Advanced HVAC Systems For Improving The Indoor Environmental Quality And Energy Performance Of California K 12 Schools Capistrano Ceiling Fan CEC 500 2007 006

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1.0 Introduction

Arnold Schwarzenegger

Governor

ADVANCED HVAC SYSTEMS FOR

IMPROVING THE INDOOR ENVIRONMENTAL

QUALITY AND ENERGY PERFORMANCE OF

CALIFORNIA K–12 SCHOOLS

PIER FINAL PROJECT REPORT

Prepared For:

California Energy Commission

Public Interest Energy Research Program

Prepared By:

Architectural Energy Corporation

January 2007

CEC-500-2007-006

Prepared By:

Donald Frey, Principal in Charge

Vernon Smith, Program Director

Boulder, Colorado

Contract No. 500-03-003

Prepared For:

California Energy Commission

Public Interest Energy Research (PIER) Program

Brad Meister

Contract Manager

Ann Peterson

PIER Buildings End-Use Energy Efficiency Team

Leader

Nancy Jenkins

PIER Energy Efficiency Research Office Manager

Martha Krebs, Ph.D.

Deputy Director

ENERGY RESEARCH AND DEVELOPMENT

DIVISION

B. B. Blevins

Executive Director

DISCLAIMER

This report was prepared as the result of work sponsored by the

California Energy Commission. It does not necessarily represent

the views of the Energy Commission, its employees or the State

of California. The Energy Commission, the State of California, its

employees, contractors and subcontractors make no warrant,

express or implied, and assume no legal liability for the

information in this report; nor does any party represent that the

uses of this information will not infringe upon privately owned

rights. This report has not been approved or disapproved by the

California Energy Commission nor has the California Energy

Commission passed upon the accuracy or adequacy of the

information in this report.

Acknowledgments

The products and outcomes presented in this report are a result of funding provided by the

California Energy Commission’s Public Interest Energy Research (PIER) Program on behalf of

the citizens of California. Architectural Energy Corporation (AEC) would like to acknowledge

the support and contributions of the following individuals and organizations in the successful

completion of this research program.

Program and Contract Management: Brad Meister and Ann Peterson, California Energy

Commission; Donald Frey and Vernon Smith, AEC.

Project Team: Charles Eley and John Arent, AEC; Morton Blatt, Energy Utilization Consultant;

Roger Wright and Stacia Okura, RLW Analytics, Inc.

Project Partners: Andrey Livchak, Halton Company; John Murphy and Gary Leupke, Trane

Company; Richard Lord, Carrier Corporation; Alan Colombo and Ron Warfield, Dry Creek

Joint Elementary School District (Coyote Ridge); Tom Rayburn and Joe Dixon, Capistrano

Unified School District (Kinoshita); Thomas Duval, Capital Engineering Consultants, Inc.; Chip

Fox, Ed Becker, and Abdullah Ahmed, San Diego Gas & Electric Company.

Program Advisory Committee (PAC): Gregg Ander, Southern California Edison; Michael Apte,

Lawrence Berkeley National Laboratory; Dave Bisbee, Sacramento Municipal Utility District;

Bill Boyce, SMUD; Richard Conrad, California Department of General Services; Joe Dixon,

Capistrano Unified School District; Rod Dow, Gordon Chong & Partners; Ken Gillespie, Pacific

Gas and Electric Company; Deborah Gold, Cal/OSHA; Randall Higa, Southern California Gas

Company; Peggy Jenkins, Air Resources Board; Terry Logee, U. S. Department of Energy; Andy

McPherson, Nacht & Lewis Architects; Ken Mozek, York International; Lowell Shields, Capital

Engineering Consultants, Inc.; Bob Thompson, U. S. EPA Headquarters; Dean Tompkins,

University of Wisconsin; Jed Waldman, California Department of Health Services; and John

Zinner, Zinner Consultants.

Additional Support: Tianzhen Hong, Jerry Moechnig, David Goldman, Camren Cordell, and

Judie Porter, AEC; Erik Ring, Tom Lunneberg, and Steven Long, CTG Energetics; market

researchers from SDV-ACCI.

Special Acknowledgements: Matching fund support from San Diego Gas and Electric Company

is appreciated and enhanced the results of the Thermal Displacement Ventilation project. The

support of school district personnel from Coyote Ridge and Kinoshita Elementary Schools is

greatly appreciated for the displacement ventilation project.

Match funding support from San Diego Gas and Electric Company and Sacramento Municipal

Utility District contributed greatly the Ultraviolet Light for Coil and Drain Pan Disinfection

project. The donation of equipment and installation services and support by the two

manufacturers for the ultraviolet light in the “C” band (UVC) study are appreciated. The

cooperation and support provided by school district personnel involved in the UVC study

contributed greatly.

Finally, the Indoor Environmental Quality Program team would like to thank the ratepayers of

California for the continued support of the PIER Program.

Please cite this report as follows:

Frey, Donald and Vernon Smith. 2006. Advanced HVAC Systems For Improving the Indoor

Environmental Quality and Energy Performance Of California K–12 Schools. Architectural Energy

Corporation for the California Energy Commission, PIER Building End-Use Energy Efficiency

Program. CEC-500-2007-006.

Preface

The Public Interest Energy Research (PIER) Program supports public interest energy research

and development that will help improve the quality of life in California by bringing

environmentally safe, affordable, and reliable energy services and products to the marketplace.

The PIER Program, managed by the California Energy Commission (Energy Commission),

conducts public interest research, development, and demonstration (RD&D) projects to benefit

the electricity and natural gas ratepayers in California.

The PIER program strives to conduct the most promising public interest energy research by

partnering with RD&D entities, including individuals, businesses, utilities, and public or

private research institutions.

PIER funding efforts are focused on the following RD&D program areas:

Buildings End-Use Energy Efficiency •

•

Energy-Related Environmental Research

Energy Systems Integration

Environmentally Preferred Advanced Generation

Industrial/Agricultural/Water End-Use Energy Efficiency

Renewable Energy Technologies

Transportation

Advanced HVAC Systems For Improving the Indoor Environmental Quality and Energy Performance

Of California K–12 Schools is the final report for the Indoor Environmental Quality K–12 project,

(contract number 500-03-303), conducted by Architectural Energy Corporation. The information

from this project contributes to PIER’s Building End-Use Energy Efficiency program.

For more information about the PIER Program, please visit the Energy Commission’s website at

www.energy.ca.gov/pier/ or contact the Energy Commission at (916) 654-5164.

iii

Table of Contents

Preface................................................................................................................................................ iii

Abstract ............................................................................................................................................... ix

Executive Summary........................................................................................................................... 1

1.0 Introduction.......................................................................................................................... 7

1.1. Background and Overview........................................................................................... 7

1.2. The Project Team............................................................................................................ 7

1.3. Report Organization ...................................................................................................... 8

2.0 Thermal Displacement Ventilation in Schools (Project 2) ............................................. 9

2.1. Introduction ....................................................................................................................9

2.2. Project Objectives ........................................................................................................... 9

2.3. Project Approach............................................................................................................ 10

2.3.1. Coordination with ongoing related PIER natural ventilation and DV research

(Task 2.1) .................................................................................................................... 10

2.3.2. CFD analysis of thermal comfort and ventilation effectiveness (Task 2.2)....... 10

2.3.3. CFD validation with full-scale mockup (Task 2.3)............................................... 12

2.3.4. Barriers study (Task 2.4) .......................................................................................... 12

2.3.5. System design options (Task 2.5)............................................................................ 13

2.3.6. Construct demonstration classroom (Task 2.6) .................................................... 14

2.3.7. Monitor performance of demonstration classrooms (Task 2.7).......................... 15

2.3.8. Product development (Task 2.8)............................................................................. 16

2.3.9. Fact sheets and guidelines (Task 2.9) ..................................................................... 17

2.3.10. Information dissemination (Task 2.10) .................................................................. 17

2.3.11. Technology transfer activities (Task 2.11) ............................................................. 18

2.3.12. Production readiness plan (Task 2.12) ................................................................... 18

2.4. Project Outcomes............................................................................................................ 18

2.5. Conclusions and Recommendations ........................................................................... 25

2.5.1. Conclusions................................................................................................................ 25

2.5.2. Commercialization potential................................................................................... 26

2.5.3. Recommendations..................................................................................................... 27

2.5.4. Benefits to California ................................................................................................ 29

3.0 Effectiveness of UVC Technology for Improving School Performance (Project 3).... 31

3.1. Introduction ....................................................................................................................31

3.2. Project Objectives ........................................................................................................... 32

3.3. Project Approach............................................................................................................ 32

3.4. Primary Data Collection................................................................................................ 36

3.4.1. Manufacturer Interviews and Literature Review................................................. 36

3.4.2. Microbial data............................................................................................................ 37

3.4.3. Engineering data ....................................................................................................... 37

3.4.4. Teacher and Classroom Surveys............................................................................. 37

3.4.5. Attendance Data........................................................................................................ 37

3.5. Project Outcomes............................................................................................................ 37

3.6. Conclusions and Recommendations ........................................................................... 40

3.6.1. Conclusions................................................................................................................ 40

3.6.2. Commercialization Potential................................................................................... 41

3.6.3. Recommendations..................................................................................................... 42

3.6.4. Benefits to California ................................................................................................ 47

4.0 Program Market Connection (Project 4)........................................................................... 49

4.1. Introduction ....................................................................................................................49

4.2. Project Objectives ........................................................................................................... 49

4.3. Project Approach............................................................................................................ 49

4.3.1. Project Administration ............................................................................................. 50

4.3.2. Program-Wide Market Connection System .......................................................... 50

4.3.3. Program Technology Transfer Plan........................................................................ 50

4.3.4. Indoor Air Quality Codes Assessments................................................................. 50

4.4. Project Outcomes............................................................................................................ 50

4.5. Conclusions and Recommendations ........................................................................... 55

4.5.1. Conclusions................................................................................................................ 55

4.5.2. Commercialization Potential................................................................................... 57

4.5.3. Recommendations..................................................................................................... 57

4.5.4. Benefits to California ................................................................................................ 58

5.0 References............................................................................................................................. 59

6.0 Glossary ................................................................................................................................ 61

7.0 Appendices........................................................................................................................... 65

List of Figures

.....................................................................................11 Figure 1. 3-D layout of CFD classroom model

............................................................................20 Figure 2. CFD modeling – base case – vertical slice

...........................................................20 Figure 3. CFD modeling – DV case 9 ft ceiling – vertical slice

Figure 4. The CO2 concentration in the occupied zone of the DV classroom is consistently lower

than the concentration at the return, a sign of good ventilation effectiveness........................ 24

Figure 5. Relative humidity, September 15, 2005. While the RH in the DV classroom is slightly

higher than the RH in control classroom, it remains within acceptable limits. ......................24

......................................................................................32 Figure 6. Example UVC disinfection systems

Figure 7. Example of a rooftop air conditioning unit in UVC study (top), schematic of a typical

unit (middle), and example of a wall-mounted air conditioning unit in UVC study (bottom)

............................................................................................................................................................35

List of Tables

..............................................................................13 Table 1. DV interviews: participant stratifications

.........................................................23 Table 2. HVAC electricity comparison, Kinoshita Elementary

................................................................................................................33 Table 3. UVC systems studied

..................................56 Table 4. Information/actions needed to overcome selected market barriers

..............................................................................................................65 Table 5. Summary attachments

vii

viii

Abstract

The three projects described in this report were designed to evaluate advanced equipment for

cooling, heating, and ventilating California’s K–12 schools that improve indoor air quality, save

energy, reduce peak demand, and reduce pollution. The program investigated the ability of

thermal displacement ventilation technology to increase economizer use, improve ventilation

effectiveness, reduce fan energy use, enhance pollutant removal, and reduce noise. The study

also examined the potential of ultraviolet light in the “C” spectrum to improve coil cleanliness,

enhance equipment service life, remove microorganisms, and reduce odor. In addition, the

program conducted market connection activities to improve the market focus of the

technologies and thereby increase the public benefits.

The results this program indicated that displacement ventilation can enable 10 to 40 percent

energy savings in California K–12 schools, depending on climate. The primary data for the

ultraviolet project showed substantial surface disinfection, but no statistically significant

reduction in heating, ventilation, and air conditioning coil energy use or absentee rates. Market

connection efforts were successfully conducted by developing access to existing information

dissemination channels through e-mail efforts, telephone conversations, articles and

publications, and presentations and meetings with influential market participants and

organizations.

Keywords: Displacement ventilation, DV, heating, ventilation, and air conditioning, ultraviolet

light, UVC, K–12 schools, energy savings, indoor environmental quality, IEQ

Executive Summary

Introduction

Schools use more than 3 percent of California’s electricity each year, and

27 percent of that electricity powers heating, cooling, and ventilation. The

way that schools are ventilated and the quantity of the ventilation used

directly affects the quality of the school environment, which has

implications for student health and overall learning performance. This

program addresses three of the four indoor environmental quality (IEQ)

target areas identified by the California Energy Commission (Energy Commission).

Purpose

The goal of the Advanced HVAC Systems For Improving Indoor Environmental Quality and Energy

Performance Of California K–12 Schools Program (IEQ–K12) was to develop and demonstrate

advanced heating, ventilation, and air conditioning (HVAC) equipment for school classrooms.

Such equipment would improve indoor environmental quality, save energy, reduce peak

demand, and, ultimately, reduce pollution for the citizens of California.

Meeting this goal yields the following benefits:

The next generation of California K–12 classrooms will be more comfortable, energy

efficient, and healthier because of the improvements mandated by Proposition 47 (State

of California 2002) and local bond funding.

•

Teachers will have more control over the IEQ and thermal comfort of their classrooms.

Students and teachers will be sick less often and more comfortable, and thus perform

better.

School districts will spend less money on energy and so are able to spend proportionally

more on books, computers and other equipment, and teachers’ salaries.

The IEQ–K12 Projects

The IEQ–K12 program, headed by Donald Frey and Vernon Smith of Architectural Energy

Corporation (AEC), included the following projects:

Thermal Displacement Ventilation (DV) in Schools (Project 2), led by Charles Eley and

John Arent of AEC

Effectiveness of UVC [ultraviolet light in the “C” band, 200-280 nanometers] Technology

for Improving School Performance (Project 3), led by Roger Wright and Stacia Okura of

RLW Analytics, Inc.

Program Market Connection (Project 4), led by Morton Blatt of Morton H. Blatt, Energy

Utilization Consultancy

Each of these three projects had different objectives, approaches and results. These elements are

summarized by project below.

Thermal Displacement Ventilation in Schools (Project 2)

Poor environments in schools adversely affect the health, performance, and attendance of

students. Many existing school air conditioning systems using conventional mixed ventilation

systems fail to provide the indoor air quality, appropriate acoustic environment, and comfort

level that produces optimal student and teacher performance. DV is a cost-effective means of

providing an optimal environment by delivering a cool air supply directly to the occupants of

the space. The air is enters the room at about 65°F (18.3°C)—approximately 10 degrees warmer

than with a conventional air conditioning system. The fresh air, supplied near the floor at a very

low velocity, falls towards the floor and spreads across the room until it encounters heat

sources. Then this air slowly rises as it picks up heat from occupants and equipment. The

warmed air also picks up contaminants as it rises towards the ceiling, where it is exhausted

from the space. This vertical airflow pattern near each occupant, often referred to as a thermal

plume, decreases the likelihood that germs will spread between occupants. This air distribution

system provides for effective ventilation, since the fresh supply air is delivered directly to each

occupant. All this can be provided at an initial cost comparable to that of many less effective

conventional mixed-ventilation systems that rely on creating fully mixed air in the room.

The overall goal of this project was to gain wide acceptance of DV in both newly constructed

and renovated K–12 schools.

DV Project Outcomes

Key information products developed for this project are listed in the Attachments section of this

report and may be found at

www.archenergy.com/ieq-k12/thermal_displacement/thermal_displace.htm.

Specifically, the following outcomes were achieved:

Coordination with related Public Interest Energy Research (PIER) natural ventilation

and DV research yielded new information and showed that computational fluid

dynamics (CFD) simulation and testing can validate existing or mandate new DV design

guidelines for best thermal comfort and air quality. The CFD analyses of different DV

classroom configurations showed specific conclusions:

•

o Nine foot (ft) ceilings are sufficient if not optimal.

o Two diffusers providing 65°F supply air are sufficient.

o Double-pane windows substantially diminished the need for perimeter heat.

o Lights contribute less heat than equipment or occupants.

o Comfort levels vary with proximity to diffusers.

o DV lowers CO2 levels and “age” of air in a space.

The Barriers Study identified cost and the lack of demonstration classrooms as key

hurdles to acceptance. Even though most respondents identified the energy and indoor

air quality (IAQ) benefits, most erroneously thought DV had a higher initial cost than

conventional systems.

Three DV system design options for California K–12 classrooms were evaluated for cost-

effectiveness and performance. Single-classroom rooftop units won as the most probable

near-term solution for widespread implementation.

•

Two demonstration DV systems were installed, commissioned, and monitored in two

classrooms. Results of the DV demonstration showed that DV can provide up to 20

percent energy savings and improve IAQ and acoustic comfort while providing

acceptable humidity levels.

