaporator coil and fins, 

only to be re-evaporated into the supply when the compressor shuts off (Shirey, 2006). The 

phenomenon is a transient effect and is called latent degradation. Packaged DX systems are 
84

much more susceptible to latent degradation, because the thermal capacity of an evaporator coil 

filled with refrigerant is significantly lower than that of a chilled water coil.

Figure 6-4 shows the sensible versus latent cooling of a DX coil test at FSEC over a 90-minute 

cycle in which the compressor is on for the first 45 minutes (Shirey et al. 2006). When the 

refrigeration compressor is on, the evaporator coil is sensibly cooling the incoming air and 

simultaneously condensing water out of the air, which is collecting on the coil and fin surface 

area. After 45 minutes, the compressor shuts off, and the supply fan continues to operate, 

causing the water coating the evaporator fin and coil to re-evaporate into the supply air. This 

negatively affects the packaged DX unit’s performance because it reduces the equipment’s 

ability to maintain proper indoor humidity levels.

Figure 6-4 Transient sensible and latent capacity of a cooling coil over an operating cycle

Credit: EnergyPlus Engineering Reference

FSEC found that latent degradation is exacerbated by excessive cycling of compressors because 

the more a compressor cycles on and off, the more water is evaporated back into the supply air. 

Figure 6-5 (from FSEC field data) shows how increased compressor cycling of a single 

compressor DX unit (represented by runtime fraction on the x-axis) results in increased latent 

degradation represented by high SHRs (Shirey et al. 2006). Figure 6-5 indicates the importance 

of latent degradation showing that a runtime fraction less than 0.4 (a compressor that is on less 

than 40% of the time) provides no latent cooling.
85

Figure 6-5 Field data showing the net impact of part-load operation on SHR

Credit: EnergyPlus Engineering Reference

Latent degradation is a greater problem for smaller packaged DX systems. The larger built-up 

systems used in small hospital and healthcare facilities are much less susceptible to latent 

degradation because (1) the units are sized more accurately with the actual cooling demand of 

the building, which reduces compressor cycling; (2) the controls of these units are more robust, 

with features such as more optimal time delays to further reduce compressor cycling; and (3) the 

units have at least four DX circuits in each packaged unit, so they can match the cooling demand 

more closely, thereby reducing the need for excessive compressor cycling.

Thus, the PC assumed the effect would be negligible and recommended that the packaged DX 

systems not be modeled with any latent degradation. However, the impact of neglecting latent 

degradation was not quantified at this time, and future study to verify this assumption is

warranted. Further investigations, including testing large built-up units and collecting field data, 

are necessary to determine whether latent degradation should be considered in designing large 

DX mechanical systems for small healthcare facilities.

If it is determined that latent degradation should generally be included for small healthcare 

facilities (or if this effect should be modeled for specific projects), EnergyPlus can capture the 

degradation of latent cooling capacity. However, it can only do this when the supply air operates 

continuously while the compressors cycle on and off to meet the cooling load. The final four 

inputs into the EnergyPlus DX model provide a means of capturing the latent degradation of a 

DX unit. These inputs are:
86

• Nominal time for condensate removal defines the time (in seconds) after the startup of a 

compressor when the water condensing on the evaporator coil begins to drain.

• Ratio of initial moisture evaporation rate and steady-state latent capacity is the ratio of 

the initial moisture evaporation rate from the cooling coil when the compressor first turns 

off to the coil’s steady-state latent capacity at rated conditions.

• Maximum cycling rate defines the maximum on-off cycling rate of the compressor 

occurring at a 50% runtime fraction.

• Latent capacity time constant is the time constant for the cooling coils’ latent capacity to 

reach steady state after the compressor starts up.

6.6.4 Decoupling Supply Fan Power From Packaged System Energy Efficiency 

Ratio

Based on ASHRAE 90.1-1999, packaged systems exceeding 240 kBtu/h (70 kW) of net cooling 

capacity (gross cooling capacity minus the supply fan heat) must meet minimum efficiency 

rating requirements of 9.0 energy efficiency ratio (EER) and 9.2 integrated part-load value 

(IPLV). The EER performance metric includes the power draws of the compressor, the supply 

fan, and the condenser fan. Yet EnergyPlus models the supply fan separately from the 

compressor and the condenser fan. With PC guidance, we developed a standard method to 

calculate the EER of a packaged system that decouples the supply fan power and includes only 

the compressor and condenser fan power consumption. This method begins by determining the 

total power draw of the packaged system, including the compressor, the supply fan, and the 

condenser fan:

6-21

6-22

Next, the supply fan power draw is calculated. With the help of the PC, we made assumptions 

about specifying 2.25 in. w.c. (560 Pa) as a typical internal pressure drop and 50% typical 

combined fan-motor-belt efficiency for a standard packaged DX unit. The external pressure drop 

of 0.75 in. w.c. (187 Pa) was based on Table 4 of the ARI Standard 340/360-2000, selecting the 

value for cooling capacities of 505,000 Btu/h (148 kW) or greater. A 7,000 (3,300 L/s) cfm flow 

rate was used, assuming 350 cfm/ton (47 (L/s)/kW) for a 240 kBtu/h (70kW) cooling capacity.

6-23

6-24

Third, the supply fan power draw was subtracted from the total packaged unit.

6-25

Lastly, a new EER was calculated that included only the compressor and condenser fan power 

draws.
87

6-26

EnergyPlus treats the supply fan separately, so the value of 11.0 is the input desired in this case. 

The EER varies significantly, depending on whether the supply fan is excluded, and an incorrect 

selection would add error to the simulation results.

6.6.5 Packaged System Full-Load Performance at Rated Conditions

The methodology to decouple supply fan power from the packaged system performance was 

repeated for the low-energy model. Table 6-31 reviews the packaged system EER before and 

after the supply fan power was decoupled. EnergyPlus uses COP instead of EER to define the 

packaged system performance at full load, so Table 6-31 also specifies the COP used in the 

models. Table 6-32 includes the minimum EER and ILPV performance.

Table 6-31 Packaged System Rated Full-Load Performance

Coefficients Baseline Low-Energy

EER with supply fan 9.0 10.0

EER without supply fan 11.0 12.6

COP without supply fan 3.24 3.69

Table 6-32 Packaged System Minimum EER and IPLV Performance for ASHRAE 90.1

ASHRAE 90.1 1999 ASHRAE 90.1 2004 ASHRAE 90.1 2007 ASHRAE 90.1 2010

EER 9.0 9.0 9.0 9.5

IPLV 9.2 9.2 9.2 9.2

Size > 240,000 Btu/h > 760,000 Btu/h > 760,000 Btu/h > 760,000 Btu/h

6.7 Air-Cooled Chiller Systems

The following sections review the performance and operational characteristics of the air-cooled 

chiller as one low-energy cooling option. We were able to model scroll and screw chillers. 

After evaluating several metrics, we chose the scroll air-cooled chiller for the low-energy model 

because of its higher performance at part-load conditions.

6.7.1 Scroll Versus Screw Compressors

The PC indicated that the choice between using a scroll or screw air-cooled chiller typically 

depends on the cooling capacity required. Commercially available scroll compressors are 

making inroads into larger systems—some even approaching 400 tons (1,407 kW)—but 

designers generally specify scroll chillers for systems smaller than 80 tons (281 kW) and screw 

chillers systems larger than 80 tons (281 kW). However, small healthcare cooling capacities fall 

in a range overlapped by both chiller types. Table 6-33 shows the typical cooling capacity 

ranges of commercially available air-cooled scroll and screw chillers. The overlapped range of 

80 to 200 tons (281 to 1,407 kW) perfectly coincides with the cooling capacities needed by small 

hospital and healthcare facilities. Consequently, air-cooled scroll and screw chillers were 

applicable, so the PC did not have a preference.
88

Table 6-33 Operational Characteristics of Air-Cooled Scroll and Screw Chillers

Scroll Chillers Screw Chillers

Typical size ranges 20–200 tons 80–500 tons

Capacity modulation Compressor cycling Slide valve

Minimum PLR Cycling limitation of a single compressor 15%

Minimum number of compressors 4 2

Cooling capacity was not sufficient to dictate which chiller type to use, so we compared the 

performance and operational characteristics. Concerning capacity modulation, screw chillers use 

a slide valve that permits infinitely variable capacity between minimum PLR, typically 15%, and 

full load. Scroll chillers, on the other hand, modulate capacity identically to packaged DX units 

by cycling a discrete number of compressors. Yet, compared to DX units, the frequency of 

cycling and potential for under- or overcooling is significantly mitigated because the chilled 

water loop has a large thermal capacitance. Designers sometimes add a tank onto the chilled 

water loop to add thermal capacity and maintain a more constant water temperature. Therefore, 

the capacity control of the screw chiller was not decisively preferable to that of the scroll chiller.

The air-cooled scroll chiller was chosen because its optimal performance at 30% to 60% PLRs 

(see Section 6.7.3) coincides with the fact that chillers predominantly operated at PLRs below 

80% throughout the year. Air-cooled screw chillers (see Section 6.7.4) experience their optimum 

performance at 80% to 100% PLR.

6.7.2 Chiller Modifier Curves

The air- and water-cooled chiller models in EnergyPlus are nearly identical. The only difference 

is that the air-cooled condensing temperature is based on the ambient dry bulb and the watercooled condensing temperature is based on the condenser water temperature provided from the 

cooling tower. Similar to the packaged DX model, the chiller model uses empirical curves 

generated from manufacturer data to modify the cooling capacity and efficiency at rated 

conditions. The capacity and COP are based on a 44°F (7°C) chilled water supply (CHWS) 

temperature and 95°F (35°C) ambient dry bulb condenser supply temperature in accordance with 

ARI Standard 550-590. Curve fits are then used to determine the cooling capacity and efficiency 

at nonrated conditions. The three curve fits are:

1. The total cooling capacity modifier curve as a function of the exiting chilled water 

temperature and the entering ambient dry bulb condensing temperature. The output is 

multiplied by the rated total cooling capacity to provide the total cooling capacity at the 

specific evaporator and condenser coil conditions.

2. The EIR modifier curve as a function of the exiting chilled water temperature and the 

entering ambient dry bulb condensing temperature. The output is multiplied by the rated 

EIR to provide the EIR at the specific evaporator and condenser coil conditions.

3. The EIR modifier curve as a function of the PLR (actual cooling load divided by the 

chiller’s available cooling capacity). The output is multiplied by the rated EIR to provide 

the EIR at the specific PLR at which the chiller operates.

Section 6.7.3 reviews the empirical curves used for the scroll chillers; Section 6.7.4 reviews

those used for the screw chillers.
89

6.7.3 Air-Cooled Scroll Chiller Performance

The empirical curves shown in Table 6-34 were developed from the manufacturer’s performance 

data for a 60-ton (211 kW) scroll chiller. Table 6-35 shows the full load and IPLV performance 

as a result of the scroll chiller empirical curves. With the same full-load 10.0 EER specified in 

the AEDG recommendation table, the empirical curves produce a 16.1 IPLV, which is much 

higher than the 11.5 IPLV in the AEDG recommendation table. The higher IPLV indicates that 

commercially available air-cooled scroll chillers can achieve much greater part-load performance 

than the PC anticipated. Figure 6-6 shows the scroll chiller performance map based on the 

empirical curves. The chiller performance map indicates that the scroll chiller performs 

optimally at 30% to 60% PLR.

Table 6-34 Scroll Air-Cooled Chiller Rated Conditions Modifier Curves

Coefficients Cooling Capacity f(CHWS*,CWS**) EIR f(CHWS,CWS) EIR f(PLR)

Constant 1.05E+00 5.83E-01 4.19E-02

x 3.36E-02 -4.04E-03 6.25E-01

x 2.15E-04 2 4.68E-04 3.23E-01

y –5.18E-03 –2.24E-04 –

y –4.42E-05 2 4.81E-04 –

xy –2.15E-04 –6.82E-04 –

Min x 0.0 0.0 0.0

Max x 20.0 20.0 1.2

Min y 0.0 0.0 –

Max y 50.0 50.0 –

* Chilled water supply

** Condenser water supply

Table 6-35 Scroll Air-Cooled Chiller Performance at ARI Rated Conditions

PLR CHWS 

Temperature

Condenser Supply

Temperature

Model 

Performance

AEDG 

Recommendations

100% 44°F 95°F 10.0 EER 10.0 EER

75% 44°F 80°F 13.7 EER –

50% 44°F 65°F 17.6 EER –

25% 44°F 55°F 19.1 EER –

16.1 IPLV 11.5 IPLV
90

Figure 6-6 Scroll air-cooled chiller performance map with a constant 44°F CHWS

6.7.4 Air-Cooled Screw Chiller Performance

The empirical curves shown in Table 6-36 were developed from the manufacturer’s performance 

data for a 144-ton (506-kW) screw chiller. Table 6-37 shows the full-load and IPLV 

performance as a result of the screw chiller empirical curves. With the same full-load 10.0 EER 

specified in the AEDG recommendation table, the empirical curves produce a 12.9 IPLV, which 

is slightly higher than the 11.5 IPLV in the AEDG recommendation table. Figure 6-7 shows the 

screw chiller performance map based on the empirical curves. Unlike the scroll chiller, the 

optimum performance of the screw chiller occurs at 80% to 100% PLR.

Table 6-36 Screw Air-Cooled Chiller Performance at ARI Rated Conditions

PLR CHWS CWS Model Performance AEDG Recommendations

100% 44°F 95°F 10.0 EER 10.0 EER

75% 44°F 80°F 12.1 EER –

50% 44°F 65°F 13.6 EER –

25% 44°F 55°F 13.0 EER –

12.9 IPLV 11.5 IPLV
91

Table 6-37 Screw Air-Cooled Chiller Rated Conditions Modifier Curves

Coefficients Cooling Capacity f(CHWS,CWS) EIR f(CHWS,CWS) EIR f(PLR)

Constant 1.06E+00 5.99E-01 7.27E-02

x 5.07E-02 –1.12E-02 9.53E-01

x –7.70E-05 2 5.10E-04 –2.66E-02

y –6.69E-03 3.71E-03 –

y –6.16E-05 2 3.40E-04 –

xy –3.60E-04 –4.07E-04 –

Min x 0.0 0.0 0.0

Max x 20.0 20.0 1.2

Min y 0.0 0.0 –

Max y 50.0 50.0 –

Figure 6-7 Screw air-cooled chiller performance map with a constant 44°F CHWS

6.7.5 ASHRAE 90.1 Minimum Performance Requirements

For reference purposes, Table 6-38 provides the minimum EER and IPLV for air-cooled chillers 

based on the different versions of ASHRAE 90.1.

Table 6-38 Air-Cooled Chiller Minimum EER and IPLV Performance for ASHRAE 90.1

ASHRAE 90.1-1999 ASHRAE 90.1-2004 ASHRAE 90.1-2007 ASHRAE 90.1-2010

EER/IPLV* 9.6/9.6 9.6/10.4 9.6/10.4 9.6/10.4

COP/IPLV** 2.80/2.80 2.80/3.05 2.80/3.05 2.80/3.05

Compressor type Any Any Any Any

Size All capacities All capacities All capacities All capacities

* EER/IPLV is based on ratio of cooling provided to power draw by the compressors and condenser fans.

** COP/IPLV is a conversion of the EER/IPLV numbers in the previous row.
92

6.8 Water-Cooled Chiller Systems

The following sections review the performance and operational characteristics of the watercooled chiller as a low-energy cooling option.

6.8.1 Compressor Type

Water-cooled chillers are available with scroll, screw, and centrifugal compressors. Centrifugal 

chillers are too large for small hospitals and healthcare facilities, because they have a starting 

capacity of approximately 170 tons (598 kW). Although scroll and screw chillers fall in the right 

size range, the PC stated that screw chillers have become the standard for water-cooled chillers 

in small hospitals and healthcare facilities (see Table 6-39). Therefore, the PC recommended the 

screw water-cooled chiller.

Table 6-39 Size Range and Operational Characteristics Comparison of Water-Cooled Chillers

Scroll Chillers Screw Chillers Centrifugal Chillers

Typical size ranges 30–200 tons 70–500 tons 170–8500 tons

Capacity modulation Compressor cycling Slide valve Inlet vanes or VFD

Minimum PLR Cycling limitation of a 

single compressor

15% 15%

Minimum number of compressors 2 2 1

6.8.2 Water-Cooled Chiller Modifier Curves

The water-cooled chiller model in EnergyPlus is identical to the air-cooled chiller model, except 

that the condensing temperature of the water-cooled chiller is based on condenser water from a 

cooling tower rather than the ambient dry bulb. The capacity and COP are based on a 44°F 

(7°C) CHWS temperature and 85°F (29°C) condenser water supply (CWS) temperature, in 

accordance with ARI Standard 550-590.

Curve fits are then used to determine the cooling capacity and efficiency at nonrated conditions. 

The three curve fits are:

• The total cooling capacity modifier curve as a function of the exiting chilled water 

temperature and the entering condenser water supply temperature. The output is 

multiplied by the rated total cooling capacity to provide the total cooling capacity at the 

specific evaporator and condenser coil conditions.

• The EIR modifier curve as a function of the exiting chilled water temperature and the 

entering condenser water supply temperature. The output is multiplied by the rated EIR 

to provide the EIR at the specific evaporator and condenser coil conditions.

• The EIR modifier curve as a function of the PLR (actual cooling load divided by the 

chiller’s available cooling capacity). The output is multiplied by the rated EIR to provide 

the EIR at the specific PLR at which the chiller is operating.

Section 6.8.3 reviews the empirical curves used for the water-cooled screw chiller.

6.8.3 Screw Water-Cooled Chiller Performance

The chiller empirical performance curves in Table 6-41 were obtained from manufacturer’s 

performance data for a 200-ton (703 kW) water-cooled screw chiller. Table 6-42 compares the 

full load and IPLV performance between the modeled water-cooled chiller and the performance 

values recommended in the AEDG. Unlike the air-cooled chiller case, for which performance 

values are recommended for the full load and IPLV, the AEDG recommendation table states that 
93

water-cooled chillers must “comply with ASHRAE 90.1.” This means the user must meet the 

more stringent of either the applicable version of Standard 90.1 or the local code requirement. 

For reference purposes, Table 6-42 provides the full load and IPLV based on an ASHRAE 90.1-

2007 water-cooled screw or scroll chiller smaller than 150 tons (528 kW). With the same fullload 15.2 EER, the empirical curves produce a 19.9 IPLV that is slightly higher than the 

ASHRAE Standard 90.1-2007 IPLV of 17.7.

Table 6-40 Screw Water-Cooled Chiller Rated Conditions Modifier Curves

Coefficients Cooling Capacity f(CHWS,CWS) EIR f(CHWS,CWS) EIR f(PLR)

Constant 1.07E+00 4.68E-01 1.41E-01

x 4.29E-02 –1.38E-02 6.55E-01

x 4.17E-04 2 6.98E-04 2.03E-01

y –8.10E-03 1.09E-02 –

y –4.02E-05 2 4.62E-04 –

xy –3.86E-04 –6.82E-04 –

Min x 0.0 0.0 0.0

Max x 20.0 20.0 1.2

Min y 0.0 0.0 –

Max y 50.0 50.0 –

Table 6-41 Screw Water-Cooled Chiller Performance at ARI Rated Conditions

PLR CHWS 

Temperature

CWS 

Temperature

Model 

Performance

AEDG 

Recommendations*

100% 44°F 85°F 15.2 15.2

75% 44°F 75°F 18.5 –

50% 44°F 65°F 21.5 –

25% 44°F 65°F 19.0 –

19.9 17.7

Figure 6-8 shows the water-cooled screw chiller performance map based on the empirical curves 

while maintaining a constant 44°F (7°C) CHWS. Figure 6-7 shows that the water-cooled screw 

chiller performs similarly to the air-cooled screw chiller, achieving optimal performance near 

full load. Yet the water-cooled screw chiller achieves an optimal performance over a larger PLR 

range of 60% to 100% and the air-cooled screw chiller reaches its optimal performance over a 

narrower PLR range of 80% to 100%. A shared disadvantage is that both operate most of the 

year below their optimal PLR.
94

Figure 6-8 Screw water-cooled chiller performance map with a constant 44°F CHWS

6.8.4 Water-Cooled Chiller Minimum Energy Efficiency Ratio and Integrated PartLoad Value Performance for ASHRAE 90.1

Table 6-42 provides the minimum EER and IPLV for air-cooled chillers smaller than 150 tons

(528 kW); Table 6-43 provides these values for chillers 150 to 300 tons (528 to 1,055 kW), 

based on the different versions of ASHRAE 90.1.

Table 6-42 Water-Cooled Screw or Scroll Chiller Minimum EER and IPLV Performance

ASHRAE 90.1-1999 ASHRAE 90.1-2004 ASHRAE 90.1-2007 ASHRAE 90.1-2010

EER/IPLV* 15.2/15.4 15.2/17.7 15.2/17.7 15.2/17.8

COP/IPLV** 4.45/4.50 4.45/5.20 4.45/5.20 4.45/5.22

Compressor type Screw/scroll Screw/scroll Screw/scroll Screw/scroll

Size < 150 tons < 150 tons < 150 tons < 150 tons

* EER/IPLV is based on ratio of cooling provided to power draw by the compressors and condenser fans.

** COP/IPLV is a conversion of the EER/IPLV numbers in the previous row.

Table 6-43 Water-Cooled Screw or Scroll Chiller Minimum 

EER and IPLV Performance for ASHRAE 90.1

ASHRAE 90.1-1999 ASHRAE 90.1-2004 ASHRAE 90.1-2007 ASHRAE 90.1-2010

EER/IPLV* 16.7/16.9 16.7/19.1 16.7/19.1 16.7/19.1

COP/IPLV** 4.90/4.95 4.90/5.60 4.90/5.60 4.90/5.60

Compressor type Screw/scroll Screw/scroll Screw/scroll Screw/scroll

Size ≥ 150 tons and

< 300 tons

≥ 150 tons and

< 300 tons

≥ 150 tons and

< 300 tons

≥ 150 tons and

< 300 tons

* EER/IPLV is based on ratio of cooling provided to power draw by the compressors and condenser fans

** COP/IPLV is a conversion of the EER/IPLV numbers in the previous row.
95

6.9 Cooling Tower Systems

The cooling tower plays an integral role in the performance of the chiller and the entire chilled 

water plant, as the cooling tower can consume significant energy. Improperly balanced and 

controlled chilled water plants sometimes consume more energy from the cooling tower than the 

chiller at lower part loads. Based on the PC recommendation, a single open cooling tower is 

connected to the chiller. The open configuration provides a lower approach (difference between 

the cooling tower leaving condenser water temperature and ambient wet bulb temperature) and 

lower cost (less copper and lighter weight) than those of a closed cooling tower (fluid cooler).

6.9.1 Cooling Tower Design and Operational Criteria

Table 6-44 compares the cooling tower design and operational criteria between ASHRAE 90.1-

2004 Appendix G and the AEDG model based on the PC recommendations. The fan 

modulation—and therefore capacity modulation—of the cooling tower are based on a VFD 

controlling the fan speed. The ASHRAE 90.1 dual-speed criterion is antiquated, because VFDs 

provide greater control, are cheaper, and achieve much lower sound pressure levels. The PC 

recommended that the cooling tower fan be able to ramp down to a 20% minimum air flow ratio. 

Both ASHRAE 90.1-2004 and the AEDG model use the same sizing strategy: achieve a 7°F

(4°C) approach to provide 85°F (29°C) CWS with a 78°F (26°C) ambient wet bulb.

Table 6-44 Comparison of Cooling Tower Design and Operational Criteria

ASHRAE 90.1 2004 AEDG Recommendations

Configuration Open tower Open tower

Fan modulation Dual speed VFD

Design CWS set point 85°F 85°F

Design ambient wet bulb 78°F 78°F

Design approach 7°F 7°F

Design cw flow 2.4 gpm/ton 1.6 gpm/ton

Design range 10°F 15°F

CW flow modulation Constant Constant

Operational CWS set point 70°F 70°F

Another major deviation from ASHRAE 90.1-2004 was the design condenser water flow rate. 

The PC recommended a 1.6 gpm/ton (0.03 (L/s)/kW) flow rate (30% lower than the 2.4 gpm/ton 

(0.04 (L/s)/kW) flow rate specified in ASHRAE 90.1-2004, referenced from ARI Standard 550-

590). As a result, the AEDG cooling tower range (difference between the cooling tower entering 

and exiting condenser water temperatures) is 5°F (3°C) higher than for 90.1-2004. The intent of 

the AEDG approach is to minimize the condenser pump energy, which can be substantial—

especially for an open cooling tower—because an open cooling tower condenser pump must 

provide sufficient head to overcome the internal pressure drop and the ambient pressure. A 

typical condenser pump can experience 60 to 75-ft (18 to 23-m) head. Therefore, the condenser 

pump, which is operated at a constant flow rate, can consume a great deal of energy. By 

lowering the condenser water flow rate by 30%, however, the PC significantly reduces the 

condenser pump power draw. Section 6.4 reviews the condenser pump design and operation in 

more detail.

Although most water-cooled chillers can operate at lower condenser water temperatures (typical 

minimum is 55°F [13°C]), the PC recommended that the cooling tower operate in a manner that 

maintains a 70°F (21°C) CWS temperature set point in accordance with ASHRAE 90.1. 
96

Although lower condenser water temperatures would improve the performance of the chiller (see 

Figure 6-8), condenser water temperatures that are too low would compromise the chiller’s 

ability to maintain the proper pressure differential between its evaporator and condenser sides, 

resulting in refrigerant back flow.

6.9.2 Cooling Tower Model

The variable-speed cooling tower model in EnergyPlus is similar to the chiller model. The 

cooling tower performance is specified at design conditions, and empirical curves fits are used to 

determine the approach temperature and fan power at off-design conditions. Table 6-44 reviews 

the specified model performance at design conditions, which include the inlet air wet bulb 

temperature, range, and approach. The cooling tower design water flow rate, air flow rate, and 

fan power are then auto-calculated using these design conditions. DOE (2009) reviews the 

calculation procedure for determining the design air flow rate and fan power.

