P.O. Box 37012, MRC 957

Washington, D.C. 20013-7012

www.scholarlypress.si.edu

ISBN (online): 978-1-935623-87-8

ISBN (print): 978-1-935623-86-1

Available for download at Open SI (http://opensi.si.edu). 

The Summit on the Museum Preservation Environment was convened at and 

organized by the Smithsonian Institution in March 2013. It was held over two days 

at venues in the National Museum of the American Indian and the Smithsonian 

American Art Museum.
EDITED BY SARAH STAUDERMAN AND WILLIAM G. TOMPKINS

PROCEEDINGS OF THE SMITHSONIAN INSTITUTION 

SUMMIT ON THE MUSEUM 

PRESERVATION ENVIRONMENT

A SMITHSONIAN CONTRIBUTION TO KNOWLEDGE

WASHINGTON, D.C.

2016
Published by 

SMITHSONIAN INSTITUTION SCHOLARLY PRESS

P.O. Box 37012, MRC 957

Washington, D.C. 20013-7012

www.scholarlypress.si.edu

Compilation copyright © 2016 by Smithsonian Institution

The Letter from the Secretary, Foreword, Introduction, Panel Discussion, and the Guides and Resources 

section are in the public domain. The rights to all other text and images in this publication, including 

cover and interior designs, are owned either by the Smithsonian Institution, by contributing authors, or 

by third parties. Fair use of materials is permitted for personal, educational, or noncommercial purposes. 

Users must cite author and source of content, must not alter or modify copyrighted content, and must 

comply with all other terms or restrictions that may be applicable. Users are responsible for securing permission from a rights holder for any other use.

Cover image: East-facing, wide-angle view from approximately 40 feet altitude of the north entrance facade 

of the Smithsonian Institution Building (“The Castle”) on Jefferson Drive S.W. at sunrise with the U.S. 

Capitol Building in the background, Washington, D.C. on Aug. 27, 2013. Photo: Eric Long, Smithsonian.

Library of Congress Cataloging-in-Publication Data

Names: Summit on the Museum Preservation Environment (2013 : Smithsonian Institution), author.

Title: Proceedings of the Smithsonian Institution Summit on the Museum Preservation Environment / 

Edited by Sarah Stauderman and William G. Tompkins.

Description: Washington, D.C. : Smithsonian Institution Scholarly Press, 2016. | Includes 

bibliographical references and index.

Identifiers: LCCN 2015028339 | ISBN 9781935623861 (pbk. : alk. paper) | ISBN 9781935623878 (e-book)

Subjects: LCSH: Museum buildings—Environmental engineering—Congresses. | Museums—Climatic 

factors—Congresses. | Museum storage facilities—Congresses.

Classification: LCC TH6057.M87 S86 2013 | DDC 069/.29—dc23 

LC record available at http://lccn.loc.gov/2015028339

ISBN (online): 978-1-935623-87-8

ISBN (print): 978-1-935623-86-1

Printed in the United States of America

c The paper used in this publication meets the minimum requirements of the American National Standard for Permanence of Paper for Printed Library Materials Z39.48–1992. 
Contents 

Letter from the Secretary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

G. Wayne Clough

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Nancy Bechtol and Scott Miller

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

Sarah Stauderman and William G. Tompkins

Presentations

7 Climate Guidelines for Heritage Collections:

Where We Are in 2014 and How We Got Here

Stefan Michalski

33 Risk Assessment and Assignment of Environment Parameters

R. Robert Waller

43 Conservation Environments, Museum Buildings, and Sustainability

Michael Henry

51 Choosing Standards and Best Practices for Environmental Design and Operation

James M. Reilly

57 An Overview of a Process and Specification:

The British Standards Institute Publicly Available Specification (PAS) 198,

“Specification for Managing Environmental Conditions for Cultural Collections”

Jonathan Ashley-Smith

69 Sustainability: Climate for Culture

Fiona Cousins

81 Panel Discussion—Relationships, Respect, and Trust:

Collaboration among Museum and Facility Professionals

Guides and Resources

91 A Guide to Discussions and Exercises Regarding the Preservation Environment:

Determining and Implementing Your Institution’s Optimal

and Sustainable Preservation Environment

99 Resources and References

101 Summit on the Museum Preservation Environment Program

105 Smithsonian Institution Declaration on the Collections Preservation Environment

Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

v

Letter from the Secretary

Since its inception in 1846, the Smithsonian Institution has been defined by its priceless collections that represent the collective memory of our nation. They help researchers and thousands 

of scientists and scholars at home and abroad understand life on our planet. They are the lifeblood of the Institution. And as we strive to remain a vital learning resource in a digital age, 

both for the American people and the citizens of the world, it is crucial that we use every tool 

at our disposal to protect these revered treasures. 

This effort begins with caring for the buildings in which our collections are held. It is why 

we are investing millions of dollars in improving our facilities, making them more resilient, 

more sustainable, and more able to provide optimal conditions to preserve the collections. The 

varying ages of our buildings present us with challenges. But so do the incredibly diverse items 

in our collections, from the 4.5-billion-year-old Allende meteorite to newborn animals, from 

the mammoth space shuttle Discovery to tiny samples of frozen tissue and DNA, from timeless 

portraits in oil to artworks that exist only as pixels and data.

The Smithsonian engages a full range of subject experts to determine the best ways of protecting our collections, and in doing so we improve communication and collaboration among 

the critical stakeholders who design, establish, and maintain preservation environments, from 

the building envelope to microclimates. Today, the Smithsonian and the museum profession 

stand at a critical crossroad. It is time to reassess past standards, practices, and behavior established in another era. Working together, we can build on current scientific research, first-hand 

experience, and risk assessments to achieve an optimal and sustainable environment within our 

respective institutions and collections.

We take our role as environmental stewards seriously, making sustainability a centerpiece 

of our preservation strategy. Sustainable approaches not only minimize the human impact of 

our activities on our environment but also reduce long-term costs and allow better use of scarce 

funds to serve collection needs. As this is being written, Smithsonian conservators and engineers are working to test seasonal temperature and relative humidity setbacks at our Museum 

Support Center in Suitland, Maryland. Permitting small seasonal shifts in set points saves energy by reducing cooling loads in the summer months and heating loads in the winter months. 

This is all accomplished while staying within acceptable temperature and humidity collections 

preservation specifications. 

Our engineers have also been modifying the existing museum air handling unit sequence 

of operations to reduce the amount of outside air that enters a museum during unoccupied 

hours. The benefits of this are twofold: it allows for a large reduction in energy usage, resulting in substantial cost savings, and it limits air contaminants and temperature and humidity 
vi Smithsonian Institution Summit on the Museum Preservation Environment

fluctuations, helping to further preserve collections. In all, more than 18 construction projects 

underway across the Smithsonian, many of which address spaces that house collections, are 

planned to attain energy efficient LEED status.

John Quincy Adams, the sixth U.S. president and a staunch supporter of the Smithsonian’s 

creation, once noted that “to furnish the means of acquiring knowledge . . . prolongs life itself 

and enlarges the sphere of existence.” That is at the heart of what museums do for their communities, and collections underlie our ability to achieve this lofty goal. 

Preserving our cultural and scientific heritage and managing the museum environment to 

ensure the long-term preservation and accessibility of collections is a collective responsibility 

shared by a variety of professional disciplines. The proceedings of the Smithsonian’s 2013 Summit on the Museum Preservation Environment offer a wealth of information to stimulate dialogs 

that will help establish and implement strategies needed for the future. I thank the Summit 

Planning Committee, especially Sarah Stauderman, Mary Rogers, and Bill Tompkins, for their 

leadership and hard work and all of the contributing speakers who made the Summit on the 

Museum Preservation Environment such a huge success and this publication possible. I think 

this resource will provide valuable guidance for museums around the world. 

G. Wayne Clough

Secretary of the Smithsonian 

December 2014
vii

Foreword

Nancy Bechtol and Scott Miller

The Smithsonian Institution held a public Summit on the Museum Preservation Environment 

in March 2013 as part of its commitment to holistic and collaborative management of its collections. We expect this proceedings volume to be the new baseline for the understanding of the 

museum preservation environment, and we hope that it catalyzes both implementation of what 

we know and further research to advance the field.

Ensuring the long-term preservation of the collections entrusted to our care through the 

development of sustainable strategies is a priority for the Smithsonian. Indeed, collections and 

their stewardship are core activities of most museums. Collections provide the intellectual base 

for scholarship, discovery, exhibition, and education, as well as documenting previous research, 

and, especially in science, allow the evidence-based validation of research. Smithsonian collections are national and global resources accessed by millions of visitors and researchers each year 

who use both traditional methods and new technologies to explore subjects from aeronautics 

to zoology. New technologies such as DNA analysis and hyperspectral imaging for research and 

visualization raise opportunities to extract new layers of information out of old collections but 

also raise new challenges in preserving the full range of physical properties of the objects.

In 1846, Congress directed the Smithsonian to create a collection of “objects of art and of 

foreign and curious research, and . . . of natural history.”1 More recently, Congress recognized the 

value of the federal scientific collections as vital to America’s “scientific enterprise.”2 U.S. government policy is now “committed to ensuring the proper management, preservation, security, and 

ethical use of Federal scientific collections to inform scientific research and maintain the Nation’s 

legacy of exploration and discovery,” and “scientific collections provide an essential base for developing scientific evidence and are an important resource for scientific research, education, and 

resource management. Scientific collections represent records of our past and investments in our 

future. Policies and procedures for maintaining, preserving, and developing Federal scientific 

collections while also increasing access to those collections for appropriate use are, therefore, 

central to their value.”3 A few of the major global challenges for which collections provide critical 

evidence include climate change, spread of invasive species, epizootic disease, loss of biological 

diversity and cultural heritage, and their impact on global ecosystems and society. 

Strengthening stewardship of our collections is fundamental to the Smithsonian’s mission, 

but the volume, characteristics, complexity, and age of our collections and the variety of discipline-specific care standards present great challenges. Therefore, we have taken an interdisciplinary approach and promoted dialogue about the preservation environment that includes the 

full range of required subject specialists—conservators, curators, scientists, architects, engineers, 

librarians, archivists, registrars, collections and facility managers, and museum administrators. 
viii Smithsonian Institution Summit on the Museum Preservation Environment

The museum and collections community needs to commit to furthering our understanding 

of the preservation environment and improving communication and collaboration among the 

critical stakeholders who share responsibility for designing, establishing, and maintaining the 

collections environment from the building envelope to microclimates. As a profession, we must 

take a pragmatic and responsible approach in carrying out our stewardship responsibilities, 

applying common sense and balancing preservation requirements, building fabric, and systems 

capabilities. The business of preserving things “forever” is not easy. Significant financial investments are required for construction and long-term maintenance, and we need to make those 

investments in the most responsible and sustainable way possible. 

With the rise of exciting new options in green building technologies, we need to strike a 

balance in addressing collections preservation and green building goals. The need to reduce our 

greenhouse gas emissions and the increasing costs for energy have placed increasing demands 

to control our temperature and humidity only to the levels that are actually required by our 

collections. By working collectively, we can figure out these exact parameters and develop new 

standards for specific collection types. 

Two themes emerged from the discussions and are documented in this volume. One is 

the importance of collaboration in establishing and maintaining preservation environments 

because no single discipline has the full perspective and responsibility. The other is the need to 

separate standards based on urban legend or tradition from evidence-based decision making. 

As acknowledged in many of the papers, Dr. Marion Mecklenburg, now retired from the Smithsonian Museum Conservation Institute, and his international team of collaborators were trailblazers in producing scientific evidence that many cultural heritage materials are much more 

resistant to temperature and humidity changes than had been generally thought.

The Smithsonian has made significant progress at raising the level of collections care, storage, and digitization, thereby improving collections accessibility. Addressing our collections 

needs in a systematic and cost-effective manner depends on a pragmatic, strategic, and integrated approach through collections assessments, long-term planning, and prioritization, taking into account physical care, digitization, intellectual content, preservation environment, and 

a series of other issues regarding the quality of collections space. This summit and the proceedings are a product of our Collection Space Planning Initiative, a multiyear highly collaborative 

and interdisciplinary effort conducted by collections and facilities management staff with a 

pan-Institutional steering committee. The planning initiative is described in the 2014 report Securing the Future for Smithsonian Collections: Smithsonian Collections Space Framework Plan, which 

reflects a new era of collaboration across professional disciplines at the Smithsonian.4

Along the way, we have found that the diversity of our disciplines, when all brought 

together to serve the greater good, can make it a challenge to communicate effectively for the 

betterment of our preservation environments and ultimately the objects they protect. Sometimes just finding a common vocabulary is a challenge! We need to share foundational knowledge on current thinking and research regarding environmental impacts on preservation, 

approaches to risk and standards, and balancing preservation and sustainability—knowledge 
Foreword ix

on which we can build our future conversations about more efficient and effective ways of 

working together.

Management of the preservation environment is a responsibility shared by collections, exhibition, and facilities staff. They need to be empowered to work together, communicate, and 

collaborate across their respective disciplines to ensure a sustainable strategy for the future of 

the world’s cultural and scientific heritage and the global environment.

Finally, we thank the Summit Planning Committee, especially Bill Tompkins, Sarah Stauderman, and Mary Rogers, for their leadership and hard work in convening both the conference 

and the proceedings.

Notes

1. 20 U.S.C. § 50 (1846).

2. 42 U.S.C. § 6624 (2010).

3. Office of Science and Technology Policy, “Improving the Management and Access to Scientific Collections” (memorandum for the Heads of Executive Departments and Agencies, Executive Office of the 

President, Office of Science and Technology Policy, Washington, D.C., March 20, 2014).

4. Smithsonian Institution, Securing the Future for Smithsonian Collections: Smithsonian Collections Space 

Framework Plan (Washington, D.C.: Smithsonian Institution, 2014).

1

Introduction

Sarah Stauderman and William G. Tompkins

T

his publication presents the proceedings of the Summit on the Museum Preservation Environment, held at the Smithsonian Institution in March 2013. The purpose of the summit 

was to start a conversation over a gap in collections management policy at the Smithsonian, namely, that Smithsonian collections and facilities management staff desire a written 

standard and best practices document for the management of environments in spaces where 

collections are housed. They acknowledged that the controlled environments of many of the 

Smithsonian’s collections were based on commonly held notions of environmental “standards” 

(i.e., 70°F/45% RH with ± variations) that are at odds with current and even historical research 

findings and not understood by stakeholders to be the final and best preservation environment 

for all collections. They further recognized that establishing environments for long-term preservation of collections must take into account mandated and socially responsible energy savings 

and sustainability goals.

The context for the summit laid in the Smithsonian’s interest in improving its collections 

management practices and also in a growing international interest in the cultural heritage field 

to improve the preservation environment for museum, archival, and library collections. The 

Smithsonian approach to discussions about the preservation environment, as shown at the summit, differs from some others in that its emphasis is on the collaborative engagement necessary 

among cultural heritage professionals and the description of an iterative process of determining 

the best and most realistic environment for collections, not to dictate set points. The Smithsonian’s contribution to the wider discussion is to lay a framework for developing procedures for 

establishing communication between all stakeholders of the preservation environment.

In setting out to host a conversation about the preservation environment, the Smithsonian’s 

goals for the summit were far-reaching:

• to familiarize Smithsonian staff with the current research on the role of environmental factors in the long-term preservation of collections

• to itemize the best collaborative approaches to establishing environmental parameters 

• to provide a forum for discussion and adoption of a new Smithsonian Institution policy 

document on the preservation environment

A fourth goal emerged during the summit discussions, which was that the Smithsonian Institution should share its deliberations, resources, and perspective with the international collections 

care and cultural facility management communities.