Technical documents and marketing collateral were developed presenting the results of

this project and technology transfer activities were conducted. Papers and articles on DV

design have been presented or published in professional venues throughout the DV

development period from 2002 to present.

Conclusions and Recommendations

Project 2 resulted in the following conclusions:

DV provides good thermal comfort for classrooms with normal ceiling heights (9 ft).

A supply of 1100 cubic feet per minute (cfm) of 65°F air is sufficient for most classrooms

in California climates.

The use of a tuned variable air volume (VAV) control strategy will optimize energy

savings.

DV can be achieved today using a variety of HVAC system designs.

DV provides many compelling benefits, including energy savings.

Recommendations from Project 2 include the following:

Adopt load calculation procedures for Title 24 Standards.

Offset cost premiums with incentives for high performance designs.

Increase education and numbers of demonstrations for wider acceptance and

implementation of DV in California schools.

Make DV technology available as off-the-shelf equipment.

Improve design options for heating with displacement diffusers to further increase

efficiency.

Initiate additional design research into potential DV use in other space types such as

libraries, gymnasiums, and auditoriums.

Continue IAQ research, such as in particle motion studies.

Effectiveness of UVC Technology for Improving School

Performance (Project 3)

This project attempted to quantify the impact of ultraviolet

irradiation in the “C” band (UVC) of evaporator coils for

disinfection and IEQ of California K–12 schools. UV is a line-

of-sight technology; when produced by a lamp it can only

provide effective disinfection on components with exposure

to direct or reflected ultraviolet radiation.

The goal of the study was to determine if UVC is effective in reducing mold and mildew in

HVAC systems, improving IEQ, and saving energy.

This study was originally funded as a purely analytical study that would quantify the benefits

of the UVC disinfection systems using existing data. A recommendation endorsed by the Project

Advisory Committee (PAC) and the Energy Commission changed the direction of the project

from an analytical model to a field study.

Outcomes

Key information products developed for this project are listed in the Attachments section of this

report and may be found at

www.archenergy.com/ieq-k12/uvc_technology/uvc_technology.htm.

Specifically, the following outcomes were noted:

Microbial analysis showed the reduction of growth on the evaporator coils, as expected.

Total fungal and bacterial colonies were reduced by 65–100 percent with the use of UVC.

•

Airflow and efficiency analyses showed a positive trend. More tests are needed to

ascertain statistical significance.

Attendance data analysis was inconclusive. More attendance data collection is needed

along with a larger sample size of UVC field tests.

Teacher and classroom surveys indicated positive feedback on some issues of health and

attendance. More research, larger sample populations, and longer test periods are

needed to draw more scientifically valid conclusions.

Some of the HVAC housings created challenges for proper installation. The success of

the technology is also dependent on the quality of the installation, which can also

depend upon the available unit configuration.

Additional adverse environmental factors were determined, including standing water,

dirty rooftops, toxic substances in the classroom, and dirty floors.

Conclusions and Recommendations

The research team could not conclusively determine if there were statistically valid

improvements in some areas. These include air flow and efficiency of the air

conditioning units with UVC disinfection systems.

UVC technology effectively reduced surface microbial levels on cooling coils. This

finding is not in question.

The potential impact of this technology on IEQ in California schools is in question. It will

be proportional to the pervasiveness of microbial growth on cooling coils and the

relationship between surface microbial growth and IEQ.

The success of the technology is dependent upon the quality of the installation. Review

and inspection of installation will help assure quality.

The primary recommendation is to increase sample sizes and allow for repetition of

sampling within the study. The limitations can be overcome with additional funding to

allow a research team to develop a comprehensive study methodology.

Both laboratory and field work are required to adequately answer research questions. A

discussion of questions and opportunities is provided in the main body of this report.

•

Labeling and testing procedures must be standardized. Currently, each manufacturer

uses only its own discretion on printed information in marketing material.

Existing measures and processes could predictably contribute to improved HVAC

system performance and IEQ. The main factors that can contribute to improved IEQ are

good ventilation and filtration, which also depend upon proper inspection and

maintenance.

Market Connection (Project 4)

The Market Connection Project was concerned with disseminating the results of the two

previously defined technology projects, DV and UVC, each designed to improve energy use

and indoor air quality in K–12 schools in California. The goal of this project was to improve the

market focus of the entire program’s activities, thereby increasing the ultimate viability and

public benefit of the resulting technology products. The information products are designed to

overcome market barriers, influence market participants, and produce desired market effects.

Outcomes

Key information products developed for the Market Connection project are listed in the

Attachments section of this report and may be found at

www.archenergy.com/ieq-k12/market_connection/market_connection_reports.htm.

Specifically, the project achieved the following outcomes:

Input was gained from influential market participants and the PAC. This helps ensure

that the needs of these influential market participants are met through their involvement

and that their feedback is utilized.

•

A Technology Transfer Plan was prepared and expert guidance provided. Market

barriers at all levels of implementation from finance to infrastructure can thus be more

easily overcome.

Key organizations have been identified. Useful organizations were identified and

tabulated according to their missions, publications, and meetings.

Fact sheets addressing issues of both DV and UVC were developed. The fact sheets were

distributed at various presentations and conferences.

Journal articles have been and continue to be published. Information on these articles for

Engineering Systems is provided in the Project 4 section of this report.

Presentations, forums, and training sessions were conducted. Among these are venues at

American Society of Heating, Ventilating, and Air Conditioning Engineers (ASHRAE)

meetings 2004–2006; the annual CASH conference; and the American Council for an

Energy Efficient Economy (ACEEE).

Guidelines for the Collaborative for High Performance Schools (CHPS) Best Practices

Manual were developed and training material was created. Training material for both

DV and UVC technologies was utilized.

Educational Specifications (EdSpecs) were produced. Model EdSpecs for siting and

construction were prepared; reference information is provided under Project 4 and in

the Attachments section of this report.

•

Application guidelines were developed. Separate guidelines for DV and UVC were

provided to meet school and equipment provider needs.

Key meetings were conducted and numerous communication activities occurred. These

included information exchanges with Carrier and Commissions Codes and Standards

personnel.

Code Action Plans and White Papers were developed and outreach efforts begun. The

focus was on identifying and assessing issues, influences, and needs that affect

implementation of DV and UVC technology in the schools.

Conclusions and Recommendations

Key market barriers for the DV and UVC technologies must be addressed.

Continued action is needed to address codes and standard issues that impede the

specification and installation of DV and UVC.

Results are encouraging but inconclusive. Additional testing is recommended.

Extending market connection activities for future PIER programs beyond the study

period for these technical projects should be considered.

Statewide energy impacts should be revisited after data from field tests is analyzed.

Benefits to California

Project 1: Administration

Project 1 comprised all and only administrative tasks, is not detailed in this final report, and has

no associated energy impacts.

Project 2: Thermal DV in Schools

The results of this project indicate that DV technology may reduce classroom cooling energy use

from 10 to 40 percent depending upon the climate. Non-energy benefits include improved

ventilation effectiveness and acoustics, which are both compelling findings.

Project 3: Effectiveness of UVC Technology for Improving School Performance

Statewide energy impacts from this technology could not be calculated due to small sample size

and inconclusive results. The UVC impact on system airflow, though not statistically significant

for this study, produced a positive trend, 1 to 2 percent improvement. The study also concluded

that the UVC technology is effective in reducing microbial growth on air conditioning cooling

coils, a non-energy benefit.

Project 4: Program Market Connection

Statewide energy impacts are not directly applicable to the market connection activities under

the PIER Indoor Air Quality (IEQ) program.

1.0 Introduction

1.1. Background and Overview

The goal of the Advanced HVAC Systems for Improving Indoor Environmental Quality and Energy

Performance of California K–12 Schools Program (IEQ-K12) was to evaluate advanced equipment

for heating ventilating, and cooling school classrooms, with an emphasis on the latter two. This

equipment improves indoor environmental quality, saves energy, reduces peak demand, and,

ultimately, reduces pollution for the citizens of California. Schools use more than 3% of

California’s electricity each year, and 27% of that electricity powers heating, cooling, and

ventilation. The way in which schools are ventilated and the quality of the ventilation directly

affects the quality of the school environment, which has implications for student health and

overall learning performance. This program addresses three of the four IEQ target areas

identified by the Commission:

The next generation of California K–12 classrooms, resulting from Proposition 47 (State

of California 2002) and local bond funding, are more comfortable and energy efficient, as

well as healthier.

•

Teachers have better control over the IEQ and thermal comfort of their classrooms.

Students and teachers are sick less often, are more comfortable, and perform better.

School districts spend less on energy and so are able to spend proportionately more of

their budgets on books, computers, and salaries.

Under the projects in this program, the project team worked with major manufacturers to

investigate innovative systems that potentially have energy and IEQ advantages over

conventional systems, to demonstrate the energy performance and cost advantages of these

systems, and to develop and distribute design tools and related information to decision makers

and school design professionals.

The IEQ-K12 program consisted of two technical projects and a market connection project.

(Information about Project 1, Program Administration, led by Donald Frey and Vernon Smith of

AEC, is not included in this report.) The three projects are as follows:

Thermal DV in Schools (Project 2), led by Charles Eley and John Arent of AEC

Effectiveness of UVC [ultraviolet light in the “C” band] Technology for Improving

School Performance (Project 3), led by Roger Wright and Stacia Okura of RLW Analytics,

Inc.

Program Market Connection (Project 4), led by Morton Blatt of Morton H. Blatt Energy

Utilization Consulting

1.2. The Project Team

The IEQ-K12 program was overseen by Program Manager Vernon Smith and Principal-in-

Charge Donald Frey, both of AEC. Vernon Smith provided administrative, financial, and

technical guidance to the project team.

Thermal Displacement Ventilation (DV) in Schools (Project 2) was led by Charles Eley and John

Arent of AEC. John Arent provided the technical expertise and was responsible for the field

demonstrations at the two school districts.

Effectiveness of UVC Technology for Improving School Performance (Project 3) was led by

Roger Wright and Stacia Okura of RLW Analytics, Inc. Stacia Okura provided the technical

expertise and was responsible for the field demonstrations at the school districts.

Program Market Connection (Project 4) was led by Morton Blatt of Morton H. Blatt Energy

Utilization Consulting. Morton Blatt provided his expertise regarding market and code issues

related to the two technologies.

The PAC representatives, named in the Acknowledgements section of this report, offered

invaluable input and helped guide the project team on numerous issues.

School district personnel provided access and feedback for the field demonstrations at Coyote

Ridge Elementary School in Roseville, northern California, and Kinoshita Elementary School in

San Juan Capistrano, southern California.

Representatives from heating, ventilation, and air conditioning (HVAC) and UVC

manufacturers supplied information about the technologies along with equipment and support.

California Energy Commission staff reviewed and provided input into the research at critical

points throughout the IEQ Program.

1.3. Report Organization

Under each project in this study, researchers investigated, or advanced the understanding of an

area of concern related to, the IEQ of K–12 classrooms. Project 1 focused on the administrative

tasks of orchestrating monthly reports, deliverables, and invoices and is not discussed in this

report. Accordingly, this report is organized into three distinct sections, one for each of the

remaining projects 2, 3, and. These sections discuss the objectives, outcomes, conclusions, and

recommendations for each project.

2.0 Thermal Displacement Ventilation in Schools (Project 2)

2.1. Introduction

Poor environments in schools influence the health, performance, and attendance of students.

Many existing school space conditioning systems that use conventional mixed ventilation

systems fail to provide the indoor air quality, acoustic acceptability, and comfort that can

produce optimal student and teacher performance. DV is a cost-effective means of providing an

optimal indoor environment by delivering cool supply air directly to the occupants in a space.

The air is enters the room at about 65°F (18.3°C), about 10 degrees warmer than with a

conventional air conditioning system. The fresh air, supplied near the floor at a very low

velocity, falls towards the floor, and spreads across the room until it comes into contact with

heat sources. The supply air slowly rises as it picks up heat from occupants and equipment. The

warmed air picks up particulates as it rises towards the ceiling, where it is exhausted from the

space. This vertical airflow pattern near each occupant is often referred to as a thermal plume;

this thermal plume makes it less likely that germs will spread between occupants. This air

distribution system provides for effective ventilation, since the fresh supply air is delivered

directly to each occupant. All this can be provided at an initial cost comparable to that of less

effective conventional mixed-ventilation systems that rely upon creating fully mixed air in the

room to achieve their ends.

The overall goal of this DV project was to gain wide acceptance of DV in both newly-

constructed and renovated K–12 schools. Specifically, the project team worked toward four

goals:

Create a DV HVAC system that uses less energy; that is, only 50% of the fan energy and

33% of the cooling energy of conventional HVAC systems.

•

Achieve a target 20% market penetration in the new construction and

retrofit/renovation market for schools.

Reduce the peak demand for electrical energy in California by 224 megawatts (MW) at

the 20% level of market penetration.

Reduce annual energy consumption in California by 380 gigawatt-hours (GWh) at the

20% level of market penetration.

2.2. Project Objectives

The objectives for Project 2 follow:

Coordinate with other natural ventilation and under-floor air distribution Public Interest

Energy Research (PIER) research projects to inform the DV project regarding relevant

recent research results

Develop definitive guidelines based on computational fluid dynamics (CFD) analyses of

eight classroom configurations for the quantity and conditions of air that must be

delivered in order to maintain thermal comfort in a variety of classroom configurations

Validate the CFD results with a full-scale mockup of one classroom designed so that it

could be reconfigured to allow study of various thermal conditions

Contact approximately 40 individuals involved in the design, construction, and

operation of California schools in order to gain an understanding of concerns about

implementing DV in new schools and in major modernizations

•

Develop at least two detailed engineering solutions for applying DV in K–12 California

classrooms including specific equipment specifications, system schematics, control

sequences, and other information

Construct two demonstration DV classrooms, one in northern California and one in

southern California

Monitor the performance of the demonstration classrooms for a period of at least 6

months

Work with manufacturers to develop new products that meet DV-related marketplace

needs

Develop a series of fact sheets for school decision makers and an engineering guide for

design professionals and work with the Collaborative for High Performance Schools

(CHPS) representatives to integrate these materials into the CHPS Best Practices Manual

for 2006

Develop a one-day training curriculum on DV for design professionals and present the

training program to technical audiences in a variety of California locations

Prepare and submit for publication at least two articles on the application of DV in

California schools in professional trade journals or technical conference proceedings

2.3. Project Approach

Key tasks and approaches by the project team are summarized below.

2.3.1. Coordination with ongoing related PIER natural ventilation and DV research

(Task 2.1)

The objective of this task was to review, coordinate, and leverage the content of work under this

project with two other Commission-sponsored research projects.

The two projects and the objectives of the review were to:

Review research, conducted at University of California (UC) San Diego and at Lawrence

Berkeley National Laboratory (LBNL), on natural ventilation modeling and algorithms

developed for EnergyPlus (PIER Contract Number 400-99-012, Element 4, Task 2.8)

Review current under-floor air distribution research by UC Berkeley, UC San Diego,

LBNL, and York International (PIER Contract Number 500-01-035)

Other work under this task included a literature search on other DV research.

2.3.2. CFD analysis of thermal comfort and ventilation effectiveness (Task 2.2)

The project team first built a CFD model of a typical California classroom, designed to comply

with the current or proposed California energy efficiency standards and validated this model

through full-scale testing (see Figure 1). The team then studied variations from the baseline case

to understand how the design parameters (such as air flow) would change with variables in

ceiling height, internal heat gains, and building envelope loads.

For the baseline case classroom, a series of CFD simulations were performed to determine the

supply rate of 65°F (18.3°C) air needed to maintain acceptable thermal conditions. A supply air

temperature (SAT) of 65°F was selected based on prior applications of DV in other locations.

Warmer air provides inadequate cooling, and colder air carries a greater risk of causing cold

feet for those sitting near the diffusers.

Through parametric CFD simulations, air volume was gradually increased in order to achieve

satisfactory thermal conditions; that is, until the average temperature at the top of the occupied

zone (60 inches [in]above the floor) was no greater than 75°F (74+1°F) (23.8°C) and the

temperature difference from the top to the bottom of the occupied zone was no greater than

5.4°F (12° C)—the recommendations of American Society of Heating, Ventilating, and Air

Conditioning Engineers (ASHRAE) Standard 55.

For the other simulation cases, the volume of air was scaled up or down from the baseline case

with thermal loads. The same diffuser area was used in all cases.

The project team determined the volume of air, the delivery velocity, the number and

configuration of delivery points, and the temperature and humidity needed to maintain thermal

comfort and IEQ for a variety of K–12 classrooms. The researchers examined the thermal needs

of typical California classrooms and related these to air temperature and volume requirements

for DV systems. This study resulted in recommended supply-air temperature and air volume

levels for the various classrooms analyzed by the team. Three-dimensional visualization

techniques were used to illustrate temperature, air quality, and movement. Under the direction

of the Architectural Energy Corporation (AEC), Halton Company performed the CFD

simulation studies for this project.

Figure 1. 3-D layout of CFD classroom model

2.3.3. CFD validation with full-scale mockup (Task 2.3)

The objective of this task was to validate the results of the CFD analysis using a full-scale

mockup of a classroom at a key industry partner’s laboratory. A CFD model was developed as a

classroom representative of current California classrooms meeting Title 24 standards. The CFD

simulation of the classroom provided detailed information on the temperature distribution and

air velocities in the room. A comparison of predicted air temperatures and air velocities with

CFD simulation predictions served to validate the CFD model. Once the model is validated,

parametric CFD runs can be performed to determine supply-air requirements for different

cooling load conditions.