The model accounts for the tower performance in the “free convection” regime, which occurs at 

low ambient wet bulb conditions where the CWS set point can be achieved while the tower fan is 

off. The cooling tower model was simulated to switch into the free convection regime once the 

cooling demand on the tower was less than or equal to 12.5% of its rated capacity. The model 

can simulate basin water heater operation, but the PC recommended that it be turned off.

The EnergyPlus calculation procedure begins by using the empirical curves to calculate the 

cooling tower approach for each time step using the following independent variables: 

• Air flow rate ratio (actual air flow rate/design air flow rate) 

• Water flow rate ratio (actual water flow rate/design water flow rate) 

• Cooling tower range

• Ambient wet bulb temperature. 

EnergyPlus provides two empirical correlations, CoolTools and YorkCalc. The user can then 

choose predefined coefficients for the selected empirical correlation or define coefficients based 

on manufacturer’s performance data. We chose the CoolTools empirical correlation, because our 

contact with one of its authors and the availability of an ASHRAE Transactions paper reviewing 

its methodology (Benton et al. 2002) has provided us considerable understanding of its 

methodology. The predefined EnergyPlus-embedded CoolTools empirical coefficients were 

used because the manufacturer’s performance data necessary to create a new set of user-defined 

coefficients was not available. These embedded empirical curve coefficients are published in 

DOE (2009). The next step in the EnergyPlus calculation procedure is to determine the 

necessary cooling tower fan speed based on the calculated approach temperature and the CWS 

set point. Although the cooling tower is sized based on an 85°F (29°C) CWS set point, it is 

operated in a manner that maintains a 70°F (21°C) CWS set point. DOE 2009 reviews the 

internal algorithm used to determine the cooling tower fan speed necessary to maintain the CWS 

temperature at or below 70°F (21°C). If the ambient wet bulb is too high, the cooling tower will 

operate the fan at full speed, but the CWS temperature will exceed 70°F (21°C).

Table 6-45 shows the fan PLF curve used to calculate the fan power ratio at each time step,

based on the cooling tower fan air flow ratio. The resulting fan power ratio is multiplied by the 

design fan power to give the fan power at each time step.
97

Table 6-45 Fan PLF Curve

Coefficients Cooling Tower Fan

C1 –0.0093

C2 0.0512

C3 –0.0838

C4 1.0419

6.10 Boilers

6.10.1 Baseline Model

The baseline heating system consisted of an atmospheric (noncondensing) boiler on a primaryonly loop with a variable-speed pump. The HHWS temperature was maintained at a constant 

180°F (82°C). The HHWR temperature varied depending on the load, but was not allowed to 

drop below 150°F (66°C). The 150°F (66°C) minimum HHWR temperature provided a 10°F

(6°C) safety factor, ensuring that the boiler would not experience HHWR of 140°F (60°C) or 

below, at which point flue gases would begin to condense. This would be disastrous to a 

noncondensing boiler, destroying both the boiler and the flue.

ASHRAE 90.1-1999, Table 6.2.1F mandates that a gas-fired boiler greater than 300,000 Btu/h

(88 kW) and less than 2,500,000 Btu/h (733 kW) must have a minimum 80% combustion 

efficiency (Ec) and 75% Et, based on the Hydronics Institute Boiler Standard. The Ec accounts 

for only the flue losses. The Et accounts for both the flue losses and the losses incurred in the 

conductive/convective/ radiative heat transfer between the hot combustion gas/flame and the 

heating hot water. Therefore, Et was used in the model because it captures the total efficiency of 

the boiler. In ASHRAE 90.1-2004 Table 6.8.1F, the minimum Ec was eliminated. This left only 

a minimum 75% Et

Based on recommendations of the PC, we modeled the baseline boiler with a 78% E

requirement and still referenced the Hydronics Institute Boiler Standard. 

t at full load. 

Boiler efficiency is a function of HHWR temperature and PLR. The HHWS temperature was 

kept constant and the variable-speed pump modulated to maintain a near-constant HHWR 

temperature, so the part-load Et

The baseline boiler performance curve as a function of PLR (see 

was strictly a function of the part-load operation of the boiler. 

Unfortunately, there is currently no part-load boiler rating standard, which is incredibly 

important considering that boilers, like other primary systems, operate most of the time well 

under their fully loaded condition. The ASHRAE Standard 155P committee is currently working 

to implement a minimum adjusted seasonal boiler system performance into ASHRAE 90.1.

Figure 6-9) was obtained from a 

library of boiler performance curves that are packaged with EnergyPlus. The performance curve 

was compared against available manufacturers’ data and was approved by the PC. Compared 

with a condensing boiler, the baseline part-load performance curve shows that the Et

Atmospheric boilers cannot achieve a low part-load operation to prevent condensation. 

Although the minimum part-load operation varies widely across manufacturers, the PC specified 

a minimum 0.4 part-load operation. Unfortunately, EnergyPlus cannot model performance 

degradation caused by cycling. To compensate, the performance curve in EnergyPlus accounts 

for this degradation by having the E

degrades at 

lower part-load operation.

t Figure 

6-9

degrade quickly under a 0.4 part-load operation (see 

). Table 6-46 shows necessary inputs into EnergyPlus used to model the baseline 

atmospheric boiler.
98

Figure 6-9 Baseline boiler part load curves

Table 6-46 Baseline Boiler EnergyPlus Input Performance Curves

EnergyPlus Input Data Baseline Boiler

Nominal Et 0.96

Coefficient 1: Constant 0.6264

Coefficient 2: x 0.6456

Coefficient 3: x –0.7772 2

Coefficient 4: x 0.3138 3

Minimum PLR 0.1

Maximum PLR 1.0

The Hydronics Institute Boiler Standard official title is BTS-2000 Testing Standard: Method to 

Determine Efficiency of Commercial Space Heating Boilers. It is published by The Hydronics 

Institute, a division of ARI. The testing standard measures the Et of the boiler at steady-state 

operation, fully loaded, and maintains the outlet temperature at 180°F (82°C). Oddly, the testing 

standard specifies that the inlet water temperature into the boiler be 35° to 80°F (2° to 27°C), 

which is much lower than the typical HHWR temperature of 150°F (66°C). Consequently, by 

using colder inlet temperatures, calculations based on the testing standard likely overstate the Et

of a typical boiler. In other words, a noncondensing boiler tested using this standard would most 

likely condense with such cold HHWR temperatures and artificially overstate its Et

Based on various manufacturers’ published data, a boiler operating with an 80°F (27°C) HHWR 

temperature achieves a 10% greater E

.

t compared with operating at the more typical 150°F

(66°C). Additionally, if operating at a 35°F (2°C) return water temperature, the Et would be 
99

boosted even further. Therefore, an item of concern is whether an atmospheric boiler that 

complies with the ASHRAE 90.1 minimum 75% Et

6.10.2 Low-Energy Model

under BTS-2000 testing conditions would 

actually operate at 65% or lower thermal under more typical operating conditions.

The low-energy heating system configuration was nearly identical to the baseline with a single 

boiler in a primary-only loop connected to a variable-speed pump. However, in the low-energy 

model, a condensing boiler replaced the atmospheric boiler. The two main benefits of a 

condensing boiler are its significantly higher thermal efficiencies, especially at low part-load 

operations, and ability to reduce to a lower PLR. Often overlooked, however, is that a 

condensing boiler will provide higher efficiencies than an atmospheric boiler only when the 

HHWR temperature drops below 140°F (60°C) and the water begins to condense in the flue.

Although PLR affects boiler performance, the main efficiency gains are realized when the 

HHWR temperature is aggressively dropped. One way that low HHWR temperatures can be 

realized by using low HHWS temperature. Yet how low the HHWS temperature can be dropped 

is limited by the HHW reheat coils in the terminal boxes, which need to maintain a certain log 

mean temperature difference above the incoming air to provide enough heat. This is especially a 

concern in perimeter zones where the incoming air sometimes needs to be heated from 55°F 

(13°C) to at least 95°F (35°C). One solution is to install two-row reheat coils serving perimeter 

zones to increase the surface area of the coil. For cold locations, a two-row reheat coil is often 

not enough and the HHWS and HHWR temperatures need to be high, which prevents the 

condensing boiler from condensing. 

One method of allowing the boiler to condense without compromising its ability to sufficiently 

heat perimeter zones is to implement an OA HHWS temperature reset schedule (see Figure 

6-10). The reset schedule maintains a higher HHWS temperature when it is cold ambient dry 

bulb and the reheat coils need a considerable amount of heat. Then, as the ambient dry bulb 

warms, the HHWS temperature can slowly decrease, which in turn decreases the HHWR 

temperature. Once the HHWR temperature drops below 140°F (60°C), the flue gases begin to 

condense and the Et of the condensing boiler increases.
100

Figure 6-10 Low-energy model HHWS OA reset schedule

In reality, the condensing boiler Et is a function of both part-load operation and HHWR 

temperature. Despite EnergyPlus’s capability to calculate HHWR temperature and use in the 

boiler Et calculation, the PC agreed to model the condensing boiler Et strictly as a function of 

part-load operation. To capture the effect of the OA air reset schedule, the PC specified a linear 

Et curve. At full load, in most climates, the boiler will achieve full load at a cold ambient 

temperature only, which demands higher HHWS and HHWR temperatures. Consequently, at 

full load the boiler will not condense, achieving an atmospheric boiler Et of 80%. As the 

ambient temperature increases, the boiler will operate at lower part-load conditions, which in 

turn will allow lower HHWS and HHWR temperatures. Therefore, the boiler Et

As is the case for atmospheric boilers, the minimum part-load operation of condensing boilers 

varies widely across manufacturers. The PC agreed to a 20% minimum part-load operation, 

although some boilers modulate down to 10%. As previously mentioned for the atmospheric 

boiler, EnergyPlus cannot model performance degradation caused by cycling when operating at 

part-loads below the minimum turn down. Therefore, the EnergyPlus condensing boiler was 

specified with a minimum turn down of 0.2. Any operation below this part load would be 

modeled with a same E

will increase as 

the part-load operation decreases.

t achieved at 0.2. Figure 6-11 and Table 6-47 show necessary inputs into 

EnergyPlus used to model the low-energy condensing boiler.
101

Figure 6-11 Baseline and low-energy boiler part-load curves

Table 6-47 Baseline and Low-Energy Boiler EnergyPlus Input Performance Curves

EnergyPlus Input Data Baseline Boiler Low-Energy Boiler

Nominal Et 0.96 1.00

Coefficient 1: Constant 0.6264 0.9667

Coefficient 2: x 0.6456 –0.1667

Coefficient 3: x –0.7772 2 0

Coefficient 4: x 0.3138 3 0

Minimum PLR 0.1 0.2

Maximum PLR 1.0 1.0

6.11 Service Water Heaters

SWH objects are components dedicated to heating, storing, and distributing domestic hot water 

to a building. A well-mixed storage tank water heater was simulated in EnergyPlus for the 

baseline and low-energy models. EnergyPlus simulates this water heater by analytically solving 

the differential equation governing the energy balance of the water tank. Conditions are solved 

separately for when the heater element or burner is on and when it is off. This approach allows 

ambient losses and parasitic loads to be separated into two cases (on and off) and accounted for 

in detail. The baseline and low-energy model water heaters are controlled by cycle to meet the 

demand load. When cycling, the heater element or burner is either on or off. The heater remains 

fully on while the tank is heated to the set point temperature of 140°F (60°C). When the set 

point is reached, the heater turns off. The heater remains off until the tank temperature falls 

below the set point temperature minus the deadband temperature difference of two degrees. The 
102

heater continuously cycles on and off to maintain the tank temperature in the dead band. Table 

6-48 shows the baseline and low-energy model water heater characteristics.

Table 6-48 Baseline Model Water Heater Characteristics

SWH Characteristic Baseline Model Low-Energy Model

Tank volume 800 gal 800 gal

Deadband temperature 2°F 2°F

Set point temperature 140°F 140°F

Control type Cycle Cycle

Maximum capacity 288 kBtu/h 288 kBtu/h

Fuel Natural gas Natural gas

Et 80% 90%

Off cycle parasitic heat fraction to tank 0.8 0.9

6.12 Humidifiers

The critical CAV AHUs in the baseline and low-energy models had electric steam humidifiers to 

maintain the RH in the spaces above 30% based on AIA 2006, which specifies a 30% RH 

minimum. However, 40% RH was used based on PC recommendations. The PC also 

recommended that the humidifier be a stand-alone unit in the AHU. Although the humidifiers 

are controlled to maintain the return air at a 40% minimum RH, EnergyPlus controls the 

humidifier to maintain a minimum RH set point for one zone served by the AHU. For the 

community hospital and the surgery center, the operating room was specified as the zone to 

control the humidifier. Table 6-49 reviews the stand-alone electric humidifier performance 

characteristics modeled in EnergyPlus. Even though an electric humidifier is essentially 100% 

efficient—because all the electricity heat is transferred to the water—the 93% resultant 

efficiency was based on the PC recommendation to account for occasional condensate 

blowdown.

Table 6-49 Stand-Alone AHU Humidifier EnergyPlus Input

Performance Characteristics Baseline and Low-Energy

Rated capacity 295 lb/h

Rated power 100 kW

Resultant efficiency 93%
103

7. Model Validation

Energy modeling of healthcare facilities is difficult because the buildings are complex. Certain 

PC members were very experienced with these difficulties and scrutinized the energy modeling 

throughout the development of the Guide. The following sections highlight certain model 

ideation procedures that were performed to improve the accuracy of the energy model and to 

prove to the PC that the model was correctly capturing all the intricate energy flows in a small 

healthcare facility.

7.1 Air Flow Verification

A unique requirement to healthcare facilities stems from AIA 2006. This guide is a reference 

standard on which many healthcare facilities are constructed. It mandates specific total air flow 

requirements (in ACH) for particular zone types. In order to correctly model the energy use of a 

healthcare facility, it was important to incorporate these total air flow requirements into the 

model, as well as validate their performance. All space types with total air flow requirements 

can be seen in Table 7-1.

Table 7-1 AIA Total Air Flow Requirements

Space Type AIA Requirements (ACH)

Anesthesia 8

Clean 4

Conference –

Corridor –

Dining –

Examination room 6

Food preparation center 10

Laboratory 6

Lounge –

Nurse station –

Nursery 6

Office –

Operating room 20*

Patient corridor 2

Patient room 6

Physical therapy 6

Procedure room 15

Radiology –

Reception area –

Recovery room 6

Soiled 10

Storage –

Toilet room 10

Trauma room 15

Triage 12

Utility –

* This value was changed from the 15 ACH that is listed in AIA 2006, based on PC recommendations.

These total air flow requirements were input into the model. The patient room wing of the 

community hospital (see Figure 7-1 and Figure 7-2) was chosen to verify that these requirements 

were being met.
104

Figure 7-1 Community hospital with patient room wing highlighted

Credit: Eric Bonnema/NREL

Figure 7-2 Community hospital patient room wing close up

Credit: Eric Bonnema/NREL
105

As Table 7-1 shows, a patient room requires 6 ACH of total air flow. Detailed hourly air flow 

data from the simulation was output for the 15 patient room zones in the community hospital. 

These data were output for three climate zones: 2A (Houston), 5A (Chicago), and 7A (Duluth) 

for the baseline and low-energy models. The annual minimum total air flow rate values were 

determined from these detailed hourly data. The patient room floor areas are not consistent (and 

thus neither are the zone volumes), so the 6 ACH requirement was converted to cubic feet per 

minute for comparison with the hourly EnergyPlus data. Table 7-2 shows this 6 ACH 

conversion to cubic feet per minute in red text and the minimum annual total air flow values for 

each patient room in the three climates for the baseline and low-energy models. As Table 7-2

shows, the 6 ACH requirement is being met for all patient rooms in all locations, demonstrating 

that the model accurately simulates the total air flow in these AIA mandated zones and furthering

confidence in the simulation results.

Table 7-2 Community Hospital Patient Room Air Flow 

Zone Name

AIA cfm

(equivalent 

to 6 ACH)

2A – Houston 5A – Chicago 7A – Duluth

Baseline 

Model cfm

Low-Energy 

Model cfm

Baseline 

Model cfm

Low-Energy 

Model cfm

Baseline 

Model cfm

Low-Energy 

Model cfm

Patient Rooms

100–101 216 267 218 216 218 215 217

Patient Rooms

103–105 432 436 436 432 436 429 435

Patient Rooms

107–109 432 436 436 432 436 429 435

Patient Room 

111 216 218 218 216 218 215 217

Patient Room 

120 216 218 218 216 218 215 217

Patient Rooms

122–124 432 436 436 432 436 429 435

Patient Room 

126 216 222 218 216 218 215 217

Patient Room 

128 216 269 218 263 218 251 217

Patient Rooms

130–132 432 481 436 472 436 457 435

Patient Room 

136 176 178 178 177 178 175 177

Patient Room 

138 288 291 291 288 291 286 290

Patient Room 

140 216 218 218 216 218 215 217

Patient Rooms

142–144 432 436 436 432 436 429 435

Patient Rooms

146–148 432 436 436 432 436 429 435

Patient Rooms

150–151 216 253 218 220 218 215 217

7.2 Utility Bill Comparisons

The community hospital and the surgery center energy models were based on real healthcare 

facilities. At the time of modeling, the community hospital had been in operation for 

approximately one year, while the surgery center was still under construction. The community 
106

hospital had been open and an entire year of monthly utility (natural gas and electric) bills were

available, so comparisons could be made between the community hospital energy model and the 

community hospital utility bills.

The owners of the community hospital provided the modeling team with a year of monthly utility 

bills for electrical energy use, electrical demand, and natural gas energy use. Monthly aggregate

data were output from the EnergyPlus simulations for electrical and natural gas energy use and 

monthly maximum data were output for electrical demand. The EnergyPlus output was then 

plotted with the utility bill for each month. The results of this comparison are shown in Figure 

7-3 through Figure 7-5.

Figure 7-3 shows the metered electrical energy use side-by-side with the modeled electrical 

energy use while Figure 7-4 shows the metered electrical demand side-by-side with the modeled 

electrical demand. The EnergyPlus modeled electrical energy use and electrical demand are

similar to the metered community hospital data. These similarities further increase our 

confidence in the simulation results.

Figure 7-5 shows the metered natural gas use side-by-side with the modeled natural gas use. The 

EnergyPlus modeled natural gas use is much lower than the metered community hospital data, 

although the annual trends are similar. The differences between the metered gas use and the 

energy model can be attributed to problems encountered in the boiler room of the community 

hospital.
107

7.2.1 Electricity Use

Figure 7-3 Community hospital electrical energy use
108

7.2.2 Electricity Demand

Figure 7-4 Community hospital electrical demand
109

7.2.3 Natural Gas

Figure 7-5 Community hospital natural gas energy use
110

8. Evaluation Results

This section contains the modeling results of the recommendations for 30% savings approved by 

the PC for the SHC-AEDG. Modeling results of the recommendations for 30% savings over 

ASHRAE 90.1-2004 are also discussed. The energy savings that are achieved as a result of 

applying these recommendations are presented. Figures of the end use comparisons are 

provided; the end-use data are presented in tabular format in Appendix E and Appendix G.

The recommendations are applicable for all small healthcare facilities within the scope of the 

Guide as a means of demonstrating 30% energy savings. The Guide recognizes that there are 

other ways of achieving 30% energy savings, and offers these recommendations as some ways, 

but not the only way to meet the energy savings target. When a recommendation contains the 

designation “Comply with Standard 90.1,” the Guide provides no recommendation for this 

component or system. In these cases, the user must meet the more stringent of either the 

applicable version of Standard 90.1 or the local code requirements.

8.1 Recommendation Tables for 30% Savings

Each recommendation tables presented in the SHC-AEDG includes a set of common items 

arranged by building subsystem: envelope, daylighting/lighting, HVAC systems, and SWH. 

Recommendations are included for each item, or subsystem, by component within that 

subsystem. For some subsystems, recommendations depend on the construction type, HVAC 

system type, or space type. For example, insulation values are given for mass, steel-framed, and 

wood-framed wall types. For others, recommendations are given for each attribute. For 

example, glass recommendations are given for size, thermal transmittance, SHGC, and exterior 

sun control.

The opaque envelope recommendations are presented for different climate zones by roof, wall, 

floor, slab, and door types. Recommendations for the thermal characteristics of the vertical 

fenestration and interior reflectance are also provided.

Daylighting recommendations are provided for specific space types to maximize sidelighting 

potential. If carefully designed, vertical fenestration and skylights can provide interior 

illumination without excessive solar heat gain. Electric lighting systems can then be 

extinguished or dimmed for most daytime hours, saving significant energy and maintenance 

costs. The key to daylighting is integrated design in which HVAC and electric lighting controls 

are optimized to take full advantage of and harvest energy savings, and added first costs of 

fenestration are offset by reduced costs in HVAC equipment. Because of the additional 

nonenergy benefits from daylighting, a design that uses daylighting should be pursued whenever 

possible. Proper daylighting design requires an integrated approach and good design skills. If 

these are possible, lighting and daylighting design can provide predictable and persistent lighting 

energy savings.

For interior electrical lighting, recommendations are provided that use efficient, state-of-the-art 

products and lighting design techniques. The recommendations provided in this section include 

whole-building LPD, light source system efficacy for lighting systems that use the most current 

energy-efficient lamps and ballasts, and integrated controls. Because lighting energy savings 

also produce cooling savings, HVAC energy savings of 10% to 15% are also possible in coolingdominated climates. Moreover, even though the cost of high-performance lighting may be about 

the same or more than that of a basic solution, the cost of HVAC capacity can also be reduced.
111

This Guide provides recommendations for one of the following three system types:

• Single-duct VAV air-handling system (indoor or outdoor) with DX cooling or a water 

chiller and a water boiler

• Water-source heat pump with a dedicated OA ventilation system

• Fan coils with a water chiller, a water boiler, and a dedicated OA ventilation system.

Some system types, however, are not recommended for critical care areas of the healthcare

facility. Unique recommendations are included for each HVAC system type, based on 

practicality of implementation and the 30% energy reduction goal. Unique recommendations for 

cooling, heating, and fan efficiencies are included for each HVAC system type in the climatespecific recommendations. Economizer use recommendations for each HVAC system type are 

also included. SWH efficiency recommendations are provided based on electric or gas water 

heaters, as well as instantaneous or gas storage units.

The recommendation table also lists references to how-to tips for implementing the 

recommended criteria. The tips are found under separate sections coded for envelope, 

daylighting, electric lighting, HVAC systems and equipment, and SWH systems and equipment 

suggestions. Besides design and maintenance suggestions that represent good design practice, 

these tips include cautions. Each tip is tied to the applicable climate zones. Additional 

recommendations and strategies are provided for energy savings above and beyond the 30% 

recommendations contained in the eight climate regions. These savings include plug loads, 

alternative HVAC systems, and renewable energy systems.

The recommendations presented are either maximum or minimum values. Minimum values 

include:

• R-values

• Mean lumens per watt

• SRI

• EER

• Integrated energy efficiency ratio (IEER)

• IPLV

• COP

• Effectiveness

• E

• E

c

• Energy factor (EF)

t

• Duct or pipe insulation thickness.

Maximum values include:

• Fenestration U-factors

• Fenestration SHGC

• Total fenestration to gross wall area ratio

• LPD
112

• Fan brake horsepower

• Fan input power per cfm of supply air flow

• Window-to-wall ratio (WWR).

The recommendations for the SHC-AEDG are shown in Table 8-1 SHC-AEDG 

Recommendations for 30% Savings Over 90.1-1999: Climate Zones 1–4 and Table 8-2. The 

recommendations for 30% energy savings over ASHRAE 90.1-2004 are the same as those for 

30% energy savings over ASHRAE 90.1-1999.
113

Table 8-1 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 1–4

Item Component Climate Zone 1 

Recommendations

Climate Zone 2 

Recommendations

Climate Zone 3 

Recommendations

Climate Zone 4 

Recommendations

Envelope

Roofs Insulation entirely above deck R-25 c.i. R-25 c.i. R-25 c.i. R-30 c.i.

SRI 78 78 78 Comply with 90.1

Walls

Mass (heat capacity > 7 Btu/ft2

) R-5.7 c.i. R-7.6 c.i. R-11.4 c.i. R-13.3 c.i.

Steel-framed R-13 + R-7.5 c.i. R-13 + R-7.5 c.i. R-13 + R-7.5 c.i. R-13 + R-7.5 c.i.

Below-grade walls Comply with 90.1 Comply with 90.1 R-7.5 R-7.5

Floors Mass R-4.2 c.i. R-10.4 c.i. R-12.5 c.i. R-14.6 c.i.

Steel-framed R-19 R-30 R-30 R-38

Slabs Unheated Comply with 90.1 Comply with 90.1 Comply with 90.1 R-15 for 24 in.