To achieve these goals, a Summit Planning Committee consisting of Smithsonian conservators, collections managers, and facilities engineers conceived of the summit’s two-part program. 

The first part (Day One), open to Smithsonian and non-Smithsonian staff and allied professionals, 
2 Smithsonian Institution Summit on the Museum Preservation Environment

was devoted to learning and understanding the issues; the second part (Day Two), open to 

Smithsonian collections and facilities management staff, was devoted to sharing knowledge, experiences, and challenges in adopting environment policy for collections at the Smithsonian. 

World-renowned preservation scientists, researchers, and engineers who could capture the 

attention of an audience that would consist of seasoned museum workers from diverse professional orientations were invited to speak at the summit. To make the speaker selections, 

publications were reviewed, and conference proceedings were examined as the committee considered the qualifications and reputations of the potential speakers. The committee sought to 

invite international expertise and to be sensitive to issues of controversy that have been raised 

by practitioners in this area. The committee sought experts who could tell the story of the 

preservation environment and promote collaboration in the field. The members of the Summit 

Planning Committee and invited speakers are pictured in Figure 1.

Additionally, the Summit Planning Committee developed a draft “Declaration on the 

Collections Preservation Environment,” which was used on Day Two as a discussion guide, 

Photograph by Michael Barnes, Smithsonian Institution.

FIGURE 1. Members of the Summit Planning Committee and invited speakers following Day One of the Summit on 

the Museum Preservation Environment program, March 5, 2013, at the National Museum of the American Indian, 

Rasmuson Theater. Front row (left to right): Mary Rogers, Kendra Gastright, Jane Passman, Wendy Jessup, Kathryn Makos. 

Second row (left to right): Richard Barden, Scott Rosenfeld, Luanne Greene (speaker), Cecily Grzywacz (speaker), Fiona 

Cousins (speaker), Sarah Stauderman, Catharine Hawks, Paula DePriest. Third row (left to right): William Tompkins, Ann 

Trowbridge, Robert Waller (speaker), Jonathan Ashley-Smith (speaker), David Hauk, Michael Henry (speaker), Paul Tintle, 

James Reilly (speaker), Stefan Michalski (speaker). Not pictured: Michael Carrancho, Susan Cary, Malcolm Collum, Kathy 

Ernst, Justin Estoque, Joshua Gorman, Gail Joice, and Sharon Park. 
Introduction 3

providing opportunities for Smithsonian staff to confer on ways to clarify stakeholder roles, 

responsibilities, and expectations as related to the preservation environment. The revised declaration is included in the Guides and Resources section of this volume.

Despite a delay in holding Day Two due to winter weather, the summit was declared a 

success by those who participated on one or both days. A heavy snowfall closed the federal 

government, including the Smithsonian, on March 6th, requiring Day Two to be rescheduled. 

Despite the weather, summit speakers and planners pictured in Figure 2 were invited to meet 

for breakfast to discuss the draft declaration, building on the energy and enthusiasm of Day 

One. We heard commendations on the enlightening presentations, the opportunities created 

for participants to have a dialogue about this important topic, and even the invited speakers’ 

collective wit. What cannot be underestimated as a factor in the success of a program such as 

this summit was the great diversity of disciplines represented by the participants and the feeling of interconnectedness it lent to the program. Not only were our subject experts describing 

how imperative it is to involve all the stakeholders in discussions about the preservation environment, but participants could look left and right down the aisles and see those other stakeholders, their colleagues, hearing the same information and devoting time to learning about 

FIGURE 2. “Pete’s Diner Declaration.” Invited Summit speakers and planners meet for breakfast at Pete’s Diner on Capitol 

Hill on March 6, 2013 after a snowstorm closed the Smithsonian, requiring Day Two to be cancelled and rescheduled. 

Pictured: (left to right): Stefan Michalski, James Reilly, Robert Waller, William Tompkins, Jonathan Ashley-Smith, Michael 

Henry, Sarah Stauderman, Cecily Grzywacz. 

Photo courtesy of William Tompkins.
4 Smithsonian Institution Summit on the Museum Preservation Environment

this important topic. Participants left knowing that the profession stands at a critical crossroad 

where it can distance itself from past standards, practices, and behavior and lay the foundation 

for the implementation of sustainable approaches and interdisciplinary collaboration and decision making in designing, maintaining, and managing the preservation environment. Summit 

participants of Day One are pictured in Figure 3.

The resources in this publication can serve as the basis of an intellectual framework onto 

which the reader can apply specific collections’ histories and vulnerabilities, local climate, and 

local system capabilities, providing support for decisions about the appropriate preservation 

environment. This framework is not going to tell you what to do; it is not prescriptive. However, valuable lessons learned at the summit and described in this publication should inform 

one’s decision making:

• When it comes to the preservation environment, one size does not fit all for performance 

specifications or for HVAC systems.

• A rich and deep understanding of collections vulnerabilities and purpose within a collecting context must be attained by custodians.

• A history of research has lead us to this point, but more review and research is needed, 

especially dedicated discussions on subject areas such as light, pollution, temperature, 

humidity, and air exchange.

• Standards are no longer prescriptive but a component part of an integrated philosophy and collective decision making based on risk assessment; therefore, collaboration 

FIGURE 3. Summit participants at Day One, March 5, 2013, at the National Museum of the American Indian, Rasmuson 

Theater. 

Photograph by Michael Barnes, Smithsonian Institution.
Introduction 5

among conservation, collections management, and facilities management disciplines is 

imperative.

• Stewardship of collections is achievable alongside stewardship of energy and natural 

resources.

• A need to be more skilled and nuanced in the approach to and understanding of the preservation environment.

The Presentations section of this publication contains edited transcripts of the presentations provided by the summit’s invited subject experts. The Guides and Resources section 

contains information that we hope contributes to the cultural community’s preservation environment and collaboration tool boxes:

• a discussion and exercise guide listing questions we asked ourselves on Day Two of the 

summit, when we examined our current working processes and resources available to address this topic and task

• selected resources

• the summit program

• the “Smithsonian Institution Declaration on the Collections Preservation Environment,” 

which is our resulting high-level guiding document that ensures the many professional 

disciplines collaborating at the Smithsonian are working toward common goals

We thank the members of the Summit Planning Committee for their dedication and vision 

in developing the summit program and this publication, Smithsonian leadership for supporting 

this wide-reaching initiative, and Smithsonian staff in all corners of the Institution for contributing to this important dialog. We thank Katharine Untch for preparing the discussion and 

exercise guide section and Valerie Greathouse, Reference Librarian, Information & Communications, at the Getty Conservation Institute, for assistance with compiling the resources list in 

that guide.

Although the “Summit on the Museum Preservation Environment” and this publication 

were made possible by numerous contributors, we especially acknowledge the immense contributions of Mary Rogers who worked diligently to help facilitate this initiative from beginning to 

end. The Summit Planning Committee and speakers are indebted to Mary for her exceptional 

project management and editorial skills, steadfast enthusiasm and compassion, and unwavering 

professionalism and dedication. Mary, we could not have accomplished this without you!

Last, we extend our gratitude to our distinguished panel of summit speakers and contributors to this volume, who, through their tireless provision of knowledge to forums, publications, 

and serendipitous discussions, continue to lead the way and the charge toward a more reasoned 

and sustainable approach to the preservation environment. 

Summit Planning Committee, 2012–2013

• Chair: Sarah Stauderman, Assistant Director for Collections Care, Smithsonian Institution 

Archives

• Richard Barden, Preservation Manager, National Museum of American History
6 Smithsonian Institution Summit on the Museum Preservation Environment

• Michael Carrancho, Deputy Director, Engineering and Design Division, Office of Planning, 

Design and Construction, Office of Facilities Engineering and Operations

• Susan Cary, Registrar, Archives of American Art

• Malcolm Collum, Chief Conservator, National Air and Space Museum

• Paula DePriest, Deputy Director, Museum Conservation Institute

• Kathy Ernst, Social Science Analyst, Office of Policy and Analysis

• Justin Estoque, Assistant Director for Operations, National Museum of the American Indian (formerly)

• Kendra Gastright, Director, Office of Facilities Management and Reliability, Office of Facilities Engineering and Operations

• Joshua Gorman, Collections Manager, Anacostia Community Museum

• David Hauk, Supervisory Electrical Engineer, Energy Management, Office of Facilities 

Management and Reliability, Office of Facilities Engineering and Operations (formerly)

• Catharine Hawks, Conservator, National Museum of Natural History

• Wendy Jessup, consultant for preventive conservation, Wendy Jessup and Associates

• Gail Joice, Collections Manager, National Museum of the American Indian

• Kathryn Makos, Industrial Hygienist, Office of Safety, Health and Environmental Management (retired)

• Sharon Park, Associate Director, Architectural History and Historic Preservation, Office of 

Planning, Design and Construction, Office of Facilities Engineering and Operations

• Jane Passman, Senior Master Planner, Office of Planning, Design and Construction, Office 

of Facilities Engineering and Operation

• Mary Rogers, Collections Program Specialist, National Collections Program

• Scott Rosenfeld, Lighting Designer, Smithsonian American Art Museum

• Paul Tintle, Facilities Manager, Museum Support Center/Garber Facility, Office of Facilities 

Management and Reliability, Office of Facilities Engineering and Operations

• William G. Tompkins, Director, National Collections Program

• Ann Trowbridge, Associate Director for Planning, Office of Planning, Design and Construction, Office of Facilities Engineering and Operation
PRESENTATION

Climate Guidelines for Heritage Collections: 

Where We Are in 2014 and How We Got Here

STEFAN MICHALSKI

© Government of Canada, Canadian Conservation Institute
ABSTRACT. The history of museum climate guidelines is developed through three overlapping strands: 

awareness of problems, doing something about them, and the slow development of the science. Topics 

covered are nineteenth-century discoveries of climate issues; the history of passive RH control and its 

science, the emergence of mechanical systems, and the logic of best available technology; the emergence 

of stringent specifications; an era of relaxation; the emergence of current specifications; a critical history 

of the science; and the five errors of argumentation about specifications. The conclusions offer a brief 

recipe for action for institutions making decisions on this topic.
Climate Guidelines for Heritage Collections 9

Introduction

Three threads run through the history of museum climate issues, each starting at different 

times. First came the awareness, long before museums existed, that some deterioration processes are determined by climate. Common word pairings such as damp with decay and drying 

with cracking demonstrate this awareness. Second came the concern to do something about the 

problem, systematized centuries ago in terms of good housekeeping, natural ventilation, and 

sealed enclosures for precious things. In the twentieth century such passive methods gave way 

to reliance on active mechanical systems. In the twenty-first century, as we shall see, the pendulum has swung back—sustainability is driving a search for the best of old and new methods. 

The third thread, and the newest, has been the slow development of a conservation science 

sufficient to answer the following question: What control, if any, do collections really need?

I am not an outsider to the history of these issues, but I have tried to be evenhanded. I 

think there has been a tendency until very recently not to do the hard work of finding relevant 

knowledge already created in other disciplines. In its absence, specifications were created on 

the basis of “best available technology,” which was understandable, but then this provisionary 

reasoning hardened into dogma and, worse, pretended to reflect collections needs. I believe that 

our last error, now that the science has grown respectable, has been to hope that science alone 

can answer the question of real-world specifications, that is, decisions. It cannot, not in other 

fields of risk management and not in ours.

The benchmark history of museum climate specifications, mechanical systems, and building design, including important sources from the non-English world, is the Ph.D. thesis by Luciani (2013). For a shorter critical history of English language sources, see the paper by Brown 

and Rose (1997). For a survey of the last few years of argumentation and implementation around 

the world, see Bickersteth (2014). For a concise history relevant to image archives, neglected in 

the “museum climate” debate, see Image Permanence Institute (2010) and Reilly (this volume). 

Nineteenth-Century Discoveries by Interested Chemists

By the late nineteenth century, the paint chemist Church (1872:247) provided a good, albeit 

incomplete, understanding of the central issue of museum climate control: “If a stream of warm 

and dry air enters a gallery . . . the canvases, frames, and panels become altered in shape and 

size each day. . . . Thus the colored films . . . are submitted to an injurious strain, which may 

end . . . in a multitude of minute fissures, and the final flaking off of portions of the paint.” Most 

of the relevant causal chain is in place: heating systems in winter cause low RH, which causes 
10 Smithsonian Institution Summit on the Museum Preservation Environment

dimensional response of the materials, which causes strain beyond the material’s limits, which 

causes fracture and delamination. The only important omission in this causal chain is that the 

climate response of the coating layers matters as much as, and often more than, the response of 

the support layers. It would take a full century before the Smithsonian researcher Mecklenburg 

(1982) identified this omission.

The nineteenth century also saw understanding of the role climate played in chemical 

deterioration. In a major study of light damage for the National Gallery of London, Russell 

and Abney (1888) demonstrated that high RH accelerated light damage and that most of the 

colorants they studied were much less affected by light when both humidity and oxygen were 

removed. By the turn of the century, the German chemist Rathgen, known as the father of conservation science, discovered that the rapid corrosion of recently excavated bronzes—called 

bronze disease because it was believed to be caused by microbes—could be stopped by very 

low RH (Rathgen, 1905).

In summary, by the end of the nineteenth century, the qualitative aspects of museum climate 

concerns were fully in place; that is, chemical decay is slower with lower RH and lower temperature, climate fluctuations can lead to cracks and delamination, and decay (mold) requires 

high RH. The only question remaining was exactly how much damage at what conditions?

The Discovery, Rejection, and Resurgence 

of Passive RH Control by Enclosures

The nineteenth-century chemists advising museums about climate issues not only elucidated 

the damage phenomena, they also developed localized means of control. Church (1890:312) 

stated, “The covering of an oil picture with glass, whatever objections may be urged against 

it from an artistic point of view, certainly secures the protection of its surface . . . the back of 

pictures, especially of those painted on canvas, is often forgotten, yet excess of moisture and 

deleterious vapours and gases often enter from behind.” This was not a perfect understanding 

since he conceived the backing board only as blocking moisture entry, oblivious to its converse 

ability to block moisture loss due to the “warm and dry air” he knew was deleterious. Still, it 

was clear advice on the multiple benefits of display enclosures and recognition that there would 

be aesthetic objections. 

Rathgen, who had shown that low RH stopped bronze corrosion, also showed how to do 

it reliably in exhibits: airtight cases (metal plus glass plus care in fabrication) together with an 

RH sorbent (in a hidden compartment linked by fabric-covered openings). The diagram of case 

design in his handbook for museum curators (Rathgen, 1905) is as relevant as ever.

A few decades later, metal and glass enclosures were used routinely to control RH of panel 

paintings by the National Gallery of Canada (Constable, 1934; see the figure labeled “Airtight 

brass case for wood panel picture, National Gallery of Canada, April 16, 1934”). Ottawa has 

the lowest winter temperatures of any national capital; in the era before humidification, the 

National Gallery of Canada was likely to have had the lowest indoor RH of any national gallery 

(10% RH is not uncommon in unhumidified buildings in winter). 
Climate Guidelines for Heritage Collections 11

Many articles on RH-controlled enclosures, both display cases and shipping crates, 

emerged in the second half of the twentieth century, but quantified modeling of their behavior 

took three decades. Sealed shipping crates subjected to large temperature changes in transit 

were understood first by Toishi (1959), who showed that wooden objects could stabilize the 

RH in the crate. Thomson (1964) developed equations for this result, and Stolow (1966) provided a practical manual with moisture data on many materials. Unlike transit crates, the issue 

with RH-controlled display cases was long-term drift of RH due to case “leakage.” Thomson 

(1977) developed a model of RH dependence on buffer capacity and case leakage, but the big 

practical mystery remained: why did cases that were built of the same materials, contained the 

same buffer, and looked identical leak so very differently? Twenty years later, Michalski (1994a) 

developed equations for the four leakage mechanisms and confirmed each one experimentally. 