A full-scale mockup of one-half of a typical classroom (32 ft x 16 ft x 10 ft height) was

constructed at the Halton test facility. The heat load in the classroom consisted of overhead

fluorescent lighting, 2 computers, 10 60-watt (W) light bulbs inside of steel cylinders to

represent students, and 3 heat tapes used to simulate solar radiation, conduction, and lighting

loads.

Air temperature and air velocity measurements were made at six different heights for each of

eight locations in the test room. The space temperatures and air velocities measured at various

locations in the room were collected using eight thermal anemometers (air velocity detectors).

These devices have a velocity accuracy of 3.94 feet per minute (fpm) (0.02 meters per second

[m/s]) ± 1% of reading within 1–200 fpm (0.05–1 m/s), a temperature accuracy that is ± 0.4° F

(0.2°C). Supply-air flow was measured using a laminar flow element (LFE) with an accuracy of

± 0.7% of the reading. Two cases were validated and both demonstrated good agreement

between the CFD simulations and the measurements. This allows researchers to conclude that

the CFD software package (Airpak 2.1.10 from Fluent Inc.) can be used as a reliable tool to

simulate thermal DV systems for a classroom environment.

2.3.4. Barriers study (Task 2.4)

The objective of this task was to perform a market research study to identify both the perceived

and encountered barriers that restrict the implementation of DV systems in the design of new

and retrofitted K–12 classrooms. Perceived and real barriers were identified through an in-

depth study that included structured interviews among leading designers, engineers,

manufacturers, decision makers, and users.

In-depth interviews—30- to 45-minute detailed telephone interviews—were held with 35

professionals in the field (see Table 1). The focus was on general knowledge, attitudes (past,

present, and future), experience, and perceived or actual problems with thermal DV in

classrooms. A mix of closed and open-ended questions was used. On occasion, some

participants were asked subsequent questions via e-mail and telephone for clarification. All

interviews were recorded for further reference.

All participants in this study had previous experience working with schools and school

districts. Those participating in the in-depth interviews derived more than 60% (and usually

more than 70%) of their business from service to schools. The participants’ experience also

reflected a variety of school and school project sizes that ranged from 15 to more than 75

classrooms.

The interview script was designed to uncover and determine participants’ level of knowledge of

and attitudes about of DV as compared to HVAC systems currently in use in California schools.

To gain the most useful insights, respondents were stratified across the following

responsibilities and experience levels. Market researchers working for SDV/ACCI contributed

significantly to this market barriers study.

Table 1. DV interviews: participant stratifications

With TDV Without TDV

Segment Experience Experience

6 3

A. HVAC Mechanical Engineers

3 3

B. School Architects / Designers

C. School District Facilities

D. Maintenance and Operations

personnel

1 3

E. Construction/Contractors

2 2

F. Manufacturers

G. Division of the State Architect

Plan Examiners

H. Users (Teachers)

Total 12 23

2.3.5. System design options (Task 2.5)

To fulfill this task, the project team evaluated and developed practical and cost-effective

engineering solutions for supplying neutral DV air to K–12 classrooms. Conventional HVAC

designs and equipment used for typical schools are not well configured for DV, which requires

higher air delivery temperatures and different load assumptions than conventional HVAC

solutions with overhead air delivery. This task involved developing load calculations for a

representative classroom building in each of two California climates in order to determine

required system cooling capacity.

The approach for this task was first to gather leading design engineers and architects for K–12

schools at a design charette to develop conceptual design options and discuss practical design

considerations. Results from the charrette were applied to detailed design solutions developed

for the project. AEC worked with CTG Energetics to develop three design solutions, using

available HVAC technology and the standard design of a typical modern classroom building in

a California coastal climate. Researchers then evaluated the options considering energy savings,

comfort, and simplicity.

An eight-classroom building was chosen as a prototype building, meeting Title 24 prescriptive

requirements, to determine typical loads. EnergyPro was used to determine design cooling

loads, assuming year-round operation in an 8:00 am–5:00 pm operating schedule. For the

southern California coastal climate of Capistrano in climate zone 6, the classroom has a design

cooling load of 28,400 British thermal units per hour (Btu/h), comprising a 22,800 Btu/h

sensible load and a 5600 Btu/h latent load. Adding the combined sensible and latent ventilation

load from 600 cubic feet per minute (cfm) of outside air, at design conditions of 85°F (29.4°C)

dry bulb and 67°F (19.4°C) wet bulb, the total system cooling load is 40,300 Btu/h (3.3 tons). A

similar load analysis for a Sacramento building, meeting current Title 24 prescriptive envelope

requirements, shows a design room cooling load of 28,600 Btu/h and a system cooling load of

40,900 Btu/h (3.4 tons). Thus, while the sensible cooling load is significantly higher for the

Sacramento classroom, the total (sensible plus latent) system cooling load is only marginally

higher.

DV systems require different load calculation procedures than conventional systems. A

procedure must account for the portion of heat gains that affect the occupied portion of the

space in order to determine required airflow. The return air temperature can then be

determined in order to calculate the required system capacity. The required DV system capacity

depends greatly on the supply air temperature (SAT) when leaving the cooling coil. Systems

that can provide 65°F (18.3°C) supply air without reheat will have a much lower cooling

requirement, since the latent load is reduced or eliminated. For the representative Capistrano

classroom building, a 3-ton nominal cooling capacity per classroom was chosen, as this is the

smallest available size that provides the required sensible cooling capacity.

The final step of this task was to address detailed design considerations that are unique to DV.

The unique design considerations addressed were diffuser selection and layout, load calculation

procedures and energy modeling, and HVAC control sequences. Several existing load

calculation procedures, documented in prior research, were reviewed for applicability to DV

applications in classrooms. Energy modeling procedures using both DOE-2 and EnergyPlus

were evaluated through simulation studies of typical California classrooms built to Title 24

standards. Control strategies were developed by first working with HVAC manufacturing

partners and refined by practical results of the two demonstration projects. The detailed design

results were packaged in the Displacement Ventilation Design Guide developed under of this

project (referenced in the Attachments section of this report).

2.3.6. Construct demonstration classroom (Task 2.6)

This task was designed to demonstrate the viability of DV in two classrooms, one in northern

California and one in southern California. Researchers developed a list of selection criteria.

School district representatives were contacted to gather data and qualitative information and to

identify candidate classrooms. Finally, a list of specific sites was recommended and presented

to district representatives. The sites selected had to meet the following key criteria:

The classroom should have a minimum ceiling height of 9 ft to allow for adequate

stratification. (A ceiling height of 12 ft is desirable, if possible).

•

The building envelope should meet the Title 24 standards.

Internal heat gains should be minimized to control the cooling load of the classroom.

If HVAC equipment is mounted on the roof, space will be required to drop the ducts so

air can be delivered near the floor.

The classroom should have the ability to conveniently locate the diffusers near the floor

and to provide for exhaust near the ceiling.

•

For existing classrooms, the classroom must be easily retrofitted and not have excessive

envelope loads.

The interior floor surface should be chosen to promote indoor air quality. (One criticism

of distribution systems that deliver supply-air at floor level, such as DV, is that

pollutants residing at floor levels may be brought up to the students’ breathing space

from rising air plumes.)

Schools meeting the CHPS selection criteria and that meet the conditions above will have many

of the desirable characteristics for DV.

Two schools were selected, and DV systems installed and commissioned. Instrumentation was

installed inside the classrooms and connected to a data collection system, and the data was

transferred to a computer sitting outside the classroom. Researchers installed the monitoring

equipment at each site, performed short-term monitoring of IAQ, and verified equipment

operation and upload data.

For the first demonstration, AEC worked with the Trane Company to design an HVAC system

specifically to meet DV requirements. The most important design requirement was tight control

of the supply-air temperature. The design selected used a heat pump with a refrigerant-water

heat exchanger that could provide chilled water for cooling and heated water for heating. The

system also included a custom outdoor air handler, with an economizer and variable-speed

drive for VAV control. The system was integrated with the school’s existing Alerton controls

network for diagnostics and analysis.

The first construction project came in well over budget, leaving very little budget for the second

demonstration. The factors contributing to the high costs were system complexity, the

requirement for a new electrical panel, and a significant cost for custom Alerton controls for

programming and graphics. For this reason, AEC held a Critical Project Review meeting with

the California Energy Commission to revise plans for the second demonstration. The

Commission desired a packaged equipment solution for DV that was not yet available from

manufacturers. This accelerated the product development tasks of the project: to design and

develop a new packaged rooftop product for DV that could be used in the Capistrano

demonstration. AEC obtained match funding from San Diego Gas & Electric’s Emerging

Technologies Program to help fund the installation and monitoring costs for the second

demonstration.

2.3.7. Monitor performance of demonstration classrooms (Task 2.7)

For this task, the project team collected detailed data for approximately nine months on the

temperature and IEQ conditions of the demonstration classrooms at the two school campuses.

For each DV classroom, a similar classroom using a conventional overhead air mixing system

for climate control was also instrumented and monitored as the control for the test.

There were two key components: monitoring of the equipment operation via the system

controller, and monitoring thermal comfort and indoor air quality inside the classroom. The

primary objectives were to:

Determine if the DV system provides thermal comfort and IEQ as well as or better than

an overhead ventilation system

•

• Confirm what supply-air volume is required to cool the space

Prior research indicates that fewer cfm are required to cool the space with DV systems, even

though the air is supplied at a higher temperature. One objective of the study was to determine

whether or not this claim is true. The Halton CFD analysis predicted a slightly higher supply-air

flow than a conventional mixing system would provide.

Measurements were taken of temperature, relative humidity, and carbon dioxide. Data on

supply- and return-air temperature and supply-air flow (determined from fan speed) were

collected via the system controller and building energy management system and reviewed

periodically. Temperature measurements, taken at four different heights for each of three

locations in each classroom, were used to evaluate thermal comfort. Temperature levels at

different heights were compared to verify that stratification levels comply with ASHRAE 55-

2004 requirements.

In addition, the team assessed the IAQ and energy use of the DV system. To evaluate IAQ,

carbon dioxide sensors were installed in the occupied zone, at the exhaust sites of each

classroom, and outside. The CO2 sensors had an accuracy of ± 30 parts per million (ppm) + 2%

of the reading. These measurements were used to evaluate ventilation effectiveness. ASHRAE

62.1-2004 states that DV systems have higher ventilation effectiveness, indicating a higher

outside air ventilation rate in the breathing zone than with mixing systems. This is the principal

documented IAQ benefit of DV systems. Since natural ventilation sources will also affect IAQ,

door status was monitored with magnetic contact switches. Data on HVAC electricity use was

recorded to compare the heating and cooling energy used by the DV classroom to that of the

conventional classroom. HVAC electricity use was monitored with WattNode pulse counters

and Magnelab 5A current transducers.

Data was collected at one-minute intervals and routinely uploaded for review. The data was

reviewed to detect any sensor malfunctions or collection issues. Teachers, students, and

maintenance personnel were contacted to verify that the system was operating correctly and

that thermal comfort was being maintained.

Match funding from San Diego Gas & Electric enabled the research team to proceed with the

monitoring activities and data analyses for the southern California Capistrano Kinoshita

Elementary School site. Although the primary expected energy benefit of DV was electricity

savings, HVAC heating energy was also monitored at Kinoshita with gas meters.

2.3.8. Product development (Task 2.8)

The objective of this task was to develop new products for DV systems in classrooms. Although

chillers with hydronic coils may be configured for DV applications, packaged direct-expansion

(DX) equipment is generally not capable of producing neutral air from 100% outside air (OA)

conditions.

New product requirements have been identified as a result of the market barriers study, the DV

design charette, work on system design options, and preliminary results of the first

demonstration classroom. New technologies for capacity modulation may be applied to new

products for DV. These products are described in more detail in the Commercialization

Potential section of the report for this project.

The outline specifications for the packaged DX unit for displacement ventilation were provided

to multiple manufacturers. The second demonstration at Kinoshita was delayed in order to

allow time for the development of a custom unit meeting these requirements.

2.3.9. Fact sheets and guidelines (Task 2.9)

Under this task, the project team developed promotional materials that highlight the benefits of

DV in classroom applications for school district personnel and an engineering guide for design

professionals and contractors. The fact sheets and guidelines developed in this task summarize

the findings of the previous tasks. The information is packaged for effective distribution to

industry and distributed to groups that make school-related decisions. The collateral was

developed jointly under this task and under the Program Market Connection (Project 4)

activities. Several of the documents are referenced in the Attachment section of this report.

2.3.10. Information dissemination (Task 2.10)

The objective of this task was to introduce the informational products to the target audiences of

school districts, school architects, engineers, construction managers, and contractors. In

California, a large share of school HVAC system design is carried out by a handful of

mechanical engineering firms. The project team worked with various organizations to unveil

the tools that emerged from this project and to help designers become more comfortable with

the DV concept.

Each school district has a set of Educational Specifications (EdSpecs) that describe, often in

detail, typical design and system concepts to be considered for each school facility. The EdSpecs

often restrict the type of HVAC system that is permitted and specify requirements for controls,

design temperatures, and other aspects. The project team developed model EdSpec language

focusing on DV for HVAC systems.

Another major focus of this task was to develop training material to be delivered at the state

energy centers. Training sessions were delivered at the Sacramento Municipal Utility District

(SMUD) facility and at the Southern California Edison (SCE) Customer Technologies

Application Center (CTAC). The seminars included an overview of the technology, a discussion

of architectural design issues and air delivery options, guidelines for diffuser specifications,

load calculation and energy modeling procedures, and performance monitoring results.

Due in part to scheduling difficulties, some of the planned seminars were not provided. In lieu

of additional seminars, AEC provided several outreach activities to school designers. These

included a design charette for the Los Angeles Unified School District (LAUSD) in May 2005, an

ASHRAE presentation at the 2005 Winter Meeting, a CASH presentation in February 2006, and

several publications.

Again, the work under this task was completed in parallel with the Program Market Connection

(Project 4) activities. More detailed information about information dissemination may be found

in the Program Market Connection section of this report.

2.3.11. Technology transfer activities (Task 2.11)

Under this task, the project team helped researchers under Project 4 develop a plan for key

decision makers that presents the experimental results, knowledge gained, and lessons learned

during the DV study. The plan provided a time-phased tabulation and description of

documents to be published and distributed to disseminate the results and increase the market

penetration of the DV technology being studied. The plan addressed market barriers that often

impede the adoption of new technologies and analyzed the roles of influential market

participants in the funding, specification, installation, and operation of the technology. Potential

advantages and disadvantages were tabulated. Information dissemination channels were

outlined for each set of market participants, including publications, periodicals, web sites, and

upcoming meetings.

The general approach to the development of the technology transfer deliverables for the

different dissemination channels was to provide varying levels of technical materials. One level

included materials of general interest such as fact sheets that have been distributed to a broad

set of market participants. Another category of deliverables were those produced specifically

for a group of market participants, such as detailed design guidelines for engineers and

architects. Other materials included technical papers, journal articles, and tailored

presentations.

Again, the work under this task was completed in parallel with the Program Market Connection

(Project 4) activities. More detailed information about the technology transfer activities may be

found in the Program Market Connection section of this report.

2.3.12. Production readiness plan (Task 2.12)

For this task, the researchers provided the project results to the manufacturing partner and

other interested organizations such as CHPS to further develop the design specifications and

equipment tested under this project. The research team will continue to promote the results of

this project and provide market and technical information on request.

2.4. Project Outcomes

A summary of the project outcomes follows. Key information products developed for this

project are listed in the Attachments section of this report and may be found at

www.archenergy.com/ieq-k12/thermal_displacement/thermal_displace.htm.

Coordination with related PIER natural ventilation and DV research yielded information

of interest.

•

Researchers reviewed a thermal plume model based on UC San Diego research designed

to help professionals understand the fundamental driving forces of displacement flow.

This analytical plume model predicts the airflow of a single thermal plume for a given

supply velocity and heat gain. The model is applicable when thermal plumes generated

by internal heat gains are the driving force of the flow. For well-insulated classrooms,

internal heat gains from occupants make a large contribution to the cooling load.

Experiment results from the DV mockup tests can be compared with predictions from

this model.

EnergyPlus offers a more accurate estimate of DV than other energy simulation

programs such as DOE-2. The CFD simulation data and mockup test data from the PIER

DV project can be used to validate the EnergyPlus model. The CFD and mockup tests

provide a more accurate estimate of the temperature profile for design cooling

conditions. The CFD and mockup tests are used primarily to estimate an appropriate

size for the system. The value of EnergyPlus is in estimating annual energy costs of the

DV system. EnergyPlus can estimate the annual savings in cooling costs of a DV system

over a conventional system. Modeling rules for DV can be incorporated into the Title 24

performance compliance procedure so that users receive proper credit for use of DV

systems.

Researchers also reviewed PIER research on under floor air distribution (UFAD) systems

to determine its applicability to DV. It was determined that due to differences between

the test setup and load patterns for the UFAD and DV systems, the UFAD test data

cannot be applied to DV in classrooms.