Doors Swinging U-0.70 U-0.70 U-0.70 U-0.50

Non-swinging U-1.45 U-0.50 U-0.50 U-0.50

Vertical

fenestration

Total fenestration to gross wall area 40% max 40% max 40% max 40% max

Thermal transmittance – all types and 

orientations U-0.43 U-0.43 U-0.43 U-0.29

SHGC – all types and orientations SHGC-0.26 SHGC-0.26 SHGC-0.26 SHGC-0.34

Visible transmittance VT-0.63 VT-0.63 VT-0.63 VT-0.69

Exterior sun control (S, E, W only) PF > 0.5 PF > 0.5 PF > 0.5 PF > 0.5

Skylights

Area (percent of roof area) 3% max 3% max 3% max 3% max

Thermal transmittance – all types U-0.75 U-0.75 U-0.75 U-0.60

SHGC SHGC-0.35 SHGC-0.35 SHGC-0.35 SHGC-0.40

Lighting/Daylighting

Interior finishes Daylit room interior surface average 

reflectance

88% > 7 ft

50% < 7 ft

88% > 7 ft

50% < 7 ft

88% > 7 ft

50% < 7 ft

88% > 7 ft

50% < 7 ft

Interior lighting

LPD 1.0 W/ft 1.0 W/ft 2 1.0 W/ft 2 1.0 W/ft 2

Lighting system efficacy (linear fluorescent 

and high-intensity discharge)

2

90 mean lumens 

per watt (MLPW) min 90 MLPW min 90 MLPW min 90 MLPW min

Lighting system efficacy (all other) 50 MLPW min 50 MLPW min 50 MLPW min 50 MLPW min

Lighting controls – general

Manual on auto off 

in all zones except 

patient care areas

Manual on auto off in 

all zones except 

patient care areas

Manual on auto off in 

all zones except 

patient care areas

Manual on auto off in 

all zones except 

patient care areas

Dimming controls daylight harvesting

Dim fixtures within 15 

ft of sidelighting edge, 

and within 10 ft of 

toplighting edge

Dim fixtures within 15 

ft of sidelighting edge, 

and within 10 ft of 

toplighting edge

Dim fixtures within 15 

ft of sidelighting edge, 

and within 10 ft of 

toplighting edge

Dim fixtures within 15 

ft of sidelighting edge, 

and within 10 ft of 

toplighting edge
114

Table 8-1 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 1–4 (con’t)

Item Component Climate Zone 1 

Recommendations

Climate Zone 2 

Recommendations

Climate Zone 3 

Recommendations

Climate Zone 4 

Recommendations

HVAC

Critical Care Access

Central

air-handling

system

DX air conditioner

(≥ 240 and < 760 kBtu/h) 10.0 EER/10.5 IEER 10.0 EER/10.5 IEER 10.0 EER/10.5 IEER 10.0 EER/10.5 IEER

DX air conditioner (≥ 760 kBtu/h) 9.7 EER/10.2 IEER 9.7 EER/10.2 IEER 9.7 EER/10.2 IEER 9.7 EER/10.2 IEER

Air-cooled chiller efficiency 10.0 EER/11.5 IPLV 10.0 EER/11.5 IPLV 10.0 EER/11.5 IPLV 10.0 EER/11.5 IPLV

Water-cooled chiller efficiency Comply with 90.1 Comply with 90.1 Comply with 90.1 Comply with 90.1

Chilled-water pump

VFD and National 

Electrical Manufacturers 

Association (NEMA)

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

Cooling tower VFD on tower fan VFD on tower fan VFD on tower fan VFD on tower fan

Gas boiler 90% Ec at peak water 90% E

temperature

c at peak water 90% E

temperature

c at peak water 90% E

temperature

c

Economizer

at peak water 

temperature

Comply with 90.1 ‘A’ zones: no

‘B’ zones: yes

‘A’ zones: no

‘B’ & ‘C’ zones: yes

‘A’ zones: no

‘B’ & ‘C’ zones: yes

Fans

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

Zone air flow setback Yes Yes Yes Yes

Noncritical Care Access

Central VAV

air-handling

system

DX air conditioner

(≥ 240 kBtu/h and < 760 kBtu/h) 10.0 EER/10.5 IEER 10.0 EER/10.5 IEER 10.0 EER/10.5 IEER 10.0 EER/10.5 IEER

DX air conditioner (≥ 760 kBtu/h) 9.7 EER/10.2 IEER 9.7 EER/10.2 IEER 9.7 EER/10.2 IEER 9.7 EER/10.2 IEER

Air-cooled chiller efficiency 10.0 EER/11.5 IPLV 10.0 EER/11.5 IPLV 10.0 EER/11.5 IPLV 10.0 EER/11.5 IPLV

Water-cooled chiller efficiency Comply with 90.1 Comply with 90.1 Comply with 90.1 Comply with 90.1

Chilled-water pump VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

Cooling tower VFD on tower fans VFD on tower fans VFD on tower fan VFD on tower fan

Gas boiler 90% Ec at peak water 90% E

temperature

c at peak water 90% E

temperature

c at peak water 90% E

temperature

c

Economizer

at peak water 

temperature

Comply with 90.1 ‘A’ zones: no

‘B’ zones: yes

‘A’ zones: no

‘B’ & ‘C’ zones: yes

‘A’ zones: no

‘B’ & ‘C’ zones: yes

Fans

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

Space temperature setback Yes Yes Yes Yes
115

Table 8-1 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 1–4 (con’t)

Item Component Climate Zone 1 

Recommendations

Climate Zone 2 

Recommendations

Climate Zone 3 

Recommendations

Climate Zone 4 

Recommendations

HVAC

Noncritical Care Access

WSHP system

Water-source heat pump

(< 65 kBtu/h)

CLG: 12 EER 86F

HTG: 4.5 COP 68F

CLG: 12 EER 86F

HTG: 4.5 COP 68F

CLG: 12 EER 86F

HTG: 4.5 COP 68F

CLG: 12 EER 86F

HTG: 4.5 COP 68F

Water-source heat pump

(≥ 65 kBtu/h)

CLG: 12 EER 86F

HTG: 4.2 COP 68F

CLG: 12 EER 86F

HTG: 4.2 COP 68F

CLG: 12 EER 86F

HTG: 4.2 COP 68F

CLG: 12 EER 86F

HTG: 4.2 COP 68F

Water pump VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

Cooling tower/fluid cooler VFD on fans VFD on fans VFD on fans VFD on fans

Gas boiler 90% Ec at peak 90% Ec at peak 90% Ec at peak 90% Ec

Economizer

at peak

Comply with 90.1 Comply with 90.1 Comply with 90.1 Comply with 90.1

EA energy recovery in dedicated OA 

system

‘A’: 50% total; ‘B’: 

50% sensible 

effectiveness

‘A’: 50% total; ‘B’: 

50% sensible 

effectiveness

‘A’ & ‘C’: 50% total; 

‘B’: 50% sensible 

effectiveness

‘A’ & ‘C’: 50% total; 

‘B’: 50% sensible 

effectiveness

Water source heat pump fans 0.4 W/cfm 0.4 W/cfm 0.4 W/cfm 0.4 W/cfm

Other fans (dedicated OA system, 

exhaust)

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

Space temperature setback Yes Yes Yes Yes

Fan coil and 

chiller system

Air-cooled chiller efficiency 10.0 EER/11.5 IPLV 10.0 EER/11.5 IPLV 10.0 EER/11.5 IPLV 10.0 EER/11.5 IPLV

Water-cooled chiller efficiency Comply with 90.1 Comply with 90.1 Comply with 90.1 Comply with 90.1

Chilled-water pump VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

Cooling tower VFD on tower fans VFD on tower fans VFD on tower fans VFD on tower fans

Gas boiler 90% Ec at peak 90% Ec at peak 90% Ec at peak 90% Ec

Economizer

at peak

Comply with 90.1 ‘A’: no

‘B’: waterside

‘A’: no

‘B’ & ‘C’: waterside

‘A’: no

‘B’ & ‘C’: waterside

EA energy recovery in dedicated OA 

system

‘A’: 50% total; ‘B’: 

50% sensible 

effectiveness

‘A’: 50% total; ‘B’: 

50% sensible 

effectiveness

‘A’ & ‘C’: 50% total; 

‘B’: 50% sensible 

effectiveness

‘A’ & ‘C’: 50% total; 

‘B’: 50% sensible 

effectiveness

Fan coil units 0.4 W/cfm 0.4 W/cfm 0.4 W/cfm 0.4 W/cfm

Other fans (dedicated OA system, 

exhaust)

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

Space temperature setback Yes Yes Yes Yes
116

Table 8-1 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 1–4 (con’t)

Item Component Climate Zone 1 

Recommendations

Climate Zone 2 

Recommendations

Climate Zone 3 

Recommendations

Climate Zone 4 

Recommendations

HVAC

Ducts and dampers

OA damper Motorized Motorized Motorized Motorized

Duct seal class

Supply and ducts 

located outdoors: 

seal class A; return 

and exhaust: seal 

class B

Supply and ducts 

located outdoors: 

seal class A; return 

and exhaust: seal 

class B

Supply and ducts 

located outdoors: 

seal class A; return 

and exhaust: seal 

class B

Supply and ducts 

located outdoors: 

seal class A; return 

and exhaust: seal 

class B

Insulation level R-6 R-6 R-6 R-6

SWH

Service water

heating

Gas storage (≥ 75 kBtu/h) 90% Et 90% Et 90% Et 90% E

Gas instantaneous

t

0.81 EF or 81% Et 0.81 EF or 81% Et 0.81 EF or 81% Et 0.81 EF or 81% E

Electric (storage or instantaneous)

t

EF > 0.99-0.0012 ×

volume

EF > 0.99-0.0012 ×

volume

EF > 0.99-0.0012 ×

volume

EF > 0.99-0.0012 ×

volume

Pipe insulation

(d < 1.5 in./d ≥ 1.5 in.) 1 in./1.5 in. 1 in./1.5 in. 1 in./1.5 in. 1 in./1.5 in.
117

Table 8-2 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 5–8

Item Component Climate Zone 5 

Recommendations

Climate Zone 6 

Recommendations

Climate Zone 7 

Recommendations

Climate Zone 8 

Recommendations

Envelope

Roofs Insulation entirely above deck R-30 c.i. R-30 c.i. R-35 c.i. R-35 c.i.

SRI Comply with 90.1 Comply with 90.1 Comply with 90.1 Comply with 90.1

Walls

Mass (heat capacity > 7 Btu/ft2) R-13.3 c.i. R-19.5 c.i. R-19.5 c.i. R-25 c.i.

Steel-framed R-13 + R-15.6 c.i. R-13 + R-18.8 c.i. R-13 + R-18.8 c.i. R-13 + R-21.6 c.i.

Below-grade walls R-7.5 R-12.5 R-15 R-17.5

Floors Mass R-16.7 c.i. R-19.5 c.i. R-20.9 c.i. R-23 c.i.

Steel-framed R-38 R-49 R-60 R-60

Slabs Unheated R-15 for 24 in. R-20 for 24 in. R-20 for 24in. R-20 for 48 in.

Doors Swinging U-0.50 U-0.50 U-0.50 U-0.50

Nonswinging U-0.50 U-0.50 U-0.50 U-0.50

Vertical

fenestration

Total fenestration to gross wall area 40% max 40% max 40% max 40% max

Thermal transmittance – all types and 

orientations U-0.29 U-0.29 U-0.29 U-0.20

SHGC – all types and orientations SHGC-0.34 SHGC-0.34 SHGC-0.34 SHGC-0.40

Visible transmittance VT-0.69 VT-0.69 VT-0.69 VT-0.65

Exterior sun control (S, E, W only) PF > 0.5 PF > 0.5 PF > 0.5 PF > 0.5

Skylights

Area (percent of roof area) 3% max 3% max 3% max 3% max

Thermal transmittance – all types U-0.60 U-0.60 U-0.60 U-0.60

SHGC SHGC-0.40 SHGC-0.40 Comply with 90.1 Comply with 90.1

Lighting/Daylighting

Interior finishes Daylit room interior surface average 

reflectance

88% > 7 ft

50% < 7 ft

88% > 7 ft

50% < 7 ft

88% > 7 ft

50% < 7 ft

88% > 7 ft

50% < 7 ft

Interior lighting

LPD 1.0 W/ft 1.0 W/ft 2 1.0 W/ft 2 1.0 W/ft 2

Lighting system efficacy (linear 

fluorescent and high-intensity discharge)

2

90 MLPW min 90 MLPW min 90 MLPW min 90 MLPW min

Lighting system efficacy (all other) 50 MLPW min 50 MLPW min 50 MLPW min 50 MLPW min

Lighting controls – general

Manual on auto off in 

all zones except 

patient care areas

Manual on auto off in 

all zones except 

patient care areas

Manual on auto off in 

all zones except 

patient care areas

Manual on auto off in 

all zones except 

patient care areas

Dimming controls daylight harvesting

Dim fixtures within 15 

ft of sidelighting edge, 

and within 10 ft of 

toplighting edge

Dim fixtures within 15 

ft of sidelighting edge, 

and within 10 ft of 

toplighting edge

Dim fixtures within 15 

ft of sidelighting edge, 

and within 10 ft of 

toplighting edge

Dim fixtures within 15 

ft of sidelighting edge, 

and within 10 ft of 

toplighting edge
118

Table 8-2 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 5–8 (con’t)

Item Component Climate Zone 5 

Recommendations

Climate Zone 6 

Recommendations

Climate Zone 7 

Recommendations

Climate Zone 8 

Recommendations

HVAC

Critical Care Access

Central airhandling

system

DX air conditioner

(≥ 240 and < 760 kBtu/h) 10.0 EER/10.5 IEER Comply with 90.1 Comply with 90.1 Comply with 90.1

DX air conditioner (≥ 760 kBtu/h) 9.7 EER/10.2 IEER Comply with 90.1 Comply with 90.1 Comply with 90.1

Air-cooled chiller efficiency 9.6 EER/11.5 IPLV 9.6 EER/11.5 IPLV 9.6 EER/11.5 IPLV 9.6 EER/11.5 IPLV

Water-cooled chiller efficiency Comply with 90.1 Comply with 90.1 Comply with 90.1 Comply with 90.1

Chilled-water pump VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

Cooling tower VFD on tower fan VFD on tower fan VFD on tower fan VFD on tower fan

Gas boiler 90% Ec at peak water 90% E

temperature

c at peak water 90% E

temperature

c at peak water 90% E

temperature

c

Economizer

at peak water 

temperature

Yes Yes Yes Yes

Fans

bhp≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp≤ cfm × 0.0012 

NEMA premium 

efficiency motors

Zone air flow setback Yes Yes Yes Yes

Noncritical Care Access

Central VAV

air-handling

system

DX air conditioner

(≥ 240 kBtu/h and < 760 kBtu/h) 10.0 EER/10.5 IEER Comply with 90.1 Comply with 90.1 Comply with 90.1

DX air conditioner (≥ 760 kBtu/h) 9.7 EER/10.2 IEER Comply with 90.1 Comply with 90.1 Comply with 90.1

Air-cooled chiller efficiency 9.6 EER/11.5 IPLV 9.6 EER/11.5 IPLV 9.6 EER/11.5 IPLV 9.6 EER/11.5 IPLV

Water-cooled chiller efficiency Comply with 90.1 Comply with 90.1 Comply with 90.1 Comply with 90.1

Chilled-water pump VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

Cooling tower VFD on tower fan VFD on tower fan VFD on tower fan VFD on tower fan

Gas boiler 90% Ec at peak water 90% E

temperature

c at peak water 90% E

temperature

c at peak water 90% E

temperature

c

Economizer

at peak water 

temperature

Yes Yes Yes Yes

Fans

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012 

NEMA premium 

efficiency motors

Space temperature setback Yes Yes Yes Yes
119

Table 8-2 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 5–8 (con’t)

Item Component Climate Zone 5 

Recommendations

Climate Zone 6 

Recommendations

Climate Zone 7 

Recommendations

Climate Zone 8 

Recommendations

HVAC

Noncritical Care Access

WSHP system

Water-source heat pump

(< 65 kBtu/h)

CLG: 12 EER 86F

HTG: 4.5 COP 68F

CLG: 12 EER 86F

HTG: 4.5 COP 68F

CLG: 12 EER 86F

HTG: 4.5 COP 68F

CLG: 12 EER 86F

HTG: 4.5 COP 68F

Water-source heat pump

(≥ 65 kBtu/h)

CLG: 12 EER 86F

HTG: 4.2 COP 68F

CLG: 12 EER 86F

HTG: 4.2 COP 68F

CLG: 12 EER 86F

HTG: 4.2 COP 68F

CLG: 12 EER 86F

HTG: 4.2 COP 68F

Water pump VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

Cooling tower/fluid cooler VFD on fans VFD on fans VFD on fans VFD on fans

Gas boiler 90% Ec at peak 90% Ec at peak 90% Ec at peak 90% Ec

Economizer

at peak

Comply with 90.1 Comply with 90.1 Comply with 90.1 Comply with 90.1

EA energy recovery in dedicated OA 

system

‘A’ & ‘C’: 50% total; 

‘B’: 50% sensible 

effectiveness

‘A’: 50% total; ‘B’: 

50% sensible 

effectiveness

‘A’: 50% total; ‘B’: 

50% sensible 

effectiveness

50% sensible 

effectiveness

Water-source heat pump fans 0.4 W/cfm 0.4 W/cfm 0.4 W/cfm 0.4 W/cfm

Other fans (dedicated OA system, 

exhaust)

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

Space temperature setback Yes Yes Yes Yes

Fan coil and 

chiller system

Air-cooled chiller efficiency 9.6 EER/11.5 IPLV 9.6 EER/11.5 IPLV 9.6 EER/11.5 IPLV 9.6 EER/11.5 IPLV

Water-cooled chiller efficiency Comply with 90.1 Comply with 90.1 Comply with 90.1 Comply with 90.1

Chilled-water pump VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

VFD and NEMA 

premium efficiency

Cooling tower VFD on tower fans VFD on tower fans VFD on tower fans VFD on tower fans

Gas boiler 90% Ec at peak 90% Ec at peak 90% Ec at peak 90% Ec

Economizer

at peak

Waterside Waterside Waterside Waterside

EA energy recovery in dedicated OA 

system

‘A’ & ‘C’: 50% total; 

‘B’: 50% sensible 

effectiveness

‘A’: 50% total; ‘B’: 

50% sensible 

effectiveness

‘A’: 50% total; ‘B’: 

50% sensible 

effectiveness

50% sensible 

effectiveness

Fan coil units 0.4 W/cfm 0.4 W/cfm 0.4 W/cfm 0.4 W/cfm

Other fans (dedicated OA system, 

exhaust)

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

bhp ≤ cfm × 0.0012

NEMA premium 

efficiency motors

Space temperature setback Yes Yes Yes Yes
120

Table 8-2 SHC-AEDG Recommendations for 30% Savings Over 90.1-1999: Climate Zones 5–8 (con’t)

Item Component Climate Zone 5 

Recommendations

Climate Zone 6 

Recommendations

Climate Zone 7 

Recommendations

Climate Zone 8 

Recommendations

HVAC

Ducts and

dampers

OA damper Motorized Motorized Motorized Motorized

Duct seal class

Supply and ducts 

located outdoors: 

seal class A; return 

and exhaust: seal 

class B

Supply and ducts 

located outdoors: 

seal class A; return 

and exhaust: seal 

class B

Supply and ducts 

located outdoors: 

seal class A; return 

and exhaust: seal 

class B

Supply and ducts 

located outdoors: 

seal class A; return 

and exhaust: seal 

class B

Insulation level R-6 R-6 R-6 R-6

SWH

Service

water

heating

Gas storage (≥ 75 kBtu/h) 90% Et 90% Et 90% Et 90% E

Gas instantaneous

t

0.81 EF or 81% Et 0.81 EF or 81% Et 0.81 EF or 81% Et 0.81 EF or 81% E

Electric (storage or instantaneous)

t

EF > 0.99-0.0012 ×

Volume

EF > 0.99-0.0012 ×

Volume

EF > 0.99-0.0012 ×

Volume

EF > 0.99-0.0012 ×

Volume

Pipe insulation (d < 1.5 in./d ≥ 1.5 in.) 1 in./1.5 in. 1 in./1.5 in. 1 in./1.5 in. 1 in./1.5 in.
121

8.2 Discussion of Recommendations

8.2.1 Envelope Recommendations

The envelope recommendations cover the range of assemblies for the opaque and fenestration 

portions of the building. Opaque elements include the roof, walls, floors and slabs, as well as 

opaque doors. Fenestration elements include the vertical glazing (including doors). The Guide 

presents recommendations for a number of components of each building element. In general, the 

insulation recommendations increase with colder climates. Control of solar loads is more critical 

in the hotter, sunnier climates, so the SHGC tends to be more stringent (lower) in climate zone 1 

and higher in climate zone 8.

8.2.2 Lighting and Daylighting Recommendations

The lighting and daylighting recommendations cover a range of performance characteristics, 

including LPD, lighting controls, and daylighting fenestration areas. The recommended LPD is 

1.0 W/ft2 (10.8 W/m2

A primary difference between ASHRAE 90.1-1999 and ASHRAE 90.1-2004 is the more 

aggressive limits on LPD. For example, operating room LPD was reduced from 7.6 W/ft

).

2 to 2.2

W/ft2 (81.8 W/m2 to 23.7 W/m2

The SHC-AEDG recommends skylights in the top floor of the surgery center only. The surgery 

center is a three-story building with a relatively small footprint, so most areas can be daylit 

through sidelighting. The PC felt that direct-beam radiation in community hospitals should be 

avoided and did not recommend skylights. The community hospital is a single-story building 

with a relatively large footprint, so to daylight interior zones without introducing direct-beam 

radiation, the Guide recommends shaded or north-facing clerestories. One benefit of a welldesigned daylighting system is that the cooling equipment can be downsized. Often this 

downsizing can pay for a significant portion of the daylighting system. Therefore, the PC 

primarily focused on nonskylight daylighting methods that provided good daylighting and could 

result in downsizing of the cooling systems. This resulted in skylight recommendations for the 

surgery center only, which would be affected less by direct-beam radiation.

). Not all low-energy models were still at 30% savings or greater

for the ASHRAE 90.1-2004 baseline.

8.2.3 HVAC Systems

Unique recommendations are included for each HVAC system type in the climate-specific 

recommendation tables. The recommendations are provided based on how ASHRAE 90.1 

specifies performance. The packaged rooftop cooling equipment efficiencies for DX and chillers 

are expressed in EERs. Commercial cooling products have IPLVs that express their performance 

during part-load operation. Heating efficiencies are expressed as Et and Ec

Cooling equipment efficiencies are generally higher in the hotter climates and lower in the colder 

climates. Boiler efficiencies are the same in all climates; because a significant portion of energy 

use for all models in all climates is reheat energy.

for furnaces and 

COPs for heat pumps.

Unique recommendations are included for each HVAC system type based on practicality of 

implementation and the goal to achieve 30% energy savings. For example, airside economizers 

are recommended for rooftop units in all climate zones except 1, 2A, 3A, and 4A, because they 

are easy to add to the system and save energy. However, higher chiller and boiler efficiencies 
122

are recommended for fan-coil systems and economizers are not because airside economizers are 

less practical for dedicated OA systems.

SWH measures include recommendations for the use of instantaneous water heaters for fuel-fired 

applications and enhanced efficiencies for storage applications. Recommendations are provided 

for enhanced pipe insulation values.

8.3 Energy Savings Results

The whole building energy savings results for the recommendations in the SHC-AEDG are 

shown in Table 8-3. Energy savings are relative to the ASHRAE 90.1-1999 baseline energy use, 

and include plug loads in the energy use of the baseline and low-energy models. The analysis 

shows that the recommendations in the SHC-AEDG met the goal of 30% or greater energy 

savings within a range of HVAC system types. Energy savings are also shown for each 

community hospital and surgery center prototype. The DX cooling system types performed the 

best because of the additional pumping power required in chiller systems. The energy savings 

for a given climate zone were greater in the community hospital than in the surgery center, 

mainly because of the surgery center’s 24-hour operation. The community hospital benefited 

more from the improved envelope because it has much more building skin than the surgery 

center.

Table 8-3 Energy Savings: ASHRAE 90.1-1999 Baseline

Location Climate 

Zone

Community Hospital Surgery Center

DX

AirCooled 

Chiller

WaterCooled 

Chiller

DX

AirCooled 

Chiller

WaterCooled 

Chiller

Miami, Florida 1A 38% 36% 36% 39% 36% 34%

Houston, Texas 2A 40% 39% 38% 39% 38% 36%

Phoenix, Arizona 2B 43% 43% 45% 44% 44% 45%

Memphis, Tennessee 3A 39% 39% 37% 38% 38% 35%

El Paso, Texas 3B 41% 43% 43% 44% 45% 45%

San Francisco, California 3C 44% 45% 43% 45% 45% 42%

Baltimore, Maryland 4A 40% 41% 39% 38% 39% 36%

Albuquerque, New Mexico 4B 42% 44% 44% 44% 45% 45%

Seattle, Washington 4C 41% 41% 40% 42% 42% 40%

Chicago, Illinois 5A 41% 40% 40% 40% 40% 38%

Boise, Idaho 5B 42% 43% 43% 43% 43% 43%

Burtlington, Vermont 6A 39% 40% 39% 38% 39% 38%

Helena, Montana 6B 41% 42% 42% 41% 42% 42%

Duluth, Minnesota 7A 39% 39% 39% 37% 37% 36%

Fairbanks, Alaska 8A 33% 33% 33% 33% 33% 32%

The energy savings results for the recommendations in the SHC-AEDG relative to ASHRAE 

90.1-2004 are shown in Table 8-4. Energy savings are also shown for each community hospital 

and surgery center prototype. The Guide recommendations result in 30% or greater energy 

savings over ASHRAE 90.1-2004 for most climates within a range of cooling system types. In 

particular, the extremely cold climates (8A) and extremely hot/humid climates (1A, 2A, and 3A) 

did not achieve 30% savings for all cooling system types for both prototypes. Table 8- shows the 

specific climates that did not achieve 30% savings over ASHRAE 90.1-2004. If the table cell is 

blank, the model met or exceeded 30% energy savings; otherwise, the percent savings value less 

than 30% is shown.
123

Table 8-4 Energy Savings: ASHRAE 90.1-2004 Baseline

Location Climate 

Zone

Community Hospital Surgery Center

DX

AirCooled 

Chiller

WaterCooled 

Chiller

DX

AirCooled 

Chiller

WaterCooled 

Chiller

Miami, Florida 1A 33% 30% 30% 31% 28% 26%

Houston, Texas 2A 35% 34% 33% 32% 31% 29%

Phoenix, Arizona 2B 39% 38% 40% 38% 38% 39%

Memphis, Tennessee 3A 34% 34% 32% 31% 32% 28%

El Paso, Texas 3B 36% 38% 38% 36% 38% 38%

San Francisco, California 3C 40% 40% 38% 39% 39% 36%

Baltimore, Maryland 4A 35% 36% 34% 32% 33% 30%

Albuquerque, New Mexico 4B 37% 39% 39% 37% 39% 38%

Seattle, Washington 4C 36% 37% 37% 36% 36% 34%

Chicago, Illinois 5A 36% 36% 36% 35% 34% 32%

Boise, Idaho 5B 37% 38% 38% 36% 37% 37%

Burtlington, Vermont 6A 35% 36% 36% 33% 33% 32%

Helena, Montana 6B 36% 37% 37% 34% 36% 35%

Duluth, Minnesota 7A 34% 35% 35% 31% 31% 31%

Fairbanks, Alaska 8A 29% 30% 29% 27% 28% 27%

Table 8-5 Energy Savings: Less Than 30% Over ASHRAE 90.1-2004 Baseline

Location Climate 

Zone

Community Hospital Surgery Center

DX

AirCooled 

Chiller

WaterCooled 

Chiller

DX

AirCooled 

Chiller

WaterCooled 

Chiller

Miami, Florida 1A – – – – 28% 26%

Houston, Texas 2A – – – – – 29%

Phoenix, Arizona 2B – – – – – –

Memphis, Tennessee 3A – – – – – 28%

El Paso, Texas 3B – – – – – –

San Francisco, California 3C – – – – – –

Baltimore, Maryland 4A – – – – – –

Albuquerque, New Mexico 4B – – – – – –

Seattle, Washington 4C – – – – – –

Chicago, Illinois 5A – – – – – –

Boise, Idaho 5B – – – – – –

Burtlington, Vermont 6A – – – – – –

Helena, Montana 6B – – – – – –

Duluth, Minnesota 7A – – – – – –

Fairbanks, Alaska 8A 29% – 29% 27% 28% 27%

The end uses for each ASHRAE 90.1-1999 baseline and low-energy model are shown in Figure 

8-1 and Figure 8-2. The end uses for each ASHRAE 90.1-2004 baseline and low-energy model 

are shown in Figure 8-3 and Figure 8-4.