The key practical insight was that if enclosure design led to cracks at the top and bottom and 

if fabrication led these cracks to exceed the thickness of paper, then leakage would jump exponentially, and RH control would be lost. 

As conservation science slowly came to understand enclosures and their “microclimates,” 

museums and galleries were abandoning them. By the mid-twentieth century, the National 

Gallery, London, was using the advent of new mechanical control systems to forego the glass 

coverings on paintings recommended 60 years earlier by Church. “Great importance has 

always been attached to the advantages of removing the glass from paintings, thus eliminating the irritating reflections” (Keeley and Rawlins, 1951:195). Museums opted for open 

display, and where cases were unavoidable for security reasons, airtightness was the least of 

the exhibit designer’s concerns. The last straw in regard to enclosures was the discovery by 

the British Museum (Oddy, 1973) that many museum case materials emitted pollutants that 

damaged objects. Airtightness of display cases, as in homes and buildings, was seen as a dilemma best avoided. 

In the last decade, however, the tide has turned. Modern low-reflectance glass and lists of 

nonpolluting building materials have already dealt with the old objections. The British Museum 

decided most cases were not threatening their contents after all (Bradley and Thickett, 1998). 

Now, sustainability (and security costs) is driving a rediscovery of RH-controlled museum enclosures. In all the new guidelines (discussed later), a clause similar to the following appears: 

“the most sensitive material . . . will always need tight control of conditions, which might best be 

achieved through the use of microclimates” (National Museums Directors’ Conference, 2009).

The Emergence of Mechanical Systems and the Need for Set Points

In 1908, the Boston Museum of Fine Arts installed a central humidification and air washing system for its Huntington Building. The engineer, McCabe (1931), became the first person faced 

with the “big” question—what RH and temperature to aim for. He proposed an RH range for 

winter humidification of 55% to 60% for paintings and other works of art. Another museum 

engineer, Macintyre, working for the National Gallery, London, in the early 1930s, suggested 

the same. Neither recorded their reasoning; it could have been based on local climate or the 
12 Smithsonian Institution Summit on the Museum Preservation Environment

capacity of the unrefrigerated air washer systems of the time. Brown and Rose (1997) argue 

convincingly it was the system capacity. What the engineers did record was the lack of useful 

information on collections needs: “optimum conditions for any particular class of paintings 

must be more or less arbitrary” (Macintyre, 1934:16). For temperature, Macintyre (1934) suggested 60°F (~16°C) “as this is the temperature at which galleries are maintained in this country 

during the winter months.” I think it is safe to say that he did not intend this as a year-round 

suggestion since the whole discussion was understood to be about a winter problem. In summary, engineers on both sides of the Atlantic conceded that no useful information on collections 

needs existed, other than a qualitative call for winter humidification, so they fell back on the 

following logic: seasonal set points would depend on a balance of human comfort and cost and 

so would, of course, vary seasonally, and RH would be determined by what we now call best 

available technology. The logic of museum climate specifications was now fully in place and 

would not change until the present.

In an area for which they did have relevant knowledge McCabe and Macintyre had definite 

(and, in my opinion, still important) advice: “The maintenance of the plant and control gear 

cannot be left to the ordinary attendant” (Macintyre, 1934:16). They recognized what we would 

now call a risk management perspective; that is, long-term reliability matters. Proper maintenance was an important idea that, unfortunately, I have seen museums learn over and over 

through events that they consider unexpected but are entirely predictable. Long-term reliability 

was not mentioned again until Michalski (1993), and the museum community remained stuck 

on where to set the RH and temperature dials.

During the First World War, the British Museum stored collections in underground tunnels, and the results of damp followed by drying were disastrous: “staining, mildew and efflorescent crystals were to be seen everywhere, and many metal artifacts were in a state of serious 

corrosion” (Plenderleith, 1998:129). For the Second World War, they were determined to avoid 

such problems in underground storage: “in general, the relative humidity of the atmosphere 

should not be allowed to rise above 70 per cent, and authorities should aim at a relative humidity of 60 per cent combined with a temperature of 60°F” (British Museum, 1939:42). The 

museum numbers 60% RH and 60°F were now a decade old, but until then, they had been 

couched in tentative terms. I think the British Museum scientist Rawlins cast the die for what 

I call “magic numbers” in his 1942 article, aimed at a general museum readership: “acceptable 

conditions . . . are 60 °F, 60%. (Which incidentally, is easy to remember.)” (Rawlins, 1942). The 

main text of his article does not prepare the reader for this conclusion, rather the opposite—he 

noted, as had all before him, the “inability to suggest a minimum temperature at which a building should be maintained.” Not only that, his own observations of a massive collection, and 

presumably those of others, suggested that “many materials accustom themselves fairly well, so 

long as large . . . variations in RH and temperature are avoided.” So Rawlins knew that the sole 

evidence he had—the objects themselves rather than science—supported only the avoidance of 

extremes, which could have been expressed as a safe range, but he fell into the trap of a central 

target, “easy to remember.” 
Climate Guidelines for Heritage Collections 13

The Emergence of Stringent Specifications 

and Perceived Collections Needs

An American conservation scientist, Buck (1964), was the first to propose tolerable RH ranges, 

and he did so for different organic materials (paper, parchment, velum, fabric, bone, ivory, 

wood, painted wood), describing the damage to each material if the bands were exceeded. In 

the end, however, he assigned the same RH band to almost all of them: 45% to 65%. This is 

the first appearance of an acceptable bandwidth of 20% RH, and after much agony, we end up 

in 2014 with exactly the same number. But first, we must pass through two decades of much 

narrower bandwidth.

The Canadian Conservation Institute (CCI) was created in 1972 as a national advisory 

agency for museums, galleries, and archives. Not surprisingly, its first publication (Macleod, 

1975) was an overview of the importance of RH in museums, and it reiterated Buck’s range of 

45% to 65% RH as tolerable. McLeod also suggested adjustments to this RH range if the building was at risk of condensation in cold winters. He proposed 35% to 55% as “an acceptable 

compromise.” Note that Macleod’s adjustment was not only about lowering the winter set point 

but also about lowering the summer set point; in effect, it was about maintaining the same 

annual RH bandwidth of 20% but lowering the average from 55% to 45%. Macleod, without 

actually stating it, implied that collections could be acclimatized to a new annual average.

Up to this point, there had been no mention in conservation recommendations of how to 

specify short-term fluctuations (hourly and daily) that were an inevitable part of mechanical 

control systems. Lafontaine (1979) addressed this issue in CCI Technical Bulletin 5. To my 

knowledge, this is the first publication containing the stringent 50% specification supported by 

± notation for daily fluctuations. This approach became the norm throughout the world within 

a few years. The recommended temperature set point was a range from 25°C (summer) to 20°C 

(for winter.) Daily fluctuations were not to exceed ±1.5°C. Optimum RH was a set point between 47% and 53%, with daily fluctuation not to exceed ±2% (so a total range of 45% to 55%). 

A compromise option was a maximum summer set point of 55% and a winter set point of 38%, 

with daily fluctuation not to exceed ±3% (so a total range of 35% to 58%). This refinement did 

not emerge from the science of materials; it was simply the best-available-technology argument 

of the 1930s taken to its contemporary limits, assuming that the switching differential of thermostats and humidistats could be used to define the limits of rapid fluctuations and that a mix 

of human comfort and building performance would define seasonal set points. 

In the first edition of the industry “bible” called The Museum Environment, Thomson (1978) 

made no explicit recommendations for climate control; instead, he summarized the available 

knowledge, noted what institutions were doing to control climate, and concluded with the 

hope that simplicity and low-energy solutions would prevail over elaborate machinery. As 

a practicing Buddhist, he was calling for what would later become known as sustainability. 

His second edition (Thomson, 1986), however, included a new appendix on specifications. 

I suspect that the only complaint about the first edition had been “where’s the cut-and-paste 
14 Smithsonian Institution Summit on the Museum Preservation Environment

specifications for my building project?” Citing Lafontaine (1979) as support, Thomson defined 

two classes of control. Class I recommended RH set points of 50% or 55%, with a fluctuation 

of ±5% (no time period was specified). He accepted that other set points were possible but 

advised that mixed collections stay within 45% to 60% (the total class I RH range was therefore 

40% to 65%, a bandwidth of 25%). The temperature recommendation was 24°C in summer 

and 19°C in winter, ±1°C, but accepted a lower limit of 10°C. Class II recommended RH “to be 

kept within the danger limits 40% and 70%” and temperature “reasonably constant to stabilise 

RH” (Thomson, 1986:269). Although I am sure that Thomson wanted readers to take all his 

clarifications on class I and class II seriously, the community focused on his central target for 

class I: 50% ± 5% RH. 

The Pendulum Swings Back to a Broader Band

By the early 1990s, CCI began to relax its climate advice to the Canadian community at conferences and workshops on the basis of a thorough review of the relevant science and conversations 

with conservators, especially those with long experience observing their collections. (Relaxed 

recommendations applied only to fluctuations; specifications for chemically unstable materials 

such as those held by archives and contemporary art collections became more firmly directed at 

lower temperature and lower RH.) When I presented CCI’s changing advice at an international 

conservation conference (Michalski, 1993), the room divided into consternation over betrayal 

versus relief for “reality.” In a CCI Newsletter article titled “Relative Humidity and Temperature 

Guidelines: What’s Happening?” (Michalski, 1994b), I provided a table of the variable risk of 

fracture for various objects and various sizes of climate fluctuation and the implications were 

clear: although it was not CCI’s opinion that risk at ±10 units (RH or temperature) fell to zero 

across a mixed collection, they considered the risk to be very small, if not zero, for most objects. 

Their guidelines had moved from black and white to shades of gray, with a definite opinion on 

which shade of gray was the point of rapidly diminishing returns.

Marion Mecklenburg had been developing similar advice for the Smithsonian. In August 

1994, the Smithsonian Institution published a press release titled “Work of Smithsonian Scientists Revises Guidelines for Climate Control in Museums and Archives” in which Mecklenburg 

was quoted: “There can be as much as 15 percent fluctuation in relative humidity and as much 

as 10 degrees Celsius difference in temperature. . . . Most museums can adequately protect their 

collections with commercially available technology, such as the heating and cooling systems 

used in grocery or retail stores.” Unfortunately, this caught the U.S. conservation community by 

surprise (McCrady, 1994), and I think it generated skepticism of the science that has persisted 

to the present day (Burmester and Eibl, 2014). I remember angry U.S. conservators phoning for 

my reaction to the press release, and their disappointment when I said that we had been saying 

similar things in Canada. The Smithsonian scientists presented their reasoning at an international conference the next month (Erhardt and Mecklenburg, 1994). They summarized their 

arguments with a bar graph of 12 classes of material in museums, with each bar partitioned into 

zones of “avoid” and “caution” (as determined by their review of the literature and their own 
Climate Guidelines for Heritage Collections 15

research). No magic RH number threaded through all the safe zones. For their bar on mechanical effects, the safe zone was given as 40% to 70% RH. 

In 1996, I joined the committee working on a new chapter for museums, galleries, and 

archives in the American Society of Heating, Refrigerating, and Air-Conditioning Engineers’ 

(ASHRAE) handbook, the engineers’ bible. We adopted the idea that mechanical risk due to 

fluctuations did follow shades of gray, so we created five classes of control, labeled AA, A, B, C, 

and D, outlined in Table 1 (unchanged in all five editions between ASHRAE, 1999 and ASHRAE, 

2015). I provided each class with a short description of the estimated risks to various kinds of 

objects. In naming the levels, I borrowed from the psychology of bond rating nomenclature (triple A, etc.), whereby one can split small differences at the top while avoiding the embarrassing 

letter B. At the time, neither the science nor the marketplace justified outright rejection of the traditional stringent option that major players had struggled to meet, so we gave it the designation 

AA. That still left the respectable designation A for what I considered the sweet spot of ±10% RH 

(called option 2 in Table 1), offered alongside an option 1 of equivalent risk that took advantage 

of stress relaxation, ±5% RH short-term fluctuations combined with a permissible seasonal set 

back of 10% RH). Two other breakthroughs in the chapter, much less noticed but much more 

significant to energy saving, were the acceptance of a local historic average RH as an annual set 

point for permanent collections and very wide permissible temperature ranges. Within Canada, 

where CCI actively promoted its use, the ASHRAE class of control nomenclature was quickly 

adopted by museum consultants and conservators. In the United States and elsewhere it was 

also adopted by engineers but not the conservation community, except those who worked with 

historic houses, who were happy to see their compromises between collections and the building 

given formal definitions. The handbook is revised every four years. The RH and temperature 

sections have changed little, but the pollution sections have developed substantially.

In 2004, the Smithsonian adopted a single new specification for its more than 640 buildings on the basis of the work of its scientists (Mecklenburg et al., 2004). These specifications 

(Table 1) defined a year round “box” of 45% ± 8% RH and 70°F ± 4°F (~21°C ± 2°C), which was 

close to ASHRAE class AA for temperature and class A for RH. Over the next five years energy 

costs were reduced by 17% (Museum Conservation Institute, 2015). 

Meanwhile, in Europe, the cat was put among the pigeons. Directors of large museums 

within the International Group of Organizers of Large-scale Exhibitions, known as the Bizot 

Group, began questioning the need for the stringent specifications. By early 2009, UK museum 

directors published National Museum Directors’ Conference (NMDC) guiding principles for 

reducing museums’ carbon footprint with a proposed interim guideline of “a stable relative 

humidity (RH) . . . in the range of 40–60% and a stable temperature in the range 16–25°C” 

(National Museum Directors’ Conference, 2009). That being said, they immediately qualified 

this with “the most sensitive material . . . will always need tight control of conditions, which 

might be best achieved through the use of microclimates.” Conservators from the National 

Archives, Tate, and University College London obtained funding for a series of expert meetings on environmental guidelines, opportunities, and risks (Bell, 2009), which concluded that 
16 Smithsonian Institution Summit on the Museum Preservation Environment

TABLE 1. Summary of current museum climate guidelines, their purpose, collateral damage, and risks due 

to out-of-range events. Abbreviations are as follows: AAMD, Association of Art Museum Directors; AIC, 

Association of Art Museum Directors; AICCM, Australian Institute for the Conservation of Cultural Materials; 

ASHRAE, American Society of Heating, Refrigerating, and Air-Conditioning Engineers; IPI, Image Permanence 

Institute; ISO, International Organization for Standardization; NMDC, National Museum Directors’ 

Conference. © Government of Canada, Canadian Conservation Institute, 2016.