Existing design guidelines published by ASHRAE and the European Federation of

Heating and Air-Conditioning Associations offer procedures for designing DV systems

for thermal comfort and air quality. The CFD simulation results and mockup test results

can validate the applicability of these guidelines to California classrooms or serve as the

basis for new design guidelines.

CFD simulation results and field test data obtained in later phases of this project showed

that while a pattern of thermal stratification is maintained, it is lower than that predicted

by the ASHRAE model. The results of this research suggest that the model introduced in

the Energy Design Resources Simulation Guidebook provides a fair estimate of the

performance of DV systems in classrooms.

The CFD analyses of different classroom configurations provided the following

outcomes:

•

In all cases, sufficient cooling and thermal comfort can be provided through two

displacement diffusers, providing 65°F (18.3°C) supply air. A supply-air flow rate of

1000 cfm to 1500 cfm of 65°F air is sufficient for most classroom cooling conditions.

A 9-ft ceiling is sufficient for thermal DV. Benefits of stratification are seen with higher

(12-ft) ceilings; as a result, less air is required to maintain the same room set-point for the

same design cooling loads.

For all cases, marginal comfort is maintained at locations close to the diffusers. The

temperatures at floor level are cool (67–68°F or 19.4–20°C) and the temperature

stratification slightly exceeds ASHRAE 55 recommendations. Adding additional

diffusers would improve comfort at locations near the corners of the room. Seated

students should be situated at a distance of at least 4 ft from the corner diffusers to stay

comfortable.

As expected, lighting loads contribute less heat to the occupied zone than occupant or

equipment loads.

DV shows improvements in ventilation effectiveness, as evidenced by lower CO2 levels

and a lower mean age of air in the occupied zone.

For classrooms with double-pane windows, perimeter heat is not required for coastal

and valley California climates. Perimeter heat is required in mountain climates where

the winter design dry-bulb is 10°F (-12°C) or less. Perimeter heat losses through the slab

cause the most comfort issues during heating conditions.

Figure 2. CFD modeling – base case – vertical slice

Figure 3. CFD modeling – DV ase 9 ft ceiling – vertical slice

Figures 2 and 3 show vertical temperature profiles at different locations in the space. At

• onstration

an do

• tem design options for California K–12 classrooms were evaluated for cost

entral boiler with individual

ackaged rooftop unit serving multiple classrooms, with

rt-

e, thermal comfort, practicality, and first

a height of 4 in above the floor, there is a temperature gradient between the interior of

the space (near the diffusers) and exterior of the space. However, at head level of seated

students (40 in) the temperature is uniform throughout the space.

The market barriers study identified initial cost and the lack of dem

classrooms as key hurdles to acceptance.

The study showed that many respondents thought DV to have a higher first cost th

conventional systems. Most participants readily identified the energy and IAQ benefits.

Other groups not experienced with DV were less convinced of the benefits. Also, all

outside air systems may not make sense in some climates; respondents in southern

California in particular were concerned about using all outside air. Many thought tha

incentive programs could offset the perceived higher first cost and greater risk if using

DV systems.

Three DV-sys

effectiveness and performance.

Three general schematic design solutions were evaluated for DV in classroom

applications, using available HVAC technology and the standard design of a typical

modern classroom building in a California coastal climate.

The first option is to use a packaged air-cooled chiller and c

fan coil units for each classroom. With typical classroom buildings, the air handlers

would likely have to be mounted on the roof. This option provides the greatest degree of

supply-air temperature control with high system efficiency and good thermal comfort at

part-load conditions. However, this option has the highest actual first cost for

equipment and installation.

The second option is a VAV p

VAV terminal units for each classroom. This option provides fan energy savings at pa

load conditions and requires relatively low maintenance. A single 25-ton unit allows for

multiple stages of cooling, providing good energy efficiency at part-load conditions.

However, this option requires more sophisticated controls and, while less expensive

than an air-cooled chiller, is more expensive than single-zone packaged units.

The third option is a separate 3-ton packaged gas-electric rooftop unit for each

classroom. This option has a substantially lower first cost than either a single packag

VAV rooftop or a central chiller. A unit with two-stage cooling, multiple speed fan, and

two-stage gas heat is the best currently available unit in terms of energy efficiency and

supply-air temperature control at part-load conditions. This system would require some

control modifications to ensure that the discharge air temperature meets DV system

requirements. However, this option is likely to have higher operating costs and

maintenance costs than the other two options.

Based upon a comparison of energy performanc

cost, researchers felt that option 3, individual-package rooftop units serving each

classroom, is the most practical application for near-term implementation in California

classrooms.

•

ne in northern and one in southern California:

strict

site

designed for the retrofit of a

d allows for a reduction in cooling output to

, calibration of controls,

ent

•

Two demonstration DV systems were installed, commissioned, and monitored in two

classrooms; o

For northern California, Coyote Ridge Elementary in the Dry Creek Joint School Distric

of Roseville, Sacramento County, was selected. This school has a high open ceiling in the

center of the classrooms with a skylight and a 9 ft ceiling around the perimeter of the

classroom. Eight new classrooms were completed in June 2004. The Coyote Ridge

classrooms are served by individually packaged HVAC rooftop units.

For southern California, Kinoshita Elementary in the Capistrano Unified School Di

of San Juan Capistrano, Orange County was selected. The school is on a

approximately 2 miles inland in southern Orange County, with a temperate climate. The

school has 6’x 6’ skylights in the center of each classroom. The perimeter of the

classroom has a suspended ceiling at a height of 9 ft. The large 14 ft x 14 ft skylight well

provides additional space for temperature stratification. The Kinoshita classrooms are

served by individually packaged HVAC rooftop units.

The research team collaborated with the manufacturer on the two installations. The firs

system at Coyote Ridge Elementary was a custom system

single existing classroom. The air handler unit was modified to adapt to the existing roof

curb for the packaged unit. The system was specifically designed for tight control of the

supply-air temperature. The system was installed for a single classroom, and was tested

and commissioned prior to monitoring.

The DV system for the second installation at Kinoshita Elementary features Copeland

Digital ScrollTM compressor technology an

as low as 10% of full capacity. This virtually eliminates the on-off cycling that commonly

occurs with small packaged systems. The unit also incorporates a variable-speed drive

for the supply fan in order to provide fan energy savings at part-load conditions. This

unit was developed as a prototype for a future product.

Commissioning activities were provided by the project team and started during the

construction phase. Activities included equipment startup

testing, adjusting and balancing, and functional testing. The commissioning activities for

the demonstration classrooms focused on ensuring the proper function of the equipm

after installation and on proper operation during the school year.

Results of the DV demonstration classrooms showed that significant energy savings are

possible.

HVAC electricity use was monitored at the control classroom and the DV classroom at

Kinoshita during the fall 2005 and spring 2006 semesters. Initially, energy monitoring

results did not show a reduction in HVAC electricity use in the DV classroom. However,

an investigation of the data showed that the DV classroom was being maintained at a

cooler average temperature. Moreover, the HVAC system’s economizer settings were

not optimally set for DV. After configuration changes were made to the DV unit, the

energy monitoring results showed energy savings of 20% over the length of the

monitored time periods (see Table 2).

Table 2. HVAC electricity comparison, Kinoshita Elementary

Period Control Unit kilowatt-hours DV Unit kWh

(kWh)

School Days (not Total Daily Average Total Daily Average

including

weekends/holidays)

8/22/05–9/30/05 392.0 kWh 19.6 kWh/day 448.0 kWh 22.4 kWh/day

10/31/05–12/14/05 330.8 kWh 10.7 kWh/day 197.9 kWh 6.4 kWh/day

2/23/06–4/18/06 128.4 kWh 2.9 kWh/day* 239.0 kWh 5.4 kWh/day

4/19/06–5/23/06 611.3 kWh 17.0 kWh/day 266.9 kWh 7.41 kWh/day

Entire Monitoring

Period

1462.5 kWh 1151.8 kWh

* During this period the supply fan was often set to” auto” during school hours. Supply fans are typically

required to be “on” during occupied hours.

It also is important to note that a direct comparison of the monitoring results of the two

Kinoshita Elementary classrooms was made difficult because the teacher in the control

classroom often set the fan to “auto” rather than the “on” position. This setting caused

the fan to operate only intermittently between February and April 2006, resulting in

lower electricity use in the control classroom but at the expense of the IAQ. Typically,

supply fans are required to be set to “on” during occupied hours. .

The DV demonstration also shows that teachers are less likely to turn off HVAC fans

due to noise, which positively affects both comfort and air quality. This is an important

finding.

The DV design allows the cooling capacity to vary continuously to meet the space load.

As a result, the supply-air temperature is controlled closely to the set point. This allows

for good space temperature control with the DV system.

The primary IAQ benefit of the DV system is improved ventilation effectiveness. In the

DV classroom, the CO2 concentration is consistently lower in the occupied zone than in

the return (see Figure 4). As a result, the outside air is delivered more effectively to the

occupants. This result was consistently shown in monitored data from both northern

and southern sites. It should be noted that this benefit prevails only when cool-to-

neutral air is supplied to the classroom.

With the use of a higher supply-air temperature, some engineers have been concerned

that DV may not provide sufficient dehumidification in some cases. The results from this

demonstration indicate that the relative humidity is maintained to acceptable levels in

the DV classroom (see Figure 5). While the conventional unit provides additional

dehumidification, DV classrooms showed improved IAQ and acoustics with acceptable

humidity levels.

Another noticeable benefit of DV is an improvement in acoustic comfort. Spot

surements of back a typ 44 decibels for

the DV classroom (with the fan at maximum speed) and 48–50 decibels for the control

a result ers are less ff fan.

mea ground noise levels showed ical rage of 40–

classroom. As , teach likely to turn o the DV

300

900

400

500

6: 14:00 16:00 18:00

ppm

600

700

800

00 8:00 10:00 12:00

CTRL-CO2-OCC CTRL-CO2-RET DV-CO2-OCC DV-CO2-RET AMBIENT-CO2

CTRL-RET

mbient

CTRL-OCC

DV-RET

DV-OCC

4. The COFigure n

2 concentration in the occupied zone of the DV classroom is consistently lower tha

the concentration at the return, a sign of good ventilation effectiveness.

6:00 8:00 10:00 12:00 14:00 16:00 18:00

DV-RH-OCC % DV-RH-RET % CTRL-RH-OCC %

D op line

D middle line

Figure

V-RH RET% t

V-RH OCC%

TRL-RH-OCC% bottom line

5. Relative humidity, September 15, 2005. While the RH in the DV classroom is slightly higher

than the RH in control classroom, it remains within acceptable limits.

Teacher feedback has been positive in the DV classroom. The teachers in both the DV

and the conventional classrooms were given surveys on the acoustics, indoor air quality,

• eloped that present

the results of this project.

Fact sheets, guidelines, case studies, presentations, and technical articles were

developed. The information has been distributed as part of the CHPS program to the

CASH, the Energy Design Resources Program, ASHRAE, and other groups that make

school-related decisions. The project team developed model EdSpec language, which

focuses on DV for HVAC systems. A detailed DV Design Guide has been developed that

provides practical design information to engineers and architects.

The collateral was developed jointly under this task and under the Program Market

Connection (Project 4) activities. Several of the documents are referenced in the

Attachment section of this report.

Technology transfer activities were conducted, including the following:

• Presentations given at the DV School design charette, ASHRAE meeting, CASH

conference and CASH representatives, American Council for an Energy Efficient

Economy (ACEEE) 2004 and 2006 Summer Study

• Article published in Engineered Systems magazine (April 2006)

Again, the work under this task was completed in parallel with the Program Market

Connection (Project 4) activities. More detailed information about information

dissemination may be found in the Program Market Connection section of this report.

The research team will continue to promote the results of this project and provide

market and technical information upon request.

2.5. Conclusions and Recommendations

2.5.1. Conclusions

• The demonstration classrooms confirmed that DV provides good thermal comfort for

classrooms with normal ceiling heights (9 ft).

The DV system did not create problems with cold drafts at floor level. The system

provides a consistent thermal stratification in the space and good ventilation

effectiveness. The effects of occupant activity and the opening of doors and windows

did limit the amount of (desirable) stratification achieved in practice.

• The DV system provides a remarkable improvement in acoustics.

•A supply of 1100 cfm of 65 F air is sufficient for most classrooms in California climates.

conditions can be met by a DV system without increases in system cooling capacity or

and thermal comfort they experienced in their classrooms. The teachers in the

displacement ventilation classrooms gave the DV system higher marks for both

acoustics and thermal comfort compared with the conventional classrooms.

Various technical documents and marketing collateral have been dev

• Training sessions held at SMUD and CTAC

Both the CFD simulation results and monitored data show that design cooling

airflow. While simulation studies indicate that up to 20% more supply air is needed w

DV, a system supply-air flow rate of 1100 cfm is less than what is typically supplied to

California classrooms in actual practice.

The use of a tuned VAV control strategy will optimize energy savings.

ith

•

The expected energy savings potential for this demonstration were not realized during

nce. With VAV systems, in which air volume is the primary

o space

•

re compatible with

current DV system design requirements. The principal design requirement is a steady

vide

le classroom. Further development of additional

d opportunities

•

excellent thermal comfort for

compelling reason to use

ncludes variable-

savings.

2.5.2.

New pr

design char

demon d to

new products for DV. These products are described below.

ge air temperature control and capacity

use in California K–12 classrooms. This

-volume units.

cooling modes.

land

the initial phase of the project. Control setting modifications and tuning dramatically

improved system performa

means of space temperature control, compressor operation is not directly tied t

temperature (and cooling requirements). Under such a VAV control strategy, tuning a

verification are critical to ensuring system performance.

DV can be achieved today using a variety of HVAC system designs.

Large, off-the-shelf HVAC units that have multiple cooling stages a

supply of 65°F air. The customized HVAC unit used at Kinoshita Elementary proved

be effective in meeting the design requirements, and is unique in its ability to pro

single-zone, VAV control for a sing

innovative HVAC design options for DV will most likely afford increase

for energy savings.

DV provides many compelling benefits.

DV has shown to provide effective ventilation and

California classrooms. Acoustic benefits alone are a sufficiently

when the HVAC system i

DV. Energy savings are significant, especially

speed drive and VAV control for fan energy

Commercialization potential

oduct requirements have been identified as a result of the market barriers study, the DV

ette work on system design options, and preliminary results of the first

stration classroom study. New technologies for capacity modulation may be applie

• Packaged DX unit with improved dischar

modulation

The results of the design charette made clear the need for a new packaged DX rooftop

unit, by far the most common HVAC system in

new product would be designed to provide the relatively constant 65°F supply air

required for thermal DV, over a range of outdoor temperatures and part-load

conditions. Existing packaged products of capacities of 5 tons or lower do not have the

capacity to provide 65°F supply air under varying outdoor conditions and load

conditions. Additionally, packaged rooftop units are typically constant

The product should have capacity modulation in both heating and

Variable capacity compressors have great potential to provide a much tighter supply-air

temperature control and energy savings during part-load conditions. The Cope

Digital Scroll™ compressor has a capacity modulation down to 10%, and has been used

in air-conditioning systems in Korea. One possible product solution is to incorporate a

variable-capacity scroll compressor in a gas-electric rooftop or a heat pump

configuration. The prototype unit installed for the Kinoshita demonstration verified the

ent ventilation

midity control,

•

the casework. Displacement

f the typical 6 in,

• r heating

ibution

10–15°F (-12 to -9°C) or less.

Therefore, the diffusion performance of displacement diffusers in heating mode is an

imp

ixed

displacement diffusers for heating

can cause short-circuiting of the supply air if the warmer supply air moves toward the

ote

the diffuser is used for heating, thereby improving diffuser performance.

2.5.3.

•

ards and

tent

potential for this product. The technology is a good match for displacem

and offers benefits of improved space temperature control, improved hu

and high efficiency.

Diffuser integrated with teaching wall

Another idea that arose from the design charette is a diffuser that could be integrated

into the casework. The diffusers could be integrated into the side of the teaching wall, or

a long, linear slot diffuser could be positioned underneath

diffuser manufacturers do not currently offer a diffuser that would work under a

casement. Perhaps the cabinet base becomes 8 in or 10 in tall instead o

providing space for low velocity air distribution. At the design charette, participants

commented on the desire for more architectural options for diffusers. As DV technolog

gains acceptance, more options should become available. A long, low diffuser has the

advantage of delivering air directly to low heights, and it takes up less wall space that

would otherwise be used by the teacher. Potentially, the casework and diffusers coul

be installed by the same contractor, with a mechanical contractor simply making the

duct connections.

Variable aperture displacement diffuser fo

Low-velocity diffusers are well suited for cooling with DV. However, the air distr

is less effective in heating mode. Previous studies caution the use of low-velocity

diffusers for heating. For California classrooms, perimeter heating is only required in

mountain climates where the winter design dry-bulb is

ortant design consideration.

In heating, the goal of the air delivery system is to achieve a thermally well-m

airspace. The idea with this product is to vary the opening area of the diffuser in heating

mode to increase the air velocity. Using low-velocity

return grille before it diffuses throughout the space. A higher air velocity will prom

mixing when

Recommendations

Adopt load calculation procedure for Title 24 Standards.