The end-use data and percent savings for the ASHRAE 90.1-1999 baseline and low-energy 

models are shown in tabular format in Appendix E. The ASHRAE 90.1-2004 baseline and lowenergy model end uses and savings are shown in tabular format in Appendix G.
124

8.3.1 End Uses for 30% Savings over ASHRAE 90.1-1999

Figure 8-1 Community hospital end uses: ASHRAE 90.1-1999 baseline
125

Figure 8-2 Surgery center end uses: ASHRAE 90.1-1999 baseline
126

8.3.2 End Uses for 30% Savings Over ASHRAE 90.1-2004

Figure 8-3 Community hospital end uses: ASHRAE 90.1-2004 baseline
127

Figure 8-4 Surgery center end uses: ASHRAE 90.1-2004 baseline
128

8.4 Bundled Energy Efficiency Measure Analysis

During the modeling process, a baseline and a low-energy model are created and compared to 

provide the percent savings numbers. The low-energy model is created by starting with the 

baseline model and applying as many of the Guide recommendations as possible. However, it is 

difficult to determine which recommendations provide the most energy savings, because they 

were all applied to the baseline model in a single operation. To better understand how each 

recommendation affects energy performance, we performed a study in which each guide 

recommendation was incrementally and aggregately applied until the low-energy model was 

obtained. This study was termed a bundled energy efficiency measure analysis, and includes 

seven steps, chosen in no particular order:

1. Apply the envelope efficiency measures, which included adding overhangs to the south 

windows, adding skylights to the surgery center, and upgrading the building materials in 

accordance with the Guide recommendations. 

2. Reduce space-by-space LPD.

3. Add daylighting controls to applicable zones.

4. Reduce fan pressure drop and increase fan efficiencies.

5. Improve DX cooling efficiencies.

6. Improve boiler and SWH efficiencies.

7. Implement a zone air flow setback strategy in which the HVAC terminal boxes mimicked 

CAV boxes during occupied times and VAV boxes during unoccupied times.

Figure 8-5 shows the bundled energy efficiency analysis results by end use for climate zones 1 

though 8 (subzone A) for the community hospital; Figure 8-6 shows the results for the surgery 

center.

The results of this analysis show the biggest energy savers are the LPD reductions and the 

implementation of a zone air flow setback. Colder climates benefited more from the improved 

boiler efficiencies and hotter climates benefited more from improved cooling efficiencies. The 

results also demonstrate the improved envelope makes a greater impact on the community 

hospital, which can be attributed to its smaller volume-to-skin area ratio. Daylighting made a 

small impact because it was applied to a small portion of the building. Fan and DX coil 

efficiency increases made a small effect because the efficiency values varied slightly from the 

baseline model.
129

Figure 8-5 Community hospital bundled EEM analysis results for climate zones 1A–8A
130

Figure 8-6 Surgery center bundled EEM analysis results for climate zones 1A–8A
131

9. Conclusion

This TSD describes the process and methodology for the development of the SHC-AEDG, which 

is intended to provide recommendations for achieving 30% whole-building energy savings in 

small hospitals and healthcare facilities over levels achieved by following Standard 90.1-1999. 

The SHC-AEDG was developed in collaboration with ASHRAE, AIA, ASHE, IESNA, USGBC, 

and DOE.

The 30% energy savings target is the first step toward achieving net-zero energy small hospitals 

and healthcare facilities. Net-zero energy facilities are buildings that draw from outside sources 

less or equal energy than they generate on site from renewable energy sources during a given 

year. Previous guides in this series include the Advanced Energy Design Guide for K-12 

Schools, Advanced Energy Design Guide for Small Office Buildings, the Advanced Energy 

Design Guide for Small Retail Buildings, and the Advanced Energy Design Guide for Small 

Warehouses and Self-Storage Buildings. Each provides user-friendly design assistance and 

recommendations to design, architectural, and engineering firms to achieve energy savings. The 

SHC-AEDG includes prescriptive recommendations by climate zone for designing the building 

envelope, fenestration lighting systems (including electrical lights and daylighting), HVAC 

systems, building automation and controls, OA treatment, and SWH. Additional savings 

recommendations are also included, but are not necessary for 30% savings. These are provided 

for exterior lighting; electricity distribution; plug, process, and phantom loads; renewable energy 

systems; combined heat and power; alternative HVAC systems; and other hot water systems. 

The SHC-AEDG contains recommendations only and is not a code or standard.

As with the previous guides in the series, the SHC-AEDG provides a simple, easy-to-use guide 

to help the building designer, contractor, or owner identify a clear prescriptive path to 30% 

energy savings over Standard 90.1-1999. The combination of a set of recommendations 

contained on a single page, along with numerous how-to tips to help the construction team 

complete the project successfully, should result in increased energy efficiency in new buildings. 

Case studies of actual small healthcare applications add to the comprehension of energyefficiency opportunities.

The ultimate goal of the Advanced Energy Design Guide partner organizations is to achieve netzero energy buildings, and the 30% savings guides represent the first step in reaching this goal. 

The SHC-AEDG marks the last in the series of 30% savings design guides. This Guide has 

furthered similar work in the healthcare energy efficiency field, as it set the stage for 

development of a large hospital best practices guide and is used in planning the next series of 

50% savings Advanced Energy Design Guides. Also, the Guide is starting to be used by the U.S. 

government healthcare facilities to meet Energy Policy Act 2005 energy efficiency requirements.
132

10. References

AIA. (2006). Guidelines for Design and Construction of Health Care Facilities. Washington 

D.C.: American Institute of Architects.

ASHRAE. (1989). ANSI/ASHRAE/IESNA Standard 90.1-1989 Energy Efficient Design of New 

Buildings Except Low-Rise Residential Buildings. Atlanta, GA: American Society of Heating, 

Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (1999). ANSI/ASHRAE/IESNA Standard 90.1-1999 Energy Standard for Buildings 

Except Low-Rise Residential Buildings. Atlanta, GA: American Society of Heating, 

Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (2001). ASHRAE Standard 62.1-2001 Ventilation for Acceptable Indoor Air Quality. 

Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (2004a). Advanced Energy Design Guide for Small Office Buildings: Achieving 

30% Energy Savings Over ANSI/ASHRAE/IESNA Standard 90.1-1999. Atlanta, GA: American 

Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (2004b). ANSI/ASHRAE/IESNA Standard 90.1-2004 Energy Standard for Buildings 

except Low-Rise Residential Buildings. Atlanta, GA: American Society of Heating, 

Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (2004c). ANSI/ASHRAE Standard 62.1-2004 Ventilation for Acceptable Indoor Air 

Quality. Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning 

Engineers, Inc.

ASHRAE. (2006). Advanced Energy Design Guide for Small Retail Buildings: Achieving 30% 

Energy Savings Over ANSI/ASHRAE/IESNA Standard 90.1-1999. Atlanta, GA: American 

Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (2007). ASHRAE Handbook: HVAC Applications. Atlanta, GA: American Society 

of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (2008a). Advanced Energy Design Guide for K-12 School Buildings: Achieving 

30% Energy Savings Over ANSI/ASHRAE/IESNA Standard 90.1-1999. Atlanta, GA: American 

Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (2008b). Advanced Energy Design Guide for Small Warehouses and Self-Storage 

Buildings: Achieving 30% Energy Savings Toward a Net Zero Energy Building. Atlanta, GA: 

American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (2009a). Advanced Energy Design Guide for Highway Lodging: Achieving 30% 

Energy Savings Toward a Net Zero Energy Building. Atlanta, GA: American Society of 

Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ASHRAE. (2009b). ASHRAE Handbook: Fundamentals. Atlanta, GA: American Society of 

Heating, Refrigerating and Air-Conditioning Engineers, Inc.

Benton, D.J.; Bowman, C.F.; Hydeman, M.; Miller. P. (2002). An Improved Cooling Tower 

Algorithm for the CoolToolsTM Simulation Model. ASHRAE Transactions 108(1).
133

DOE. (2004). Buildings Database. http://eere.buildinggreen.com. Last accessed February 

2010.

DOE. (2009). EnergyPlus Energy Simulation Software Version 3.1. 

www.eere.energy.gov/buildings/energyplus/. Washington, D.C.: U.S. Department of Energy.

EIA. (2003). 2003 Commercial Buildings Energy Consumption Survey. Washington DC: EIA.

Available from http://eia.doe.gov/emeu/cbecs/cbecs2003/introduction.html. Last accessed 

February 2010

Energy Design Resources. (2007). Advanced Variable Air Volume System Design Guide. San 

Francisco, CA: Pacific Gas and Electric Company.

GGHC. (2007). Green Guide for Health Care: Best Practices for Creating High Performance 

Healing Environments, Version 2.2. www.gghc.org: Last accessed August 2009.

Griffith, B.; Long, N.; Torcellini, P.; Judkoff, R.; Crawley, D.; Ryan, J. (2007). Methodology 

for Modeling Building Energy Performance across the Commercial Sector. Golden, CO: 

National Renewable Energy Labortatory, Report No. TP-550-41956.

Jarnagin, R.E.; Liu, B.; Winiarski, D.W.; McBride, M.F.; Suharli, L.; Walden, D. (2006). 

Technical Support Document: Development of the Advanced Energy Design Guide for Small 

Office Buildings. Richland, WA: Pacific Northwest National Laboratory, Report No. PNNL16250.

Judkoff, R.; Neymark, J. (1995). International Energy Agency Building Energy Simulation Test 

(BESTEST) and Diagnostic Method. Golden, CO: National Renewable Energy Laboratory, 

Report No. TP-472-6231.

Liu, B.; Jarnagin, R.E.; Winiarski, D.W.; Jiang, W.; McBride, M.F.; Crall, C. (2006). Technical 

Support Document: Development of the Advanced Energy Design Guide for Small Retail 

Buildings. Richland, WA: Pacific Northwest National Laboratory, Report No. PNNL-16031.

Loren Cook. (2009). Compute-A-Fan® Software Version 9.0. Springfield, MO: Loren Cook 

Company, www.lorencook.com/about/destools.shtml. Last accessed February 2010.

McGraw Hill. (2009). Dodge Construction Data. http://dodge.construction.com. Last accessed 

February 2010.

Rabi, A., Kreider, J. (1994). Heating and Cooling of Buildings: Design for Efficiency. New 

York: McGraw Hill.

Shirey, D.B.; Henderson, H.I; Raustad, R.A. (2006). Understanding the Dehumidification 

Performance of Air-Conditioning Equipment at Part-Load Conditions. Cocoa, FL: Florida 

Solar Energy Center, Report No. FSEC-CR-1537-05. 

www.fsec.ucf.edu/en/publications/pdf/FSEC-CR-1537-05-es.pdf.

Torcellini, P.; Deru, M.; Griffith, B.; Benne, K.; Halverson, M.; Winiarski, D.; Crawley, D.B. 

(2008). DOE Commercial Building Benchmark Models: Preprint. NREL Report No. CP-550-

43291. Golden, CO: National Renewable Energy Laboratory.

Torcellini, P.; Pless, S.; Deru, M.; Griffith, B.; Long, N.; Judkoff, R. (2006). Lessons Learned 

from Case Studies of Six High-Performance Buildings. Golden, CO: National Renewable 

Energy Laboratory, Report No. TP-550-37542.
134

USGBC. (2006). New Construction and Major Renovation, Version 2.2. Washington D.C.: 

Leadership in Energy and Environmental Design, U.S. Green Buildings Council.
135

Appendix A Project Committee Meeting Agendas

A.1 Meeting #1 Agenda

Agenda Meeting #1

Advanced Energy Design Healthcare

Project Committee Meeting

ASHRAE Headquarters

1791 Tullie Circle

Atlanta, GA 30329

404-636-8400

Thursday, September 4, 2008, 8:30 am – 5:30 pm

Friday, September 5, 2008, 8:00 am – 2:00 pm

1. Welcome 8:30

2. Introductions

3. Review of Agenda 9:00

4. AEDG Overview 9:10

a. Organization of AEDG Series

b. Committee make-up structure/partnering organization

c. Scoping Document formation

d. Small healthcare facilities focus

e. Definition of Project Committee/Focus Group/Resource Group

5. Lessons Learned on the previous Guides 9:40

6. Break 10:00

7. Future Meeting Schedule 10:15

8. Review and Questions on Scoping Document 10:30

a. Context of the other AEDGs

b. Goals & Objectives of the Guide

c. Target Audience

d. Review of Scoping document

e. Resolve scope issues:

i. 100% OA?

ii. Facility types appropriate? 

iii. Energy Savings Methods (plug or not plugs)

iv. Process loads

f. Peer Review Process

9. Lunch 12:30

a. Review travel expense reimbursement procedures

10. Outline of AEDG 1:30

a. Review outline of previous Guides

b. Discuss possible modifications/changes

c. How will this guide be unique?

11. Analysis Engine 2:30

a. Modeling experiences from K-12 Schools AEDG

12. Break 3:00

13. Benchmark/Reference Building – How is it defined? 3:15
136

a. Define typical parameters to cover facility types in scope

i. Baseline HVAC system types

ii. Type/Number/Size of space types in prototypes

iii. Process and plug loads

14. Development of AEDG-Healthcare 8:00

15. Review outline of previous Guides

a. Architectural Features

b. Lighting Criteria

c. Envelope Criteria

d. HVAC/Process water heating/cooling

e. Commissioning

f. Case Studies

g. Bonus Savings

h. Foreword

i. Other?

16. Break 10:15

17. Development of AEDG-Healthcare (cont.) 10:45

a. Architectural Features

b. Lighting Criteria

c. Envelope Criteria

d. HVAC/Process water heating/cooling

e. Commissioning

f. Case Studies

g. Bonus Savings

h. Foreword

i. Other?

18. Lunch 12:00

19. Finalize Focus Group 1:00

a. Roster confirmation

b. Develop draft questions

20. Finalize Resource Group

a. Roster confirmation

b. Technical Committees to be represented?

c. Other representatives?

d. How utilize this expertise?

21. Additional Issues

22. Review of Action Items 1:30

23. Next Meeting

24. Adjourn 2:00
137

A.2 Conference Call #1 Agenda

Conference Call 10/15/2008, 12:00pm to 2:00pm EST

Items to discuss:

1. Review of old Action Items

2. Comments on Meeting #1 minutes

3. Who is coming to the focus group meeting? PC Meeting #2?

4. Update from HVAC subcommittee

5. Propose to expand scope:

a. Included in the scope:

i. Small Acute Care, Small Inpatient Community Hospital and Outpatient 

Surgical Center will all be similar and should be included in the scope.

ii. Small Acute Care Hospitals

iii. Small Inpatient (Primary Care) Community Hospitals

iv. Outpatient Surgical Facilities

v. Primary Care Outpatient Centers

vi. Small Primary (Neighborhood) Outpatient Facilities

vii. Freestanding Outpatient Diagnostic and Treatment Facilities

viii. Freestanding Urgent Care Facilities

ix. Freestanding Birthing Centers (similar to outpatient surgical facilities)

x. Medical Offices Buildings?

xi. Gastrointestinal Endoscopy Facilities (similar to outpatient surgical 

facilities)

xii. Renal Dialysis Centers (similar to medical offices buildings)

b. Excluded:

i. Facilities over 70,000 sq ft.

ii. Facilities with central plants or campus plants

iii. Strip mall doc in a box medical facilities. While non-freestanding 

facilities are important facilities, they are covered under other guides such 

as AEDG-SO and AEDG-SR

6. Develop on updated focus group agenda/questions

a. Items to send to focus group

i. Agenda/questions (see K-12 focus group questions below)

ii. Examples from SO and SR guides

iii. Scoping document

iv. 35% concept draft/outline?

7. Baseline Determination

a. Prototype development

i. Community hospital

ii. Surgical Facility

8. Review of new Action Items

9. Review of future meeting schedule
138

A.3 Meeting #2 Agenda

Agenda Meeting #2

Advanced Energy Design Guide-SHC

Project Committee Meeting

ASHRAE Headquarters

1791 Tullie Circle

Atlanta, GA 30329

404-636-8400

Wednesday, October 29, 2008, 8:00 am – 5:30 pm

Thursday, October 30, 2008, 8:00 am – 2:00 pm

1. Welcome 8:00

2. Introductions and Review of Agenda 8:15 

3. Meeting Goals (to be done before we leave):

a. Establish prototypes so NREL can start running simulations

b. Develop action item list to get to 65% text completion

c. Determine appropriate set of starting recommendations

4. Review next meeting and call schedule

5. Old Action Items Review 8:45 

6. Discuss Results from yesterday’s Focus Group 9:00

7. Break 9:30

8. Baseline Discussion 9:45

a. Review possible prototype model characteristics 

i. Determine typical floor plans for surgery center and small hospital

ii. “Typical” HVAC systems

9. Lunch 12:00

10. Continue discussion on #8 1:00

11. Begin list of energy efficiency measures (EEMs) 2:00

a. Required measures vs. suggested measures

b. Cost and performance data

c. How do we model the measure?

d. Starting list of measures to consider for each section:

i. QAs/Commissioning

ii. Envelope

iii. Lighting

iv. HVAC

v. SWH

vi. Medical Equipment, Kitchen, Laundry

vii. Bonus Savings

12. Break 3:00

13. Development of AEDG-SHC by subcommittee 3:15

a. Introduction/Foreword

b. Chapter 1 (Why, Who, How to use guide)

c. Chapter 2 (Process for Achieving Savings)

d. Chapter 3 (Recommendation Tables)
139

e. Chapter 4 (Case Studies)

f. Chapter 5 (How to recommendations)

i. QAs/Commissioning

ii. Envelope

iii. Lighting

iv. HVAC

v. SWH

vi. Medical Equipment, Kitchen, Laundry

vii. Bonus Savings

14. Continue #13 from Thursday 8:30

15. Reconvene as group and discuss draft 10:30

16. Discussion of Cover and other format issues 11:45

17. Lunch 12:00

18. Additional Issues 1:00

19. Review of Action Items 1:30

20. Adjourn 2:00
140

A.4 Focus Group Agenda and Questions

Focus Group Agenda for the

SHC Advanced Energy Design Guide

ASHRAE Headquarters

1791 Tullie Circle

Atlanta, GA 30329

404-636-8400

October 28, 2008

1. Welcome – Pless

2. Introductions: Give Name/Affiliation and experience in working on energy related issues 

in Healthcare

3. Review of Agenda – Pless

4. AEDG Overview – Colliver

a. Organization of AEDG series

b. Review of scoping document and background

5. Group discussions addressing the below questions:

6. What energy strategies should be addressed in the guide?

a. Brainstorm energy strategies you would use

b. Brainstorm additional energy strategies you would consider (pros and cons of 

each)

c. Strategies you would not consider and why

d. Strategies that you would need for a 30% savings small hospital

7. What would an appropriate format look like (show examples and discuss)? What would 

be most helpful/usable way to present recommendations and results?

8. What makes a valuable case study?

a. What type of info would you like to see?

b. How much detail should be provided?

c. Are photos helpful?

d. How many case studies are appropriate?

e. Do you prefer whole building v. individual technology case studies?

f. Is the level of detail in the past case studies appropriate?

9. Adjourn and discuss outstanding logistical issues (travel reimbursement)

Group discussion questions to consider:

1. For the healthcare facilities that you are involved with, what is common practice relative 

to the local energy standard or code? 

a. “What energy standard/code?”

b. “Healthcare facilities are exempt from the local energy standard/code.”

c. “They meet the local energy standard/code.”

d. “They are 10% better than code.”

2. How difficult do you think achieving 30% energy savings would be? Do you think the 

30% goal is achievable?
141

3. What energy-saving strategies should be recommended in the guide? What strategies 

would you not consider and why not? What types of energy efficiency design and 

operational strategies have you included in your past projects? What systems use the 

most energy? What systems have the most potential for savings?

a. Envelope measures

b. Lighting measures

c. Daylighting

d. HVAC measures

e. Service hot water measures

f. Medical equipment

g. Renewables

h. Combined heat and power

i. Commissioning

4. What would influence you to design/build a healthcare facility that saved 30% energy? 

Or not to?

a. Would you be willing to spend more money to achieve a sustainable building that 

could be used as a model to the community or nation?

5. Does the scope of this guide include those facility types that would be most beneficial to 

you? Should the scope cover additional healthcare facility types?

a. Describe what you consider to be a typical small hospital or surgical facility (size, 

types of spaces, usage patterns).See the facility types included in our scoping 

document.

6. What types of HVAC systems are you currently using in your facilities? (consider each 

facility type included in our scope)

a. What has been your operational experience (good or bad) with this type of HVAC 

system?

b. What has been your maintenance experience (good or bad) with this type of 

HVAC system?

c. Would you consider using a different HVAC system type than you typically do?

d. Would you be willing to consider water-cooled equipment, such as water-cooled 

chillers?

7. Do you feel recommendations should be individual to specific facility types (small acute 

care hospital, outpatient surgical facilities, primary care outpatient center, etc.) or 

generalized?

8. What makes a case study valuable to you?

a. What type of information should it contain?

b. How much detail should be provided?

c. How many case studies are appropriate?

d. Do you prefer whole building vs. individual technology case studies?

e. Do you have any whole building or technology specific case studies we can 

include this guide

9. What would an appropriate recommendation table and guide format look like (see past 

AEDG examples)? What would be most helpful/usable way to present recommendations 

and results?
142

A.5 Meeting #3 Agenda

Agenda Meeting #3

Advanced Energy Design Guide-SHC

Project Committee Meeting

National Renewable Energy Laboratory, TTF Conference Room

1617 Cole Blvd

Golden, CO 80401

303-384-6365 (work)

720-878-5646 (cell)

Wednesday, December 10, 2008, 8:30 am – 5:30 pm

Thursday, December 11, 2008, 8:00 am – 2:00 pm

1. Welcome and submit wireless access paperwork 8:30

2. Introductions: Review of Agenda 8:45

a. Comments? Adjustments? Additions?

3. Meeting Goals (to be done before we leave):

a. Establish energy efficiency measures to include in the advanced guide tables by 

climate zone

b. Identify holes in draft—determine appropriate scope and depth to each section, 

and content we can work through while we are here

c. Develop action item list to get to 65% Draft completed by 12/19/08

4. Next meeting 2/11-2/12 in Atlanta to review and address comments and prepare 

responses.

a. Preparation for San Francisco meeting in April?

b. See future meeting dates in Appendix B

5. Comments on Meeting#2 minutes

6. Old Action Items Review 9:00

7. 65% Review process 9:15

a. Review notification 

b. Collection of “review remarks”

c. Assembly of “review remarks”

d. Response to “review remarks”

8. Break and TTF Lab Tour – Torcellini 9:45

9. Discuss prototype simulation results 10:15

a. Review prototype model inputs

b. Review baseline energy performance by climate

c. Additional prototype model input needs

10. Lunch 12:00

11. Review Status and Comments of each Chapter of current 65% Draft 1:00

a. Foreword

b. Chapter 1 (intro)

c. Chapter 2 (process)

d. Chapter 3 – Recommendation table structure

i. Review recommendation table spreadsheet and CZ1 Sample
143

ii. Need to determine what type of plug/process loads to include in 

recommendation table

e. Chapter 4 – Case Studies

i. Review current list of case studies later

f. Chapter 5 – How To Tips 

i. Quality Assurance

ii. Envelope 

iii. Lighting/Daylighting 

iv. HVAC 

v. SWH

vi. Bonus savings by strategy type 

12. Break 2:45

13. Break into groups to further develop each section 3:00

a. HVAC

b. Lighting

c. Envelope/Daylighting

d. Case studies

14. Case study review 4:30

a. Review current list of possible case studies (Pless)

b. Absolute size limit? Under construction case studies?

c. What can we include in the 65% draft? Releases?

d. Others?