Guideline

Tolerable 

rangea

Tolerable 

short-term 

fluctuationb

Annual 

set point 

or average

Summer 

set point

Winter 

set point

Bizot, NMDC

(Velios, 2014)

40%–60% RH

15°C–25°C

59°F–77°F

±10% RH/day 

AIC, AAMD

(Velios, 2014)

±5% RH/day

AICCM

(Velios, 2014)

±5% RH/day

±4°C/day

Smithsonian 2007d

(Erhardt et al., 2007)

37%–53% RH 

~19°C–23°C

66°F–74°F

45% RH ~21°C

70°F

ASHRAE class AAe

(all references to 

“ASHRAE” are from 

ASHRAE, 2015)

45%–55% RH

14°C–28°C

57°F–82°F

±5% RH

±2°C

50% RH or 

historic average

15°C–25°C

(loan rooms 

21°C/50% RH)

Up 5°C Down 5°C

ASHRAE class A, 

option 1e

35%–65% RH

9°C–28°C

48°F–82°F

±5% RH

±2°C

Up 

5°C

10% RH

Down 10°C, 

10% RH

ASHRAE class A, 

option 2e

40%–60% RH

9°C–28°C

48°F–82°F

±10% RH

±2°C

Up 

5°C

Down 10°C

ASHRAE class Be ±10% RH

±5 °C

Up 

5°C

10% RH

Down

 10°C 

10% RH

ASHRAE class C 25%–75% RH

Not over 30°C (86°F)

ASHRAE class D Below 75% RH 
Climate Guidelines for Heritage Collections 17

Purpose of these conditions 

(i.e., risks that are reduced)c

Collateral damage 

to mixed collections 

in these conditions 

(i.e., risks that remain)

Risk due to RH spikes 

over ±20% but 

duration less than 

1 hourc

Risk due to a 

sustained RH 

fluctuation over 

±20%, e.g., system 

or shipping failurec

1. Prevent cracking, flaking, and 

deformation of medium- to 

high-vulnerability objects, e.g., 

paint layers on organic supports, 

constrained assemblies of organic 

materials

2. Film, photograph, document 

access room: reduce handling 

breakage due to brittleness, 

reduce misalignment in 

dimension critical playback

3. Glass, metals: reduce corrosion 

compared to higher RH

ASHRAE AA, A, B, C: As in point 1 

above, but probability of damage 

increases with each class (not cited in 

ASHRAE, but risk due to any class is 

negligible for the next X years if the 

collection has already experienced X

years of the conditions specified for 

that class, except for objects restored 

or acquired within X years) 

1. Most twentiethcentury rubber and 

plastic materials 

decay rapidly, e.g., 

in modern and 

contemporary art, 

industrial, and 

domestic collections

2. Most archival material 

(acidic paper, image 

media, electronic 

media) has short 

(unacceptable) 

lifetimes

3. Contaminated base 

metals and pyrites 

corrode faster than if 

at lower RH.

1. For thin objects with 

response time under 

1 hour, if unenclosed, 

probability of 

cracking and flaking 

of high-vulnerability 

objects is high; 

medium vulnerability 

is medium

2. Objects thicker than 

1 mm or thin objects 

inside moderately 

airtight packages 

and enclosures, 

e.g., paintings with 

backing boards, have 

small risk; if airtight 

enclosure, e.g., glass 

and backing board on 

paintings, no risk 

3. Exposed 

contaminated metals 

if spike is to high RH: 

large risk 

1. If unenclosed, 

probability of 

cracking and flaking 

of high-vulnerability 

objects is high; 

medium vulnerability 

is medium

2. Mold: in ~2 days if 

90% RH, in ~10 days 

if 80% RH, in ~100 

days if 70% RH

3. Exposed 

contaminated 

metals if sustained 

high RH: large risk 

of disintegration, 

flaking, efflorescence, 

maybe total loss

Prevent mold; prevent worst forms 

of cracking, flaking, deformation 

due to damp; prevent very rapid 

corrosion 

Going over 75% RH 

elevates all risks of 

points 1, 2, and 3 above

Going over 75% RH 

elevates all risks of 

points 1, 2, and 3 above

Going over 75% RH 

elevates all risks of 

points 1, 2, and 3 above

(continued)
18 Smithsonian Institution Summit on the Museum Preservation Environment

a new museum climate standard should be fast-tracked through the British Standards Institute. The result was Publicly Available Specification (PAS) 198:2012, “Specification for Managing Environmental Conditions for Cultural Collections” (British Standards Institute, 2012). It 

broke away from picking numbers and instead advised how to think through a climate control 

decision. 

By 2010, the U.S. conservation community started to take notice. Matthew Siegal at the Boston Museum of Fine Arts invited heads of conservation from museums and galleries all over the 

United States to discuss climate specifications (Hatchfield, 2011). The two conservators responsible for probably more international traveling exhibitions than anyone else—Mervin Richards 

(National Gallery of Art, United States) and Sarah Staniforth (National Trust, United Kingdom)—

stated that they had already lived with a de facto range of 40% to 60% RH among borrowers and 

had not seen problems. An interim statement very similar to that of the NMDC in the United 

Kingdom was proposed. My memory of the meeting was heated discussion over the exact definition of short-term fluctuation limits and concern that the clause about conservators having the 

last word on loans would be neglected. Nevertheless, within two years, an interim guideline was 

TABLE 1. (Continued).

Guideline

Tolerable 

rangea

Tolerable 

short-term 

fluctuationb

Annual 

set point 

or average

Summer 

set point

Winter 

set point

IPI cool storagef

(All “IPI” are from 

Adelstein 2009)

Unspecified. RH fluctuations not 

important if proper packaging. 

Temperature increases will erode lifetime 

(can be calculated). ISO standards 

provide more detailed specifications.

~12°C

~54°F

Up not 

allowed

Down if it 

saves money

IPI cold storage ~4°C

~40°F

IPI freezing storage ~0°C

~32°F

Dry storage metals No formal specifications exist, but 30% RH slows down deterioration of most problematic 

metals enough. Salt-contaminated iron has very slow corrosion down to ~10% RH 

(Watkinson and Tanner, 2008).

a

“Tolerable range” refers to the entire range of RH values permitted, including all fluctuations. It is not the range in system set points, 

which is an operational specification; it is a performance specification for the entire space containing collections. Also called “the box” 

in reference to the four-sided zone drawn on a chart of RH and temperature, such as the psychometric chart. It is not desirable, only tolerable. All readings over the year must fit in this zone. Current guidelines do not consider that HVAC engineers’ design to a percentile, 

typically 1% design conditions (~4 days per year outside limits), since the naive assumption of users has been that engineers design to 

0% chance of excess conditions (meaningless and/or impossible). It is important for museums that designers and operators know which 

parameter to favor during overload conditions, RH or temperature. In all cases it is RH first.

b The plus-minus symbol (e.g., ±X) means that the RH or temperature can range up X and down X from a set point or an average value, a 

peak-to-peak range of 2X. Some standards do not specify the exact time frame; most are per day.
Climate Guidelines for Heritage Collections 19

adopted by the American Institute for Conservation of Historic and Artistic Works (AIC), and it 

was endorsed by the Association of Art Museum Directors in May 2013 and forwarded to the 

International Institute for the Conservation of Artistic and Historic Works (IIC) and the International Council of Museums Committee for Conservation (ICOM-CC; Kerschner, 2013).

Specifications as of 2014: 

Do the Ratified Guidelines Apply Only on Loans?

In September 2014, the two major international conservation organizations, ICOM-CC and 

IIC, prepared a common statement on climate control guidelines that was ratified by vote at 

their conferences. It begins with a text about sustainability and so forth that many will treat as a 

preamble and proposes simply that the term “interim” be dropped from the guidelines of Bizot, 

NMDC, AIC, and the Australian Institute for the Conservation of Cultural Materials, all of which 

are individually provided in an appendix, without synthesis (Velios, 2014). This proposal leaves 

the reader to sort out that the different guidelines do share the same acceptable range, or box, 

of 40% to 60% RH and 15°C to 25°C but vary in regard to short-term fluctuations (see Table 

Purpose of these conditions 

(i.e., risks that are reduced)c

Collateral damage 

to mixed collections 

in these conditions 

(i.e., risks that remain)

Risk due to RH spikes 

over ±20% but 

duration less than 

1 hourc

Risk due to a 

sustained RH 

fluctuation over 

±20%, e.g., system 

or shipping failurec

Increase lifetime of unstable 

materials in archives, also in 

museums and galleries. Lifetime ~3 

times longer compared with that at 

20°C/68°F

As in points 1 and 2 

above; no risk if well 

packaged

As in points 1 and 2 

above; no risk if well 

packaged

Lifetime ~10 times longer 

compared with that at 20°C/68°F

Acrylic paints, some 

thick plastics at risk of 

cracking 

Lifetime ~20 longer compared with 

that at 20°C/68°F

c

Vulnerability categories of low, medium, high, and very high are defined in Michalski (1996), and also described at www.cci-icc.gc.ca.

d

The Smithsonian guideline specifies only the total box, recognizing that in practice energy considerations will usually, but not necessarily, push competent operation toward use of the lower left corner of the box in winter and the upper right corner in summer.

e For ASHRAE the tolerable range is derived from the seasonal set points plus short-term fluctuations, and for comparison to other 

guidelines, an annual average set point of 21°C/50% RH is assumed. Note that ASHRAE allows this annual set point to vary more, but it 

is meant to be selected once on the basis of local climate and usage reasons, not used as part of seasonal adjustment. 

f

See Adelstein (2009).
20 Smithsonian Institution Summit on the Museum Preservation Environment

1). The ICOM-CC and IIC statement notes that these guidelines were developed for international loan exhibitions, thereby implying that specifications for permanent collections remain 

up to individual users who should think through the issues raised in the main text, which are 

essentially a condensed version of the decision-making advice in PAS 198 (British Standards 

Institute, 2012). I suspect that users without technical resources will be content to say “what’s 

good enough for my loans is good enough for me.” 

Metals, Glass, Minerals, Pyrites, Photographs, Newspaper, 

Tapes, Plastics, and More Do Not Agree with Human Comfort

As we have seen, museum and gallery climate specifications originated in the desire to reduce 

cracking and flaking of paintings due to very low RH and very high RH. Many other collections—furniture, ivories, parchment, fine art on paper—seemed to fit the same argument. No 

exotic machinery was needed, just upgrading of the machines that humans already wanted for 

their own comfort. But a second theme existed in the background—many important collections are better served by climates uncomfortable to humans. In this section I develop the three 

strands—awareness, specification, and science—together since they are much more closely 

linked than for paint and wood.

The awareness that copper and iron alloys corrode rapidly when damp must have arisen 

as soon as each metal was made into something usable, but the first museum specification 

was Rathgen’s (1905) call for very low RH cases to stop bronze disease. Passive control via 

airtight cases became firmly established as the responsibility of conservators or maybe the exhibit personnel but not facilities managers or their engineers. Active desiccant dehumidifiers 

were attached to cases in the 1970s, but it was only in the late 1990s that the responsibility for 

machines supporting display cases, by now used for middle RH as well as low RH, began to 

move from the conservators to the facilities managers. In my experience, such machines must 

become part of facilities maintenance if they are to survive beyond their initial conservation 

champions. Industry and the military have protected the interiors of large metal objects with 

desiccant dehumidifiers since at least the 1970s, but museums have only recently considered 

their application to large objects, such as the interior of airplanes (Darren Priday, Manager, Michael Beetham Conservation Centre, Royal Air Force Museum, personal communication, 2015) 

and the bottom half of an ocean liner (Watkinson and Tanner, 2008).

In the 1960s, glass acquired special museum RH status through the work of Brill (1975), 

a scientist at the Corning Museum. Glass brought a new wrinkle—two RH phenomena in 

conflict, one with a lower RH limit, the other with an upper limit—that remains a source of 

research and discussion to the present day. Koob (2012) discusses glasses that are not preserved 

by any RH but whose decay is certainly slowed down by an optimum RH. 

Although the corrosion products of metal and glass are minerals, mineral collections as 

such were not given RH specifications until the systematic work of Waller (1992), who simultaneously (like Rathgen) demonstrated simple methods for reliable passive RH control of specimens. At the same time, natural history museums discovered the special RH needs of fossils 
Climate Guidelines for Heritage Collections 21

containing pyrites. Pyrite itself is better off at very low RH (Howie, 1992), but when it is present 

in fossils, a compromise with cracking of other components may be necessary. 

By the late 1920s, it was clear that some papers and the plastic base of films were aging 

quickly; that is, they had poor “stability.” By the 1930s, scientists at the National Bureau of 

Standards (NBS) had measured the much higher relative stability of rag papers compared with 

wood pulp papers (Scribner, 1939). The NBS also showed the much better stability of the new 

acetate films compared with old nitrate film, so they recommended use of acetate films for 

microfilming archives (Hill and Weber, 1936). These “accelerated ageing” studies were based 

on the fact that higher than normal temperature speeds up chemical self-destruction, and the 

extrapolations were shown to correlate fairly well with natural ageing (Scribner, 1939). The obvious corollary—that low temperatures would slow down chemical self-destruction of unstable 

materials—did not occur to anyone for a remarkably long time. 

By the mid-1950s, users noted that acetate film was also degrading (Adelstein, 1995) and 

by the end of the 1950s William K. Wilson and colleagues (1954) at NBS measured the decay 

of acetate films used as a laminating material. Not until the 1960s and 1970s did film manufacturers study the problem (Adelstein et al., 1995). Meanwhile, a second photographic stability 

issue arose—color dye fading. By 1970, Kodak published elegant work (Adelstein et al., 1970) 

quantifying the benefits of cold storage on color lifetime, using the Arrhenius method, a basic 

tool of chemical kinetics that would become a mainstay of conservation science, much used, 

much debated. In the mid-1970s, Jim Wallace, director of Smithsonian Photographic Services, 

became an early adopter of the cold storage strategy, probably in light of the nitrate-acetate 

problem (Roby, 2013). The color loss problem, however, did not seem to influence the behavior 

of manufacturers or archivists until 1980, when director Martin Scorsese complained loudly 

about it (Wilhelm and Brower, 1993:306). Henry Wilhelm, an independent researcher and 

industry gadfly who had advised Scorsese, eventually published a massive tome on the failings 

of the materials, the need for cold storage, and the means for doing so at small and large scales 

(Wilhelm and Brower, 1993). In 1978, J. Reilly started a university-based research laboratory 

that by 1985 became the Image Permanence Institute (IPI; Image Permanence Institute, 2010). 

Through Reilly’s proselytizing and IPI’s user-friendly tools, lifetime and cold storage finally became part of the ordinary archivist’s mindset, if not behavior. 

In 1986, D. Sebera presented a graphical tool for predicting the relative lifetime of paper 

at any combination of temperature and RH, later made part of the online information from the 

U.S. Commission on Preservation and Access (Sebera, 1994). Although the data and equations 

behind it have subsequently been refined or hidden inside digital black boxes, I think the 

graphic remains influential because for the first time the preservation community could “see” 

that they had a continuum of options, many shades of gray, and they had to choose on the basis 

of the purpose of the collection, not on any clear-cut jump in deterioration. 

William K. Wilson had been a junior member of the 1930s group at NBS studying paper 

ageing (Scribner, 1939: acknowledgement). Sixty years later, after a distinguished career carrying out or directing ageing studies, he was asked to chair the National Information Standards 
22 Smithsonian Institution Summit on the Museum Preservation Environment

Organization (NISO) committee tasked with developing specifications for libraries and archives. 

He could not convince the traditionalists that magic numbers from museums may not be appropriate. At the time, the preservation strategies in vogue were microfilming and mass deacidification (both soon destined to hit feasibility walls). The NISO committee was deadlocked, so 

Wilson published an unratified but nevertheless NISO-sponsored report on guidelines, the first 

of its kind for NISO (Wilson, 1995). 

Magnetic tape preservation advice made a curious (wrong) detour from the path of “colder 

and dryer equal longer lifetime.” Researchers in the tape industry produced a graphic of lifetime curves strangely suggesting indefinite lifetime at 30% RH, regardless of temperature. In 

my opinion, this recommendation was a misapplication of data on two phenomena that were 

counterbalanced in the short term but not in the long term (Michalski, 2000: endnote 23). 

Their graphic led many to believe (wrongly) that tapes would survive at room temperature. The 

IPI, with its advice on film well established, has turned its gaze to magnetic media and plans to 

clarify these issues (Bigourdan et al., 2006). 