To provide an accurate estimate of energy use of DV systems, the Title 24 Stand

Alternate Calculation Method (ACM) must be revised to include a procedure for

modeling DV systems. A procedure has been recommended for modeling the

stratification and predicting the supply-air flow requirements for DV systems. While

this procedure would require an independent review, the model outputs are consis

with CFD simulation results and field data from this study. Additional monitored data

from other DV installations would most likely strengthen the case for inclusion of the

model.

•

s carry a

cedures that can provide an accurate estimate of energy savings

•

n the

tes.

• DV technology must become available as off-the-shelf equipment.

nce HVAC system options for

t. A

lutions for displacement ventilation.

•

this concern by developing products that increase

e availability of these

•

ace types. While CFD is a good design tool, it will increase project soft costs and

Incentives for high performance designs will help offset cost premiums.

While DV has the potential to be competitive with traditional systems, it doe

slight cost premium because the HVAC designs for displacement ventilation require

more sophisticated control strategies. Programs such as Southern California Gas and

Electric’s Savings By Design could offer incentives. However, load calculation and

energy modeling pro

must be adopted.

More demonstrations and education are needed.

Gaining acceptance for DV in California schools will require more examples of

successful applications and a significant education campaign. The research from this

project suggests that familiarity with DV is low among all professionals involved i

classroom design process. While many of the architects and engineers without DV

experience were familiar with the theory of DV and its benefits, most had little workin

knowledge of it and questioned the specifics of how the system might be implemented.

The education of engineers represents the crucial front line of acceptance. Architects,

contractors, construction managers, maintenance personnel, and facilities managers als

are looking for more than just information on material costs and specifications. They are

looking for experiences and success stories of DV used in similar situations and clima

A significant desire and need exists for low-maintena

California K–12 classrooms. Although other HVAC system designs can be readily

designed to meet DV requirements, school districts strongly prefer to use package

rooftop units for each classroom. The DV prototype unit developed for the Kinoshita

demonstration is unique in its ability to meet requirements for DV in a packaged uni

sustained educational outreach to market participants is recommended to further the

development of packaged unit so

Improved design options are needed for heating with displacement diffusers.

It is well known that low-velocity displacement diffusers are not designed for heating.

Although adequate comfort in the heating season was maintained in the two

demonstration classrooms, the air distribution pattern was not ideal. The supply of very

warm air at a very low velocity through displacement diffusers will cause some of the

warm supply air to rise to the ceiling before it reaches the occupants. European

manufacturers have addressed

discharge air velocity to improve heating performance. Th

products in the United States market would make DV a more compelling solution in

applications with greater heating needs.

Additional design guidance is needed for other space types.

This PIER project showed that DV design is relatively straightforward for simple spac

types such as classrooms. DV has also been successfully used in libraries and

gymnasiums. However, the design of DV for spaces with higher ceilings is not as simple

Many design professionals recommend the use of CFD analysis when using DV for

these sp

could be a deterrent to the widespread application of DV. Additional research is needed

•

ave questioned whether or not the air patterns from DV would cause

o the breathing zone. Particle count

al field

2.5.4.

The res

10–40%

effectiv

to determine thermal stratification patterns and optimal diffuser layouts for school

gymnasiums, libraries, and auditoriums without the use of time-consuming simulatio

studies.

Additional IAQ research is needed.

This project focused on the air quality benefit of improved ventilation effectiveness.

Some researchers h

particles to be drawn upwards from carpet and int

studies were not feasible within the monitoring budget of this project. Addition

studies would clarify whether respirable particle counts are higher or lower in the

breathing zone.

Benefits to California

ults of this project indicate that DV technology may reduce classroom cooling energy use

depending on the climate. Non-energy-cost benefits include improved ventilation

eness and improved acoustic quality, which are both compelling findings.

3.0 Effectiveness of UVC Technology for Improving School Performance (Project 3)

3.1. Introduction

This project quantified the impact of ultraviolet irradiation in the “C” band on evaporator coil

disinfection and IEQ of California K–12 schools. The goal of the study was to determine if UVC

is effective in reducing mold and mildew in HVAC systems, improving IEQ, and saving energy.

UV is a line-of-sight technology; when produced by a lamp it can only provide effective

disinfection on components with direct or reflected exposure to ultraviolet irradiation. For this

study, the project team, RLW Analytics, focused on surface disinfection systems that

manufacturers claim kill mold and bacteria growing on cooling coil, drain pan, and other

surfaces in the supply-air stream. The UVC lamps in these systems are mounted in the HVAC

system supply duct, usually right above the evaporator coil. Because microbial colonies act as

insulating agents, removing the microbial buildup should result in increased air flow and

energy efficiency of the HVAC unit. In addition, the removal of these microbes can improve the

IEQ by eliminating the cause of potential contamination of the air passing by the dirty coils and

drain pan.

In the past 12 years, some manufacturers have begun to produce UVC systems designed

specifically for HVAC systems. Manufacturers have re-engineered their main line of UVC

products to work in HVAC systems because the non-HVAC-specific lamps suffered drastic

output losses, specifically a loss in “killing power” when exposed to cold or moving air.

According to some manufacturers, not all of the products on the market have these adjustments.

Since the application of UVC disinfection technology in HVAC systems is relatively new, there

are currently no codes or performance standards for the industry, making product comparisons

difficult. The International Ultraviolet Association is currently working to establish

performance standards. ASHRAE is forming a standards committee to address this issue as

well. Output levels at specific temperatures and safety features for each disinfection system

should be tested by an independent laboratory and clearly stated in the marketing material to

allow for comparisons between products. Equally important is the total application of UVC

lamps within the geometry of the system. The number of lamps and the spacing between rows

of lamps is critical to the actual distribution of UVC energy over a given surface.

The UVC disinfection system consists of an assembly whose primary components serve similar

functions to those of a standard fluorescent fixture. This includes the UVC lamp, lamp socket,

ballast, associated wiring, and enclosure. Mercury vapor is the gas used in the lamps, which

produces UVC irradiation. Inert gases are used to illuminate the lamps. UVC bulbs are made of

quartz or soda barium glass, which transmits UVC, rather than common “soft” glass, used in

fluorescent lamps, which largely absorbs UVC. The mounting arrangements vary depending on

the configuration and physical constraints of the equipment upon which it is installed, and have

been designed with flexibility in mind in order to be adaptable to a variety of field conditions.

The enclosures, ballasts, and related components can be installed internally in or externally on

the equipment that it serves. Some examples of typical UVC disinfection systems are pictured in

Figure 6.

Figure 6. Example UVC disinfection systems

Within the HVAC industry, UVC technology is applied to packaged, unitary, and built-up (site

constructed) air-conditioning equipment, on both direct-expansion and chilled-water cooling

systems. The irradiation process can be applied to the cooling coil, condensate pan, AC unit

internal surfaces, and air distribution systems.

fection

sult

air

il.

• Quantify any changes in average daily attendance (ADA) as a result of the decrease in

K–12 schools and to obtain utility billing and attendance data from these schools in

order to determine if there were any significant decreases in kWh usage and increases in ADA

when comparing the pre- and post-UVC periods. As a result of some initial research into the

As mentioned previously, this study investigated the use of UVC to provide surface disin

of the cooling coil and condensate drain pan. The reduction in buildup on the coils could re

in an increased system capacity by increasing air flow across the coils and improving coil-to-

heat transfer, resulting in energy savings due to the resulting increase in efficiency. A recent

study showed that the reduced air flows that result from coil fouling cause typical efficiency

and capacity degradations of less than 5%. However, the losses can be much greater for

marginal systems or in extreme conditions. (Seigel) The disinfection systems also may reduce

fungal-related odors and alleviate air quality concerns in the indoor environment, and also

reduce the need for costly chemical or pressure washing treatments of the cooling co

3.2. Project Objectives

The primary purposes of the study were as follows:

• Understand whether or not UVC surface disinfection systems reduce the energy

consumption of AC units and, if so, to quantify the reduction

the microbial levels after the UVC disinfection systems are installed

• Understand whether or not UVC surface disinfection systems reduce the microbial

growth on air-conditioning (AC) cooling coil surfaces and, if so, to quantify the amount,

which might be used to explain improvements in IEQ and, potentially, ADA

3.3. Project Approach

This study was originally funded as a purely analytical study that would quantify the benefits

of the UVC disinfection systems using existing data. Through the course of the project, several

factors changed the direction of the project from an analytical model to a field study. The team

originally planned to work with a single manufacturer to identify the existing UVC systems in

California

number of installed systems in California K–12 schools, it was determined that there were not

sufficient numbers of systems installed in classrooms where students were in the rooms for the

majority of the school day, providing inadequate data to complete the ADA analysis.

The researchers recommended that a comparative field study be performed in place of the

analytical study in order to provide some research into the field effectiveness of the UVC

disinfection systems. With concurrence from the PAC members and the Energy Commission,

the research team reassessed the study budget and goals and transformed the project into a field

study. While the field study was designed to provide exploratory research into measuring UVC

efficiency and ADA changes, th not sufficient to provide the large sample sizes,

comprehensive testing, and customized instrumentation needed to provide more robust and

definitive results.

s were included in this study. Both

lled

nditioning units just one or two lamps provide effective

icrobial growth

The UV

Rooftop conventional permanent

school t

after th

market led on an exterior

wall of loy

conven

coil pro this study

. The UVC systems that were chosen for this study can be

e budget was

At the outset of this project, the research team spoke with 12 manufacturers of UVC disinfection

systems for HVAC systems to discuss current UVC products and technologies, market barrier

product availability, customer demand, markets served, and available research.

Two manufacturers of UVC disinfection system

manufacturers produce surface- and air-treatment disinfection systems. The two manufacturers

donated equipment, technical support, and installation services to the study. The research team

is appreciative of their generosity and support. This study was designed to be a technology,

rather than a product, assessment. Therefore, no manufacturer names are disclosed. The

disinfection systems are analyzed separately in this report and will be referred to as system,

treatment, or group ‘A’ and ‘B’ in subsequent sections.

The disinfection systems were installed downstream of and adjacent to the cooling coil and

provided irradiation to both surfaces, except for a few units in which the systems were insta

upstream due to downstream internal space limitations. This approach is widely employed by

installers because on small air co

coverage of the surfaces that are most likely to have m

C technology was applied to both packaged rooftop and wall-mounted AC units.

units are the most common type of air conditioning units for

buildings. The wall-mounted style is often referred to as a “Bard” (heat pump style) uni

e manufacturer that originally developed the configuration and currently dominates the

for California portable classroom HVAC units. These units are instal

portable classrooms. Both types of cooling systems, rooftop and wall-mounted, emp

tional direct expansion/refrigerant vapor compression systems with a direct expansion

viding the cooling in the air stream. All UVC disinfection systems provided in

were standard production units

generally characterized as shown in Table 3. Figure 7 shows example installations.

Table 3. UVC systems studied

Units Treatment A Treatment B

One Lamp Units 30 Watts 36 Watts

Two Lamp Units 30 and 20 Watts 21 Watts

The two lamp fixtures were typically used in units with space constraints. The smaller wattage

lamps were typically used for drain pan irradiation.

Economizer

Fan Box

and

Motor

Supply

Outside

Air

Return

PAN

Figure 7. Example of a rooftop air conditioning unit in UVC study (top), schematic of a typical unit

(middle), and example of a wall-mounted air conditioning unit in UVC study (bottom)

The most common installation approach was to mount the UVC ballast and wiring externally

on the casing of the cooling equipment with only the lamp or tube penetrating into the system

while the power supply remains external. All disinfection systems used in this study were rated

for outside installations and, with one exception, were mounted on either the side or the top of

the AC units. The UVC disinfection systems can be wired either so that they are in operation

continuously or only when the AC is on. The UVC disinfection systems in this study were

powered on continuously, so they were in operation regardless of a call for cooling.

The team investigated the study goals by performing a side-by-side comparison of two

treatment groups receiving UVC disinfection systems to a control group receiving no UVC

treatment. Measurements were taken before and after turning on the UVC disinfection systems

in order to compare changes in AC efficiency, microbial contamination, and ADA between the

treatment and control groups. The study period commenced in August 2005 and lasted

approximately six weeks.

A total of 54 AC units at nine schools within thr

included in the study. Of the 54 AC units, 36 received UVC treatments. A total of 18 AC units

were included in each of the three study groups, one control group, and treatment groups A

and B. Identical AC units serving similar grade-level classrooms comprised each of the three

study groups. Both packaged rooftop and wall-mount-type units were included in the study.

The study goal was to determine the impact of DV technology on typical AC systems in

California schools; therefore, the study did not specifically target fouled coils. However, the

team did exclude units that were less than four years old to ensure that newer coils were not in

the study.

The three districts that were included in the study were located in cooling climates and had

year-round school schedules. Districts with year-round schedules were targeted in order to

ensure that the units in the study were running throughout the summer with the exception of

two-to three-week breaks between sessions. The level of coil fouling was approximately that

expected during a normal cooling season. Elementary grade levels were selected to ensure that

students were in the same classrooms all day for full school days to enable adequate pre- and

post-ADA analysis.

3.4. Primary Data Collection

The research team performed a variety of primary data collection tasks consisting of survey,

microbial, and engineering information. There were five primary sources for data gathered and

analyzed for this study, which are categorized and described as follows:

3.4.1. Manufacturer Interviews and Literature Review

The research team began the study by contacting the major manufacturers across the country in

order to better understand current UVC disinfection products and technologies, market

barriers, product availability, customer demand, markets served, and existing research. This

background research was used to inform the selection of the surface disinfection technology to

be included

ee school districts across California were

in the study, and to provide background information about the technology.

3.4.2. Microbial data

sed

he state of various other malfunction indicators. Incorrect

y. The

tion of

the units. The units underwent the same set of measurements as were taken during

s were also surveyed during the pre-installation site visits. They provided

ut the thermostat controls, the ventilation in the rooms,

ny fteen of the teachers participated in a follow-up survey to

uring the

r this

project are listed in the Attachments section of this report and may be found at

www.archenergy.com/ieq-k12/uvc_technology/uvc_technology.htm

The research team collected microbial samples from the surface of cooling coils prior to and

after the installation of the UVC disinfection systems. A single swab sample was taken from the

cooling coil fin edge and fin face from each AC unit over one square inch using an absorption

spear. The on-site team followed the sample handling techniques as directed by the

microbiology lab that performed the testing. These surface samples were analyzed for

culturable fungi and bacteria. The laboratory provided the research team with estimates of the

number of colony-forming units (CFUs) per area sampled per coil. These lab results were u

to analyze the reduction in CFUs on treated units relative to the control group units. This

analysis was performed in order to determine improvements in IEQ and, potentially, AD

3.4.3. Engineering data

The research team collected data to support the evaluation of in-situ air conditioner efficiency.

The team first qualified each unit to ensure that the units were in proper working order

measuring operating pressures and temperatures and determining diagnosis-level refrigerant

charge, air flow, coil condition, and t

condenser fan speed, or incorrect evaporator fan speed, and were excluded from the stud

selected units were then subjected to extensive measurements to evaluate system efficiency.

Careful measurements were taken using high-quality calibrated instruments during steady-

state operation of the system in order to evaluate the field-operating efficiency and capacity o

the systems. These measurements quantified pressure drop across the evaporator coil, cooling

capacity, and efficiency readings. On/off event motor loggers were installed for the dura

the study period in order to quantify run-time of the units in cooling mode (fan plus

compressor). At the end of the study, field staff returned to retest the operating efficiency and

capacity of

the first visit. The resulting data were used to quantify UVC-related impacts on energy

efficiency.

3.4.4. Teacher and Classroom Surveys

To supplement the analysis of the changes in biological contamination on the cooling coil, oth

field observations were collected that are typically used in the assessment of indoor air quality.

The observations account for the condition of the area or building in question. The teachers in

the studied classroom

information to the research team abo

and a other IEQ observations. Fi

determine what, if any, changes they noticed as a result of the UVC disinfection systems.

3.4.5. Attendance Data

Average daily attendance data were collected from each school district for each classroom in the

study. Attention was paid to ensure that the same students were in the classrooms d

study period. The study period began approximately three weeks after the beginning of the

school year. Any changes in ADA were analyzed and summarized.

3.5. Project Outcomes

A summary of the UVC project outcomes follows. Key information products developed fo

• Microbial analysis showed the reduction of growth on the evaporator coils, as expected.

of the

obial

t statistically significant for this study,

–2% improvement. This suggests that further laboratory

end

rage daily attendance data were collected from each school district for each

clas aid to ensure that the same students were in the

the air cools quicker; in a matter of seconds it gets cold in

of the teachers

rrelation between the units and attendance. In fact, many

eachers in one

ttendance.” However,

Microbial samples were taken from the surface of the cooling coils for each of the unit

prior to and after the installation of the UVC disinfection systems. The samples were

taken on the leading coil fin edge and fin face using sterile swabs. Each sample was sen

to a microbiology lab for quantitative fungal and bacterial testing. The results

microbial analysis indicate that the two treatments notably reduce levels of micr

growth on the evaporator coils. Total fungal and gram-positive bacteria reductions were

65–100% of colony forming units.

• Air flow and efficiency analyses showed a positive trend.