15. Return to hotel 5:30

16. Depart to dinner 6:15

17. Meet at Denver West Marriott Lobby for NREL shuttle 7:45

18. Coordinate transportation back to airport 8:00

19. Summarize content and recommendation development status 8:15

a. Identify what can be done by the end of the day

b. Identify what can be done by 12/19

20. Break into groups to further develop each section 8:30

a. HVAC

b. Lighting

c. Envelope/Daylighting

d. Foreword/Intro/Process chapters

21. Break 10:00

22. Continue breakout 10:15

23. Lunch 12:00

24. Review development status and identify additional issues 1:00

a. Foreword 

b. Chapter 1 (intro)

c. Chapter 2 (process)

d. Chapter 3 – Recommendation table structure

i. Review recommendation table spreadsheet and CZ1 Sample

e. Chapter 4 – Case Studies

i. review current list of case studies later

f. Chapter 5 – How To Tips
144

i. Quality Assurance

ii. Envelope

iii. Lighting/Daylighting

iv. HVAC

v. SWH

vi. Bonus savings by strategy type 

25. Review of Action Items 1:45

26. Adjourn 2:00
145

A.6 Meeting #4 Agenda

Agenda Meeting #4

Advanced Energy Design Guide-SHC

Project Committee Meeting

ASHRAE Headquarters

1791 Tullie Circle

Atlanta, GA 30329

404-636-8400

Wednesday, February 11, 2009, 8:00 am – 5:30 pm

Thursday, February 12, 2009, 8:00 am – 2:00 pm

1. Welcome 8:00

2. Introductions and Review of Agenda 8:15

3. Meeting Goals (to be done before we leave):

a. Review simulation results

b. Address and document responses to remarks.

c. Identify holes in draft

d. Develop action item list to get to 90% Draft completed by 5/11/09

4. Review all materials we will be using the next 2 days

a. PC meeting #4 Agenda

b. PC meeting #3 Meeting Report

c. 65% Draft – PDF

d. 90% Draft – working word draft 

e. 65% Draft Review Remarks Matrix

f. 65% Draft Review Remarks Matrix-with additional remarks

g. Proposed case study list

h. Current recommendations spreadsheet

5. Review next meeting and call schedule 8:30

6. Comments on PC meeting #3 Report and Old Action Items Review

a. See appendix A for Action Item list and section/chapter assignments

7. Update of related activities in energy efficiency and Healthcare 

a. Standard 189.2

b. TC 9.6 Energy Subcommittee

c. Conferences

i. Healthcare Design

ii. ASHE

iii. ASHRAE 

8. Discuss simulation results 9:00

a. Review energy savings calculation process

b. Prototypes

i. Surgery Center

ii. Community hospital

c. Baseline sweep results

d. Discuss advanced energy measures currently modeled

i. Update recommendation spreadsheet
146

e. Can we develop a list of possible additional savings measures?

i. Envelope

ii. LPDs and daylighting

iii. EERs, IPLV

iv. Fan efficiency or pressure drop

v. ERVs, Economizers, DCV in non-clinical spaces?

f. Additional model inputs – Doebber to collect during breakout sessions

9. Break 10:30

10. Process for updating 65% review draft 10:45

a. Address review remark responses and update remark matrix

b. 65% word draft by section to get a final 90%

11. Review general 65% draft remarks and determine responses 11:00

a. Overall observations

b. Problems based on first look?

c. Major holes in 65% draft?

12. Lunch 12:00

13. Continue discussion on #11 1:00

14. Address outstanding TBD sections of the 65% draft 2:00

15. Case study review 5:00

a. Review current list of possible case studies

b. we need to start making decisions on which case studies to include

16. Recap progress addressing review remarks and identify additional work for Thursday

17. Dinner 5:30

18. Further content development and remark responses of by subcommittee 8:00

a. Introduction/Foreword

b. Chapter 1 (Why, Who, How to use guide)

c. Chapter 2 (Process for Achieving Savings)

d. Chapter 3 (Recommendation Tables)

e. Chapter 4 (Case Studies)

f. Chapter 5 (How to recommendations)

i. QAs/Commissioning

ii. Envelope

iii. Lighting

iv. HVAC

v. SWH

vi. Medical Equipment, Kitchen, Laundry 

vii. Bonus Savings

19. Reconvene as group and discuss draft 11:00

20. Discussion of Cover and other format issues 11:45

21. Lunch 12:00

22. Additional Issues 1:00

23. Review of Action Items 1:30

24. Adjourn 2:00
147

A.7 Meeting #5 Agenda

Agenda Meeting #5

Advanced Energy Design Guide-SHC

Project Committee Meeting

Anshen + Allen Architects (Room TBD)

901 Market Street, Sixth floor

San Francisco, CA 94103

Monday, April 27, 2009, 8:00 am – 5:00 pm

Tuesday, April 28, 2009, 8:00 am – 2:00 pm

1. Welcome 8:00

2. Introductions and Review of Agenda 8:15

3. Meeting Goals (to be done before we leave):

a. Review simulation results

b. Identify holes in draft

c. Develop action item list to get to 90% draft completed by 5/11/09

d. Evaluate case studies

4. Review next meeting/call schedule

a. Last meeting in Atlanta?

5. Comments on PC meeting #4 Report and Old Action Items Review

a. See appendix A for Action Item list and section/chapter assignments

6. Process for drafting 90% review draft 8:30

a. Process and timing for posting 90% draft 

b. We need to make sure we have addressed review remark responses as we said we 

would

c. Summary response document

7. Discuss simulation results 9:00

a. Review energy savings calculation process

b. Prototypes

i. Surgery Center

ii. Community hospital

c. Baseline and proposed design sweep results

d. Discuss advanced energy measures currently modeled

i. Update recommendation spreadsheet and 90% draft

8. Break 10:30

9. Identify holes in 90% draft 11:00

a. Assign action items by section

10. Lunch 12:00

11. Address outstanding TBD sections of the 90% draft 1:00

12. Afternoon Break 2:45

13. Continue #11 3:00

14. Case study review and assignments for follow-up 4:00

a. Riverside Clinic Example In Appendix C

b. Case study assignment list

i. Patrick Dollard Health Center (NY)
148

ii. Fasseas Cancer Clinic (AZ)

iii. D’Amour Center for Cancer Care (MA)

iv. Riverside Medical Clinic (CA)

v. Rapid City Heart Doctor (SD)

vi. Valley Health Center at Gilroy & Fair Oaks (AC)

vii. Contra Costa County (CA)

viii. North West Option (new)

ix. Midwest Option (new)

x. 251 Medical Center (TX)

xi. Parrish Healthcare Center (FL)

xii. Queen of Valley Hospital (CA)

xiii. Oakes Community Hospital – not to be used unless necessary

15. Recap progress in 90% draft and identify additional work for Tuesday 4:45

16. Dinner 5:00

17. Further content development by subcommittee (Break up into groups) 8:00

a. Introduction/Foreword

b. Chapter 1 (Why, Who, How to use guide)

c. Chapter 2 (Process for Achieving Savings)

d. Chapter 3 (Recommendation Tables)

e. Chapter 4 (Case Studies)

f. Chapter 5 (How to recommendations)

i. QAs/Commissioning

ii. Envelope

iii. Lighting

iv. HVAC

v. SWH

vi. Medical Equipment, Kitchen, Laundry

vii. Bonus Savings

18. Reconvene as group and discuss draft 11:00

19. Discussion of Cover and other format issues 11:45

20. Lunch 12:00

21. Additional Issues 1:00

22. Review of Action Items 1:30

23. Adjourn 2:00

24. Tour of Federal Court House 2:00
149

A.8 Meeting #6 Agenda

Agenda Meeting #6

Advanced Energy Design Guide-SHC

Project Committee Meeting

Erdman (Room TBD)

1 Erdman Place

Madison, WI 53717

Thursday, June 4, 2009, 8:00 am – 5:00 pm

Friday, June 5, 2009, 8:00 am – 3:00 pm

1. Welcome 8:00

2. Introductions and Review of Agenda 8:15

a. Erdman building tour?

3. Meeting Goals (to be done before we leave):

a. Review simulation results

b. Address 90% review remarks

c. Develop action item list to get to final draft completed by 6/30/09

d. Evaluate case studies

4. Review publication schedule

5. Comments on PC meeting #5 Report and Old Action Items Review

a. See appendix A for Action Item list and section/chapter assignments

6. Review of general 90% review draft remarks 8:30

a. Summary response document process

7. Identify holes in 90% draft – All 9:00

a. Items to complete in the next 2 days

b. Items to complete by June 30 

8. Break 10:00

9. Discuss simulation results 10:15

a. Review energy savings calculation process

b. Prototypes

i. Surgery Center

ii. Community hospital

c. Baseline and proposed design sweep results

d. Discuss advanced energy measures currently modeled

i. Do we need to modify any recommendations?

10. Lunch 12:00

11. Subcommittee breakout to address 90% draft remarks 1:00

12. Afternoon Break 2:45

13. Continue #11 3:00

a. HVAC subcommittee to review detailed energy model results

14. Review subcommittee progress and identify additional work for Friday 4:45

15. Identify Dinner location 5:00

16. Review status of goals 8:00

17. Case study status and assignments for follow-up 8:15

a. Case study format and development guidance
150

b. Case study assignment list

i. Patrick Dollard Health Center (NY)

ii. Fasseas Cancer Clinic (AZ)

iii. D’Amour Center for Cancer Care (MA)

iv. Riverside Medical Clinic (CA)

v. Rapid City Heart Doctor (SD)

vi. Valley Health Center at Gilroy & Fair Oaks (AC)

vii. Contra Costa County (CA)

viii. North West Option (new)

ix. Midwest Option (new)

x. 251 Medical Center (TX)

xi. Parrish Healthcare Center (FL)

xii. Queen of Valley Hospital (CA)

xiii. Oakes Community Hospital – not to be used unless necessary

18. Further content development by subcommittee (Break up into groups) 9:00

a. Introduction/Foreword -

b. Chapter 1 (Why, Who, How to use guide)

c. Chapter 2 (Process for Achieving Savings)

d. Chapter 3 (Recommendation Tables)

e. Chapter 4 (Case Studies)

f. Chapter 5 (How to recommendations)

i. QAs/Commissioning

ii. Envelope

iii. Lighting

iv. HVAC

v. SWH

vi. Medical Equipment, Kitchen, Laundry

vii. Bonus Savings

19. Reconvene as group and discuss draft 11:00

a. What additional graphics do we need?

b. What additional side bar technology case studies do we need?

20. Discussion of Cover and other format issues 11:45

21. Lunch 12:00

22. Additional issues and review of action items 1:00

23. Additional breakout as needed 1:30

24. Adjourn 3:00
151

Appendix B Responses to 65% Draft Review Remarks

SUMMARY RESPONSE TO

PEER REVIEW REMARKS AND RECOMMENDATIONS

RECEIVED ON

65% TECHNICAL REFINEMENT DRAFT OF

ADVANCED ENERGY DESIGN GUIDE:

SMALL HOSPITALS AND HEALTHCARE FACILITIES

April 30, 2009

On January 5, 2009, the Project Committee for the Advanced Energy Design Guide – Small 

Healthcare (AEDG-SHC) issued a 65% Technical Refinement Draft of the document Advanced 

Energy Design Guide for Small Hospitals and Healthcare Facilities. Following the review period 

of January 5-16, 2009, the AEDG-SHC Project Committee met on February 11-12, 2009 to 

review the recommendations received.

The committee received 137 remarks and review recommendations from 12 reviewers 

representing AIA, IESNA, USGBC and the ASHRAE membership at large. The following 

documents the Project Committee’s summary response to those remarks and recommendations. 

Although many of the suggestions dealt with details presented in the draft, this summary 

includes responses only to significant technical recommendations, especially those in which 

there was disagreement with what had been written or omitted. The specific and detailed 

suggestions and remarks have been, and will continue to be, reviewed and digested by the 

Project Committee as it prepares the next draft of the guide. The review remarks received fall 

into the following six categories.

General Comments:

1. The intent of the guide is to provide a prescriptive list of measures to achieve 30% 

savings over Standard 90.1-1999. We emphasize that the guide presents a way, not the 

only way to achieve 30% energy savings so not all possible strategies will be included, 

especially specialty items. A balanced, multi-option approach is recommended. 

2. Per the direction of the AEDG Steering Committee, the 30% goal is based on site energy 

use and uses Standard 90.1-1999 as the baseline measurement. This is to be consistent 

with all the AEDG guides in the series.

3. Criteria used in the advanced case will be no less stringent than Standard 90.1-2007 

(including addenda as and at and the metal buildings update for roofs and walls).

4. References will be added as needed and both the references and additional resources list 

will be updated to include the most recent versions of 90.1 (2007) and the IMC (2009) 

and to delete unnecessary references.

5. The numbering and in-text references for the figures and tables will be updated and 

corrected throughout the document prior to publication of the document. 

6. The use of acronyms will be standardized in the document and additional definitions will 

be added as needed.

7. The formatting of the document including headings is handled by ASHRAE publications 

and will be consistent with all the AEDG guides in the series.
152

Foreword

1. While the information on revenue in the Foreword will be reworded to include concerns 

for patient satisfaction, the information on lowering overall cost will remain as the 

committee feels that this information is crucial to the adoption of the capital costs 

required. 

2. Savings information will be verified and revised as needed.

Introduction (Chapter 1)

1. The addition of energy savings relative to 90.1-2007 is dependent up on available 

resources and while this comparison will likely be done for future guides, it may or may 

not be done for this guide.

2. The explanation on site versus source energy will be rewritten for clarity on energy 

efficiencies and costs.

How to Use an Integrated Design Approach (Chapter 2)

1. Information in this section will be substantiated with references or rewritten as 

appropriate.

2. The energy modeling graph in Figures 2.1 is a placeholders showing information from a 

previous guide. Updated graphs will be inserted when the analysis is completed and prior 

to publication.

3. The tables in this chapter were developed using standard industry practice and 

terminology and the committee feels that minimal changes are needed. The need for 

accurate record drawings will be added to Table 2.4 in addition to O&M manuals.

4. The committee feels that the TAB (Testing and Balancing) contractor and the ME 

(Mechanical Engineer) roles are adequately represented in chapter 2 tables under the 

subcontractor, designers, and consultants categories. However, additional information on 

TAB will be added to the commissioning section in the guide. Healthcare experience for 

these professionals is discussed in Chapter 1.

5. The discussion on drivers for integrated design in the healthcare industry will be 

rewritten to improve the clarity and accuracy of the information.

Recommendations by Climate (Chapter 3)

1. General

a. The minimum and maximum value lists in the chapter overview will be updated 

to reflect the recommendations in the guide.

2. Envelope

a. The SRI values in climate zones 1-3 will be corrected from decimals to whole 

numbers.

b. The c.i. designation will be added where missing in the Recommendation Tables.

c. The roof insulation recommendations will be changed to R-30 in climate zones 4-

6 and to R-35 in climate zones 7 and 8.

d. The committee notes that floors with solar gains are no different than north walls. 

Both experience dry bulb temperatures, but the recommended insulation level for 

floors is less than that for walls. While un-insulated floor over parking garages 

can provide “free cooling,” it is more efficient to use economizer cycles and 

insulate the floor.

3. Daylighting and Lighting

a. The 1.1 W/SF is the initial target value (30% off the 90.1-1999), but will be 

evaluated as per the simulation results and adjusted as needed.
153

b. The automatic dimming control recommendation will be clarified to not include 

patient rooms where occupant control of lights and window shades should govern.

4. HVAC and SWH

a. The automatic setback recommendation for critical care areas will be deleted in 

favor of air flow setback where permissible.

b. Energy recovery ventilation is only recommended in those systems types where it 

was needed to reach the 30% savings target.

c. Since a major use of heating water is reheat, which is required in every zone, the 

boiler should be high efficiency in all zones. The recommended efficiencies for 

cooling systems do vary by climate zone.

d. The exhaust energy recover recommendations in the tables will be corrected to 

correspond with the information in the Chapter 5 How-to tips.

Technology Examples and Case Studies (Chapter 4)

1. The detail in the case studies is dependent upon the case studies received, but the PC will 

make every effort to include case studies that reflect the recommendations included in the 

guide.

How to Implement Recommendations (Chapter 5)

1. Quality Assurance & Commissioning

a. The importance of reviewing submittals will be added to this section; however, 

documentation of on-going energy monitoring is beyond the scope of this 

document.

2. Envelope

a. The discussion on thermal mass will be modified to include heating loads as well 

as cooling loads.

b. Cavity insulation is recommended in EN4 because the exterior sheathing 

insulation is more expensive and the cavity insulation helps reduce the sheathing 

thickness and the accompanying attachment issues

c. The WWR recommendations reflect the values that were modeled. A caution will 

be added to the WWR discussion regarding potential increase of heating and 

cooling loads.

d. NFRC ratings are for the overall fenestration unit including the edge and frame.

e. The fenestration options in Table 5-3 were analyzed using LCC analysis and 

shown to be cost effective using the same economic assumptions from 90.1.

f. The example in EN22 will cite high continuous windows versus punched 

windows without trying to distinguish vertical windows

3. Daylighting and Lighting

a. The numbering and organization of the lighting section will be adjusted as needed 

to reduce redundancy in the information.

b. The wording on high light output ballasts in EL2 will be modified to clarify the 

difference between ballast input power and overall system efficacy.

c. The description of T8 lamps will state that these are one of the more commonly 

specified lighting systems for healthcare facilities.

d. User-intuitive controls and ease of maintenance will be emphasized in the 

discussion on lighting controls; however, the committee feels that a caution about 

minimizing bulb types is not needed.
154

e. The values in Table 5-5 are in ANSI/IES-RP29-2006 and the committee agrees 

that they are somewhat constrained by the IES lighting design method 

illuminance categories that do not always adequately address the visual needs in 

all applications (such as OR’s).

f. While the values in Table 5-8 will be updated, the values are consistent with and 

apply the same methodology as previous guides.

g. The influence of EISA 2007 and the effect of tilt factor and lamp performance 

will be added to the discussion in EL5

h. While 90.1 does not explicitly allow for control via keyed or timed switch that 

restricts when higher power usage occurs in low use spaces, the committee will 

incorporate this methodology into the discussion on general lighting control 

strategies as an exception to maximum lighting power density.

i. The discussion on occupancy based control will be updated to include discussion 

on bypass-off switches, a caution on the use of ultrasonic sensors in mechanical 

rooms, and the suggestion that lighting sensors can be linked to HVAC controls to 

eliminate the need for a second sensor system. The use of occupancy sensors in 

patient care corridors is being reexamined, and patient control of the environment 

will be emphasized as the overriding concern in patient rooms.

j. Information on photo cell sensors will be added to the discussion on control of 

exterior lighting.

k. While the committee feels that indirect lighting can be an energy efficient option, 

task-ambient and direct-indirect approaches will be also be included in the 

discussion in DL18.

l. Exit lighting is addressed in EL6; however lighting of ATMs which is a limited 

application and egress lighting which is governed by local codes will not be 

addressed in the guide.

4. HVAC and SWH

a. The discussion of flex duct in HV 11 will be expanded to include additional 

applications.

b. While hospitals require ducted returns for all patient care areas, some outpatient 

facilities permit the use of plenum return.

c. While partially covered already, additional information indicating the energy 

optimization and minimization potential of effective DDC controls.

d. The committee feels that the information in this section on economizers, air flow 

monitors, and reheat is accurate and appropriate.

e. The committee feels that some of the suggested information on dampers, duct 

liner, and filter use are relevant to an energy design guide.

5. Bonus/Additional Savings

a. Exterior Lighting will be addressed as a bonus savings.

b. Additional information will be added about integrating metering from distribution 

equipment into a comprehensive building management system; however, no 

change is needed regarding emergency power. The distribution system derives 

supply from either the utility or the emergency power supply system, but the 

entire distribution system is being metered at all times.
155

Appendix C Community Hospital Baseline Scorecards

Table C-1 Community Hospital Baseline Scorecard: Climate Zones 1A–3B

ASHRAE 90.1-2004 Climate Zone 1A 2A 2B 3A 3B

Program

Building name Community 

Hospital

Community 

Hospital

Community 

Hospital

Community 

Hospital

Community 

Hospital

Location Miami, 

Florida

Houston, 

Texas

Phoenix, 

Arizona

Memphis, 

Tennessee

El Paso, 

Texas

Form

Total floor area (ft2 [m2]) 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976]

Number of floors 1 1 1 1 1

Window fraction (window to wall ratio)

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

Skylight/TDD percent 0.0% 0.0% 0.0% 0.0% 0.0%

Azimuth 0.00 0.00 0.00 0.00 0.00

Fabric

Exterior walls

Construction type Steel-framed Steel-framed Steel-framed Steel-framed Steel-framed

Construction description R-13 R-13 R-13 R-13 R-13

R-value (ft2·h·°F/Btu [m2

·K/W]) 7.22 [1.27] 7.22 [1.27] 7.22 [1.27] 7.22 [1.27] 7.22 [1.27]

Gross dimensions – total area (ft2 [m2]) 24,061 [2,235] 24,061 [2,235] 24,061 [2,235] 24,061 [2,235] 24,061 [2,235]

Net dimensions – total area (ft2 [m2]) 17,638 [1,639] 17,638 [1,639] 17,638 [1,639] 17,638 [1,639] 17,638 [1,639]

Wall to skin ratio 0.27 0.27 0.27 0.27 0.27

Tilts and orientation Vertical Vertical Vertical Vertical Vertical

Roof

Construction type IEAD IEAD IEAD IEAD IEAD

Construction description R-15 c.i. R-15 c.i. R-15 c.i. R-15 c.i. R-15 c.i.

R-value (ft2·h·°F/Btu [m2·K/W]) 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61]

Gross dimensions – total area (ft2 [m2]) 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016]

Net dimensions – total area (ft2 [m2]) 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016]

Roof to skin ratio 0.73 0.73 0.73 0.73 0.73

Tilts and orientation Horizontal Horizontal Horizontal Horizontal Horizontal
156

Table C-1 Community Hospital Baseline Scorecard: Climate Zones 1A–3B (con’t)

ASHRAE 90.1-2004 Climate Zone 1A 2A 2B 3A 3B

Fabric

Windows

Dimensions – total area (ft2 [m2

S: 1,060 [98]

])

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 

[571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

U-Factor (Btu/h·ft2·oF [W/m2

S: 1.21 [6.88]

·K]) E: 1.21 [6.88]

N: 1.21 [6.88]

W: 1.21 [6.88]

S: 1.21 [6.88]

E: 1.21 [6.88]

N: 1.21 [6.88]

W: 1.21 [6.88]

S: 1.21 [6.88]

E: 1.21 [6.88]

N: 1.21 [6.88]

W: 1.21 [6.88]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.57 [3.24]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.57 [3.24]

W: 0.57 [3.24]

SHGC

South: 0.25

East: 0.25

North: 0.33

West: 0.25

South: 0.25

East: 0.25

North: 0.44

West: 0.25

South: 0.25

East: 0.25

North: 0.44

West: 0.25

South: 0.25

East: 0.25

North: 0.26

West: 0.25

South: 0.25

East: 0.25

North: 0.26

West: 0.25

Visible transmittance

South: 0.25

East: 0.25

North: 0.33

West: 0.25

South: 0.25

East: 0.25

North: 0.44

West: 0.25

South: 0.25

East: 0.25

North: 0.44

West: 0.25

South: 0.25

East: 0.25

North: 0.26

West: 0.25

South: 0.25

East: 0.25

North: 0.26

West: 0.25

Operable area (ft2 [m2]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Skylights/TDD

Dimensions – total area (ft2 [m2

]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

U-Factor (Btu/h·ft2·oF [W/m2·K]) 1.21 [6.92] 1.21 [6.92] 1.21 [6.92] 0.69 [3.92] 0.69 [3.92]

SHGC 0.36 0.36 0.36 0.39 0.39

Visible transmittance 0.36 0.36 0.36 0.39 0.39

Operable area (ft2 [m2

]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Foundation

Foundation type Mass floor Mass floor Mass floor Mass floor Mass floor

Construction

Carpet over heavy 

concrete and 

insulation

Carpet over 

heavy concrete 

and insulation

Carpet over heavy 

concrete and 

insulation

Carpet over 

heavy concrete 

and insulation

Carpet over heavy 

concrete and 

insulation

R-value (ft2·h·°F/Btu [m2·K/W]) 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37]

Average min/max under-slab temperatures Min: 72.5 [22.5]

Max: 73.7 [23.1]

Min: 68.6 [20.4]

Max: 73.4 [23.0]

Min: 66.6 [19.2]

Max: 70.9 [21.6]

Min: 67.8 [19.9]

Max: 72.8 [22.7]

Min: 66.6 [19.2]

Max: 71.4 [21.9]

Dimensions 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976]
157

Table C-1 Community Hospital Baseline Scorecard: Climate Zones 1A–3B (con’t)

ASHRAE 90.1-2004 Climate Zone 1A 2A 2B 3A 3B

Fabric

Interior Partitions

Construction 2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

Dimensions – total area (ft2 [m2

]) 61,137 [5,680] 61,137 [5,680] 61,137 [5,680] 61,137 [5,680] 61,137 [5,680]

Internal Mass

Construction 6-in. wood 6-in. wood 6-in. wood 6-in. wood 6-in. wood

Dimensions – total area (ft2 [m2

]) 128,651 [11,952] 128,651 [11,952] 128,651 [11,952] 128,651 [11,952] 128,651 [11,952]

Thermal properties (lb/ft2 [kg/m2

]) 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0]

HVAC

Heating Type Natural gas Natural gas Natural gas Natural gas Natural gas

Cooling Type DX DX DX DX DX

HVAC Autosizing

Air-conditioning (tons [kW]) 241.9 [850.8] 246.4 [866.6] 237.3 [834.6] 244.6 [860.3] 210.2 [739.3]

Heating (kBtu/h [kW]) 2,103.6 [616.5] 2,055.6 [602.4] 2,117.1 [620.5] 2,044.4 [599.1] 1,944.7 [569.9]

HVAC Efficiency

Air-conditioning (COP) 3.24 3.24 3.24 3.24 3.24

Heating efficiency (%) 80 80 80 80 80

HVAC Control

Economizer No No Yes No Yes

Fan and pump loads

Supply fan volumetric flow rate (cfm [m3/s]) 80,812.9 [38.1] 83,570.6 [39.4] 90,601.2 [42.8] 82,580.8 [39.0] 91,106.6 [43.0]

Service water heating

SWH type NG Storage Tank NG Storage Tank NG Storage Tank NG Storage Tank NG Storage Tank

Et (%) 80 80 80 80 80

Internal Loads and 

Schedules

Lighting

Average power density (W/ft2 [W/m2]) 1.85 [19.90] 1.85 [19.90] 1.85 [19.90] 1.85 [19.90] 1.85 [19.90]

Schedule See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5

Plug Loads

Average power density (W/ft2 [W/m2

]) 2.06 [22.20] 2.06 [22.20] 2.06 [22.20] 2.06 [22.20] 2.06 [22.20]

Schedule See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8

Occupancy

Average people (#/1000 ft2 [#/100 m2]) 10.48 [11.29] 10.48 [11.29] 10.48 [11.29] 10.48 [11.29] 10.48 [11.29]

Schedule See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9
158

Table C-2 Community Hospital Baseline Scorecard: Climate Zones 3C–5A

ASHRAE 90.1-2004 Climate Zone 3C 4A 4B 4C 5A

Program

Building name Community 

hospital

Community 

hospital

Community 

hospital

Community 

hospital

Community 

hospital

Location San Francisco, 

California

Baltimore, 

Maryland

Albuquerque, 

New Mexico

Seattle, 

Washington

Chicago, 

Illinois

Form

Total floor area (ft2 [m2]) 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976]

Number of floors 1 1 1 1 1

Window fraction (window to wall ratio)

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

Skylight/TDD percent 0.0% 0.0% 0.0% 0.0% 0.0%

Azimuth 0.00 0.00 0.00 0.00 0.00

Fabric

Exterior Walls

Construction type Steel-framed Steel-framed Steel-framed Steel-framed Steel-framed

Construction description R-13 R-13 R-13 R-13 R-13 + R-3.8 c.i.