The Slow and Unfinished Science of Damage and Its Application

The first museum study on cracking was instigated by “an apparent increase” in “blistering 

and flaking” of panel paintings in the National Gallery, London, after the “exceptionally dry 

weather of 1929” (Stilwell and Knight, 1934). Ten authentic panel paintings of supposed 

“little value” were cut into strips, some exposed to extreme RH fluctuations, some to forced 

bending. Most of the project focused on comparing moisture barrier coatings for the back of 

the panels. The attempt to create damage by RH cycles failed because it was made at 40°C to 

“speed up” moisture diffusion—a bad idea since that made the ground and paint more flexible. The only damage concept that emerged clearly in the conference reports is the a priori 

belief that only the RH response of the support matters, whether wood (Stilwell and Knight, 

1934) or canvas (Macintyre, 1934), a mistake that continued until Mecklenburg (1982) corrected it 50 years later.

I think the observations that triggered the research are more valuable than the research. 

No gallery RH readings are available, but let’s assume that the “dry weather of 1929” was 

actually the winter of 1928–1929 because it was the fifth coldest in the entire century, unusual in terms of sustained cold (Weather-history, 2006). This is important because panels 

with exposed backs take about a week to reach three-quarters of full response (Stilwell and 

Knight, 1934: Test IV). February 11 to 19 was the coldest week, averaging −4.6°C (Weatherhistory, 2006). If the gallery was heated in winter to 15.5°C (60°F) as Macintyre (1934) states 

and assuming conservatively an outdoor average RH of ~80% and no gallery humidification 

in place, then average RH for the week would have dropped to 20%. The RH fluctuation 

responsible for the widely noticeable damage was not 20% or 30% but a 40% drop from the 

summer value of 60%. 

In the early 1920s, Harley Nelson of the New Jersey Zinc Company led a group of researchers trying to understand the cracking of linseed oil house paints. In a series of papers (reviewed 
Climate Guidelines for Heritage Collections 23

in Michalski, 1991), Nelson and colleagues measured several key mechanical phenomena in a 

range of paints and varnishes: stress relaxation over time, moisture adsorption at various RH, 

and the dramatic effect of RH on elasticity and strength. In the early 1950s, F. L. Browne published a long series of articles (reviewed in Michalski, 1991) on the dimensional response of oil 

paints to RH as well as measuring its curing shrinkage, known later in paint research as “internal stress,” a key to understanding cracks in paint. By 1980, a great deal of relevant research had 

accumulated in the paint literature, but none of it seemed to enter the museum conservation 

field. The only “science” that permeated explanations of RH damage was the tiresome diagram 

of how different cuts of wood warped from the green state.

In the late 1970s, Marion Mecklenburg, a private paintings conservator frustrated with 

inadequate explanations of cracking in paintings, took up the study of mechanical engineering. He built his own tensile testers and began measuring tension in restrained samples as 

the RH changed, first samples from an old painting on canvas, then new samples of each 

layer in a painting: canvas, glue, and paint. In 1982, he provided a report to the Smithsonian 

called “Some Aspects of the Mechanical Behavior of Fabric Supported Paintings” (Mecklenburg, 1982) that laid the foundation for all subsequent modeling in the field. He established 

that the tension in a laminar structure is the sum of tensions from each layer; the change in 

tension due to an RH change depends not only on change in dimension but also on change 

in elasticity because the solid layers (glue, ground, paint, varnish) shrink and stiffen at low 

RH and expand and soften at high RH, whereas the woven layer does the opposite. When one 

measures the tension in restrained specimens of old paintings as RH varies from 5% to 95% 

and back again, as Mecklenburg did (replicated by others soon afterward), one obtains the 

now familiar hockey stick curve, with a valley from 50% to 75% RH, a long curved climb to 

maximum tension at low RH entirely due to the solid layers, and an upturn beyond about 85% 

RH due to canvas tightening. 

A few years later, paint industry researchers Pererea and Van Eynde (1987) published what 

I realized was the larger model within which Mecklenburg’s ideas could fit (they were unaware 

of the field of museum conservation). They used the context of viscoelastic mechanics to explain “hygrothermal stresses,” including those arising from curing shrinkage, and provided the 

correct integral equation. 

By the time of the 1991 Art in Transit conference (Mecklenburg, 1991), museum conservatorship had advanced considerably. Mecklenburg and his Smithsonian colleagues presented 

computer modeling that generated the same patterns of cracks one often sees in paintings 

on canvas, some by drops in RH, others by drops in temperature. After modeling preexisting 

flaws in panel paintings, their final advice was cautious: “All panel paintings should be maintained in a very narrow relative humidity environment” (Mecklenburg and Tumosa, 1994:190). 

I presented a critical review of the copious “unknown” literature that supported and extended 

Mecklenburg’s data and placed it all within a viscoelastic framework (Michalski, 1991). (Just 

before all the stacks in the Canadian central government research library were closed to users, 

I had skimmed the table of contents of every volume of every journal in the paint, glue, and 
24 Smithsonian Institution Summit on the Museum Preservation Environment

textile industries back to 1900). Since the conference was on vibration in transit, I had also 

begun to develop a fatigue mechanics approach that I later applied to multiple fluctuations 

(Michalski, 2014) because the following question always came up: What about thousands of 

small fluctuations? 

Three years later, Mecklenburg and his colleagues were no longer concluding with “a 

very narrow relative humidity environment” but rather the opposite (Smithsonian Institution, 1994; Erhardt and Mecklenburg, 1994). No change in the science had occurred, but the 

presumed question had been changed from “What is tolerable under a worst-case scenario 

for a panel painting?” to “What is tolerable for a typical object in the group known to be 

vulnerable?” This latter question has guided all of Mecklenburg and colleagues’ articles on 

specifications to the present (all key publications up to 2007 are online in the Smithsonian 

Library’s DSpace Repository at https://repository.si.edu, under Museum Conservation Institute). Mecklenburg’s approach to the question is as follows: Assume that the “yield point” of 

materials is the criterion for unacceptable damage, that is, the amount it can stretch and still 

rebound completely. Assume that the most representative geometry for vulnerable objects in 

the whole collection is uniform constraint of the vulnerable component, e.g., a uniform paint 

layer held uniformly by some other stronger component, and assume that this component is at 

zero stress at the climate set point. (In my own advice, I refer to such assemblies as “medium 

vulnerability.”) Now calculate the fluctuation that will cause the strain that reaches the yield 

strain, taking into account the nonlinear relation of shrinkage to RH for materials such as 

wood. Having done this for various materials, he and his colleagues conclude that 30% to 60% 

RH is safe “for general collections” but then state “There are exceptions...severely degraded 

materials, objects with weak or degraded adhesives (especially veneers and inlays), or objects 

such as drums and Japanese screens with pre-existing stresses should be kept in more stable 

environments.” They suggest enclosures for such objects. Their final recommended range for 

building control is 37% to 53% RH but which exceptions this “conservative” range does or 

does not cover is left unclear (Erhardt, 2007). This category of “exceptions” is precisely what 

concerns conservators.

My own work on the science since 1994 has also built on Mecklenburg’s (1982) foundations, adding real-world flaws, fuzziness, and fatigue (Michalski, 2013), and someday I would 

like to be able to predict the curves of Figure 1, but until then my approach to specifications 

and tolerable fluctuations has changed little since I surveyed what was known 20 years ago (Michalski, 1991, 1993, 1994b) and introduced the idea of proofed fluctuation (Michalski, 1993). 

I will address this in the next section.

Fortunately, new researchers have entered the field, most notably the group in Cracow 

under the leadership of Roman Kozlowski. A key contribution was their measurement of fatigue 

cracking in samples of gesso on poplar subjected to thousands of mechanical cycles applied to 

the wood to simulate its expansion and contraction by RH fluctuations. By computer modeling 

the maximum plausible frequency of cycling of a panel by RH, they concluded that gesso on 

wood could tolerate ±15% RH fluctuations for at least a century (Rachwał et al., 2012). 
Climate Guidelines for Heritage Collections 25

What is Stable? What is Safe? What is Tolerable? The Five Errors

Throughout the decades of pontification on climate specifications, the one thing everyone 

seemed to agree on was the absolute goodness of a “stable” climate. “Stable is safe” has become 

the rallying cry of the new traditionalists (Burmester and Eibl, 2014). We have seen the obvious 

exceptions: metals, glass, and minerals; their issue is staying within sharp RH boundaries, not 

fluctuations. Even archive advisers used to be adamant about stability for chemical and mechanical reasons until very recently, but the old bugaboo that fluctuations speed up chemical 

self-destruction above and beyond simple addition of each moment’s effect has been laid to rest 

by IPI (Bigourdan and Reilly, 2003). Furthermore, paper conservators are beginning to accept 

(correctly, I believe) that unrestrained expansion and contraction of paper sheets is not a danger; the National Archives (2013) just finished a test of a repository previously stable at 45% 

RH that is now allowed to float up in summer (50%) but down even lower in winter (30%), 

thereby saving not only energy but collection lifetime. For archive records that are mechanically 

© Government of Canada, Canadian Conservation Institute, 2016

FIGURE 1. Cumulative population distributions of vulnerability to RH fluctuations. Red solid lines show data for fresh 

mammalian teeth, which represent ivory and behave like wood in terms of having different responses across the grain; 

canines have solid cores and hence are more vulnerable to splitting than molars, which are hollow (Williams 1991). 

Dotted lines represent three vulnerability classes (very high, high, medium), each one double the vulnerability of the 

next, defined in Michalski (1996). The dashed black line shows the vulnerability of a mixed collection, which can contain 

all vulnerability classes, including some objects with no vulnerability. Upper scales show equivalent RH fluctuations 

due to fatigue at 1,000 cycles (e.g., a millennium of seasonal lows) and at 10,000 cycles (e.g., 30 years of daily cycles 

to objects thin enough to respond), based on Michalski (2014). The bright green vertical line at ±20% RH represents 

various proofed fluctuations: either one cycle of ±20% RH or 1,000 cycles of ±13% RH or 10,000 cycles of ±9% RH; it 

truncates all distributions precisely, such as most of the high vulnerability objects (green zone). The vertical red line near 

the center represents flaking of panel paintings in the National Gallery (N.G.) London in 1929 due to a 40% RH drop 

(estimated in the section on the science of damage). If almost 100% of the collection flaked, it would mean it was a high 

vulnerability collection (top star). If less than 20% of the panels flaked, it implies that they were a medium vulnerability 

collection or even a mixed collection (lowest two stars). The role of heritage science is to collect data and build models for 

these plots and to confirm them through observations of actual collections and to do the same for mechanical risks from 

temperature fluctuations. 
26 Smithsonian Institution Summit on the Museum Preservation Environment

vulnerable to fluctuations, advisers are beginning to integrate package performance with flexibility in system operation (Bigourdan, 2012), opening the door to off-peak utility use, etc. 

What, then, about the vulnerable stuff? I think there have been five errors in argumentation 

on all sides. 

Error 1: Assuming Stability Means Just Most of the Time

For human comfort and preservation of chemically unstable materials, being within specification 99% of the time is good enough, great even. For mechanical damage, it is not: 3 days per 

year, or 30 days per decade, outside specifications is all that matters in the end. In risk analysis, 

hazards such as fluctuations vary over a continuum from frequent-trivial to rare-catastrophic, 

e.g., earthquakes, car collisions, etc. The largest contributions to total risk, the best events to 

try and reduce, are usually from the middle to high end of the range—the not so rare but still 

serious events. Table 2 examines the risk from two types of fluctuation events: the frequent ones 

we obsess about and the occasional failures we do not discuss. It is not necessary to be precise 

about what “tiny” or “large” damage means (although I believe these terms are technically defensible). The point of Table 2 is just the logic of long-term preservation: less frequent but larger 

fluctuations are the biggest risk to museum collections unless, of course, the object is inside an 

enclosure. Even if there is a tiny increase in risk by having ±10% RH compared with ±5% RH, 

it does not actually matter to total risk because that is dominated by the one bad event. 

Error 2: Unverified (Unbelievable?) Claims of Control

Jonathan Ashley-Smith first raised the following concern in the United Kingdom, and Matthew 

Siegal has reiterated it in the United States: many museums, even those with well-intentioned 

systems, do not stay within ±5% RH. Even ±10% might be exceeded once in a while. Rather 

than the hypocrisy issue raised by others, I am concerned with the two arguments based on 

TABLE 2. Risk from a mix of routine RH fluctuations plus a rare failure event in 30 years, for an object of very 

high vulnerability, i.e., never exposed beyond ±5% RH before today.

Conditions

Damage due 

to the routine 

fluctuations

Damage due to 

a failure event of 

30% RH fluctuation Total risk per 30 years

Control to ±5% RH, 

except one failure event 

in 30 years

None + Large;

Small if fluctuation shorter 

than response time

= Large;

Small if fluctuation shorter 

than response time

As above, object enclosed. None + None = None

Control to ±10% RH, 

except one failure event 

in 30 years

Tiny

None if m>>n 

+ Large;

Small if fluctuation shorter 

than response time

= Large;

Small if fluctuation shorter 

than response time

As above, object enclosed. None + None = None
Climate Guidelines for Heritage Collections 27

these claims: (1) the feasibility of tight specifications for everyone and (2) the precautionary 

counterfactual scenario (i.e., my collection is undamaged, and I have never gone beyond ±5% 

RH; therefore, I have no proof that conditions are safe beyond ±5% RH, and damage becomes 

a possibility, so precaution tells me to never go there). This argument is legitimate, but its truth 

rests in the truth of the ±5% control, that is, how long “never” was. I think it is common that 

good systems maintain ±5% RH in one location for weeks, longer if the weather is benign, but 

in a nineteenth-century building with crowds and limited ductwork, I doubt that each object 

stays within ±5% RH through all seasons, and I know that control has not lasted decades. 

Overloads happen. Heating-cooling changeover gets erratic. Systems get repaired and replaced 

(never mind accuracy, which makes anyone who has done rigorous RH measurement sigh). 

Until galleries claiming such control share seamless and verifiable climate data, not only does 

their argument ring hollow, but the community loses its best chance to understand the vulnerability of collections because I do believe their observation of no damage. 

Error 3: Ignoring the Reality of Proofed Fluctuation

A history of deviations from perfection, as noted in error 1, can be seen as bad news, but there 

is good news too. Whatever the worst fluctuation that a collection has experienced, anything 

less will cause very little risk, unless the collection has aged chemically (decades for old paint). 

Michalski (2014) provides a method for extrapolating to multiple future cycles from a single 

worst historic fluctuation of ±X% RH; for example, at ±0.9X% up to 30 future fluctuations are 

tolerable, at ±0.65X% up to 1,000 future fluctuations are tolerable, etc. 

Error 4: Ignoring the Fact That the Value at Risk 

Does Not Reside in Original Old Material

Old things have certainly seen at least ±20% RH fluctuations in their time and often more. If 

old furniture and paintings appear flawless today, it is only because of restorations. Any original 

seams or layers vulnerable to ±20% RH popped long ago. If an old object is actually vulnerable 

to fluctuations smaller than ±20% RH, it is primarily the reglued seams and painted infills that 

fall apart, not original material. I am not advocating the popping of good (and expensive) restorations and the collateral damage that comes with repetitive restoration; I am only asking that 

we stop pretending that it is nonnegotiable original material that is at risk in the range being 

debated because it is primarily restorations that are at risk. Thus, an additional reason that the 

risk from unusual fluctuations in Table 2 is much larger than that of frequent small fluctuations 

is the greater value of the material involved. Original material is at risk to small fluctuations only 

in new objects, and such collections do warrant separate decision making.