The UVC impact on system air flow, though no

produced a positive trend, 1

tests or field tests over a longer period may produce more statistically significant results

There were no statistically significant impacts on efficiency and no distinguishable tr

such as the trend identified in the air flow analysis other than a mild positive trend as

noted. In future research, true energy impacts must be studied in terms of a systems air

flow and efficiency degradation over time and the impact of disinfection systems on

preventing this decline. As previously mentioned, one study showed that air flow

restrictions that result from coil fouling can cause typical efficiency and capacity

degradations of less than 5%; however, the degradations can be much greater for

marginally functional systems or extreme conditions. Fouled coils were not targeted for

inclusion in this study and were in fact systematically excluded from this study, and the

on-site team did not observe much fouling of the coils; therefore, it is not surprising tha

air flow and efficiency impacts were inconclusive.

• Attendance data results were inconclusive.

Ave

sroom in the study. Attention was p

classrooms during the study period. The study period began approximately three weeks

after the beginning of the school year. After analyzing data, researcher did not find a

strong correlation between the reduction of microbial growth and student attendance.

More attendance data is needed along with a larger sample size of UVC field tests in

order to draw conclusions that are more scientific.

• Teacher and classroom surveys indicated positive feedback for some issues.

In the survey, 13 of the 15 teachers stated that the room did cool more quickly. One

teacher stated, “It feels like

here.” In addition, 13 respondents (87%) said that the room seemed to be less stuffy.

• Concerning attendance, the responses were not as clear.

When asked, 47%of respondents said attendance had improved; 33% said it had not

improved; and 20% said they did not know if there was a change. None

were able to confirm a co

teachers had new groups of students by the time the post-installation surveys were

administered, which made it difficult to see changes in student health. T

district said they were in the middle of a “district-wide push on a

in comparing the responses from teachers in the UVC group to those in the control

group, researchers found that the teachers in UVC-treated rooms reported an

improvement in attendance (5 out of 7) while those in the control group stated that thei

attendance had not improved (4 out of 6).

Sixty percent of the teachers asked about the prevalence of air quality issues stated th

there were fewer air-quality-related illnesses than before the study period began. One

teacher made the statement “Students who have air quality related illnesses seem to be

less affected by them,” while anoth

er said “There are fewer kids with asthma than in last

ere was no improvement.

and 1

r of

ed,

• ges for proper installation.

it of

this study, the technicians were

adiating the condensate pan;

the opposite side of the pan

•

year’s class.” Twenty-seven percent of teachers said that th

Thirteen percent of the teachers said they could not tell any difference in the amount or

severity of air-quality illness. When asked if illnesses had decreased, there was an even

split of yes and no responses. Seven teachers said yes, seven said no, and one responded

don’t know. The majority of the yes responses came from UVC teachers, while only one

teacher in the control group noted a decrease in illness. The majority of the control

group teachers did not find a decrease in illnesses.

The responses to questions about using the AC less and opening doors and windows

more often than in the two months prior to the study period were split: 7 yes, 7 no,

don’t know. The responses were evenly split among UVC and control groups. Fou

the teachers commented that it was district policy to keep doors and windows clos

possibly to conserve energy. None of the teachers reported any new staining or mold

growth. One teacher stated she had smelled moldy smells in the past but that they were

gone now. She was in the UVC test group, but the information can only be treated as

anecdotal due to the small sample size.

Some of the HVAC housings created challen

The effectiveness of UVC can be limited by the AC unit configurations. In pursu

economy, rooftop and wall-mounted units employ very compact designs. It is common

to find the evaporator fan housing within 2 in of the cooling coil on one side and the

same distance for the air filter on the other side. For example, fan housings may obscu

access to coils. These types of configurations result in less-than-ideal lamp locations. Th

greatest irradiation area per lamp is afforded when the lamps are installed

perpendicular to the coil fins. In some instances for

forced to install the lamps parallel to the coil fins, a less advantageous position for

irradiation. The success of the technology is also dependent on the quality of t

installation. Installers often rely on their own judgment to compensate for challenges

the field. The field staff for this project made some observations of installations

performed in space-constrained systems. For example, an inspection of one installatio

shows that the lamp was installed with the intention of irr

however, it was placed on the upstream side of the coil on

due to space constraints. In another instance, the lamp lens was in contact with the fa

housing, which may contribute to premature lamp failure. Review of installers’

approaches and inspection of their work are useful in assuring quality installation.

Environmental issues were found.

The research team made a number of environmental observations at the schools wh

performing engineering measurements. These observations indicate that there

additional areas where attention could be paid to potential sources of IEQ problems and

energy-saving opportunities in California K

ile

are

–12 schools such as dirty rooftop surfaces,

3.6.

3.6.1.

•

for the six-week study was a small

• he

id provide notable findings.

ial

• on

•

standing water near classroom and outdoor air intake areas, cleaning supplies in

classrooms, and lack of door mats at the entry to each classroom that may contribute to

the level of contaminants transferred to interior floors.

Conclusions and Recommendations

Conclusions

The research team could not conclusively determine if there were any improvements in

air flow or efficiency of the air conditioning units with UVC disinfection systems.

With the small sample size, large error bounds, and study limitations discussed earlier,

the analysis did not determine with statistical significance that the technology

significantly affected airflow or efficiency. The trend

increase in air flow in units with either of the two manufacturers’ disinfection systems

and inconclusive impacts on efficiency. True energy impacts must be studied not only as

an improvement in efficiency or air flow, but in terms of the degradation of a system’s

air flow and efficiency over time and the disinfection system’s impact on slowing the

decline of unit performance. Coils that are fouled may be the best application for this

technology, in order to produce greater energy savings through coil disinfection.

The microbial sampling, which was undertaken primarily to explain the results from t

energy analysis and the ADA analysis, d

The study did find that the UVC technology is effective in reducing surface microb

levels on cooling coils. The research team did not find high concentrations of fungi or

bacteria on the cooling coils in the study. This could be due to the fact that California’s

climate is relatively dry compared to the rest of the country, which equates to a smaller

latent load. Since microbial activity is correlated with the amount of moisture present,

the more humid the climate, the more applicable this technology. Additionally, this

technology is probably more applicable in regions with high annual cooling hours or in

more inland climate zones where the potential for mold growth may be greater.

This study concludes that UVC technology is effective in reducing microbial growth

air conditioning cooling coils.

However, the impact of this technology on IEQ in California schools would be directly

proportional to the pervasiveness of microbial growth on cooling coils and the

relationship between surface microbial growth and IEQ. The presence and magnitude of

microbial activity on the population of existing classroom cooling coils is

uncharacterized at present. The UVC technology may be best suited for application in

AC units in classrooms with pre-existing or substantial microbial growth, or classrooms

with IEQ problems.

The success of the technology is dependent on the quality of the installation.

Installers often rely on their own judgment to compensate for challenges in the field.

Review of installers’ approaches and inspection of their work are useful in assuring

quality installation.

Commercialization Potential

ers purchase the UVC disinfection systems to improve indoor air quality. The

cturers contacted at the beginning of this study agree th

3.6.2.

Custom

manufa at very few buildings in the

country have UVC disinfection systems installed in their HVAC systems. Most thought the

, with more installations occurring in the South

the e these regions are characterized by longer cooling seasons and high

reacted

A fund

people

technol

dissem

to unde

lessene

overcom

Many m

nearly ach

the mo

painful

cause cataracts. Regardless of th

this stu

human

units, p

when s

It is im

familia

In addi

equipm

consen it wiring, air filter materials, and fan drive belts are

subject

require

Until th ser should

careful ,

installa

can pro and references for local contractors familiar with the technology. It

was the r was

invaluable in the proper and safe application of the UVC disinfection systems. For market

commercialization, manufacturers must continue to address these issues and provide customer

support.

percentage of buildings with UVC was below 5%

and on East Coast sinc

humidity. Most installations currently occur in retrofit applications when the end users have

to mold and moisture problems.

amental barrier to the adoption of UVC for AC systems is that potentially interested

are not aware of the benefits of the technology. Many have misconceptions that UVC

ogy will produce ozone or will damage eyesight. More information needs to be

inated that states the benefits of the technology in simple terms that are easy for people

rstand. Consumers need to be shown the cost payback of the technology in terms of

d chemical cleaning costs and possible energy savings. Once the information barrier is

e, the sale is relatively easy.

anufacturers claim that the lamps have low penetrating ability and that UVC light is

completely absorbed by the outer, dead layer of skin. They say that the light can re

st superficial layer of the eye, if exposed, where overexposure can cause reddening and

but temporary irritation, but claim it cannot penetrate to the lens of the eye and cannot

e effects, the UVC disinfection systems that were included in

dy were all safely enclosed within the HVAC systems and were not in direct view of

s. As a further safety option, door safety interlocks can be wired into the circuitry of AC

reventing accidental exposure to UVC light by interrupting power to the UVC lamp

pecific access doors and or panels are opened.

portant for any individual who installs and maintains these systems to be completely

r with any hazards posed, and potential damage that can be caused by, UVC radiation.

tion to human safety, there are other issues that could potentially arise from the

ent components and wiring being directly exposed to UVC radiation. There is no clear

sus on whether such items as un

to deterioration due to UVC exposure. Originally, Underwriters Laboratory (UL)

d that lamp wiring be shielded with metal, but they have since removed that

ment.

ere are federal standards for the industry that address this issue, the end u

ly read and understand the manufacturer’s installation and safety data prior to selection

tion, and maintenance of these disinfection systems. In many instances, manufacturers

vide information on

research team’s experience that the technical support from each manufacture

3.6.3.

The pri g

within t this PIER project, researchers have documented the limitations in

dy, the number of microbial samples taken, the

microbial disinfection effectiveness near to and

that

ist the standards committee in setting regulations as to

oved that requirement. Teflon, used to

aterial.

ing to some manufacturers, not all of the UVC for HVAC products on the market

have been adjusted properly to work inside the units. At such low temperatures, the

ss.

Recommendations

mary recommendation is to increase sample sizes and allow for repetition of samplin

the study. Throughou

terms of the numbers of AC units in the stu

engineering data that were logged, etc. The limitations can be overcome with additional

funding (estimated by researchers to be in the $2 million range). This funding would allow a

research team to develop a comprehensive study methodology that allows for primary data

collection in order to directly answer all possible research questions. Both laboratory and field

work are required to answer these research questions.

Some of the outstanding research questions and study opportunities are as follows:

• What is the irradiation efficacy and

distant from UVC lamps?

An important factor to study is the irradiation efficacy directly under, and at specified

distances from, the UVC lamp. A number of research studies have been written

describe output measurement procedures and some suggest required documentation of

the process (Sagges and Robinson 2005). A common metric measurement such as

microwatts per square centimeter, at specified distances, should be addressed by a

standard. This would also ass

how much distance can be placed between the lamps when installed to provide

sufficiently effective irradiation. To test the overall efficacy factor, microbial samples

would have to be taken at prespecified distances from the lamp, with ideally at least five

samples being taken at each distance on each coil.

• Does the UVC irradiation cause deterioration of non-metal HVAC equipment?

There is no clear consensus on whether or not such items as unit wiring, air filter

materials, packaged unit case insulation, and fan drive belts are subject to deterioration

due to UVC exposure. Originally, Underwriters Laboratory required that system wiri

be shielded with metal, but they have since rem

shield outdoor wiring, is resistant to all bandwidths of UV and so is a possible defense

for wiring exposed to UVC. An independent laboratory needs to perform tests to

determine what type of materials and parts should be shielded and with what m

A standard should be established to address this issue.

• Are the UVC disinfection systems designed to work properly in the cooling

environment?

Accord

lamps may not be performing optimally once installed in the HVAC systems since som

lamps are tested at room temperature. Laboratory testing under HVAC conditions of all

of the products being offered on the market is needed to confirm or disprove this

assertion. Laboratory testing is also needed to test output in general. As mentioned

above, a number of research studies have been written that describe output

measurement procedures and some suggested required documentation of the proce

• What would the recommended repetition of cooling-coil surface sample quantities and

have

e upstream and downstream sides of

s the

icrobial activity on cooling coils, it would be best to collect

•

procedures for all products on the

•

rrow

locations reveal?

The microbial reduction findings would be optimized with a robust sampling plan.

When looking at any particular cooling coil, the degree of microbial growth varies fr

spot to spot. If one were to inspect multiple locations on a coil, some areas would

more colonies, others fewer. In order to characterize the entire coil, additional samplin

points for each coil are necessary to calculate an average level of contamination for ea

coil. It is now recommended that a minimum of five samples be taken per coil (i.e., five

repetitions per sample). It is also logical to ask th

the coil experienced different microbial growth. For instance, the coil fin edge on the

upstream side would see impingement of debris and airborne spores, wherea

downstream side would see a greater accumulation of condensate. To gain a

comprehensive picture of m

up to 10 samples on both the upstream and downstream sides of the cooling coil for

culturable and non-culturable fungi and bacteria.

Can UVC be used effectively as a preventative measure to inactivate destructive bio-

agents?

UVC might be effectively used for cleaning building ventilation air in order to preven

contamination by chemical agents that would otherwise be used for this purpose. The

Environmental Protection Agency (EPA) and the Research Triangle Institute are

currently investigating this research question through the EPA’s Technology Testing

and Evaluation Program. This study is currently outlining the laboratory test parameters

that could be used to develop standardized testing

market.

What is the probable UVC output degradation over time?

The UVC products currently on the market are rated for varying hours of useful life. In

order to test the life of the products, a study should be performed over a 12-month

period. This will allow for at least three testing intervals within the year. Those

treatments that degrade over time will have less disinfection effectiveness at the end of

the study. Such a study might also show a reduction in more resilient strands of mold in

a longer test period. In addition, a school attendance analysis would be strengthened by

having at least one year of pre- and post-data.

What is the ability of UVC to penetrate into the cooling coil fins?

There are currently no thorough research studies on how long it takes UVC to penetrate

into the coil fins. This is the subject of one proposed research project request being

prepared by ASHRAE TG 2.UVAS. It is widely accepted that a one-to-two month study

period will show high levels of microbial reduction on the irradiated surfaces. However,

tests should be performed to determine the optimal length of time needed for the UVC

irradiation to penetrate deep into the coil. UV levels can be quite low deep in the na

spots between fins. As the fins clear, more UVC is able to get in and reflect deeper in

the coil. A minimum depth to test would be a depth similar to that reached by the

research team with the swab sampling technique.

•

r in conditioned space?

gal

. Latent load should be correlated

seasons. The presence of mold in the building structure, along with elevated

chers. A study could address the effects of wiping

n the classroom, AC air

•

ould include those for fungi and a

•

rable

entilation air supply into classrooms

could affect and improve academic performance. The U.S. General Accounting Office in

What might be the relative contribution of AC system, classroom, and outdoor

contaminants to ai

Many sources contribute to the air quality characteristics in the HVAC system air

stream. Some of the more significant factors are the seasonal and incidental conditions

that affect the airborne count of mold spores, quantity of outdoor (ventilation) air being

brought in to the conditioned space, seasonal weather conditions that affect the latent

load on the system, AC unit air filter efficiency, air filter bypass conditions, and

classroom contaminants. It is important to understand the source of contamination to

determine the most appropriate mitigation method.

When trying to determine what types of microbial sampling to perform, the research

team realized that a study is needed to quantify the correlation between surface fun

colonies and air stream spore counts. In addition, this study should quantify the

relationship between outdoor contamination and seasonal weather conditions on indoo

air quality in order to control for these effects using filtration or other methods. The

season affects the amount of latent load on the AC

with effects on system performance and the amount of fungal proliferation during

different

levels of volatile organic compounds (VOCs), formaldehyde, and many other

contaminants may compromise the indoor air quality. Supplies customarily provided

for children’s activities in classrooms (paints, markers, glues, paper, and clay) as well as

the activities themselves (cutting, filing, scraping of wood) can also have an impact. In

addition, classroom occupants, particularly students, introduce contaminants from their

home environments and through exposure to other students and the outdoors at lunch

and recess. Children living in less desirable environments may introduce agents outside

the control of school districts and tea

off shoes on floor mats and of washing hands before enteri g

stream testing for culturable bacteria, and other practices to detect and prevent

contaminants from entering the classroom via its occupants.

Detection in particular might entail the following considerations:

There are many potential locations for airborne microbial tests such as on air duct

surfaces; in the AC air stream (upstream and downstream from the cooling coil); and

elsewhere in the outdoor, return, and classroom air. To bring greater clarity to the

influence of these many factors, desirable tests w

spore trap analysis.

Microbiological testing of classroom air could use interval data for endotoxins, microbial

antigenic proteins, culturable bacteria and fungi, volatile organic compounds,

formaldehyde, carbon dioxide and monoxide, and other particulates.

What is the quantifiable amount of outdoor air being supplied to classrooms and what

are its true effects on indoor air quality?

It is a widely supported conjecture that there is an important relationship between the

amount of ventilation air and the concentration of airborne contaminants, or measu

IEQ. Numerous studies imply that an increase in v

1995 conducted a study that found that nearly one third of all schools surveyed

unsatisfactory ventilation in the classrooms

reported

. That same survey indicated that nearly two

es in an

mode, and also heating mode.

•

fered,

disinfection that higher

o provide reliable

er.

UVC te

microb coils. However, while awaiting the future widespread deployment

of UVC

IEQ wi

• efficiency

ufacturers have available filters in the typical

•

thirds of the U.S. student population receives its education in buildings that, due to

deterioration of the facility, warrant major repairs or renovations.