R-value (ft2·h·°F/Btu [m2·K/W]) 7.22 [1.27] 7.22 [1.27] 7.22 [1.27] 7.22 [1.27] 11.06 [1.95]

Gross dimensions – total area (ft2 [m2]) 24,061 [2,235] 24,061 [2,235] 24,061 [2,235] 24,061 [2,235] 24,061 [2,235]

Net dimensions – total area (ft2 [m2]) 17,638 [1,639] 17,638 [1,639] 17,638 [1,639] 17,638 [1,639] 17,638 [1,639]

Wall to skin ratio 0.27 0.27 0.27 0.27 0.27

Tilts and orientation Vertical Vertical Vertical Vertical Vertical

Roof

Construction type IEAD IEAD IEAD IEAD IEAD

Construction description R-10 c.i. R-15 c.i. R-15 c.i. R-15 c.i. R-15 c.i.

R-value (ft2·h·°F/Btu [m2·K/W]) 9.69 [1.71] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61]

Gross dimensions – total area (ft2 [m2]) 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016]

Net dimensions – total area (ft2 [m2

]) 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016]

Roof to skin ratio 0.73 0.73 0.73 0.73 0.73

Tilts and orientation Horizontal Horizontal Horizontal Horizontal Horizontal
159

Table C-2 Community Hospital Baseline Scorecard: Climate Zones 3C–5A (con’t)

ASHRAE 90.1-2004 Climate Zone 3C 4A 4B 4C 5A

Fabric

Windows

Dimensions – total area (ft2 [m2

S: 1,060 [98]

])

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

U-factor (Btu/h·ft2·oF [W/m2

S: 1.21 [6.88]

·K]) E: 1.21 [6.88]

N: 0.73 [4.15]

W: 1.21 [6.88]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

SHGC

South: 0.61

East: 0.61

North: 0.61

West: 0.61

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

Visible transmittance

South: 0.61

East: 0.61

North: 0.61

West: 0.61

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

Operable area (ft2 [m2]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Skylights/TDD

Dimensions – total area (ft2 [m2

]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

U-factor (Btu/h·ft2·oF [W/m2

·K]) 1.21 [6.92] 0.69 [3.92] 0.69 [3.92] 0.69 [3.92] 0.69 [3.92]

SHGC 0.61 0.49 0.49 0.49 0.49

Visible transmittance 0.61 0.49 0.49 0.49 0.49

Operable area (ft2 [m2]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Foundation

Foundation type Mass floor Mass floor Mass floor Mass floor Mass floor

Construction

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

R-value (ft2·h·°F/Btu [m2·K/W]) 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37]

Average min/max underslab temperatures Min: 67.8 [19.9]

Max: 68.8 [20.4]

Min: 67.4 [19.7]

Max: 72.6 [22.6]

Min: 66.5 [19.2]

Max: 71.3 [21.8]

Min: 67.5 [19.7]

Max: 70.0 [21.1]

Min: 67.1 [19.5]

Max: 72.3 [22.4]

Dimensions 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976]
160

Table C-2 Community Hospital Baseline Scorecard: Climate Zones 3C–5A (con’t)

ASHRAE 90.1-2004 Climate Zone 3C 4A 4B 4C 5A

Fabric

Interior Partions

Construction 2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

Dimensions – total area (ft2 [m2

]) 61,137 [5,680] 61,137 [5,680] 61,137 [5,680] 61,137 [5,680] 61,137 [5,680]

Internal Mass

Construction 6-in. wood 6-in. wood 6-in. wood 6-in. wood 6-in. wood

Dimensions – total area (ft2 [m2]) 128,651 [11,952] 128,651 [11,952] 128,651 [11,952] 128,651 [11,952] 128,651 [11,952]

Thermal properties (lb/ft2 [kg/m2]) 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0]

HVAC

Heating Type Natural gas Natural gas Natural gas Natural gas Natural gas

Cooling Type DX DX DX DX DX

HVAC Autosizing

Air-conditioning (tons [kW]) 194.3 [683.4] 232.9 [819.1] 206.9 [727.7] 182.9 [643.3] 226.0 [794.8]

Heating (kBtu/h [kW]) 1,789.7 [524.5] 2,026.0 [593.8] 1,875.9 [549.8] 1,847.3 [541.4] 2,002.0 [586.7]

HVAC Efficiency

Air-conditioning (COP) 3.24 3.24 3.24 3.24 3.24

Heating efficiency (%) 80 80 80 80 80

HVAC Control

Economizer Yes No Yes Yes Yes

Fan and Pump Loads

Supply fan volumetric flow rate (cfm [m3/s]) 70,999.3 [33.5] 81,894.0 [38.7] 93,177.2 [44.0] 74,576.9 [35.2] 80,202.8 [37.9]

Service Water Heating

SWH type NG storage tank NG storage tank NG storage Tank NG storage tank NG storage tank

Et (%) 80 80 80 80 80

Internal Loads and 

Schedules

Lighting

Average power density (W/ft2 [W/m2

]) 1.85 [19.90] 1.85 [19.90] 1.85 [19.90] 1.85 [19.90] 1.85 [19.90]

Schedule See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5

Plug Loads

Average power density (W/ft2 [W/m2]) 2.06 [22.20] 2.06 [22.20] 2.06 [22.20] 2.06 [22.20] 2.06 [22.20]

Schedule See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8

Occupancy

Average people (#/1000 ft2 [#/100 m2]) 10.48 [11.29] 10.48 [11.29] 10.48 [11.29] 10.48 [11.29] 10.48 [11.29]

Schedule See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9
161

Table C-3 Community Hospital Baseline Scorecard: Climate Zones 5B–8A

ASHRAE 90.1-2004 Climate Zone 5B 6A 6B 7A 8A

Program

Building name Community 

Hospital

Community 

Hospital

Community 

Hospital

Community 

Hospital

Community 

Hospital

Location Boise, 

Idaho

Burlington, 

Vermont

Helena, 

Montana

Duluth, 

Minnesota

Fairbanks, 

Alaska

Form

Total floor area (ft2 [m2]) 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976]

Number of floors 1 1 1 1 1

Window fraction (window to wall ratio)

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

South: 0.19

East: 0.12

North: 0.42

West: 0.16

Total: 0.26

Skylight/TDD percent 0.0% 0.0% 0.0% 0.0% 0.0%

Azimuth 0.00 0.00 0.00 0.00 0.00

Fabric

Exterior Walls

Construction type Steel-framed Steel-framed Steel-framed Steel-framed Steel-framed

Construction description R-13 + R-3.8 c.i. R-13 + R-3.8 c.i. R-13 + R-3.8 c.i. R-13 + R-7.5 c.i. R-13 + R-7.5 c.i.

R-value (ft2·h·°F/Btu [m2·K/W]) 11.06 [1.95] 11.06 [1.95] 11.06 [1.95] 14.76 [2.60] 14.76 [2.60]

Gross dimensions – total area (ft2 [m2]) 24,061 [2,235] 24,061 [2,235] 24,061 [2,235] 24,061 [2,235] 24,061 [2,235]

Net dimensions – total area (ft2 [m2]) 17,638 [1,639] 17,638 [1,639] 17,638 [1,639] 17,638 [1,639] 17,638 [1,639]

Wall to skin ratio 0.27 0.27 0.27 0.27 0.27

Tilts and orientation Vertical Vertical Vertical Vertical Vertical

Roof

Construction type IEAD IEAD IEAD IEAD IEAD

Construction description R-15 c.i. R-15 c.i. R-15 c.i. R-15 c.i. R-20 c.i.

R-value (ft2·h·°F/Btu [m2·K/W]) 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 19.76 [3.48]

Gross dimensions – total area (ft2 [m2]) 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016]

Net dimensions – total area (ft2 [m2

]) 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016] 64,752 [6,016]

Roof to skin ratio 0.73 0.73 0.73 0.73 0.73

Tilts and orientation Horizontal Horizontal Horizontal Horizontal Horizontal
162

Table C-3 Community Hospital Baseline Scorecard: Climate Zones 5B–8A (con’t)

ASHRAE 90.1-2004 Climate Zone 5B 6A 6B 7A 8A

Fabric

Windows

Dimensions – total area (ft2 [m2

S: 1,060 [98]

])

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

S: 1,060 [98]

E: 572 [53]

N: 3,449 [320]

W: 1,069 [99]

Total: 6149 [571]

U-factor (Btu/h·ft2·oF [W/m2

S: 0.57 [3.24]

·K]) E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.46 [2.61]

E: 0.46 [2.61]

N: 0.35 [1.99]

W: 0.46 [2.61]

SHGC

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.49

West: 0.39

South: 0.39

East: 0.39

North: 0.49

West: 0.39

South: 0.49

East: 0.49

North: 0.64

West: 0.49

South: 0.46

East: 0.46

North: 0.46

West: 0.46

Visible transmittance

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.49

West: 0.39

South: 0.39

East: 0.39

North: 0.49

West: 0.39

South: 0.49

East: 0.49

North: 0.64

West: 0.49

South: 0.46

East: 0.46

North: 0.46

West: 0.46

Operable area (ft2 [m2

]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Skylights/TDD

Dimensions – total area (ft2 [m2

]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

U-factor (Btu/h·ft2·oF [W/m2

·K]) 0.69 [3.92] 0.69 [3.92] 0.69 [3.92] 0.69 [3.92] 0.58 [3.29]

SHGC 0.49 0.49 0.49 0.68 0.49

Visible transmittance 0.49 0.49 0.49 0.68 0.49

Operable area (ft2 [m2

]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Foundation

Foundation type Mass floor Mass floor Mass floor Mass floor Mass floor

Construction

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

R-value (ft2·h·°F/Btu [m2

·K/W]) 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37]

Average min/max underslab temperatures Min: 66.7 [19.3]

Max: 706 [21.5]

Min: 66.9 [19.4]

Max: 71.4 [21.9]

Min: 66.4 [19.1]

Max: 70.4 [21.3]

Min: 66.5 [19.1]

Max: 69.7 [20.9]

Min: 65.1 [18.4]

Max: 67.3 [19.6]

Dimensions 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976] 64,326 [5,976]
163

Table C-3 Community Hospital Baseline Scorecard: Climate Zones 5B–8A (con’t)

ASHRAE 90.1-2004 Climate Zone 5B 6A 6B 7A 8A

Fabric

Interior Partitions

Construction 2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

Dimensions – total area (ft2 [m2

]) 61,137 [5,680] 61,137 [5,680] 61,137 [5,680] 61,137 [5,680] 61,137 [5,680]

Internal Mass

Construction 6-in. wood 6-in. wood 6-in. wood 6-in. wood 6-in. wood

Dimensions – total area (ft2 [m2

]) 128,651 [11,952] 128,651 [11,952] 128,651 [11,952] 128,651 [11,952] 128,651 [11,952]

Thermal properties (lb/ft2 [kg/m2

]) 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0]

HVAC

Heating Type Natural gas Natural gas Natural gas Natural gas Natural gas

Cooling Type DX DX DX DX DX

HVAC Autosizing

Air-conditioning (tons [kW]) 195.0 [685.8] 208.3 [732.6] 189.5 [666.5] 194.0 [682.3] 158.9 [558.9]

Heating (kBtu/h [kW]) 1,905.2 [558.4] 1,988.8 [582.9] 1,878.2 [550.4] 1,943.1 [569.5] 2,032.9 [595.8]

HVAC Efficiency

Air-conditioning (COP) 3.24 3.24 3.24 3.24 3.24

Heating efficiency (%) 80 80 80 80 80

HVAC Control

Economizer Yes Yes Yes Yes Yes

Fan and Pump Loads

Supply fan volumetric flow rate (cfm [m3/s]) 85,044.1 [40.1] 77,199.0 [36.4] 83,860.1 [39.6] 76,140.0 [35.9] 68,894.8 [32.5]

Service Water Heating

SWH type NG storage tank NG storage tank NG storage tank NG storage tank NG storage tank

Et (%) 80 80 80 80 80

Internal Loads and 

Schedules

Lighting

Average power density (W/ft2 [W/m2

]) 1.85 [19.90] 1.85 [19.90] 1.85 [19.90] 1.85 [19.90] 1.85 [19.90]

Schedule See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5

Plug Loads

Average power density (W/ft2 [W/m2

]) 2.06 [22.20] 2.06 [22.20] 2.06 [22.20] 2.06 [22.20] 2.06 [22.20]

Schedule See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8

Occupancy

Average people (#/1000 ft2 [#/100 m2

]) 10.48 [11.29] 10.48 [11.29] 10.48 [11.29] 10.48 [11.29] 10.48 [11.29]

Schedule See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9
164

Appendix D Surgery Center Baseline Scorecard

Table D-1 Surgery Center Baseline Scorecard: Climate Zones 1A–3B

ASHRAE 90.1-2004 Climate Zone 1A 2A 2B 3A 3B

Program

Building name Surgery 

Center

Surgery

Center

Surgery 

Center

Surgery 

Center

Surgery 

Center

Location Miami,

Florida

Houston, 

Texas

Phoenix, 

Arizona

Memphis, 

Tennessee

El Paso,

Texas

Form

Total floor area (ft2 [m2]) 40,946 [3,804] 40,946 [3,804] 40,946 [3,804] 40,946 [3,804] 40,946 [3,804]

Number of floors 3 3 3 3 3

Window fraction (window to wall ratio)

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

Skylight/TDD percent 0.00 0.00 0.00 0.00 0.00

Azimuth 0.00 0.00 0.00 0.00 0.00

Fabric

Exterior Walls

Construction type Steel-framed Steel-framed Steel-framed Steel-framed Steel-framed

Construction description R-13 R-13 R-13 R-13 R-13

R-value (ft2·h·°F/Btu [m2·K/W]) 7.22 [1.27] 7.22 [1.27] 7.22 [1.27] 7.22 [1.27] 7.22 [1.27]

Gross dimensions – total area (ft2 [m2

]) 16,720 [1,553] 16,720 [1,553] 16,720 [1,553] 16,720 [1,553] 16,720 [1,553]

Net dimensions – total area (ft2 [m2]) 13,178 [1,224] 13,178 [1,224] 13,178 [1,224] 13,178 [1,224] 13,178 [1,224]

Wall to skin ratio 0.53 0.53 0.53 0.53 0.53

Tilts and orientation Vertical Vertical Vertical Vertical Vertical

Roof

Construction type IEAD IEAD IEAD IEAD IEAD

Construction description R-15 c.i. R-15 c.i. R-15 c.i. R-15 c.i. R-15 c.i.

R-value (ft2·h·°F/Btu [m2·K/W]) 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61]

Gross dimensions – total area (ft2 [m2]) 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373]

Net dimensions – total area (ft2 [m2]) 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373]

Roof to skin ratio 0.47 0.47 0.47 0.47 0.47

Tilts and orientation Horizontal Horizontal Horizontal Horizontal Horizontal
165

Table D-1 Surgery Center Baseline Scorecard: Climate Zones 1A–3B (con’t)

ASHRAE 90.1-2004 Climate Zone 1A 2A 2B 3A 3B

Fabric

Windows

Dimensions – total area (ft2 [m2

S: 1,228 [114]

])

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

U-factor (Btu/h·ft2·oF [W/m2

S: 1.21 [6.88]

·K]) E: 1.21 [6.88]

N: 1.21 [6.88]

W: 1.21 [6.88]

S: 1.21 [6.88]

E: 1.21 [6.88]

N: 1.21 [6.88]

W: 1.21 [6.88]

S: 1.21 [6.88]

E: 1.21 [6.88]

N: 1.21 [6.88]

W: 1.21 [6.88]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.57 [3.24]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.57 [3.24]

W: 0.57 [3.24]

SHGC

South: 0.25

East: 0.25

North: 0.33

West: 0.25

South: 0.25

East: 0.25

North: 0.44

West: 0.25

South: 0.25

East: 0.25

North: 0.44

West: 0.25

South: 0.25

East: 0.25

North: 0.26

West: 0.25

South: 0.25

East: 0.25

North: 0.26

West: 0.25

Visible transmittance

South: 0.25

East: 0.25

North: 0.33

West: 0.25

South: 0.25

East: 0.25

North: 0.44

West: 0.25

South: 0.25

East: 0.25

North: 0.44

West: 0.25

South: 0.25

East: 0.25

North: 0.26

West: 0.25

South: 0.25

East: 0.25

North: 0.26

West: 0.25

Operable area (ft2 [m2]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Skylights/TDD

Dimensions – total area (ft2 [m2]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

U-factor (Btu/h·ft2·oF [W/m2·K]) 1.21 [6.92] 1.21 [6.92] 1.21 [6.92] 0.69 [3.92] 0.69 [3.92]

SHGC 0.36 0.36 0.36 0.39 0.39

Visible transmittance 0.36 0.36 0.36 0.39 0.39

Operable area (ft2 [m2

]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Foundation

Foundation type Mass floor Mass floor Mass floor Mass floor Mass floor

Construction

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

R-value (ft2·h·°F/Btu [m2·K/W]) 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37]

Average min/max under-slab temperatures Min: 72.5 [22.5]

Max: 73.7 [23.1]

Min: 68.6 [20.4]

Max: 73.4 [23.0]

Min: 66.6 [19.2]

Max: 70.9 [21.6]

Min: 67.8 [19.9]

Max: 72.8 [22.7]

Min: 66.6 [19.2]

Max: 71.4 [21.9]

Dimensions 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373]
166

Table D-1 Surgery Center Baseline Scorecard: Climate Zones 1A–3B (con’t)

ASHRAE 90.1-2004 Climate Zone 1A 2A 2B 3A 3B

Fabric

Interior Partitions

Construction 2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

Dimensions – total area (ft2 [m2

]) 39,960 [3,712] 39,960 [3,712] 39,960 [3,712] 39,960 [3,712] 39,960 [3,712]

Internal Mass

Construction 6-in. wood 6-in. wood 6-in. wood 6-in. wood 6-in. wood

Dimensions – total area (ft2 [m2

]) 81,304 [7,553] 81,304 [7,553] 81,304 [7,553] 81,304 [7,553] 81,304 [7,553]

Thermal properties (lb/ft2 [kg/m2

]) 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0]

HVAC

Heating type Natural gas Natural gas Natural gas Natural gas Natural gas

Cooling type DX DX DX DX DX

HVAC Autosizing

Air-conditioning (tons [kW]) 148.9 [523.7] 153.5 [539.8] 147.8 [520.0] 154.3 542.8] 133.2 [468.4]

Heating (kBtu/h [kW]) 1,101.2 [322.7] 1,133.51 [332.2] 1,206.7 [353.7] 1,141.0 [334.4] 1,089.9 [319.4]

HVAC Efficiency

Air-conditioning (COP) 3.24 3.24 3.24 3.24 3.24

Heating efficiency (%) 80 80 80 80 80

HVAC Control

Economizer No No Yes No Yes

Fan and Pump Loads

Supply fan volumetric flow rate (cfm [m3/s]) 49,491.8 [23.4] 52,085.7 [24.6] 59,809.4 [28.2] 52,208.9 [24.6] 58,355.0 [27.5]

Service Water Heating

SWH type NG Storage Tank NG Storage Tank NG Storage Tank NG Storage Tank NG Storage Tank

Et (%) 80 80 80 80 80

Internal Loads and 

Schedules

Lighting

Average power density (W/ft2 [W/m2]) 1.86 [19.97] 1.86 [19.97] 1.86 [19.97] 1.86 [19.97] 1.86 [19.97]

Schedule See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5

Plug Loads

Average power density (W/ft2 [W/m2]) 1.80 [19.42] 1.80 [19.42] 1.80 [19.42] 1.80 [19.42] 1.80 [19.42]

Schedule See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8

Occupancy

Average people (#/1000 ft2 [#/100 m2]) 10.13 [10.90] 10.13 [10.90] 10.13 [10.90] 10.13 [10.90] 10.13 [10.90]

Schedule See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9
167

Table D-2 Surgery Center Scorecard: Climate Zones 3C–5A

ASHRAE 90.1-2004 Climate Zone 3C 4A 4B 4C 5A

Program

Building name Surgery 

Center

Surgery 

Center

Surgery 

Center

Surgery 

Center

Surgery 

Center

Location San Francisco, 

California

Baltimore,

Maryland

Albuquerque, 

New Mexico

Seattle, 

Washington

Chicago,

Illinois

Form

Total floor area (ft2 [m2]) 40,946 [3,804] 40,946 [3,804] 40,946 [3,804] 40,946 [3,804] 40,946 [3,804]

Number of floors 3 3 3 3 3

Window fraction (window to wall ratio)

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

Skylight/TDD percent 0.0% 0.0% 0.0% 0.0% 0.0%

Azimuth 0.00 0.00 0.00 0.00 0.00

Fabric

Exterior Walls

Construction type Steel-framed Steel-framed Steel-framed Steel-framed Steel-framed

Construction description R-13 R-13 R-13 R-13 R-13 + R-3.8 c.i.

R-value (ft2·h·°F/Btu [m2

·K/W]) 7.22 [1.27] 7.22 [1.27] 7.22 [1.27] 7.22 [1.27] 11.06 [1.95]

Gross dimensions – total area (ft2 [m2]) 16,720 [1,553] 16,720 [1,553] 16,720 [1,553] 16,720 [1,553] 16,720 [1,553]

Net dimensions – total area (ft2 [m2]) 13,178 [1,224] 13,178 [1,224] 13,178 [1,224] 13,178 [1,224] 13,178 [1,224]

Wall to skin ratio 0.53 0.53 0.53 0.53 0.53

Tilts and orientation Vertical Vertical Vertical Vertical Vertical

Roof

Construction type IEAD IEAD IEAD IEAD IEAD

Construction description R-10 c.i. R-15 c.i. R-15 c.i. R-15 c.i. R-15 c.i.