Error 5: Answering a Different Question from the One Asked

A good politician listens politely to the interviewer’s question and then answers a different question, for which he has a very good answer. Who had the “right” question depends 

on your perspective. I think conservators looking for climate advice intended the following 
28 Smithsonian Institution Summit on the Museum Preservation Environment

question: What is the maximum fluctuation tolerable by any and all objects in my collection? In other words, what rule covers the exceptions as well as the typical objects. I think 

scientists annoyed at conservators not listening to their “rational guidelines” (Erhardt, 2007) 

had given a good answer to a different (and simpler) question: What is the fluctuation that 

science predicts will be tolerable by typical objects within each of the groups known to be 

vulnerable? I think the proper question to science, illustrated in Figure 1, will answer both 

these questions: What is the distribution curve for critical fluctuations across the various objects in a collection (from which we can then derive averages and exceptions)? When we can 

answer that question, we will have a tool that we can bring to the table alongside curatorial 

and technical expertise to answer the real question: What is the best sustainable climate we 

can provide for our collections? 

Conclusions

Creating climate specifications for collections is like buying a suit: a one-size-fits-all outfit is 

very precise but looks awful on almost everyone, an off-the-rack suit in one’s own size is pretty 

good and works for most of us, but a tailored suit looks best, usually lasts longer, and costs less 

in the long run. However, the initial costs and time required are high, and there will always be 

naysayers who cannot see the difference. 

What advice would I give to the management of a large museum looking for a set of climate 

control specifications? Read and act on the decision-making approach of PAS 198 (British Standards Institute, 2012). During negotiations, please avoid errors 1 to 5 in the previous section. 

That said, the process is unclear and daunting, so here are my action recipes for three levels of 

increasing opportunities for sustainable design but increasing effort:

1. For one size fits all, use Smithsonian or AIC, IIC, ICOM-CC, and Bizot specifications and 

adjust where necessary considering the commentary in Table 1.

2. For off the rack, look at the museum chapter in ASHRAE (2015) and IPI Media Storage: 

Quick Reference (Adelstein, 2009). Conservators select preferred targets, engineers and architects indicate cost options, and they negotiate. 

3. For a custom fit, use the following recipe: (a) Curators analyze the implications of the institution’s mandate for preservation criteria of each collection. (b) Conservators analyze the 

vulnerabilities of the collections to various climates. (c) Engineers and architects analyze 

the implementation options for various climates in terms of life cycle costs and energy. 

Then everyone sits together and negotiates an optimum for the institution. It is probably 

wise to iterate this process a few times, that is, first build shared awareness, then identify 

areas of overlap, then refine.

Finally, let’s recognize that the only realistic method for long-term RH stability is an airtight enclosure, whether an object is on display or in transit or in storage. If one truly believes 

that an object must never exceed a certain range in RH, it is irrational to expect mechanical 

systems to be that perfect. Once in place, enclosures open the door to many savings in design 

and operation of that mechanical system. 
Climate Guidelines for Heritage Collections 29

References

Adelstein, Peter Z. 2009. IPI Media Storage: Quick Reference. 2nd ed. Rochester: Image Permanence Institute. http://www.imagepermanenceinstitute.org/webfm_send/301 (accessed January 10, 2015).

Adelstein, P. Z., C. L. Graham, and L. E. West. 1970. “Preservation of Motion-Picture Color Films Having 

Permanent Value.” Journal of the SMPTE 79(11):1011–18. http://dx.doi.org/10.5594/J13565.

Adelstein, P. Z., J. M. Reilly, D. W. Nishimura, and C. J. Erbland. 1995. “Stability of Cellulose Ester Base 

Photographic Film: Part III—Measurement of Film Degradation.” SMPTE Journal 104(5):281–91. 

http://dx.doi.org/10.5594/J15292.

American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). 1999. “Museums, 

Libraries and Archives.” In ASHRAE Handbook: Heating, Ventilating and Air-Conditioning: Applications, 

pp. 20.1–20.13. Atlanta, GA: ASHRAE. 

———. 2015. “Museums, Galleries, Archives and Libraries.” In ASHRAE Handbook: Heating, Ventilating 

and Air-Conditioning: Applications, pp. 23.1–23.22. Atlanta, GA: ASHRAE.

Bickersteth, Julian. 2014. “Environmental Conditions for Safeguarding Collections: What Should Our 

Set Points Be?” Studies in Conservation, 59(4):218–224. http://dx.doi.org/10.1179/20470584

14Y.0000000143. 

Bigourdan, J. 2012. “Understanding Temperature and Moisture Equilibration: A Path towards Sustainable Preservation Strategies.” Paper presented at IAQ 2012, London. https://www.imagepermanence

institute.org/webfm_send/605 (accessed January 10, 2015).

Bigourdan, J., and J. M. Reilly. 2003. Effects of Fluctuating Environments on Paper Materials: Stability and 

Practical Significance for Preservation. Rochester, NY: Image Permanence Institute, Rochester Institute 

of Technology. 

Bigourdan, J., J. M. Reilly, K. Santoro, and G. Salesin. 2006. Final Report to the National Endowment for 

the Humanities, Division of Preservation and Access, NEH GRANT # PA-50123-03: The Preservation 

of Magnetic Tape Collections: A Perspective. Rochester, NY: Image Permanence Institute. 

Bell, N. 2009. EGOR: Environmental Guidelines: Opportunities and Risks. http://www.heritagescience

.ac.uk/Research_Projects/projects/Cluster/Bell (accessed January 10, 2015).

Brill, R. H. 1975. “Crizzling-a Problem in Glass Conservation.” Studies in Conservation 20(Supplement-1):121–34. http://dx.doi.org/10.1179/sic.1975.s1.021.

Bradley, S., and D. Thickett. 1998. “The Pollutant Problem in Perspective.” Paper presented at Indoor Air 

Pollution: Detection and Mitigation of Carbonyls, Glasgow, UK. http://iaq.dk/iap/iap1998/1998_05

.htm (accessed January 10, 2015).

British Museum. 1939. Air Raid Precautions in Museums, Picture Galleries and Libraries. London: British 

Museum. 

British Standards Institute. 2012. PAS 198:2012, Specification for Managing Environmental Conditions 

for Cultural Collections. London: British Standards Institute.

Brown, J. P., and W. Rose. 1997. Development of Humidity Recommendations in Museums and Moisture Control in Buildings. Conservation On-Line. http://cool.conservation-us.org/byauth/brownjp

/humidity1997.html#fn16 (accessed January 10, 2015).

Buck, R. D. 1964. A Specification for Museum Airconditioning. Museum News, 43(4):53–57.

Burmester, A., and M. Eibl. 2014. Stable Is Safe. The Munich Position on Climate and Cultural Heritage 

(Version 01.04.2014). http://www.doernerinstitut.de/downloads/Statement_Doerner_Bizot_en.pdf 

(accessed January 10, 2015).

Church, A. H. 1872. “Chemistry of the Fine Arts VI.” In Cassell’s Technical Educator: An Encyclopaedia of 

Technical Education, vol. 3, pp. 246–248. London: Cassell, Petter, and Glapin.

———. 1890. The Chemistry of Paints and Painting. London: Seeley.

Constable, W. C. 1934. “Appendix III. Framing and the Control of Humidity.” In Some Notes on Atmospheric Humidity in Relation to Works of Art, pp. 39–42. London: Courtauld Institute of Art.
30 Smithsonian Institution Summit on the Museum Preservation Environment

Erhardt, D., and M. F. Mecklenburg. 1994. “Relative Humidity Re-examined.” In Preventive Conservation: 

Practice, Theory and Research. Preprints of the Contributions to the Ottawa Congress, ed. A. Roy and P. Smith, 

pp. 32–38. London: International Institute for the Conservation of Artistic and Historic Works.

Erhardt, D., C. S. Tumosa, and M. F. Mecklenburg. 2007. “Applying Science to the Question of Museum 

Climate.” In Museum Microclimates: Contributions to the Conference in Copenhagen, ed. T. Padfield and 

K. Borchersen, pp. 11–18. Copenhagen: National Museum of Denmark. http://conservationphysics

.org/mm/erhardt/erhardt.pdf.

Hatchfield, P. 2011. Crack, Warp, Shrink, Flake: A New Look at Conservation Standards. Museum, January–February, 40–51.

Hill, J. R., and C. G. Weber. 1936. “Stability of Motion Picture Films as Determined by Accelerated Aging.” 

Journal of the Society of Motion Picture Engineers 27(6):677–690.

Howie, Frank M. 1992. “Pyrite and Marcasite.” In The Care and Conservation of Geological Material: Minerals, Rocks, Meteorites, and Lunar Finds, pp. 70–84. Oxford, UK: Butterworth-Heinemann. 

Image Permanence Institute. 2010. From Silver Image to Silver Anniversary: A Look Back at 25 Years of AwardWinning Preservation Research at RIT’s Image Permanence Institute. Rochester, NY: Image Permanence 

Institute, Rochester Institute of Technology.

Keeley, T., and I. Rawlins. 1951. Air Conditioning at the National Gallery, London, Its Influences upon the 

Preservation and Presentation of Pictures. Museum International, 4(3):194–197.

Kerschner, R. L. 2013. AIC Working Group Informs IIC and ICOM-CC Work on Museum Environmental 

Guidelines. AIC News, September, 8.

Koob, S. P. 2012. Crizzling Glasses: Problems and Solutions. Glass Technology: European Journal of Glass 

Science and Technology, Part A, 53(5):225–227.

Lafontaine, R. H. 1979. Environmental Norms for Canadian Museums, Art Galleries, and Archives. Technical 

Bulletin 5. Ottawa: Canadian Conservation Institute.

Luciani, A. 2013. Historical Climates and Conservation Environments. Historical Perspectives on Climate 

Control Strategies within Museums and Heritage Buildings. Ph.D. diss., Politecnico di Milano, Milan. 

https://www.politesi.polimi.it/handle/10589/74423 (accessed January 1, 2015).

Macintyre, J. 1934. “Some Problems Connected with Atmospheric Humidity.” In Some Notes on Atmospheric Humidity in Relation to Works of Art, pp. 7–16. London: Courtauld Institute of Art.

Macleod, K. J. 1975. Relative Humidity: Its Importance, Measurement, and Control in Museums. Technical 

Bulletin 1. Ottawa: Canadian Conservation Institute.

McCabe, J. 1931. Humidification and Ventilation in Art Museums. Museum News, September 1, 7–8.

McCrady, E. 1994. Temperature & RH Guidelines Challenged by Smithsonian. Abbey Newsletter, 

18(4–5):44–45.

Mecklenburg, M. F. 1982. Some Aspects of the Mechanical Behavior of Fabric Supported Paintings. Washington, D.C.: Smithsonian Institution. 

———, ed. 1991. Art in Transit: Studies in the Transport of Paintings. Washington, D.C.: National Gallery 

of Art.

Mecklenburg, M. F., and C. S. Tumosa. 1991. “Mechanical Behavior of Paintings Subjected to Changes in 

Temperature and Relative Humidity.” In Art in Transit: Studies in the Transport of Paintings, ed. M. F. 

Mecklenburg, pp. 173–217 Washington, D.C.: National Gallery of Art.

Mecklenburg, M. F., C. S. Tumosa, and D. Erhardt. 2004. New Environmental Guidelines at the Smithsonian Institution. Papyrus, 5(3):16–17.

Michalski, S. 1991. “Paintings—Their Response to Temperature, Relative Humidity, Shock, and Vibration.” In Art in Transit: Studies in the Transport of Paintings, ed. M. F. Mecklenburg, pp. 223–248. 

Washington, D.C.: National Gallery of Art.

———. 1993. “Relative Humidity: A Discussion of Correct/Incorrect Values.” In Preprints of the ICOM 

Committee for Conservation 10th Triennial Meeting, Washington, DC, 22–27 August 1993, vol. 2, pp. 

624–629. Paris: ICOM Committee for Conservation.
Climate Guidelines for Heritage Collections 31

———. 1994a. Leakage Prediction for Buildings, Cases, Bags and Bottles. Studies in Conservation, 

39(3):169–186. http://dx.doi.org/10.2307/1506596. 

———. 1994b. Relative Humidity and Temperature Guidelines: What’s Happening? CCI Newsletter, 

14:6–8.

———. 1996. Quantified Risk Reduction in the Humidity Dilemma. APT Bulletin, 27(3):25–29. http://

dx.doi.org/10.2307/1504412. [Vulnerability table adapted and online at http://www.cci-icc.gc.ca

/resources-ressources/carepreventivecons-soinsconspreventive/vuln-eng.aspx (accessed September 16, 

2015).] 

———. 2000. Guidelines for Humidity and Temperature in Canadian Archives, Technical Bulletin No. 23. Ottawa: Canadian Conservation Institute.

———. 2013. “Stuffing Everything We Know about Mechanical Properties into One Collection Simulation.” In Climate for Collections: Standards and Uncertainties, ed. Jonathan Ashley-Smith, Andreas 

Burmester, and Melanie Eibl, pp. 349–361. Munich: Doerner Institute.

———. 2014. “The Power of History in the Analysis of Collection Risks from Climate Fluctuations and 

Light.” In ICOM Committee for Conservation 17th Triennial Meeting, Melbourne, 15–19 September 2014, 

ed. J. Bridgland, pp. 1–8. Paris: ICOM Committee for Conservation. 

Museum Conservation Institute. 2015. Culmination of 20 Years of Green, Energy Savings Research. 

http://www.si.edu/mci/english/research/consulting/MuseumEnvironment.html (accessed January 10, 

2015).

National Archives. 2013. National Archives Extends Life Expectancy of Its Textual Records at Its College 

Park Facility and Saves Energy at the Same Time. http://www.archives.gov/preservation/environmental

-control/improved-environment-and-energy-savings.pdf (accessed January 10, 2015).

National Museum Directors’ Conference. 2009. NMDC Guiding Principles for Reducing Museums’ Carbon 

Footprint. http://www.nationalmuseums.org.uk/media/documents/what_we_do_documents/guiding

_principles_reducing_carbon_footprint.pdf (accessed August 8, 2014).

Oddy, W. A. 1973. An Unsuspected Danger in Display. Museums Journal, 73(1):27–28.

Perera, D. Y., and D. V. Eynde. 1987. “Moisture and Temperature Induced Stresses (Hygrothermal Stresses) 

in Organic Coatings.” Journal of Coatings Technology 59(748):55–63.

Plenderleith, H. J. 1998. A History of Conservation. Studies in Conservation, 43(3):129–143. http://dx.doi

.org/10.1179/sic.1998.43.3.129. 

Rachwał, B., Ł. Bratasz, L. Krzemien ́, M. Łukomski, and R. Kozłowski. 2012. Fatigue Damage of the Gesso 

Layer in Panel Paintings Subjected to Changing Climate Conditions. Strain, 48(6):474–481. http://

dx.doi.org/10.1111/j.1475-1305.2012.00844.x. 

Rathgen, F. 1905. The Preservation of Antiquities: A Handbook for Curators. Translated by George A. Auden 

and Harold A. Auden. Cambridge: Cambridge University Press.

Rawlins, F. 1942. The Control of Temperature and Humidity in Relation to Works of Art. Museums Journal, 

41(March):279–283. 

Roby, M. 2013. Unlocking the Vault. The Bigger Picture (blog), February 28. http://siarchives.si.edu/blog

/unlocking-vault (accessed January 10, 2015).

Russell, W. J., and W. de W. Abney. 1888. The Action of Light on Watercolours. London: HMSO.

Scribner, B. W. 1939. Comparison of Accelerated Aging of Record Papers with Normal Aging for 8 Years. 

Washington, D.C.: US Government Printing Office. http://nvlpubs.nist.gov/nistpubs/jres/23/jresv23

n3p405_A1b.pdf. 