Additionally, there is energy savings potential when utilizing outdoor air for space

cooling needs, referred to as the economizer cycle. Minimum or enhanced levels of

ventilation air can also be introduced independent of the heating or cooling mod

HVAC system. Special attention should be placed on portable classrooms, where units

may not be providing outside air when not in cooling

Particular focus and analysis of the effects of insufficient versus minimum or enhanced

levels of ventilation air would be fortuitous.

What are the best sampling techniques to determine UVC-related impacts?

A six-month planning period would enable the research team to determine the most

appropriate sampling techniques and tools to use for surface and air samples. As

mentioned previously, there is no broad consensus on appropriate air sampling

techniques for this type of study. Therefore, thorough secondary research and in-depth

discussions with a team made up of IAQ experts, researchers, and UVC disinfection

system manufacturers must take place before any air sampling is attempted. To allow

for comparison between air sampling results, a set of standard testing protocols could

also be developed based on future research.

Standardize labeling and testing procedures.

One critical factor that would assist with the widespread adoption of UVC disinfection

systems for HVAC systems is the development of standardized labeling and testing

procedures for the products on the market. Currently, there are no such standards; each

manufacturer uses its own discretion on selecting the type of information offered on

marketing material. There are no standardized industry tests for the products of

allowing too much room for products that do not provide the

quality products do. Consumers currently rely on manufacturers t

information about their products. It would be a great improvement if the informati

came from a standardized laboratory facility that could verify the manufacturers’ claims

and allow for comparisons between suppliers, eliminating uncertainty for the consum

chnology can and will contribute more to IEQ in California schools by reducing

ial growth on cooling

technology, much can be done in the way of proper maintenance now to ensure better

th existing equipment, including the following:

Increase air filter efficiency: The use of air filters that have a minimum

reporting value (MERV) rating of 8 or greater would provide a significant improvement

in the prevention of the passage of airborne allergens including pollen, mold spores, an

coarser particulate matter. Numerous man

1-in and 2-in depths.

Increase air filter replacement frequency: Appropriate change-out frequency will

prevent excessive dirt loading of air filters and the resulting degradation of air flow and

performance. It is apparent that increased frequency of replacement would benefit

numerous units.

Check for air filter bypass: Filter bypass is due primarily to poor construction of the f

rack assembly, which allows wide tolerances between the filter and

• ilter

its mating surface.

•

ents to achieve the minimum requirements

62.

•

ashing.

• taminants and particulates are

lly

•

ent in performance.

• r over-

•

s, especially in monetarily constrained school districts. The new

This, along with substandard installation of replacement filters, results in appreciabl

debris buildup on the evaporator coil and therefore a decrease in air flow and AC un

efficiency. Correcting bypass conditions through appropriate alterations to filter racks,

as well as stipulating better filter replacement methods, would produce beneficial results

to AC performance and IEQ.

Verify/increase ventilation air: This involves the retrofitting to code of existing outdoor

air dampers, controls, and associated compon

for ventilation air as noted in the California Energy Code and ASHRAE standard

Improve areas near air intakes: Areas near packaged HVAC units where outside air

supplies are drawn are often overlooked in routine maintenance. These area within th

classroom and outdoor activity areas commonly receive little attention from schoo

district maintenance crews. To improve IEQ, condensation, rainwater, and other liquids

should drain away from the air intake side of a unit. Routine cleaning crews should

report visibly poor conditions to maintenance, and roofs should be regularly inspected

for evidence of mold, mildew, standing water, etc.

Mitigate contaminants introduced by occupants: Many contaminants could be reduced

by the introduction of door mats and hand w

Encourage use of door mats: Many indoor con

transported from outdoors via shoes. Dirt, mold, plant matter, pesticides, and lead are

routinely brought into the classroom on the soles of shoes. Track-off mats are essentia

long door mats and provide a very effective and passive means of extracting debris from

shoes. Use of the mats at the exterior entry to each classroom or classroom building

would be beneficial.

Encourage hand washing: Many contaminants introduced into the classroom by

students and teachers are transported via their hands. Interaction with other students,

the outdoors, and home environments could lead to the introduction of microbial

species into the classroom. The use of this strategy, hand washing, along with track-off

mats limits potential sources of IEQ problems to those under the control of school

districts.

• Clean coils: Some of the evaporator coils had slight-to-heavy accumulations of

particulate debris. In many instances, a one-time vacuuming or washing of evaporator

and condenser coils effected a notable improvem

Test and adjust refrigerant charge: It is common to find AC units that are under- o

charged with refrigerant. Correcting this condition often brings about a notable

reduction in energy costs and premature equipment failure and improves performance.

Retire the oldest units: It is common for units to remain in service well beyond typical

replacement time limit

Department of Energy Air Conditioning Standard (Department of Energy) sets the

minimum efficiency of small units (<5.5 ton cooling capacity) to seasonal energy

efficiency ratio (SEER) 13, and prices should drop as these become base models for

manufacturers. Replacing units more than 20 years old with these new SEER 13-certified

• t

gines and other equipment. Implementing a program to

• ,

3.6.4.

The UV y significant for this study, produced

a positi

longer ts. Statewide energy impacts from

this tec e results.

This stu

conditi

would

relation

microbial activity on the population of existing classroom cooling coils is uncharacterized at

present s with

pre-exi

units could result in significant energy savings, and falling prices would yield shorter

payback periods.

Reduce diesel exhaust emissions: Diesel exhaust is a prevalent source of air pollution a

many school sites and is often produced by school buses and traffic on major nearby

roadways. When inspecting used air filters at several different school sites, there was

evidence of this problem. The presence of black particulate matter on the filters indicates

pollution from combustion en

reduce diesel exhaust emissions can have a positive impact on air quality and the

incidence of asthma and other respiratory issues. Similar pollution sources in the

school’s proximity, such as airports and manufacturing facilities, should be mitigated to

ensure optimal IEQ.

Clean cool roofs: White, cool roofs are meant to reflect solar radiation from roof surfaces

thereby reducing heat transfer during the warmer months. The research team observed

many cool roofs that had a buildup of dirt and debris, resulting in a darker roof and

thereby reducing reflection benefits.

Benefits to California

C impact on system air flow, though not statisticall

ve trend, a 1–2% improvement. This suggests that further laboratory or field tests over a

time period may produce statistically significant resul

hnology could not be ascertained due to the small sample size and inconclusiv

dy concludes that the UVC technology is effective in reducing microbial growth on air

oning cooling coils. However, the impact of this technology on IEQ in California schools

be proportional to the pervasiveness of microbial growth on cooling coils and the

ship between surface microbial growth and IEQ. The presence and magnitude of

. The UVC technology may be best suited for application in AC units in classroom

sting microbial growth or IAQ problems.

4.0 Program Market Connection (Project 4)

4.1. Introduction

The market connection project was concerned with disseminating the results of two technology

projects designed to improve energy use and indoor air quality in K–12 schools in California.

One of the technology projects examined the use of DV for delivering fresh air more effectively

to students and teachers; the other tested UVC for cleaning air-handling units and improving

their cooling performance.

The goal of this project was to improve the market focus of the program’s activities, thereby

increasing the ultimate viability and public benefits of the technology products resulting from

the program. Specifically, the market connections effort was intended to result in the

production of a number of information products designed to overcome market barriers,

influence market participants, and produce desired market effects.

4.2. Project Objectives

The objectives of this project follow:

• Involve influential market participants at all stages of program planning and execution

to make sure that the design, conduct, and documentation of the program achieves

results with maximum market penetration and benefits. This level of involvement

ensures that the needs of influential market participants are met.

• Draw on the expertise of the PAC market participants and other important players, as

well as use existing information channels, meetings, and publications, to ensure that

information about the project’s technology enhancements is disseminated to those who

can influence school facility construction and operations.

• Provide specific expert guidance to the program, and project participants as well as

technology developers on technology transfer approaches, formats, and content

requirements needed to meet infrastructure and design specifier needs in order to

maximize market success.

• Disseminate consistent and appropriate information in effective forms of

communication to relevant market actors and consumers to enable understanding and

further acceptance of all program products. These materials should be designed to

convince those concerned that the new technologies work; that the risks of adopting

these technologies are minimal; and that the corresponding energy and cost savings,

along with environmental benefits, are considerable.

• Understand the basis for codes and standards that affect the adoption of the proposed

technology enhancements, identify individuals who could influence the acceptance of

desired changes in codes and standards, and identify the results needed to affect the

changes.

4.3. Project Approach

The project was executed by completing key activities and creating products within four main

task areas: Project Administration, Program Wide Market Connection System, Program

Technology Transfer, and Indoor Air Quality Codes Assessment. Key aspects of these main

tasks are summarized below.

4.3.1. Project Administration

The objective of this task was to verify that satisfactory progress was made toward achieving

arket Connection System

ecute the Technology Transfer Plan by developing and

ximize the benefits of this PIER research and the

in K–12 schools in California. The following

produc

•

4.3.4.

The ob

facilitat

change be

used by

4.4.

A summ

market

at www

the market connections objectives of this program. This task provided the format for continuous

updates between IEQ team members and involvement with the PAC members. The task

consisted of these elements: a program kick-off meeting, bi-weekly phone calls, monthly

progress reports, Program Advisory Committee meetings, and a Project Final Report.

4.3.2. Program-Wide M

The objectives of this task were to develop a plan to identify market barriers impeding the

market penetration of DV and UVC technologies in California schools and to determine what

actions and products are needed to overcome those barriers. This task consisted of preparing a

Technology Transfer Plan.

4.3.3. Program Technology Transfer Plan

The objective of this task was to ex

delivering the products needed to ma

appropriate use of DV and UVC technologies

ts were developed as part of this task:

Promotional fact sheets and brochures

Articles in trade publications and engineering journals

Presentations and forums for DV and UVC

CHPS training session information and materials for incorporation into CHPS Best

Practices Manual

EdSpec Models for DV and UVC applications

Communication conduits for disseminating information

Applications guides for off-the-shelf DV and UVC equipment for schools

Indoor Air Quality Codes Assessments

jective of this task was to identify codes and standards that might need to be modified to

e adoption of project results, define information needs that must be supplied to affect

s to applicable codes and standards, and present that information in a format that can

codes and standards- and guideline-setting bodies.

Project Outcomes

ary of the project outcomes follows. Key information products developed for the

connection project are listed in the Attachments section of this report and may be found

.archenergy.com/ieq-k12/market_connection/market_connection_reports.htm.

Input was

• solicited and gained from influential market participants and the PAC.

ipants were involved at all stages of the IEQ Program planning

is also

eir influence was utilized.

Influential market partic

and execution to assure that the projects were designed, conducted and documented in

manner that achieved results that maximized market penetration and benefits. Th

assured that the needs of these influential market participants were met through their

involvement and that th

Four meetings were conducted with the PAC participants during the program. Input

A d with the objective of overcoming

ance was provided on the approaches, format, and content

req e and specifier needs to maximize market

ial

ion

rovide a single-package, direct-expansion HVAC

t. In addition, influential parties suggested

classroom demonstration in

es.

•

viding outreach and technology information dissemination for

tions dealing with schools were

sions, key publications and periodicals,

nizations as well as some of

les:

o te, e-newsletter

Savings By Design: Case studies and design briefs as part of the Energy Design

raining sessions at utility energy centers

rce

was gained and integrated into the projects. A highlight of the meetings was a walk-

through tour of the DV technology installations at Coyote Ridge Elementary School in

Roseville, California, and Kinoshita Elementary School in San Juan Capistrano,

California.

• A Technology Transfer Plan was prepared and expert guidance was provided.

etailed Technology Transfer Plan was prepared

market barriers affecting market participants involved in specification, financing,

installation, operation, maintenance, and use of DV and UVC technologies in K–12

schools in California (Blatt 2004).

Specific expert guid

uirements needed to meet infrastructur

success. This information consisted of cost assessments and benchmarks for the two

technologies, technical assessments of coil fouling, and an assessment of the potent

benefits of UVC for coil cleaning. Market connection and market potential informat

from a manufacturer’s point of view was gained in the course of influencing a

participating HVAC manufacturer to p

unit that met the needs of the DV projec

obtaining additional cooling test data for the Capistrano

order to provide a more compelling case for code chang

Key organizations were identified.

Organizations pro

specific market participants as well as organiza

identified and tabulated according to their mis

and key meetings. The following list comprises these orga

the products and meetings that served as information dissemination vehic

Alliance to Save Energy: Green Schools Upda

o California’s CASH: Annual conference in February

o DesignShare: The International Forum for Innovative Schools, e-newsletter

o Healthy Schools Network: Guidebooks

Resources Program; t

o Sustainable Buildings Industry Council: High Performance Schools Buildings Resou

and Strategy Guide, workshops

CHPS: Best practices manuals, training sessions

o United States Green Building Council: Standards for government buildings

o Whole Building Design: Whole Building Design Guide

•

The DV fact sheet contained information on and answers to the following frequently

avings By Design?

How does it fit into sustainable building practices?

ailable?

C technology for coil

•

ted with secondary research on field

tems,

sys et Light for Coil

Ap or Displacement” (Engineered Systems 2006B).

m the editor of Engineered Systems

• ted.

Presentations were conducted throughout the course of the Program for the purposes of

informing market participants, eliciting involvement from influential participants, and

Fact sheets were developed.

Fact sheets were produced for both DV and UVC to address issues and market barrie

impeding the acceptance of these technologies in California. The fact sheets were

distributed at various presentations and conferences.

asked questions:

o What are the system benefits?

o How does this technology fit in with Leadership in Energy and Environmental

Design (LEED™), CHPS, and S

o How can the technology increase neighborhood property values?

o What are the building requirements?

o What is the applicability to retrofit situations and relocatables?

o What kinds of HVAC systems can be used?

o What are the best ways to handle heating, humidity, field experience, and cost?

The UVC fact sheet provided information on and answers to the following frequently

asked questions:

o What are the technology benefits?

What are the types of systems av

o What about sizing and operation?

o What are the safety issues?

o What has been the field experience so far?

o What is the probable cost?

o What are the variables affecting the cost-effectiveness of UV

cleaning?

Journal articles have been published.

Material from the fact sheets was supplemen

experience with the DV and UVC technologies to produce articles for Engineered Sys

a magazine focused on “practical applications for innovative HVACR mechanical

tems engineers.” The article in the March 2006 issue, “Ultraviol

Cleaning in Schools,” (Engineered Systems 2006A) was followed by an article in the

ril 2006 issue, “The Right Place f

Electronic versions of these articles were obtained fro

and distributed to a wide audience, as delineated in the Technology Transfer Pla

Presentations, forums, and training sessions were conduc

using participant involvement to both shape the results of and disseminate the

of these informational events:

aheim in January 2004. These included a presentation to the

Energy Standard for Buildings Except

004)

eded to better

VC technology.

experience with DV

icient Economy Summer Study Conference on

he Asilomar Conference Center in Pacific Grove,

CASH conference held in February 2006

were prepared and given. The CASH DV

urface disinfection (Okura 2006) presentation

m web site.

energy centers. These presentations were

n Sacramento on April 27, 2006, and at the SCE

rainee in utilizing these materials as training tools for a training session or

•

ria,

, air

lines for UVC

operation and maintenance issues, commissioning, and references. These guidelines

information about the technical projects.

Technical presentations, forums, and training sessions occurred at several venues.

Several ASHRAE and other venues typified the range

o Informal presentations were made to ASHRAE technical committees at the Winter

meeting in An

mechanical subcommittee of ASHRAE 90.1:

Low-Rise Residential Buildings

o Forums were held at the ASHRAE Chicago (January 2004) and Nashville (June 2

meetings on issues relating to work that needed to be done in order to apply UVC

systems to commercial buildings and on research and programs ne

inform the HVAC community about U

o Seminars were held at the ASHRAE meeting in Chicago on field

and UVC technologies.

o Forums also occurred at the ASHRAE Denver (June 2005) meeting and the ASHR

Quebec meeting (June 2006).

o A presentation on Computational Fluid Dynamic Modeling was made at the

American Council for an Energy Eff

Buildings (held in August 2004 at t

California).

o The proposal prepared for a session at the

in Sacramento was accepted; presentations

presentation (Eley 2006) and UVC s

may be found on the Progra

o Training presentations were made at utility

made at the SMUD facility i

Customer Training and Assistance Center in Irwindale on May 2, 2006. The DV an

UVC presentations were appended with explanatory notes that could be used by a

trainer or t

for self-study.

Guidelines for CHPS Best Practices Manual were developed.

The CHPS organization has developed a series of best practices manuals for Planning

(Volume I) and Design Guidelines (Volume II), as well as four other volumes on crite

maintenance and operations, commissioning, and relocatable schools. The results of t

research conducted under this IEQ Program were used to update the DV guidelines a

to create new guidelines for UVC. The revised-draft guidelines for DV (Collaborative for

High Performance Schools A) contain updated information on applicability, codes and

standards, cost effectiveness, advantages, disadvantages, design tools, design details

distribution requirements, and references. The new draft guide

(Collaborative for High Performance Schools B) contains recommendations, description,

variations and options, applicability, applicable codes, integrated design implications,

cost effectiveness, attributes, benefits, disadvantages, design tools, design information,

have been transmitted to CHPS personnel and will be used as starting points for

technologies in the next version of Volume

these

II of the CHPS Best Practices Manual.