R-value (ft2·h·°F/Btu [m2·K/W]) 9.69 [1.71] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61]

Gross Dimensions – total area (ft2 [m2]) 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373]

Net Dimensions – total area (ft2 [m2]) 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373]

Roof to skin ratio 0.47 0.47 0.47 0.47 0.47

Tilts and orientation Horizontal Horizontal Horizontal Horizontal Horizontal
168

Table D-2 Surgery Center Baseline Scorecard: Climate Zones 3C–5A (con’t)

ASHRAE 90.1-2004 Climate Zone 3C 4A 4B 4C 5A

Fabric

Windows

Dimensions – total area (ft2 [m2

S: 1,228 [114]

])

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

U-factor (Btu/h·ft2·oF [W/m2

S: 1.21 [6.88]

·K]) E: 1.21 [6.88]

N: 0.73 [4.15]

W: 1.21 [6.88]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

SHGC

South: 0.61

East: 0.61

North: 0.61

West: 0.61

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

Visible transmittance

South: 0.61

East: 0.61

North: 0.61

West: 0.61

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.36

West: 0.39

Operable area (ft2 [m2]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Skylights/TDD

Dimensions – total area (ft2 [m2]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

U-factor (Btu/h·ft2·oF [W/m2·K]) 1.21 [6.92] 0.69 [3.92] 0.69 [3.92] 0.69 [3.92] 0.69 [3.92]

SHGC 0.61 0.49 0.49 0.49 0.49

Visible transmittance 0.61 0.49 0.49 0.49 0.49

Operable area (ft2 [m2

]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Foundation

Foundation type Mass floor Mass floor Mass floor Mass floor Mass floor

Construction

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

R-value (ft2·h·°F/Btu [m2

·K/W]) 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37]

Average min/max under-slab temperatures Min: 67.8 [19.9]

Max: 68.8 [20.4]

Min: 67.4 [19.7]

Max: 72.6 [22.6]

Min: 66.5 [19.2]

Max: 71.3 [21.8]

Min: 67.5 [19.7]

Max: 70.0 [21.1]

Min: 67.1 [19.5]

Max: 72.3 [22.4]

Dimensions 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373]
169

Table D-2 Surgery Center Baseline Scorecard: Climate Zones 3C–5A (con’t)

ASHRAE 90.1-2004 Climate Zone 3C 4A 4B 4C 5A

Fabric

Interior Partitions

Construction 2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

Dimensions – total area (ft2 [m2]) 39,960 [3,712] 39,960 [3,712] 39,960 [3,712] 39,960 [3,712] 39,960 [3,712]

Internal Mass

Construction 6-in. wood 6-in. wood 6-in. wood 6-in. wood 6-in. wood

Dimensions – total area (ft2 [m2]) 81,304 [7,553] 81,304 [7,553] 81,304 [7,553] 81,304 [7,553] 81,304 [7,553]

Thermal properties (lb/ft2 [kg/m2]) 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0]

HVAC

Heating Type Natural gas Natural gas Natural gas Natural gas Natural gas

Cooling Type DX DX DX DX DX

HVAC Autosizing

Air-conditioning (tons [kW]) 115.1 [404.9] 147.8 [519.9] 131.1 [461.1] 114.0 [400.9] 143.4 [504.4]

Heating (kBtu/h [kW]) 1,002.5 [293.8] 1,156.3 [338.9] 1,062.3 [311.3] 1,059.6 [310.5] 1,165.2 [341.5]

HVAC Efficiency

Air-conditioning (COP) 3.24 3.24 3.24 3.24 3.24

Heating efficiency (%) 80 80 80 80 80

HVAC Control

Economizer Yes No Yes Yes Yes

Fan and Pump Loads

Supply fan volumetric flow rate (cfm [m3/s]) 45,676.7 [21.6] 51,755.6 [24.4] 59,264.3 [28.0] 47,907.5 [22.6] 50,235.6 [23.7]

Service Water Heating

SWH type NG Storage Tank NG Storage Tank NG Storage Tank NG Storage Tank NG Storage Tank

Et (%) 80 80 80 80 80

Internal Loads and 

Schedules

Lighting

Average power density (W/ft2 [W/m2

]) 1.86 [19.97] 1.86 [19.97] 1.86 [19.97] 1.86 [19.97] 1.86 [19.97]

Schedule See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5

Plug Loads

Average power density (W/ft2 [W/m2]) 1.80 [19.42] 1.80 [19.42] 1.80 [19.42] 1.80 [19.42] 1.80 [19.42]

Schedule See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8

Occupancy

Average people (#/1000 ft2 [#/100 m2

]) 10.13 [10.90] 10.13 [10.90] 10.13 [10.90] 10.13 [10.90] 10.13 [10.90]

Schedule See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9
170

Table D-3 Supply Center Baseline Scorecard: Climate Zones 5B–8A

ASHRAE 90.1-2004 Climate Zone 5B 6A 6B 7A 8A

Program

Building name Surgery 

Center

Surgery 

Center

Surgery 

Center

Surgery 

Center

Surgery 

Center

Location Boise, 

Idaho

Burlington, 

Vermont

Helena, 

Montana

Duluth, 

Minnesota

Fairbanks, 

Alaska

Form

Total floor area (ft2 [m2]) 40,946 [3,804] 40,946 [3,804] 40,946 [3,804] 40,946 [3,804] 40,946 [3,804]

Number of floors 3 3 3 3 3

Window fraction (window to wall ratio)

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

South: 0.24

East: 0.19

North: 0.21

West: 0.13

Total: 0.20

Skylight/TDD percent 0.0% 0.0% 0.0% 0.0% 0.0%

Azimuth 0.00 0.00 0.00 0.00 0.00

Fabric

Exterior Walls

Construction type Steel-framed Steel-framed Steel-framed Steel-framed Steel-framed

Construction description R-13 + R-3.8 c.i. R-13 + R-3.8 c.i. R-13 + R-3.8 c.i. R-13 + R-7.5 c.i. R-13 + R-7.5 c.i.

R-value (ft2·h·°F/Btu [m2·K/W]) 11.06 [1.95] 11.06 [1.95] 11.06 [1.95] 14.76 [2.60] 14.76 [2.60]

Gross dimensions – total area (ft2 [m2]) 16,720 [1,553] 16,720 [1,553] 16,720 [1,553] 16,720 [1,553] 16,720 [1,553]

Net dimensions – total area (ft2 [m2

]) 13,178 [1,224] 13,178 [1,224] 13,178 [1,224] 13,178 [1,224] 13,178 [1,224]

Wall to skin ratio 0.53 0.53 0.53 0.53 0.53

Tilts and orientation Vertical Vertical Vertical Vertical Vertical

Roof

Construction type IEAD IEAD IEAD IEAD IEAD

Construction description R-15 c.i. R-15 c.i. R-15 c.i. R-15 c.i. R-20 c.i.

R-value (ft2·h·°F/Btu [m2·K/W]) 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 14.82 [2.61] 19.76 [3.48]

Gross dimensions – total area (ft2 [m2

]) 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373]

Net dimensions – total area (ft2 [m2]) 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373]

Roof to skin ratio 0.47 0.47 0.47 0.47 0.47

Tilts and orientation Horizontal Horizontal Horizontal Horizontal Horizontal
171

Table D-3 Surgery Center Baseline Scorecard: Climate Zones 5B–8A (con’t)

ASHRAE 90.1-2004 Climate Zone 5B 6A 6B 7A 8A

Fabric

Windows

Dimensions – total area (ft2 [m2

S: 1,228 [114]

])

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

S: 1,228 [114]

E: 624 [58]

N: 1,046 [97]

W: 420 [39]

Total: 3,318 [308]

U-Factor (Btu/h·ft2·oF [W/m2

S: 0.57 [3.24]

·K]) E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.57 [3.24]

E: 0.57 [3.24]

N: 0.46 [2.61]

W: 0.57 [3.24]

S: 0.46 [2.61]

E: 0.46 [2.61]

N: 0.35 [1.99]

W: 0.46 [2.61]

SHGC

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.49

West: 0.39

South: 0.39

East: 0.39

North: 0.49

West: 0.39

South: 0.49

East: 0.49

North: 0.64

West: 0.49

South: 0.46

East: 0.46

North: 0.46

West: 0.46

Visible transmittance

South: 0.39

East: 0.39

North: 0.36

West: 0.39

South: 0.39

East: 0.39

North: 0.49

West: 0.39

South: 0.39

East: 0.39

North: 0.49

West: 0.39

South: 0.49

East: 0.49

North: 0.64

West: 0.49

South: 0.46

East: 0.46

North: 0.46

West: 0.46

Operable area (ft2 [m2]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Skylights/TDD

Dimensions – total area (ft2 [m2]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

U-Factor (Btu/h·ft2·oF [W/m2·K]) 0.69 [3.92] 0.69 [3.92] 0.69 [3.92] 0.69 [3.92] 0.58 [3.29]

SHGC 0.49 0.49 0.49 0.68 0.49

Visible transmittance 0.49 0.49 0.49 0.68 0.49

Operable area (ft2 [m2

]) 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0] 0.0 [0.0]

Foundation

Foundation type Mass floor Mass floor Mass floor Mass floor Mass floor

Construction

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

Carpet over heavy 

concrete and 

insulation

R-value (ft2·h·°F/Btu [m2

·K/W]) 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37] 2.11 [0.37]

Average min/max under-slab temperatures Min: 66.7 [19.3]

Max: 706 [21.5]

Min: 66.9 [19.4]

Max: 71.4 [21.9]

Min: 66.4 [19.1]

Max: 70.4 [21.3]

Min: 66.5 [19.1]

Max: 69.7 [20.9]

Min: 65.1 [18.4]

Max: 67.3 [19.6]

Dimensions 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373] 14,782 [1,373]
172

Table D-3 Surgery Center Baseline Scorecard: Climate Zones 5B–8A (con’t)

ASHRAE 90.1-2004 Climate Zone 5B 6A 6B 7A 8A

Fabric

Interior Partitions

Construction 2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

2 × 4 steel frame 

gypsum board

Dimensions – total area (ft2 [m2]) 39,960 [3,712] 39,960 [3,712] 39,960 [3,712] 39,960 [3,712] 39,960 [3,712]

Internal mass

Construction 6-in. wood 6-in. wood 6-in. wood 6-in. wood 6-in. wood

Dimensions – total area (ft2 [m2]) 81,304 [7,553] 81,304 [7,553] 81,304 [7,553] 81,304 [7,553] 81,304 [7,553]

Thermal properties (lb/ft2 [kg/m2]) 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0] 16.6 [81.0]

HVAC

Heating Type Natural gas Natural gas Natural gas Natural gas Natural gas

Cooling Type DX DX DX DX DX

HVAC Autosizing

Air-conditioning (tons [kW]) 125.7 [442.1] 127.5 [448.4] 119.0 [418.4] 118.7 [417.3] 104.2 [366.5]

Heating (kBtu/h [kW]) 1,125.8 [330.0] 1,173.1 [343.8] 1,140.5 [334.3] 1,175.2 [344.4] 1,307.1 [383.1]

HVAC Efficiency

Air-conditioning (COP) 3.24 3.24 3.24 3.24 3.24

Heating efficiency (%) 80 80 80 80 80

HVAC Control

Economizer Yes Yes Yes Yes Yes

Fan and pump loads

Supply fan volumetric flow rate (cfm [m3/s]) 55,105.1 [26.0] 48,439.9 [22.9] 53,801.7 [25.4] 47,888.7 [22.6] 45,863.0 [21.6]

Service Water Heating

SWH type NG Storage Tank NG Storage Tank NG Storage Tank NG Storage Tank NG Storage Tank

Et (%) 80 80 80 80 80

Internal Loads and 

Schedules

Lighting

Average power density (W/ft2 [W/m2

]) 1.86 [19.97] 1.86 [19.97] 1.86 [19.97] 1.86 [19.97] 1.86 [19.97]

Schedule See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5 See Figure 5-5

Plug Loads

Average power density (W/ft2 [W/m2]) 1.80 [19.42] 1.80 [19.42] 1.80 [19.42] 1.80 [19.42] 1.80 [19.42]

Schedule See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8 See Figure 5-8

Occupancy

Average people (#/1000 ft2 [#/100 m2

]) 10.13 [10.90] 10.13 [10.90] 10.13 [10.90] 10.13 [10.90] 10.13 [10.90]

Schedule See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9 See Figure 5-9
173

Appendix E Determining Plug Loads for Small Healthcare

Facilities

Table E-1 provides information about plug loads for small healthcare facilities.
174

Table E-1 Plug Loads for Small Healthcare Facilities

Zone

Green 

Guide for 

Healthcare

(W/ft2)

Savings 

by Design

(W/ft2

Surgery 

Center 

Prototype 

) Model

(W/ft2)

Measured 

Data

Final

(W/ft2)

Comments

Anesthesia 1.0 – 1.9 – 2.0

Many numbers used because the 

space is small and there is

potential for computers, task 

lighting, and an anesthesia 

machine.

Clean 2.0 2.0 0.1 – 2.0

The equipment is variable. Using 

the more conservative 2.0 W/ft2

specified by Savings by Design

(the only room where something 

other than 1.0 W/ft2

Conference

for a hospitalrelated zone type was specified).

0.1 0.1 0.4 – 1.0

Contains significant electrical 

equipment such as projectors, 

computers, and televisions. 

Standby power could be improved.

Corridor 0.1 0.1 0.2 – 0.4

The need has increased because

electrical equipment is frequently 

used here. Corridors require 

significant square footage, which 

will increase total kWh. This has 

limited effect on total cfm, which is 

already 0.9 cfm/ft2

, as the load 

density is relatively low. The 

requirement is 2 ACH, which 

meets ~20 Btu/h-ft2 [5.7 W/ft2

Dining

].

0.1 0.1 NA – 1.0

Using the lower number because 

laptop computers are being used

increasingly in dining halls, and 

vending machines consume 

considerable energy with no 

standby capability.

Emergency 

room

4.0 – NA – 1.5

Requires a great deal of

equipment, but it is spread out, so 

the load is slightly lower than the 

anesthesia room.

Examination 

room

1.0 – 1.0 – 1.1

Similar to an office with a 

computer and probably task 

lighting. Will use 1.1 W/ft2

Food 

preparation 

(same 

as an office).

center

3.0 1.0 4.5 – 4.0

Uses task lighting, ovens, 

microwaves, ice machines, and 

refrigerators. Will use a number 

between the Green Guide (3 W/ft2)

and Issaquah (4.5 W/ft2

Laboratory

)

recommendations.

4.0 1.0 NA – 3.0

Reduced from 5 W/ft2, which was 

much too high; 3 W/ft2

Lobby

is 

reasonable. 

1.0 – 0.0 – 0.4 Similar to a typical corridor without

equipment.
175

Table E-1 Plug Loads for Small Healthcare Facilities

Zone

Green 

Guide for 

Healthcare

(W/ft2)

Savings 

by Design

(W/ft2

Surgery 

Center 

Prototype 

) Model

(W/ft2)

Measured 

Data

Final

(W/ft2)

Comments

Lounge 1.0 – 4.5 – 3.0

These typically have vending 

machines, TVs, refrigerators, 

coffee machines, task lights, etc. 

Some diversity will be added, but 

will remain high.

Nurse station 0.25 0.3 3.0 – 2.00

The Issaquah model showed 

numerous computers and task 

lights in this relatively small space. 

However, it is open to the corridor,

so the flow rate is lower because 

some heat will transfer out.

Nursery 1.5 1.0 NA – 1.0 Seems quite close to office loads.

Office 1.0 – 1.3 – 1.1 The most well-established load.

Operating 

room

4.0 1.0 0.7 1.5 kW 4.0

Based on Vernon's measurement 

of an OR in San Francisco, the 

mean load was 1.6 kW; spikes 

reached 11 kW. Using 1.6 kW 

divided by Issaquah has ~450 ft2

per OR and Bremen is ~700 ft2

Patient room

per 

OR. Green Guide states 4 W.

1.0 1.0 0.0 2.0

Has a lot of equipment in a small

space and probably does not have 

a standby mode. However, 4 is 

high, so 2 will be used.

Pharmacy 1.0 1.0 NA 1.0

Number seems reasonable, as a 

pharmacy has little electrical 

equipment.

Physical 

therapy 1.0 1.0 0.6 1.5 Higher than office because of

exercise equipment.

Procedure 

room

1.0 1.0 0.1 3.0

Numbers seem reasonable

because of considerable 

equipment. Even at 5 W/ft2

Radiology

, it is 

still under the ACH requirement.

9.0 1.0 8.4 5.9 kW 10.0

Michael Metyer sent file showing 

heat gain of 5 MRIs. Lowest was 

20 kBtu/h for 600 ft2 resulting in 30 

Btu/h-ft2. Therefore using 10 W/ft2

Reception area

.

1.0 – 0.3 1.1 Same as office.

Recovery room 1.0 1.0 5.4 3.0 Has a lot of monitoring equipment 

in a small space.

Soiled 2.0 1.0 2.3 2.0

Has a washer that uses 

considerable electrical energy to 

heat water, but much is wasted.

Storage 0.1 – 0.0 0.1

There is a difference between 

active and passive storage. 

Passive storage is assumed, so 

0.1 W/ft2

Toilet room

suffices.

0.1 – 0.0 0.4

People use many appliances in 

these bathrooms, so this seems 

reasonable.

Trauma room 4.0 1.0 NA 2.0 Similar to anesthesia room.

Triage 4.0 – NA 2.0 Similar to anesthesia room.
176

Table E-1 Plug Loads for Small Healthcare Facilities

Zone

Green 

Guide for 

Healthcare

(W/ft2)

Savings 

by Design

(W/ft2

Surgery 

Center 

Prototype 

) Model

(W/ft2)

Measured 

Data

Final

(W/ft2)

Comments

Utility 0.1 0.1 20.5 5.0

Same number as for an electricity

room, as many utility rooms have 

transformers or are elevator 

rooms.

Peak power

42,672 W – 60,456 W – 60,468 W CBECS hospital data assume plug 

loads remain constant over 24 h 

use 1.7 W/ft2

. The 2.5–3.0 W/ft2 1.0 W/ft

figure includes all electricity.

– 2 1.5 W/ft – 2 1.5 W/ft

Annual energy

2

274,723 kWh – 389,216 

kWh – 389,295 kWh CBECS data present 

approximately 50 kBtu/ft2 for plug 

loads ,which equates to 14.6 

kW·h/ft

6.7 kW-h/ft

2

– 2 9.5 kWh/ft – 2 9.5 

kWh/ft

22.9 kBtu/ft

2

– 2 32.4 

kBtu/ft2 – 32.4 kBtu/ft2
177

Appendix F Energy Savings End Use Tables: ASHRAE 90.1-1999 Baseline

Table F-1 Community Hospital End Uses: Climate Zones 1A–4A

Climate Model

Electricity (kBtu/ft2) Gas (kBtu/ft2

Total End 

Uses

) Percent 

Heating Cooling Lights Equip Fans Pumps Humid Heating Equip Water Savings Systems

1A

Baseline 0.0 76.5 34.8 35.8 30.9 1.6 0.2 53.9 9.0 8.4 250.8 N/A

DX 0.0 48.3 14.3 35.8 16.3 1.3 0.1 21.7 9.0 7.4 154.3 38.5%

AC 0.0 50.0 14.3 35.8 16.3 3.2 0.1 24.6 9.0 7.4 160.7 35.9%

WC 0.0 46.0 14.3 35.8 16.3 8.0 0.1 24.6 9.0 7.4 161.5 35.6%

2A

Baseline 0.0 66.5 34.8 35.8 31.4 1.6 3.1 76.9 9.0 10.0 269.2 N/A

DX 0.0 40.9 14.3 35.8 16.2 1.3 1.6 33.0 9.0 8.9 161.1 40.2%

AC 0.0 40.6 14.3 35.8 16.2 2.9 1.5 34.8 9.0 8.9 164.0 39.1%

WC 0.0 38.2 14.3 35.8 16.2 7.6 1.5 34.8 9.0 8.9 166.3 38.2%

2B

Baseline 0.0 53.7 34.8 35.8 33.5 1.7 23.5 85.1 9.0 9.1 286.2 N/A

DX 0.0 30.8 14.3 35.8 16.3 1.3 13.3 33.1 9.0 8.1 162.0 43.4%

AC 0.0 30.8 14.3 35.8 16.3 2.4 12.9 32.7 9.0 8.1 162.3 43.3%

WC 0.0 23.4 14.3 35.8 16.3 6.1 12.9 32.8 9.0 8.1 158.7 44.6%

3A

Baseline 0.0 54.9 34.8 35.8 30.1 1.6 7.5 86.4 9.0 11.3 272.1 N/A

DX 0.0 33.7 14.3 35.8 16.1 1.3 4.1 41.7 9.0 10.1 166.1 39.0%

AC 0.0 31.8 14.3 35.8 16.1 2.7 3.9 42.8 9.0 10.1 166.5 38.8%

WC 0.0 30.9 14.3 35.8 16.1 7.4 3.9 42.8 9.0 10.1 170.4 37.4%

3B

Baseline 0.0 38.0 34.8 35.8 33.6 1.5 41.0 78.3 9.0 10.9 283.1 N/A

DX 0.0 21.9 14.3 35.8 16.5 1.2 25.3 32.2 9.0 9.7 166.0 41.4%

AC 0.0 20.1 14.3 35.8 16.5 2.1 23.4 31.2 9.0 9.7 162.0 42.8%

WC 0.0 16.5 14.3 35.8 16.5 4.8 23.4 31.2 9.0 9.7 161.2 43.1%

3C

Baseline 0.0 23.0 34.8 35.8 29.2 1.5 6.1 98.4 9.0 12.7 250.6 N/A

DX 0.0 11.7 14.3 35.8 13.9 1.2 3.4 38.6 9.0 11.3 139.3 44.4%

AC 0.0 8.9 14.3 35.8 13.9 1.9 3.0 40.3 9.0 11.3 138.5 44.7%

WC 0.0 9.8 14.3 35.8 13.9 4.8 3.0 40.3 9.0 11.3 142.2 43.2%

4A

Baseline 0.0 44.5 34.8 35.8 30.0 1.6 12.6 98.5 9.0 12.9 279.9 N/A

DX 0.0 27.2 14.3 35.8 16.0 1.3 7.0 46.0 9.0 11.5 168.2 39.9%

AC 0.0 24.1 14.3 35.8 16.0 2.5 6.4 46.5 9.0 11.5 166.2 40.6%

WC 0.0 24.6 14.3 35.8 16.0 6.9 6.4 46.5 9.0 11.5 171.1 38.9%
178

Table F-2 Community Hospital End Uses: Climate Zones 4B–8A

Climate Model

Electricity (kBtu/ft2) Gas (kBtu/ft2

Total End 

Uses

) Percent 

Heating Cooling Lights Equip Fans Pumps Humid Heating Equip Water Savings Systems

4B

Baseline 0.0 27.9 34.8 35.8 34.2 1.5 47.3 84.3 9.0 12.7 287.5 N/A

DX 0.0 15.9 14.3 35.8 16.9 1.2 29.9 31.7 9.0 11.3 166.1 42.2%

AC 0.0 13.4 14.3 35.8 16.9 1.9 28.2 30.3 9.0 11.3 161.2 43.9%

WC 0.0 11.3 14.3 35.8 16.9 4.8 28.2 30.3 9.0 11.3 161.1 44.0%

4C

Baseline 0.0 16.4 34.8 35.8 27.4 1.5 13.3 92.9 9.0 13.6 244.7 N/A

DX 0.0 9.4 14.3 35.8 14.4 1.2 7.9 40.4 9.0 12.1 144.6 40.9%

AC 0.0 7.5 14.3 35.8 14.4 1.7 7.5 41.5 9.0 12.1 144.0 41.2%

WC 0.0 7.9 14.3 35.8 14.4 4.3 7.5 41.5 9.0 12.1 146.9 39.9%

5A

Baseline 0.0 25.8 34.8 35.8 29.5 1.6 24.3 102.2 9.0 14.0 277.0 N/A

DX 0.0 15.6 14.3 35.8 15.3 1.3 14.0 46.7 9.0 12.5 164.5 40.6%

AC 0.0 14.9 14.3 35.8 15.3 2.0 13.9 47.3 9.0 12.5 165.1 40.4%

WC 0.0 13.6 14.3 35.8 15.3 5.3 13.9 47.3 9.0 12.5 167.1 39.7%

5B

Baseline 0.0 18.4 34.8 35.8 30.9 1.5 38.3 95.2 9.0 13.8 277.8 N/A

DX 0.0 10.6 14.3 35.8 15.6 1.2 22.4 40.3 9.0 12.3 161.7 41.8%

AC 0.0 9.4 14.3 35.8 15.6 1.7 20.6 40.1 9.0 12.3 159.1 42.8%

WC 0.0 7.9 14.3 35.8 15.6 3.7 20.6 40.1 9.0 12.3 159.5 42.6%

6A

Baseline 0.0 20.4 34.8 35.8 28.7 1.6 25.8 107.9 9.0 15.1 279.2 N/A

DX 0.0 14.0 14.3 35.8 15.0 1.4 14.9 51.9 9.0 13.4 169.6 39.2%

AC 0.0 11.4 14.3 35.8 15.0 1.9 14.8 52.4 9.0 13.4 167.9 39.9%

WC 0.0 10.6 14.3 35.8 15.0 4.5 14.8 52.4 9.0 13.4 169.8 39.2%

6B

Baseline 0.0 14.5 34.8 35.8 30.9 1.5 43.4 100.9 9.0 15.2 286.1 N/A

DX 0.0 9.5 14.3 35.8 15.7 1.3 25.3 44.8 9.0 13.5 169.2 40.9%

AC 0.0 6.9 14.3 35.8 15.7 1.6 23.9 44.4 9.0 13.5 165.2 42.3%

WC 0.0 6.0 14.3 35.8 15.7 3.1 23.9 44.4 9.0 13.5 165.8 42.1%

7A

Baseline 0.0 12.8 34.8 35.8 28.5 1.5 30.5 113.4 9.0 46.6 283.1 N/A

DX 0.0 8.6 14.3 35.8 14.7 1.3 17.2 57.5 9.0 14.8 173.4 38.7%

AC 0.0 6.6 14.3 35.8 14.7 1.7 17.1 57.9 9.0 14.8 172.0 39.2%

WC 0.0 6.4 14.3 35.8 14.7 3.7 17.1 57.9 9.0 14.8 123.8 38.6%

8A

Baseline 0.0 7.7 34.8 35.8 26.1 1.6 34.0 138.0 9.0 18.5 305.6 N/A

DX 0.0 5.4 14.3 35.8 14.7 1.5 21.3 46.3 9.0 16.5 205.1 32.9%

AC 0.0 3.9 14.3 35.8 14.7 1.7 21.0 46.5 9.0 16.5 203.7 33.3%

WC 0.0 3.8 14.3 35.8 14.7 2.8 21.0 46.5 9.0 16.5 204.8 33.0%
179

Table F-3 Surgery Center End Uses: Climate Zones 1A–4A

Climate Model

Electricity (kBtu/ft2) Gas (kBtu/ft2

Total End 

Uses

) Percent 

Heating Cooling Lights Equip Fans Pumps Humid Heating Equip Water Savings Systems