Sebera, D. K. 1986. “A Graphical Representation of the Relationship of Permanence to Environmental 

Conditions.” In New Directions in Paper Conservation: 10th Anniversary Conference of the Institute of 

Paper Conservation, 14–18 April 1986, Oxford, p. F2. Leigh, UK: Institute of Paper Conservation.

———. 1994. Isoperms: An Environmental Management Tool. Washington, D.C.: Commission on Preservation and Access. http://www.clir.org/pubs/reports/isoperm/isop-app.html (accessed August 26, 

2014).
32 Smithsonian Institution Summit on the Museum Preservation Environment

Smithsonian Institution. 1994. Work of Smithsonian Scientists Revises Guidelines for Climate Control 

in Museums and Archives. Smithsonian Institution news release, August 21. [Reprinted in Abbey 

Newsletter, 18:4–5, 1994.]

Stilwell, S. T. O., and R. A. G. Knight. 1934. “Appendix I. Investigation into the Effect of Humidity Variations on Old Panel Paintings on Wood.” In Some Notes on Atmospheric Humidity in Relation to Works of 

Art, pp. 17–33. London: Courtauld Institute of Art.

Stolow, N. 1966. Controlled Environment for Works of Art in Transit. London: Butterworths.

Thomson, G. 1964. “Relative Humidity—Variation with Temperature in a Case Containing Wood.” Studies 

in Conservation 9(4):153–69.

Thomson, G. 1978. The Museum Environment. 1st ed. London: Butterworths.

———. 1977. “Stabilization of RH in Exhibition Cases: Hygrometric Half-Time.” Studies in Conservation,

22 (2): 85–102.

———. 1986. The Museum Environment. 2nd ed. London: Butterworths.

Toishi, K. 1959. “Humidity Control in a Closed Package.” Studies in Conservation, 4(3):81–87. http://dx

.doi.org/10.1179/sic.1959.018.

Velios, A. 2014. IIC Announces Declaration on Environmental Guidelines. https://www.iiconservation

.org/node/5168 (accessed January 10, 2015).

Waller, R. 1992. “Temperature and Humidity-Sensitive Mineralogical and Petrological Specimens.” In The 

Care and Conservation of Geological Material: Minerals, Rocks, Meteorites, and Lunar Finds, ed. F. Howie, 

pp. 25–50. London: Butterworth-Heinemann. 

Watkinson, D., and M. Tanner. 2008. “SS Great Britain: Conservation and Access–Synergy and Cost.” Studies in 

Conservation, 53(Supplement-1):109–114. http://dx.doi.org/10.1179/sic.2008.53.Supplement-1.109.

Weather-history. 2006. The Severe Winter of 1928–29. Historic Weather—Netweather Community Forums. https://forum.netweather.tv/topic/33865-the-severe-winter-of-1928-29/ (accessed September 

16, 2015).

Wilhelm, H., and C. Brower. 1993. The Permanence and Care of Color Photographs. Grinnell, Iowa: The Preservation Publishing Company. http://www.wilhelm-research.com/pdf/HW_Book_761_Pages_HiRes

_v1c.pdf. 

Williams, S. L. 1991. “Investigation of the Causes of Structural Damage to Teeth in Natural History Collections.” Collection Forum, 7:13–25.

Wilson, W. K., and B. W. Forshee. 1959. “Degradation of Cellulose Acetate Films.” Society of Plastics Engineers Journal, 15:146–56.
PRESENTATION

Risk Assessment and Assignment 

of Environment Parameters

R. ROBERT WALLER
ABSTRACT. Despite many decades of experience concerning ourselves with environmental parameters for the protection of cultural property as outlined by Michalski (this volume), huge gaps in our 

knowledge as well as uncertainties of many kinds remain. It is in exactly these situations of scant firm 

knowledge and high uncertainty that a risk analysis approach is most beneficial. The purpose of this 

paper is not to exhaustively describe how a risk analysis approach deals with reducing knowledge gaps 

and other forms of uncertainty. Instead, the emphasis here is on developing a clear understanding of 

what a risk is, how it is defined, and how various parts of an institution are able to contribute, according 

to their particular perspective, to collection-environment risk analysis. This information will lead to enhanced understanding of environmental parameter specifications and a more effective and cost-effective 

definition and application of those standards.
Risk Assessment and Assignment of Environment Parameters 35

Introduction

The programmatic activities of any museum, including the simple holding of collections over 

time, will inevitably expose its collections to risks of deterioration, damage, and loss. Exposure 

to risk can occur when collections are on exhibition or on loan, in transit, in storage, or while 

they are being handled, treated, or studied. The underlying principles of collection management—of striking a balance between the dual goals of preservation and accessibility—is a form 

of risk management that ensures informed decision making with input from all of the critical 

stakeholders responsible for protecting collections against damage, loss, and exposure to harmful environmental conditions. Risk assessment is therefore a principal component of sound collection stewardship. It should be approached in an informed, deliberate, and scientific manner. 

Demonstrating the dangers to collections posed by an inappropriate environment, even 

when that environment is the often-quoted 70°F/50% RH “standard specification,” tachyhydrite, 

a rare mineral, will dissolve within several hours when exposed to conditions of 70°F/50% RH 

for just a few hours. A time-lapse video of this process was produced by the Canadian Museum 

of Nature (2016). Although this particular video was staged, it does demonstrate the extreme 

vulnerability of some parts of museum collections. For any specified environmental condition 

(temperature, relative humidity, pollutant, and light level) examples can be found of collection 

items that will not just be unstable, but will deteriorate or be damaged very rapidly. Therefore, 

it is helpful for us to give up hope of any single, simple set of environmental specifications that 

will be universally applicable to collections. It is essential for us to consider variations in the 

sensibilities of collection items, as well as issues of maintaining specified conditions both over 

time and throughout collection spaces.

The term risk is familiar to everybody and is increasingly used in connection with collection 

care and management. By now, a variety of collection risk assessment approaches and methods 

exists. Most are designed for a particular purpose or to emphasize a particular perspective and 

work best when applied to similar situations. Examples include the following: 

• The approach of English Heritage combines collection risk, condition, and significance 

audits, yielding a combined measure of the scale of conservation issues as well as recommendations for broad priorities (Xavier-Rowe and Fry, 2010). 

• The Canadian Conservation Institute uses ABC scales that prioritize recommendations for 

reducing risks in conservation reports and, through International Centre for the Study of 

the Preservation and Restoration of Cultural Property (ICCROM) courses, has suggested 

the broader application of these simple scales (ICCROM, 2007).
36 Smithsonian Institution Summit on the Museum Preservation Environment

• Heritage Preservation provides a guide to identifying potential disasters and reducing their 

effects; it is designed mainly to connect collection care staff to the emergency preparedness 

and management field (Heritage Preservation, 2013).

• The University of California Berkeley Library is developing an approach for placing library 

collection risks within an overall University of California, Berkeley, enterprise risk management system (Ogden, 2012). 

• The Cultural Property Risk Analysis Method (CPRAM) of the Canadian Museum of Nature embeds risk awareness and competence throughout collection-holding institutions 

(Waller, 2003). It is most suited for application to medium to large institutions.

Although this paper is at a general level that is broadly applicable to any risk analysis process, 

the following discussion draws largely on the CPRAM model as the most fully developed and 

described model.

An underlying principle of risk assessment is the necessity of a system-based approach. In 

the case of collection risk assessment, the preservation system must mesh with other collection 

and institutional systems if it is to be effective. Consequently, CPRAM is based on a systems 

understanding of collection management that comprises three subsystems (see Figure 1). These 

are development (collection planning, acquisition, curatorship), preservation (preventive care, 

conservation treatment, object storage and housing), and use (research, education, exhibitions). 

In application, risk assessment must embrace uncertainty in four dimensions: model structure, 

variability, ignorance, and randomness. 

Model Structure

The first source of uncertainty, model structure, tends to be the largest. At the most fundamental 

level, an implicit assumption in model structures is that the future will resemble the past and 

that the past can serve as a guide to the future. This assumption arises naturally because all of 

our empirical evidence comes from the past. But it is important to bear in mind that it is an 

FIGURE 1. Preservation must be seen as a subsystem of a broader collection management system.
Risk Assessment and Assignment of Environment Parameters 37

assumption, and the future may in some respects diverge substantially from expectations based 

on past experience.

The most important aspect of a risk model is a goal. Risk models are based on a clear long-term 

operational goal and define risk as a deviation from that goal. For example, consider a hypothetical collection of 25 objects: five ceramics, five prints, five textiles, five natural history specimens, 

and five works of art. The goal for this collection is defined as moving it forward undamaged and 

intact 100 years into the future. Of course, reality usually has other plans: some objects will fade or 

deteriorate, some objects will be damaged, and some may be lost on account of various agents of 

deterioration and types of risk. There will also be small chances of a catastrophic event that will affect the entire collection. These departures from the goal of preserving the collections for a specific 

time period in the future are the risks we seek to identify, understand, and reduce. 

The definition of what is known as a “specific risk” (Waller, 2003) can be broken down into 

three parts: sources, paths, and effects of departures from a defined goal. For purposes of illustration, I will apply these concepts to RH in this paper, but the concepts apply to any type of 

environmental hazard. In the case of RH, one can think of the three elements of risk as follows:

Source. What is the original cause or problem that could lead to departure from the goal? For 

example, it could be a set point that is not achieved, a temperature gradient, or an HVAC failure.

Path. What parts of the collection are fully exposed to the source RH and thus potentially at 

risk? How are they, or can they be, protected? For example, some vulnerable objects could be 

given additional protection to mitigate risk through storage within cabinets and/or containers. 

Those containers serve as blocks to the path aspect of the risk.

Effect. What kind of damage (i.e., mold, hydrolysis, corrosion, or fracture) is done to the 

collection as a result of departures from the goal?

In general, understanding the source of risk is often routed within the domain of facilities 

management. Understanding the path to damage is largely within the domain of collection care. 

Finally, understanding the material effect of a risk is within the domain of conservation science 

(although interpretation of the value impact of those effects must be based on collection user 

judgments elicited by collection care professionals). How do the three domains work together 

in risk assessment and management to collaboratively safeguard collections?

Facilities management staff are responsible for seeing that set points are achieved, that temperature gradients are controlled, that buildings and collection hardware combine to minimize 

the effect of HVAC systems failure on collections, and that building-level plans are in place for 

when HVAC systems fail. Collection care personnel are responsible for knowing which collections are sensitive or vulnerable to variations in temperature and humidity and for mitigating 

exposure to those conditions, for example, by housing collection items in storage cabinets, 

containers, or other protective microenvironments. Conservation scientists are responsible for 

understanding and quantifying the effects (damage) RH may have on vulnerable collections. 
38 Smithsonian Institution Summit on the Museum Preservation Environment

Variability, Ignorance, and Randomness

Embracing uncertainty also means coming to terms with the variability, ignorance, and randomness of risk and capturing these within the risk model. Again, it is helpful to think in 

terms of sources, paths, and effects and of the three professional, discipline-specific domains 

associated with them.

Facilities Management

Facilities management, in collaboration with collection care teams, can conduct periodic intensive environmental audits to characterize RH variability through time and space (Ntanos 

and VanSnick, 2010; the “investigative” monitoring suggested by Brown and Rose, 1997). Collection care must continue to provide verification monitoring (the “confirmatory” monitoring 

suggested by Brown and Rose, 1997) to avoid problems known as common mode failure, where 

a single technical problem can compromise both the controls for and operation of an HVAC 

system. In such cases, like flying through clouds without instruments, all sense of the real situation can be lost. Facilities management, notwithstanding the sophistication of modern building 

management systems, might perceive this collection care environmental monitoring as a potential guardian angel in watching for this rare but potentially disastrous common mode failure.

Facilities management should also characterize the expected frequency and severity of environmental excursions expected over long-term system operations over several decades from, 

for example, (1) cases of load exceeding capacity because of a run of unusually damp days, (2) 

control system interruptions that cause spikes in RH, (3) multiple-day power interruptions at regional or national levels, and (4) failure rates during HVAC system wear-in and wear-out phases 

as well as the midlife phase. In risk assessment, thinking about such expected departures from 

specifications over decades-long periods is at least as important as looking at short-term data.

Collection Care

Collection care identifies the most sensitive objects and the overall distribution of sensitivity 

across objects. For example, within a collection of panel paintings, you have a range of sensitivities from paintings on wood, which are among the most vulnerable of collection objects, 

to paintings on honeycomb aluminum substrates, which are highly stable. Likewise, after two 

hours of exposure to high RH, most pyrite crystals remain stable, but some do not. In a collection in which some parts are more vulnerable, highly sensitive items may need special protection at the object level or case level. In those situations a limited budget for environmental 

controls might be better invested in hardware and/or packaging and buffering materials than in 

building- or room-level mechanical systems. Of course, the distribution of vulnerability varies 

between kinds of collections; in some, practically all objects will be similarly vulnerable. Enhancing our ability to characterize and communicate variable environmental sensitivities across 

various kinds of collections is a major current challenge for the collection care profession.

Collection care also needs to characterize procedural controls on environmental exposures 

at the collection and object levels. Problems at these levels can thwart the best efforts of facilities 
Risk Assessment and Assignment of Environment Parameters 39

management. For example, if a collection item is wetted during cleaning, it may take many 

weeks to completely dry. Placing that item in a well-sealed cabinet can raise the RH level within 

the cabinet to near 100% RH for many weeks. Similarly, placing cabinets against a cold wall or 

in an area subject to water leaks may cause extreme high relative humidity levels that no facilitywide mechanical system can control.

Conservation Science

A key role for conservation science is characterization of damage functions for representative 

sensitive materials, structures, and objects. Fortunately, we can draw on a rapidly growing pool 

of information provided by, for example, Mecklenburg (2007a, 2007b), Lankester and Thickett 

(2013), Strlic et al. (2013), and Thickett et al. (2013). 

Conservation scientists also can take the lead in working with collection care personnel, 

facilities management staff, and risk analysts to bring all these analyses together to create an 

overall risk model. In doing so, adopting a comprehensive model that facilitates shared understanding (Waller, 2008) will be important.

A comprehensive risk model that will allow rational risk-risk and risk-cost trade-offs will 

do the following:

• comprehensively consider all sources of deviations in RH (and other environmental factors) and express them as distributions reflecting frequency of occurrence coupled with 

anticipated severity measured as extent and duration of deviations

• consider what parts of a collection are susceptible to these deviations and the damage functions in the case of a deviation, adjusting for distributed collection-level controls (such as 

objects receiving special protective measures, storage, or housing) 

• pull together expertise from across the fields of facilities, collections, and conservation 

science

Conclusion

The three key elements for defining a specific, quantifiable risk from a hazard-damage concept 

are the source of the hazard, the path taken by the hazardous agent from the source to collection, and the effect of the agent on collection items in material change and in loss of utility 

value. Each of these three elements is primarily associated with one of three major collection 

stewardship functions: facilities management, collection care, and conservation science, respectively. These professions must work together to characterize, identify, and manage risks. 

Effective risk management requires establishing a systematic process for characterizing 

risks and developing strategies to address them. Because we work with scarce and incomplete 

knowledge, risk assessment can never be foolproof, but it will improve over time as more data 

are gathered and our understanding both broadens and deepens. 

Risk managers need to do the best they can with any given state of knowledge and be open 

to adjustments as new knowledge becomes available. They need to establish a process for developing specifications that is inclusive of all relevant subject matter experts; otherwise, risks will 
40 Smithsonian Institution Summit on the Museum Preservation Environment

be missed or misunderstood. They should also systematically document everything they do; if 

not, lessons learned this week will be forgotten by next week. 

Risk assessment is not easy, but it can be easier than you might fear provided you follow a 

clear path.