•

arch

• Educational Specifications were produced.

env

200 ber

nee C options to be considered in the facility planning; and the

con requirements; acoustic requirements; HVAC System

issu

•

spe ld

mee formation to help them select appropriate

tech ) and

200

• Key meetings were conducted and numerous

ation personnel at a

CHPS training material was created.

Training material for both DV and UVC technologies was created and will be used by

CHPS representatives to provide future training to various audiences including

itects, school and utility representatives, and consulting engineers.

Educational Specifications, often known as EdSpecs, are used as guidelines for the siting

and construction of school facilities to provide comfortable, healthy, productive learning

ironments. Model EdSpecs were prepared for UVC (Blatt 2006A) and for DV (Blatt

6B) were reviewed by Tom Rayburn of Capistrano Unified School District. A num

of examples are provided in each model EdSpec. For example, for the model DV EdSpec,

the examples ranged between a simple statement of facility objectives; building HVAC

ds; suggestions for HVA

most detailed specifications. This last example, the most detailed specifications,

sisted of an overview of facility

requirements; and climate-related issues. Similarly, for the UVC system, the most

detailed specifications provided information on climate and environmental issues,

intenance and operational issues, HVAC/UVC system requirements, and safety

es.

Application guidelines were developed.

idelines were developed to assist school facility decision makers, equipment

cifiers, and manufacturers in assessing whether DV and UVC for coil cleaning cou

t their needs, and to provide them with in

system configurations and components. Separate guidelines are provided for each

nology: Application Guidelines for Off-the-Shelf DV Equipment (Blatt 2006C

plications Guidelines for Ultraviolet Lighting Equipment for Coil Cleaning (Blatt

6D).

communication activities occurred.

A presentation on market issues was given to Carrier Corpor

meeting of the California Energy Commission on August 13, 2004. The meeting was

designed to provide Carrier with an overview of PIER research that might be of interest

with a specific focus on DV.

A presentation on Title 24 Issues was prepared for delivery to California Energy

Commission Codes and Standards personnel and was transmitted to them along with a

detailed e-mail message in fall 2004. The presentation dealt with the benefits of UVC; th

limitations of Title 24 in assuming system performance in the as-built condition; and the

actions needed to address field degradation with consideration to issues such

inspection, commissioning, retro-commissioning, and performance measurement. DV

benefits were outlined and the need for handling the differences in mixed-ventilation

systems and DV were described along with modeling suggestions on how to best

facilitate these changes.

•

ment with the activities of ASHRAE, an

ram results.

ransfer Plan and Code Action Plans, as

can

• ction Plans and White Papers were developed and outreach efforts begun.

developed. They provided assessments of the

nformation regarding the issues impeding the acceptance of these technologies

4.5.

4.5.1.

•

nted

Other communication activities consisted in part of “word of mouth” efforts to involve

influential market participants.

One focus of these efforts was involve

organization influential in reaching specifiers, users, and manufacturers, to organize

forums that encourage discussion of the attributes of DV and UVC and the issues

surrounding each technology’s use. Efforts were fruitful: ASHRAE forums and

presentations were approved that afforded dissemination of Market Prog

In the course of developing the Technology T

well as gathering general information on market connections activities needed to

encourage the adoption of these and other new technologies in schools, numerous

telephone conversations and e-mail exchanges occurred. These connections with

individuals who are involved in maintaining information channels with influential

market participants and with code- and guideline-setting bodies has helped to ascertain

the issues involved in handling DV and UVC technologies for such codes and

guidelines. The results of these contacts and communications were incorporated into the

Technology Transfer Plan and Code Action Plan.

Existing information channels, meetings, and publications were utilized to deliver

accurate and timely information regarding DV and UVC technologies to those who

influence school facility construction and operations.

Code A

Code action plans and white papers were

codes and standards issues affecting the adoption of DV and UVC technologies,

identified individuals and organizations that could influence the acceptance of desired

changes in codes and standards, and identified the changes needed to properly account

for the attributes of DV and UVC systems in schools.

This information, which included the secondary research on DV and UVC benefits and

the results obtained from this IEQ Program, were included in the Code Action White

Papers. I

has already been disseminated to influential code-, standard-, and guideline-setting

bodies in the course of developing these plans and white papers. Some actions have

already been taken to include the recommended changes in existing codes, standards

and guidelines, in part as a result of these interactions. The Code Action White Papers

have been transmitted to numerous interested individuals and organizations.

Conclusions and Recommendations

Conclusions

Key market barriers for DV and UVC technologies must be addressed.

Influential market participants and their market roles have been identified. Barriers that

inhibit market penetration of new technologies for each of these market participants

have been determined and actions needed to overcome these barriers described. Barrie

such as performance uncertainties, hidden costs, and product availability were

identified. These barriers must be properly addressed through incentives, docume

case studies, guidelines, and other actions needed for both technologies to succeed.

Table 4 below summarizes these barriers along with the action recommended for

addressing the each issue.

Table 4. Information/actions needed to overcome selected market barriers

Information/Actions Needed to Overcome Selected Market Barriers

Market Barrier Information/Action Needed

osts of identifying efficient

quipment

Product directory showing characteristics and performance

P erformance uncertainties Case studies documenting performance with testimonials

Acquisition costs Guidelines for specifying and purchasing

Financing Benefits information, sources of funding

Hidden costs Installation, operation, and maintenance guidelines

High purchase price Rebates or other financial incentives

Codes and standards Documented performance

Product availability Publicity and other actions in this table

•

around the differences between

o be

rgy

, and

Savings By Design programs.

With UVC s dard is needed to assure that acceptable

VC system design (sizing), installation, field performance,

se goals in

Continued action is needed to address codes and standard issues that impede the

specification and installation of DV and UVC systems.

The main codes and standards issues with DV revolve

conventional mixed-ventilation systems and stratified DV systems. These differences

occur in the areas of room air flow patterns, sizing, room air temperature distribution,

ventilation effectiveness, thermal loads and indoor pollutants, supply-air quantity and

temperature, control strategies, and economizer operation. Existing standards need t

modified to assure that DV is handled fairly. These standards are principally the Ene

Code provisions (Part 6) of the State of California Building Code (Title 24) and the

ASHRAE 90.1 standards. Other corollary programs, based in part on the California

Energy Code (Title 24, Part 6) and ASHRAE standards, are the CHPS, LEED™®

ystems, a comprehensive UVC stan

practice is defined for U

maintenance, lamp replacement, and safety. An emerging effort with the

mind is being led by the International Ultraviolet Association. Title 24, ASHRAE, CHPS,

LEED™®, and Savings by Design standards and programs need to be modified to assure

that efficiency improvements associated with the use of UVC lamps are incorporated.

The general problem with receiving credit for UVC systems is that building codes and

standards and the corollary programs based on these standards assume that the coils are

clean and do not account for the degradation in performance that naturally occurs ov

time.

Results are encouraging but

• inconclusive.

The ves

indoor air quality in K

savings d gs due to

increased economizer use and some savings due to reduced cooling loads. Energy

savings of 10–40% are expected, depending on the climate.

s for UVC technology in coil cleaning showed substantial surface disinfection

icant reducti

findi ,

onsidered surp on system

n is better understood.

4.5.2. rcialization Poten

Specific com under the

respective sections for Project 2 and P

Market connection efforts for these tw ntinue with influential market

participants and organizations for the nsistent and relevant

formation needs to be delivered in effective media forms to relevant market actors,

nd-standards governing bodies in order to enable understanding and

cceptance of the new DV and UVC products. Market barriers and issues of concern must be

overcom

technol

4.5.3.

•

of air-handling units and UVC light systems should be

•

results of the IEQ Program indicate that DV reduces energy use and impro

–12 schools in California. The primary data for DV showed

uring the month of November 2005 of ≥ 39% with most of the savin

The result

but no statistically signif

rates. These preliminary

on in HVAC coil energy use or student absentee

ngs, while different from what was originally expected

should not be c rising once the influence of coil fouling

performance degradatio

Comme tial

mercialization information for the DV and UVC technologies is provided

roject 3 of this report.

o technologies need to co

California K–12 schools market. Co

consumers, and codes-a

e by promoting understanding and by continuing research activities for both

ogies.

Recommendations

Additional testing is recommended.

With DV systems, more data is needed from the Capistrano test classroom in order to

corroborate the findings that the system provides cooling energy savings and indoor air

quality improvement. If possible, additional data should be obtained in order to perform

validation of the “load partitioning” being considered by Title 24 personnel as a means

for enabling the use of programs such as DOE-2.1 or DOE-2.2 to model displacemen

systems. If this data and corresponding correlations were made available, the case for

implementing code changes to accommodate the use of these technologies would be

stronger. A much larger sample

evaluated, with some of these test UVC units placed in situations that would include

moist, microbial-rich conditions that encourage coil fouling and loss of performance

Market connection activities for future PIER programs should be extended beyond the

period of performance for the technical projects.

This action would enable the more effective distribution and dissemination of the

research results to key market participants, and to be able to adequately follow up

questions and requests with answers, additional information, published articles, as well

as with presentations in meetings and other venues critical to reaching and influencing

key market participants.

• ed after data from field tests is analyzed.

oth

4.5.4.

Statew ct

4) activ

Statewide energy impacts should be revisit

It is recommended that the estimates of energy impact and market penetration for b

the DV and the UVC technologies be revisited after better data is available on

performance improvements. Market penetration estimates can be made based on life-

cycle cost calculations, payback periods, and market research (that includes intervie

with key infrastructure participants).

Benefits to California

ide energy impacts are not directly applicable to the Program Market Connection (Proje

ities conducted under the PIER IEQ program.

5.0

Blatt, M d HVAC Systems for Improving Indoor Environmental

Quality

California Energy Commission, February 13, 20

1, 2004

Blatt, M

in Calif

Energy

g Indoor Environmental Quality and Energy Performance in

Blatt, Morton H., 2006C. “Improving Indoor Environmental Quality and Energy Performance in

California K-12 Schools,” Application Guidelines for Off-the-Shelf Displacement Equipment, for the

California Energy Commission, May 24, 2006.

Blatt, Morton H. 2006D. “Improving Indoor Environmental Quality and Energy Performance in

California K-12 Schools,” Application Guidelines for Ultraviolet Lighting Equipment for Coil

Cleaning, for the California Energy Commission, May 19, 2006.

Collaborative for High Performance Schools. 2006. Best Practices Manual. Available at

http://www.chps.net/index.htm. Accessed April 29, 2006.

Collaborative for High Performance Schools A. “GuidelineTC2: DV System,” Draft for the Next

Version of the CHPS Best Practices Manual, Volume II, Design

Collaborative for High Performance Schools B. “GuidelineTC26: Ultraviolet Lights for Coil

Cleaning,” Draft for the Next Version of the CHPS Best Practices Manual, Volume II, Design.

Department of Energy. DOE Air Conditioning Standard, effective on all units manufactured

after January 23, 2006.

Eley, Charles and Arent, John. 2006. “DV: Design and Application,” SMUD Presentation, April

27, 2006.

Sagges and Robinson, 2005. p. 21, IUVA News, Volume 7, No. 3, p. 21.

Siegel, et al., Lawrence Berkeley National Laboratory

State of California. 2002. Kindergarten-University Public Education Facilities Bond Act of 2002.

Summary available at http://www.smartvoter.org/2002/11/05/ca/state/prop/47/. Accessed

April 28, 2006.

Engineered Systems. 2006A. “Ultraviolet Light for Coil Cleaning in Schools,” Engineered

Systems, March 2006, pp. 50–60, 95.

Engineered Systems. 2006B. “The Right Place for Displacement,” Engineered Systems, April 2006,

pp. 56–62.

References

orton H. 2004. “Advance

and Energy Performance in California K-12 Schools,” Technology Transfer Plan, for the

04 with revised deliverables dates on December

orton H., 2006A. “Improving Indoor Environmental Quality and Energy Performance

ornia K-12 Schools”, EdSpec Model for Ultraviolet Lights for Coil Cleaning, for the California

Commission, May 16, 2006.

Blatt, Morton H., 2006B. “Improvin

California K-12 Schools”, EdSpec Model for DV HVACE Applications, for the California Energy

Commission, May 16, 2006.

Okura, Stacia. 2006. “An Introduction to UVC Surface Disinfection and Evaluation of its Use in

California K-12 Air Conditioning Systems,” SMUD Presentation, April 27, 2006.

6.0 Glossary

Specific terms and acronyms used throughout this report are defined as follows.

Acronym Definition

AC air conditioning

ACEEE American Council for an Energy Efficient Economy

ACM alternate calculation method

AEC Architectural Energy Corporation

ADA average daily attendance

ASHRAE American Society of Heating, Ventilating, and Air Conditioning Engineers

Bioaerosols Airborne products that include microorganisms, their fragments and spores,

metabolic gases, and other toxins and waste products

Btu British thermal unit

CASBO California Association of School Business Officials

CASH Coalition of Adequate School Housing

CFD computational fluid dynamics

cfm cubic feet per minute

CFU Colony-forming unit

CHPS Collaborative for High Performance Schools

CSBA California School Board Association

CTAC Customer Technologies Application Center

DOE-2 An hourly building energy simulation software package

DV displacement ventilation

DX Direct expansion (refers to the thermodynamic process where the refrigerant

in an air-conditioning or heat pump system expands directly in the cooling

coil or evaporator). Technology is commonly used in packaged and split

system equipment.

EdSpec Educational Specification (the document that sets forth the requirements that

design professionals must follow when they design new schools or

modernize existing schools)

EnergyPlus A subhourly building energy simulation software package

EPA U.S. Environmental Protection Agency

Acronym Definition

C on, and air-conditioning

school

LEED™ Leadership in Energy and Environmental Design™

MEV minimum efficiency reporting value

Modernization A set of extensive improvements to an existing school that often includes air

usly only heated. The scope of a

include new lighting systems, controls, and

d through DV systems, which is at a temperature

imum humidity of about 60%.

visory Committee)

earch

RD&D

SAT re

SDG&E mpany

t foot

GWh gigawatt-ho

HVA Heating, ventilati

IAQ Indoor air quality

IEQ Indoor environmental quality

in inch

K–12 Kindergarten through high

kWh kilowatt-hour

LBNL Lawrence Berkeley National Laboratory

conditioning for spaces that were previo

modernization project may also

finishes, among others.

MW megawatt

Neutral air Conditioned air delivere

between about 63°F and 68°F and with a max

OA outside air

PAC Program Advisory Committee (or Project Ad

PG&E Pacifica Gas and Electric Company

PIER Public Interest Energy Res

ppm parts per million

research, development and demonstration

supply air temperatu

SCE Southern California Edison Company

San Diego Gas and Electric Co

SEER seasonal energy efficiency ratio

SMUD Sacramento Municipal Utility District

Acronym Definition

UC ersity of California

distribution

” band

C ile organic compound

Univ

UFAD under-floor air

UL Underwriters Laboratory

UVC ultraviolet in the “C

VAV variable air volume

VO Volat

W watt

7.0 Appendices

his section lists the appendices to the final report of the Advanced HVAC Systems for Improving

al Quality and Energy Performance of California K–12 Schools Program, Contract

Number 500-03-003, conducted by Architectural Energy Corporation (AEC).

The final report and these appendices are intended to provide a complete record of the

program’s objectives, methods, findings, and accomplishments. Architects, school designers

and specifiers, contractors, school district owners and operators, manufacturers, researchers,

and the energy efficiency community should find the report and the attachments highly

applicable to their interests. Table 5 summarizes information about each attachment, including

the Energy Commission’s publication number, the title of the report or the type of publication,

and a short description. To obtain copies of these a or other reports produced within this

contract, or for more information on the PIER Program, please visit

www.energy.ca.gov/pier/buildings

Indoor Environment

or contact the Energy Commission’s Publications Unit at

(916) 654-5200. All research products are also available through AEC at

www.archenergy.com/ieq-k12/.

Table 5. Summary attachments

Publication Number Title Short Description

CEC-500-2003-XXXA Thermal Displacement

Ventilation (DV) in Schools

Final Report

Final report provided

overview of project results

CEC-500-2003-XXXB Thermal Displacement

Ventilation (DV) in Schools

Research Report

Research report detailing

technical results

CEC-500-2003-XXXC Thermal Displacement

Ventilation (DV) Design

Guide

Design guide for design teams

and school facility personnel

CEC-500-2003-XXXD Effectiveness Of UVC

Technology For Improving

School Performance Final

Report

Final report provided

overview of project results

CEC-500-2003-XXXE Program Market Connection

Final Report

Final report provided

overview of project results

CEC-500-2003-XXXF DV and UVC Fact Sheets Promotional material

CEC-500-2003-XXXG DV and UVC Training

Presentations

Promotional material

CEC-500-2003-XXXH EdSpec Models for DV HVAC

Applications and UVC

Applications

Sample Inputs for Educational

Specifications

CEC-500-2003-XXX Application Guides for Application Guidelines

Compatible Off-the-Shelf

Equipment for Use in DV and

UVC Applications in Schools

CEC-500-2003-XXX Code Action White Papers

and Brochures for DV and

UVC Technologies

Code action documents

Advanced HVAC Systems For Improving The Indoor Environmental Quality And Energy Performance Of California K 12 Schools Capistrano Ceiling Fan CEC 500 2007 006

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