1A

Baseline 1.3 60.1 23.9 28.0 21.8 0.8 0.1 31.2 4.4 0.8 172.4 N/A

DX 1.1 38.4 9.7 28.0 10.5 0.6 0.0 11.9 4.4 0.7 105.5 38.8%

AC 1.1 38.7 9.7 28.0 10.5 2.1 0.0 14.7 4.4 0.7 109.9 36.2%

WC 1.1 37.8 9.7 28.0 10.5 6.9 0.0 14.7 4.4 0.7 113.9 33.9%

2A

Baseline 6.6 52.2 23.9 28.0 22.0 0.8 1.6 41.3 4.4 0.9 181.7 N/A

DX 5.2 33.1 9.7 28.0 10.5 0.7 0.9 17.0 4.4 0.8 110.4 39.2%

AC 5.3 31.8 9.7 28.0 10.5 1.9 0.7 18.9 4.4 0.8 112.0 38.3%

WC 5.3 31.7 9.7 28.0 10.5 6.7 0.7 18.9 4.4 0.8 116.7 35.7%

2B

Baseline 7.1 42.8 23.9 28.0 24.2 0.8 13.1 44.6 4.4 0.9 189.7 N/A

DX 5.5 25.4 9.7 28.0 10.8 0.6 6.0 15.2 4.4 0.8 106.4 43.9%

AC 5.5 24.9 9.7 28.0 10.8 1.5 5.7 15.3 4.4 0.8 106.6 43.8%

WC 5.5 19.8 9.7 28.0 10.7 5.2 5.7 15.3 4.4 0.8 105.1 44.6%

3A

Baseline 9.5 43.6 23.9 28.0 21.8 0.8 4.5 46.2 4.4 1.0 183.6 N/A

DX 8.9 27.8 9.7 28.0 10.5 0.7 2.4 20.8 4.4 0.9 114.2 37.8%

AC 8.9 25.4 9.7 28.0 10.5 1.7 2.1 21.7 4.4 0.9 113.4 38.2%

WC 8.9 26.1 9.7 28.0 10.5 6.6 2.1 21.7 4.4 0.9 119.0 35.2%

3B

Baseline 7.5 30.0 23.9 28.0 23.9 0.7 25.5 40.6 4.4 1.0 185.5 N/A

DX 6.5 17.8 9.7 28.0 10.6 0.5 12.1 14.1 4.4 0.9 104.6 43.6%

AC 6.5 16.1 9.7 28.0 10.6 1.2 11.2 13.7 4.4 0.9 402.4 44.8%

WC 6.5 13.8 9.7 28.0 10.6 3.9 11.2 13.7 4.4 0.9 102.7 44.6%

3C

Baseline 10.8 17.0 23.9 28.0 20.1 0.7 2.6 47.8 4.4 1.1 156.5 N/A

DX 7.2 8.7 9.7 28.0 8.5 0.6 1.1 16.6 4.4 1.0 85.7 45.2%

AC 7.2 6.9 9.7 28.0 8.5 1.2 1.0 18.9 4.4 1.0 86.8 44.5%

WC 7.2 7.8 9.7 28.0 8.5 3.9 1.0 18.9 4.4 1.0 90.4 42.2%

4A

Baseline 14.2 35.6 23.9 28.0 21.6 0.8 7.5 51.4 4.4 1.2 188.6 N/A

DX 12.2 22.8 9.7 28.0 10.4 0.7 4.0 23.8 4.4 1.0 117.0 37.9%

AC 12.2 19.5 9.7 28.0 10.4 1.5 3.6 24.1 4.4 1.0 114.6 39.2%

WC 12.2 21.0 9.7 28.0 10.4 6.1 3.6 24.1 4.4 1.0 120.6 36.0%
180

Table F-4 Surgery Center End Uses: Climate Zones 4B–8A

Climate Model

Electricity (kBtu/ft2) Gas (kBtu/ft2

Total End 

Uses

) Percent 

Heating Cooling Lights Equip Fans Pumps Humid Heating Equip Water Savings Systems

4B

Baseline 10.4 21.9 23.9 28.0 24.4 0.7 29.9 42.2 4.4 1.1 186.9 N/A

DX 8.3 12.8 9.7 28.0 10.8 0.6 14.6 14.8 4.4 1.0 105.0 43.8%

AC 8.3 10.8 9.7 28.0 10.9 1.0 13.9 14.0 4.4 1.0 102.1 45.4%

WC 8.3 9.4 9.7 28.0 10.8 3.0 13.9 14.0 4.4 1.0 102.6 45.1%

4C

Baseline 13.6 13.0 23.9 28.0 20.0 0.7 6.8 49.5 4.4 1.2 161.0 N/A

DX 11.2 7.1 9.7 28.0 8.9 0.6 2.7 19.0 4.4 1.1 92.9 42.3%

AC 11.2 5.8 9.7 28.0 8.9 1.0 2.6 20.4 4.4 1.1 93.2 42.1%

WC 11.2 6.2 9.7 28.0 8.9 3.2 2.6 20.4 4.4 1.1 95.9 40.4%

5A

Baseline 17.7 20.6 23.9 28.0 21.3 0.8 14.3 52.3 4.4 1.2 184.5 N/A

DX 15.4 12.4 9.7 28.0 9.7 0.7 6.6 22.2 4.4 1.1 110.3 40.2%

AC 15.4 11.9 9.7 28.0 9.7 1.3 6.6 23.4 4.4 1.1 111.5 39.6%

WC 15.4 11.4 9.7 28.0 9.7 4.0 6.6 23.4 4.4 1.1 113.6 38.4%

5B

Baseline 15.3 14.8 23.9 28.0 22.5 0.8 22.3 49.2 4.4 1.2 182.4 N/A

DX 12.9 8.6 9.7 28.0 10.1 0.6 9.9 19.4 4.4 1.1 104.8 42.6%

AC 12.9 7.6 9.7 28.0 10.1 1.0 9.2 19.2 4.4 1.1 103.2 43.4%

WC 12.9 6.5 9.7 28.0 10.1 2.6 9.2 19.2 4.4 1.1 103.8 43.1%

6A

Baseline 21.0 16.3 23.9 28.0 20.6 0.8 15.6 54.1 4.4 1.3 186.0 N/A

DX 18.1 11.0 9.7 28.0 9.4 0.7 7.5 24.7 4.4 1.2 114.7 38.3%

AC 18.1 9.0 9.7 28.0 9.4 1.2 7.5 25.7 4.4 1.2 114.2 38.6%

WC 18.1 8.7 9.7 28.0 9.4 3.4 7.5 25.7 4.4 1.2 116.1 37.6%

6B

Baseline 19.6 11.6 23.9 28.0 22.4 0.8 26.5 50.3 4.4 1.3 188.7 N/A

DX 16.4 4.6 9.7 28.0 10.1 0.7 12.4 21.0 4.4 1.2 111.5 40.9%

AC 16.4 5.6 9.7 28.0 10.1 1.0 11.9 20.9 4.4 1.2 109.1 42.2%

WC 16.4 5.0 9.7 28.0 10.1 2.2 11.9 20.9 4.4 1.2 109.7 41.8%

7A

Baseline 24.8 10.3 23.9 28.0 20.5 0.8 18.9 55.7 4.4 1.4 188.6 N/A

DX 22.2 6.8 9.7 28.0 9.3 0.7 9.0 27.3 4.4 1.3 118.8 37.0%

AC 22.2 5.3 9.7 28.0 9.3 1.0 8.9 28.0 4.4 1.3 118.3 37.3%

WC 22.2 5.3 9.7 28.0 9.3 2.6 8.9 28.0 4.4 1.3 119.9 36.5%

8A

Baseline 37.2 6.3 23.9 28.0 19.4 0.9 23.2 71.1 4.4 1.6 215.9 N/A

DX 34.4 4.2 9.7 28.0 9.3 0.9 12.4 40.8 4.4 1.4 145.7 32.5%

AC 34.4 3.0 9.7 28.0 9.3 1.0 12.3 41.2 4.4 1.4 144.9 32.9%

WC 34.4 3.1 9.7 28.0 9.3 2.0 12.3 41.2 4.4 1.4 145.9 32.4%
181

Appendix G Energy Savings End Use Tables: ASHRAE 90.1-2004 Baseline

Table 10-1 Community Hospital End Uses: Climate Zones 1A–4A

Climate Model

Electricity (kBtu/ft2) Gas (kBtu/ft2

Total End 

Uses

) Percent 

Heating Cooling Lights Equip Fans Pumps Humid Heating Equip Water Savings Systems

1A

Baseline 0.0 71.3 20.4 35.8 28.3 1.5 0.2 55.6 9.0 8.4 230.5 N/A

DX 0.0 48.3 14.3 35.8 16.3 1.3 0.1 21.7 9.0 7.4 154.3 33.1%

AC 0.0 50.0 14.3 35.8 16.3 3.2 0.1 24.6 9.0 7.4 160.7 30.3%

WC 0.0 46.0 14.3 35.8 16.3 8.0 0.1 24.6 9.0 7.4 161.5 29.9%

2A

Baseline 0.0 61.9 20.4 35.8 28.9 1.5 2.6 78.2 9.0 10.0 248.4 N/A

DX 0.0 40.9 14.3 35.8 16.2 1.3 1.6 33.0 9.0 8.9 161.1 35.1%

AC 0.0 40.6 14.3 35.8 16.2 2.9 1.5 34.8 9.0 8.9 164.0 34.0%

WC 0.0 38.2 14.3 35.8 16.2 7.6 1.5 34.8 9.0 8.9 166.3 33.0%

2B

Baseline 0.0 49.9 20.4 35.8 30.8 1.5 21.6 85.5 9.0 9.1 263.6 N/A

DX 0.0 30.8 14.3 35.8 16.3 1.3 13.3 33.1 9.0 8.1 162.0 38.5%

AC 0.0 30.8 14.3 35.8 16.3 2.4 12.9 32.7 9.0 8.1 162.3 38.4%

WC 0.0 23.4 14.3 35.8 16.3 6.1 12.9 32.8 9.0 8.1 158.7 39.8%

3A

Baseline 0.0 50.8 20.4 35.8 28.1 1.5 6.6 87.2 9.0 11.3 250.7 N/A

DX 0.0 33.7 14.3 35.8 16.1 1.3 4.1 41.7 9.0 10.1 166.1 33.7%

AC 0.0 31.8 14.3 35.8 16.1 2.7 3.9 42.8 9.0 10.1 166.5 33.6%

WC 0.0 30.9 14.3 35.8 16.1 7.4 3.9 42.8 9.0 10.1 170.4 32.0%

3B

Baseline 0.0 34.9 20.4 35.8 30.5 1.4 38.3 78.4 9.0 10.9 259.7 N/A

DX 0.0 21.9 14.3 35.8 16.5 1.2 25.3 32.2 9.0 9.7 166.0 36.1%

AC 0.0 20.1 14.3 35.8 16.5 2.1 23.4 31.2 9.0 9.7 162.0 37.6%

WC 0.0 16.5 14.3 35.8 16.5 4.8 23.4 31.2 9.0 9.7 161.2 37.9%

3C

Baseline 0.0 21.0 20.4 35.8 26.7 1.5 5.4 97.8 9.0 12.7 230.2 N/A

DX 0.0 11.7 14.3 35.8 13.9 1.3 3.4 38.6 9.0 11.3 139.3 39.5%

AC 0.0 8.9 14.3 35.8 13.9 2.5 3.0 40.3 9.0 11.3 138.5 39.9%

WC 0.0 9.8 14.3 35.8 13.9 6.9 3.0 40.3 9.0 11.3 142.2 38.2%

4A

Baseline 0.0 41.2 20.4 35.8 27.6 1.4 11.1 99.5 9.0 12.9 259.0 N/A

DX 0.0 27.2 14.3 35.8 16.0 1.2 7.0 46.0 9.0 11.5 168.2 35.1%

AC 0.0 24.1 14.3 35.8 16.0 1.8 6.4 46.5 9.0 11.5 166.2 35.8%

WC 0.0 24.6 14.3 35.8 16.0 3.8 6.4 46.5 9.0 11.5 171.1 33.9%
182

Table G-2 Community Hospital End Uses: Climate Zones 4B–8A

Climate Model

Electricity (kBtu/ft2) Gas (kBtu/ft2

Total End 

Uses

) Percent 

Heating Cooling Lights Equip Fans Pumps Humid Heating Equip Water Savings Systems

4B

Baseline 0.0 25.4 20.4 35.8 31.0 1.4 44.2 83.4 9.0 12.7 263.2 N/A

DX 0.0 15.9 14.3 35.8 16.9 1.2 29.9 31.7 9.0 11.3 166.1 36.9%

AC 0.0 13.4 14.3 35.8 16.9 1.8 28.2 30.3 9.0 11.3 161.2 38.8%

WC 0.0 11.3 14.3 35.8 16.9 3.8 28.2 30.3 9.0 11.3 161.1 38.8%

4C

Baseline 0.0 15.1 20.4 35.8 25.3 1.3 12.0 94.7 9.0 13.6 227.3 N/A

DX 0.0 9.4 14.3 35.8 14.4 1.2 7.9 40.4 9.0 12.1 144.6 36.4%

AC 0.0 7.5 14.3 35.8 14.4 1.7 7.5 41.5 9.0 12.1 144.0 36.7%

WC 0.0 7.9 14.3 35.8 14.4 4.3 7.5 41.5 9.0 12.1 146.9 35.4%

5A

Baseline 0.0 23.8 20.4 35.8 27.1 1.5 22.1 103.3 9.0 14.0 257.1 N/A

DX 0.0 15.6 14.3 35.8 15.3 1.3 14.0 46.7 9.0 12.5 164.5 36.0%

AC 0.0 14.9 14.3 35.8 15.3 2.0 13.9 47.3 9.0 12.5 165.1 35.8%

WC 0.0 13.6 14.3 35.8 15.3 5.3 13.9 47.3 9.0 12.5 167.1 35.0%

5B

Baseline 0.0 16.8 20.4 35.8 28.1 1.4 34.7 95.4 9.0 13.8 255.4 N/A

DX 0.0 10.6 14.3 35.8 15.6 1.2 22.4 40.3 9.0 12.3 161.7 36.7%

AC 0.0 9.4 14.3 35.8 15.6 1.7 20.6 40.1 9.0 12.3 159.1 37.7%

WC 0.0 7.9 14.3 35.8 15.6 3.7 20.6 40.1 9.0 12.3 159.5 37.5%

6A

Baseline 0.0 18.9 20.4 35.8 26.5 1.5 23.5 109.8 9.0 15.1 260.5 N/A

DX 0.0 14.0 14.3 35.8 15.0 1.4 14.9 51.9 9.0 13.4 169.6 34.9%

AC 0.0 11.4 14.3 35.8 15.0 1.9 14.8 52.4 9.0 13.4 167.9 35.5%

WC 0.0 10.6 14.3 35.8 15.0 4.5 14.8 52.4 9.0 13.4 169.8 34.8%

6B

Baseline 0.0 13.2 20.4 35.8 28.1 1.4 39.2 101.3 9.0 15.2 263.6 N/A

DX 0.0 9.5 14.3 35.8 15.7 1.3 25.3 44.8 9.0 13.5 169.2 35.8%

AC 0.0 6.9 14.3 35.8 15.7 1.6 23.9 44.4 9.0 13.5 165.2 37.3%

WC 0.0 6.0 14.3 35.8 15.7 3.1 23.9 44.4 9.0 13.5 165.8 37.1%

7A

Baseline 0.0 11.8 20.4 35.8 26.1 1.4 27.5 115.3 9.0 46.6 264.0 N/A

DX 0.0 8.6 14.3 35.8 14.7 1.3 17.2 57.5 9.0 14.8 173.4 34.3%

AC 0.0 6.6 14.3 35.8 14.7 1.7 17.1 57.9 9.0 14.8 172.0 34.9%

WC 0.0 6.4 14.3 35.8 14.7 3.7 17.1 57.9 9.0 14.8 173.8 34.2%

8A

Baseline 0.0 7.1 20.4 35.8 24.3 1.5 30.9 141.9 9.0 18.5 289.5 N/A

DX 0.0 5.4 14.3 35.8 14.7 1.5 21.3 86.3 9.0 16.5 205.1 29.2%

AC 0.0 3.9 14.3 35.8 14.7 1.7 21.0 86.5 9.0 16.5 203.7 29.6%

WC 0.0 3.8 14.3 35.8 14.7 2.8 21.0 86.5 9.0 16.5 204.8 29.3%
183

Table G-3 Surgery Center End Uses: Climate Zones 1A–4A

Climate Model

Electricity (kBtu/ft2) Gas (kBtu/ft2

Total End 

Uses

) Percent 

Heating Cooling Lights Equip Fans Pumps Humid Heating Equip Water Savings Systems

1A

Baseline 1.4 55.0 14.2 28.0 19.7 0.7 0.1 29.4 4.4 0.8 153.7 N/A

DX 1.1 38.4 9.7 28.0 10.5 0.6 0.0 11.9 4.4 0.7 105.5 31.4%

AC 1.1 38.7 9.7 28.0 10.5 2.1 0.0 14.7 4.4 0.7 109.9 28.5%

WC 1.1 37.8 9.7 28.0 10.5 6.9 0.0 14.7 4.4 0.7 113.9 25.9%

2A

Baseline 7.0 47.8 14.2 28.0 20.0 0.7 1.5 38.9 4.4 0.9 163.3 N/A

DX 5.2 331 9.7 28.0 10.5 0.7 0.9 17.0 4.4 0.8 110.4 32.4%

AC 5.3 31.8 9.7 28.0 10.5 1.9 0.7 18.9 4.4 0.8 112.0 31.4%

WC 5.3 31.7 9.7 28.0 10.5 6.7 0.7 18.9 4.4 0.8 116.7 28.5%

2B

Baseline 7.6 39.4 14.2 28.0 22.1 0.7 11.9 42.5 4.4 0.9 171.5 N/A

DX 5.5 25.4 9.7 28.0 10.8 0.6 6.0 15.2 4.4 0.8 106.4 37.9%

AC 5.5 24.9 9.7 28.0 10.8 1.5 5.7 15.3 4.4 0.8 106.6 37.9%

WC 5.5 19.8 9.7 28.0 10.7 5.2 5.7 15.3 4.4 0.8 105.1 38.7%

3A

Baseline 10.1 39.9 14.2 28.0 19.8 0.7 4.0 44.0 4.4 1.0 166.1 N/A

DX 8.9 27.8 9.7 28.0 10.5 0.7 2.4 20.8 4.4 0.9 114.2 31.2%

AC 8.9 25.4 9.7 28.0 10.5 1.7 2.4 21.7 4.4 0.9 113.4 31.7%

WC 8.9 26.1 9.7 28.0 10.5 6.6 2.4 21.7 4.4 0.9 119.0 28.3%

3B

Baseline 8.0 27.0 14.2 28.0 21.3 0.7 22.9 37.1 4.4 1.0 164.5 N/A

DX 6.5 17.8 9.7 28.0 10.6 0.5 12.1 14.1 4.4 0.9 104.6 36.4%

AC 6.5 16.1 9.7 28.0 10.6 1.2 11.2 13.7 4.4 0.9 102.4 37.7%

WC 6.5 13.8 9.7 28.0 10.6 3.9 11.2 13.7 4.4 0.9 102.7 37.5%

3C

Baseline 11.4 15.4 14.2 28.0 18.2 0.7 2.4 45.6 4.4 1.1 141.3 N/A

DX 7.2 8.7 9.7 28.0 8.5 0.6 1.1 16.6 4.4 1.0 85.7 39.3%

AC 7.2 6.9 9.7 28.0 8.5 1.2 1.0 18.9 4.4 1.0 86.8 38.5%

WC 7.2 7.8 9.7 28.0 8.5 3.9 1.0 18.9 4.4 1.0 90.4 36.0%

4A

Baseline 15.1 32.6 14.2 28.0 19.6 0.7 6.8 49.3 4.4 1.2 171.8 N/A

DX 12.2 22.8 9.7 28.0 10.4 0.7 4.0 23.8 4.4 1.0 117.0 31.9%

AC 12.2 19.5 9.7 28.0 10.4 1.5 3.6 24.1 4.4 1.0 114.6 33.3%

WC 12.2 21.0 9.7 28.0 10.4 6.1 3.6 24.1 4.4 1.0 120.6 29.8%
184

Table G-4 Surgery Center End Uses: Climate Zones 4B–8A

Climate Model

Electricity (kBtu/ft2) Gas (kBtu/ft2

Total End 

Uses

) Percent 

Heating Cooling Lights Equip Fans Pumps Humid Heating Equip Water Savings Systems

4B

Baseline 11.0 19.6 14.2 28.0 21.6 0.6 26.8 38.9 4.4 1.1 166.2 N/A

DX 8.3 12.8 9.7 28.0 10.8 0.6 14.6 14.8 4.4 1.0 105.0 36.8%

AC 8.3 10.8 9.7 28.0 10.9 1.0 13.9 14.0 4.4 1.0 102.1 38.6%

WC 8.3 9.4 9.7 28.0 10.8 3.0 13.9 14.0 4.4 1.0 102.6 38.3%

4C

Baseline 14.6 11.7 14.2 28.0 18.0 0.7 6.1 47.2 4.4 1.2 146.0 N/A

DX 11.2 7.1 9.7 28.0 8.9 0.6 2.7 19.0 4.4 1.1 92.9 36.4%

AC 11.2 5.8 9.7 28.0 8.9 1.0 2.6 20.4 4.4 1.1 93.2 36.2%

WC 11.2 6.2 9.7 28.0 8.9 3.0 2.6 20.4 4.4 1.1 95.9 34.3%

5A

Baseline 18.7 18.8 14.2 28.0 19.2 0.8 12.9 50.1 4.4 1.2 168.4 N/A

DX 15.4 12.4 9.7 28.0 9.7 0.7 6.6 22.2 4.4 1.1 110.3 34.5%

AC 15.4 11.9 9.7 28.0 9.7 1.3 6.6 23.4 4.4 1.1 111.5 33.8%

WC 15.4 11.4 9.7 28.0 9.7 4.0 6.6 23.4 4.4 1.1 113.6 32.5%

5B

Baseline 16.2 13.4 14.2 28.0 20.2 0.7 20.0 46.4 4.4 1.2 164.6 N/A

DX 12.9 8.6 9.7 28.0 10.1 0.6 9.9 19.4 4.4 1.1 104.8 36.3%

AC 12.9 7.6 9.7 28.0 10.1 1.0 9.2 19.2 4.4 1.1 103.2 37.3%

WC 12.9 6.5 9.7 28.0 10.1 2.6 9.2 19.2 4.4 1.1 103.8 37.0%

6A

Baseline 22.2 14.8 14.2 28.0 18.6 0.8 14.0 52.0 4.4 1.3 170.2 N/A

DX 18.1 11.0 9.7 28.0 9.4 0.7 7.5 24.7 4.4 1.2 114.7 32.6%

AC 18.1 9.0 9.7 28.0 9.4 1.2 7.5 25.7 4.4 1.2 114.2 32.9%

WC 18.1 8.7 9.7 28.0 94. 3.4 7.5 25.7 4.4 1.2 116.1 31.8%

6B

Baseline 20.6 10.3 14.2 28.0 19.9 0.7 23.4 47.1 4.4 1.3 170.0 N/A

DX 16.4 7.6 9.7 28.0 10.1 0.7 12.4 21.0 4.4 1.2 111.5 34.4%

AC 16.4 5.6 9.7 28.0 10.1 1.0 11.9 20.9 4.4 1.2 109.1 35.9%

WC 16.4 5.0 9.7 28.0 10.1 2.2 11.9 20.9 4.4 1.2 109.7 35.5%

7A

Baseline 26.1 9.3 14.2 28.0 18.4 0.8 16.8 53.3 4.4 1.4 172.5 N/A

DX 22.2 6.8 9.7 28.0 9.3 0.7 9.0 27.3 4.4 1.3 118.8 31.2%

AC 22.2 5.3 9.7 28.0 9.3 1.0 8.9 28.0 4.4 1.3 118.3 31.4%

WC 22.2 5.3 9.7 28.0 9.3 2.6 8.9 28.0 4.4 1.3 119.9 30.5%

8A

Baseline 39.0 5.7 14.2 28.0 17.5 0.9 20.7 68.6 4.4 1.6 200.5 N/A

DX 34.4 4.2 9.7 28.0 9.3 0.9 12.4 40.8 4.4 1.4 145.7 27.3%

AC 34.4 3.0 9.7 28.0 9.3 1.0 12.3 41.2 4.4 1.4 144.9 27.7%

WC 34.4 3.1 9.7 28.0 9.3 2.0 12.3 41.2 4.4 1.4 145.9 27.2%
185

Appendix H Fan Performance Characteristics

H.1 Baseline and Low-Energy Equivalent Fan Summary

The following appendix summarizes the calculation methodology for determining the motorbelt-fan combined efficiency for modeling the supply, return, and exhaust fan. See Section 6.3

for a detailed explaination and example of the calculation procedure.
186
187
188
189
190

H.2 NEMA Motor Premium Efficiencies

Table H-1 Motor Premium Efficiencies

Motor Size

(hp)

Motor Efficiency

(%)

1 85.5

1.5 86.5

2 86.5

3 89.5

5 89.5

7.5 91.7

10 91.7

15 92.4

20 93.0

25 93.6

30 93.6

40 94.1

50 94.5

60 95.0

75 95.4

100 95.4

125 95.4

150 95.8

200 96.2
191

H.3 Fan Efficiency Charts
F1147-E(10/2008)

REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, 

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this 

collection of information, including suggestions for reducing the burden, to Department of Defense, Executive Services and Communications Directorate (0704-0188). Respondents 

should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a 

currently valid OMB control number.

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION.

1. REPORT DATE (DD-MM-YYYY)

March 2010

2. REPORT TYPE

Technical Report

3. DATES COVERED (From - To)

4. TITLE AND SUBTITLE

Technical Support Document: Development of the Advanced Energy 

Design Guide for Small Hospitals and Healthcare Facilities -- 30% 

Guide

5a. CONTRACT NUMBER

DE-AC36-08-GO28308

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

E. Bonnema, I. Doebber, S. Pless, and P. Torcellini

5d. PROJECT NUMBER

NREL/TP-550-46314

5e. TASK NUMBER

BEC7.4001

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401-3393

8. PERFORMING ORGANIZATION

REPORT NUMBER

NREL/TP-550-46314

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S)

NREL

11. SPONSORING/MONITORING

AGENCY REPORT NUMBER

12. DISTRIBUTION AVAILABILITY STATEMENT

National Technical Information Service

U.S. Department of Commerce

5285 Port Royal Road

Springfield, VA 22161

13. SUPPLEMENTARY NOTES

14. ABSTRACT (Maximum 200 Words)

This Technical Support Document describes the process and methodology for the development of the Advanced 

Energy Design Guide for Small Hospitals and Healthcare Facilities, which is intended to provide recommendations 

for achieving 30% whole-building energy savings in small hospitals and healthcare facilities over levels achieved by 

following the ANSI/ASHRAE/IESNA Standard 90.1-1999.

15. SUBJECT TERMS

technical support document; tsd; aedg; advanced energy design guide; healthcare; hospital

16. SECURITY CLASSIFICATION OF: 17. LIMITATION 

OF ABSTRACT

UL

18. NUMBER 

OF PAGES

19a. NAME OF RESPONSIBLE PERSON

a. REPORT

Unclassified

b. ABSTRACT

Unclassified

c. THIS PAGE

Unclassified 19b. TELEPHONE NUMBER (Include area code)

Standard Form 298 (Rev. 8/98)

Prescribed by ANSI Std. Z39.18