References

Brown, J. P., and William B. Rose. 1997. Development of Humidity Recommendations in Museums and 

Moisture Control in Buildings. Conservation OnLine. http://cool.conservation-us.org/byauth/brownjp

/humidity1997.html (accessed July 16, 2014).

Canadian Museum of Nature. 2016. Mineral Deterioration: Light, Humidity: http://www.viddler.com/v

/13f461b3 (accessed February 1, 2016).

Heritage Preservation. 2013. Risk Evaluation and Planning Program. http://www.heritagepreservation.org

/REPP/index.html (accessed June 13, 2014).

International Centre for the Study of the Preservation and Restoration of Cultural Property (ICCROM). 

2007. ICCROM-CCI Course on Preventive Conservation: Reducing Risks to Collections. http://www

.iccrom.org/ifrcdn/eng/prog_en/01coll_en/archive-preven_en/2006_10risks_en.shtml (accessed 

June 13, 2014).

Lankester, Paul, and David Thickett. 2013. “Delivering Damage Functions in Enclosures.” In Climate for Collections: Standards and Uncertainties, ed. Jonathan Ashley-Smith, Andreas Burmester, and Melanie Eibl, 

pp. 337–348. London: Archetype Publications. http://www.doernerinstitut.de/downloads/Climate

_for_Collections.pdf (accessed July 16, 2014).

Mecklenburg, M. F. 2007a. Determining the Acceptable Ranges of Relative Humidity and Temperature in 

Museums and Galleries: Part 1, Structural Response to Relative Humidity. Washington, D.C.: Smithsonian Museum Conservation Institute. http://www.si.edu/mci/downloads/reports/Mecklenburg-Part1

-RH.pdf (accessed July 16, 2014).

———. 2007b. Determining the Acceptable Ranges of Relative Humidity and Temperature in Museums 

and Galleries: Part 2, Structural Response to Temperature. Washington, D.C.: Smithsonian Museum 

Conservation Institute. http://www.si.edu/mci/downloads/reports/Mecklenburg-Part2-Temp.pdf (accessed July 16, 2014).

Ntanos, Kostas, and Sarah VanSnick. 2010. “Environmental Assessment without Limits at the National Archives.” Paper presented at “Choices in Conservation: Practice versus Research,” International Council for Museums-Committee for Conservation (ICOM-CC) Graphic Documents Working Group, 

Copenhagen, October 6–8.

Ogden, B. W. 2012. PRISM: Software for Risk Assessment and Decision-Making in Libraries. Collections, 

8(4):323–329.

Strlic, Matija, David Thickett, Joel Taylor, and May Cassar. 2013. Damage Functions in Heritage Science. 

Studies in Conservation, 58(2):80–87. http://dx.doi.org/10.1179/2047058412Y.0000000073.

Thickett, David, Rebecca Chisholm, and Paul Lankester. 2013. Development of Damage Functions for 

Copper, Silver and Enamels on Copper. In Climate for Collections: Standards and Uncertainties, ed. 

Jonathan Ashley-Smith, Andreas Burmester, and Melanie Eibl, pp. 325–336. London: Archetype 

Publications. http://www.doernerinstitut.de/downloads/Climate_for_Collections.pdf (accessed July 

16, 2014).

Waller, Robert. 2003. Cultural Property Risk Analysis Model: Development and Application to Preventive Conservation at the Canadian Museum of Nature. Göteborg Studies in Conservation 13. Göteborg: Göteborg Acta Universitatis Gothoburgensis.

———. 2008. “Comprehensive Risk Assessment: Applying the Cultural Property Risk Analysis Model 

to the Canadian Museum of Nature.” In Real-Time and Deliberative Decision Making, ed. I. Linkov, 
Risk Assessment and Assignment of Environment Parameters 41

E. Ferguson, and V. S. Magar, pp. 179–190. NATO Science for Peace and Security Series, Series C, 

Environmental Security. Dordrecht, Netherlands: Springer.

Xavier-Rowe, Amber, and Claire Fry 2010. State of EH Collections Report. London: English Heritage. 

http://www.english-heritage.org.uk/publications/eh-collections-report/SOC_Report_Final_23

_Nov_2010.pdf (accessed June 13, 2014).

PRESENTATION

Conservation Environments, Museum 

Buildings, and Sustainability

MICHAEL HENRY
ABSTRACT. This paper explains the chapter in the American Society of Heating, Refrigerating, and 

Air-Conditioning Engineers’ handbook pertaining to museums to nonengineers, especially collection 

managers and conservators. This paper focuses on the relationship between collections environmental 

control and envelopes, that is, the structures that protect interior environments from external conditions, specifically from the damaging forces of thermal energy and moisture.
Conservation Environments, Museum Buildings, and Sustainability 45

Introduction

James M. Reilly, director of the Image Permanence Institute, likes to say that “geography is preservation destiny.” The external climate drives changes in the environment within a building that 

can affect collections, and climate is determined in large part by geography. 

From a building engineering perspective, there are 17 climate zones in the United States 

and its territories, defined by their characteristic long-term regional statistics for temperature, 

moisture vapor, precipitation, and other climatic factors. Moisture zones vary from east to west 

and are designated by letters: A, moist; B, dry, and C, marine. Thermal zones vary from south to 

north and are designated by numbers from 1, hot, to 8, subarctic. Some examples are as follows: 

• Washington, D.C., is in zone 4A: mixed/humid. Heating loads are greater than cooling 

loads. To keep interior environments safe for most collections, structures in this zone need 

dehumidification throughout much of the year, especially in summer, as well as humidification during the winter.

• Boston is in zone 6A: cold/humid. It has a colder and drier climate than Washington, D.C. 

Collections structures in this zone do not need as much cooling as in Washington but still 

require dehumidification in the summer as well as humidification during winter and the 

colder months in spring and fall.

• Phoenix is in zone 2B: hot/dry. The climate in this zone is mainly dry, but there is an annual 

spike in moisture during the summer, which creates the need for some dehumidification of 

collections spaces in addition to humidification during the remaining months.

• Miami is in zone 1A: very hot/humid. The need for dehumidification of collections structures in this zone is year-round, even during the winter months when there may be a small 

heating load.

Expected Climate Changes

Global climate change adds new complications because it means the frequency and severity of 

climate events may differ in the future from what we have come to expect from the past. For example, we generally use historical temperature and moisture data to size an HVAC system with 

a 20–35 year life span or to design a building envelope meant to last 50–100 years or more, as 

in the case of monumental buildings such as those at the Smithsonian Institution. But climate 

change means the future may, relative to our historical data, hold the prospect of increased duration and frequency of extreme conditions, increased thermal and moisture loads, greater risk 

of flooding, and other associated changes. Climate change projections for the northeast United 
46 Smithsonian Institution Summit on the Museum Preservation Environment

States, for instance, suggest that over the next several decades, we may see substantial increases 

in average temperatures; shorter winters with fewer cold days and more precipitation; more 

extremely hot days; longer, hotter summers; and sea level rise.

These changes have implications for structures that house collections, such as longer periods of heavy cooling loads, greater risk of power interruptions, increased dehumidification 

needs (but possibly less need for humidification in winter), and more storms, with associated 

increases in moisture load and collateral effects. 

The Building Envelope

The building envelope is a collection’s first line of defense against the exterior climate. It maintains the desired interior environment, provides some protection when systems fail, and, when 

properly designed, can reduce the thermal and moisture loads and the need for, and expense of, 

temperature and relative humidity management by the HVAC system. The envelope consists of 

any portion of the structure exposed to the exterior climate, both above and below grade, such 

as roofs, walls, floors, doors, windows, eaves, gables, and so on. Exterior thermal and moisture 

effects mediated by the building envelope include the following:

• thermal gains from solar radiation and thermal losses from reradiation at night

• absorbed water from rain 

• water vapor from drying of absorbed water

• thermal losses and gains due to conduction with soil or outside air

• thermal and water vapor losses and gains from infiltration of air through the envelope

• moisture gains in both the liquid and vapor state from soil moisture

Use of a building adds thermal and moisture loads within the envelope such as thermal 

gains from lights and equipment, thermal and water vapor gains from occupants, and thermal 

and moisture gains from building systems. Another consequence of occupation is the need for 

exterior air for ventilation, with the associated thermal and moisture loads to bring the air to the 

desired interior temperature and relative humidity. 

The thermal and moisture performance of the building envelope sets the basic parameters 

for what can be achieved in the internal environment. Common sources of guidance for collections environment building envelopes include jurisdictional codes (building, fire, systems, 

and energy conservation codes) and chapter 23 of ASHRAE Handbook: Heating, Ventilating and 

Air-Conditioning: Applications (American Society of Heating, Refrigerating, and Air-Conditioning 

Engineers [ASHRAE], 2011). Additional guidance for historic and monumental buildings is 

provided in Association for Preservation Technology and American Institute for the Conservation (1992), National Park Service (1995), and American Institute for the Conservation of Art 

and Historic Artifacts (2014).

Chapter 23 of the ASHRAE Handbook

Chapter 23 of the ASHRAE handbook is the definitive source for information on building envelopes and collections environments, although this may not be widely known in the community 
Conservation Environments, Museum Buildings, and Sustainability 47

of building engineers and architects, where museum work is not a day-to-day activity. It provides information and guidance but not implementation methodology, which must be worked 

out in each case by the architects, engineers, and collections personnel of each project or building on the basis of the specifics of the climate, building envelope, HVAC system, and the environmental vulnerabilities of the collection.

This chapter breaks down building envelopes into several classes based on construction 

characteristics and occupancy considerations that determine the thermal and moisture performance of the envelope. It then identifies the corresponding realistically achievable environmental control. The following three classes are examples: 

• Class IV: Heavy masonry, composite walls, storm windows. Performance characteristics 

include low to moderate air and moisture exchange, high thermal mass, moderate moisture 

buffering mass, and solar radiant gain at windows. 

• Class V: Insulated, vapor retardant, double glazed, with vestibules. Materials are thin and 

light compared to those in class IV. Performance characteristics include low air and moisture exchange rates, low to moderate thermal mass, low moisture buffering mass, and solar 

radiant gain on dark surfaces.

• Class VI: Tight construction, perimeter buffer, limited occupancy. Performance characteristics include low air and moisture exchange rates, low to moderate thermal mass, low 

moisture buffering mass, and interior spaces buffered from exterior surfaces by cavities or 

corridors. Purpose-built museum storage facilities might fall into this class.

Some specialized envelopes used for collections are not covered by chapter 23 of the 

ASHRAE handbook. These include subgrade structures and vaults, which tend to be thermally 

stable, and greenhouse-like glass structures, like some modern museums, which have high 

solar gain and tend to be thermally unstable.

Chapter 23 of the ASHRAE handbook defines five different classes (AA–D) of environmental control for museums, galleries, libraries, and archives, each class presenting a different set of 

risks and benefits to collections. Most purpose-built museums perform in classes A or B, with 

some in AA. In practice, temperature control is typically very tight (AA), but moisture control 

may be closer to B (±10%) because it is easier to control temperature fluctuations than relative 

humidity variations. 

Nonmechanical Strategies for Improving Envelope Performance

A widespread tendency is to focus on the mechanical systems for environmental control. However, interior environments can also benefit from “passive” strategies that focus on building 

envelope performance. 

Although the term passive is common in this context, nonmechanical is perhaps more accurate since the strategies in question require commissioning and maintenance, just like mechanical systems. These nonmechanical strategies can help to reduce thermal and moisture loads on 

the interior environment, moderate fluctuations, and thereby allow a building system to operate 

near peak efficiency more often. The employment of nonmechanical envelope strategies can 
48 Smithsonian Institution Summit on the Museum Preservation Environment

also reduce the required size and capacity of mechanical systems. Some essential nonmechanical strategies include the following: 

• incorporating vapor retarders in the envelope 

• controlling moisture at the source with roof and subgrade drainage and other strategies to 

keep surface and subsurface water away from the building

• minimizing uncontrolled air and moisture exchange at windows, doors, flues, and envelope perforations 

• minimizing or controlling direct and indirect solar gain with strategies such as landscaping 

for shade, shades/blinds/filters on windows and skylights, and cool roofs

• zoning interiors according to environmental needs, with more stable needs in inner spaces, 

and less stable needs along perimeters and under roofs

• separating collections zones from people zones and recognizing that the thermal comfort 

expectations of visitors will differ from museum staff because of differences in clothing as 

well as duration of stay and level of activity 

• managing peak visitor counts, especially on peak cooling days

Thermal mass is an important nonmechanical strategy for achieving stability in interior 

environments. It affects the exchange of thermal energy between interior and exterior and can 

buffer swings in relative humidity as well. However, there are limits on what can be done with 

thermal mass; the volume-to-mass ratio must be right to realize the benefits, and this balance 

is difficult to achieve with large, voluminous buildings.1

 Some new building materials—both 

phase-change materials and moisture-absorbing materials—hold out the prospect of effective 

moisture buffering as well as thermal stability with less mass.

Multiple envelopes (“box-in-box” enclosures, such as an inner collections storage area 

surrounded by perimeter corridors) are an effective way of controlling interior environmental 

zones. Cascading envelopes make inner spaces more stable because such spaces are removed 

from direct exposure to the exterior environment. 

Data and Simulations

Envelope damage and the resulting hazards to collections can arise from the interaction of 

liquid water, water vapor, temperature, materials, and other factors in various, extremely complex ways. Understanding these risks requires a dynamic simulation of heat and moisture effects, such as the WUFI (German acronym for transient heat and moisture transport) computer 

model (http://www.wufi-pro.com). But a note of caution is required: although a program like 

WUFI can be very useful, even the most sophisticated simulations should be applied with 

awareness that the assumptions on which the model is based may be idealized and not represent real-world variations in envelope construction. 

More generally, monitoring temperature and relative humidity provides valuable data on 

the conditions surrounding collections. But again, it is important to think about what these data 

mean and how they might be misleading. Do not simply print out data logger charts and look at 
Conservation Environments, Museum Buildings, and Sustainability 49

the trend line; analyze the data, parse them by season, and look at ranges and fluctuations with 

respect to both long- and short-term time frames. 

Building Systems

Finally, although most of this paper has focused on envelopes rather than building systems, a 

few closing words on systems are in order: 

• Keep it simple and comprehensible.

• Make them resilient.

• Separate dehumidification from cooling.

• Minimize outside air; if you need a lot, precondition it, especially for moisture reduction.

• Prioritize RH control over temperature control.

• Provide ample space for service and repair.

• Commission the system.

• More is not always better.

Note

1. Structures that are below grade or bermed effectively have infinite thermal mass around the building 

and are very thermally stable. The downside is that soil moisture is a huge concern for below-grade 

structures, so below-grade portions of these buildings must be water and vapor tight.

References

American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). 2011. “Museums, 

Galleries, Archives and Libraries.” In ASHRAE Handbook: Heating, Ventilating and Air-Conditioning: 

Applications, pp. 23.1–23.22. Atlanta, GA: ASHRAE.

American Institute for the Conservation of Art and Historic Artifacts. 2014. Code of Ethics and Guidelines 

for Practice. http://www.conservation-us.org/about-us/core-documents/code-of-ethics-and-guidelines

-for-practice#.VbYfpvlVhHw (accessed September 16, 2015).

Association for Preservation Technology and American Institute for the Conservation. 1992. New Orleans 

Charter for Joint Preservation of Historic Structures and Artifacts. http://cool.conservation-us.org

/bytopic/ethics/neworlea.html (accessed September 16, 2015). 

National Park Service. 1995. Secretary of the Interior’s Standards for the Treatment of Historic Properties. 

Washington, D.C.: Department of the Interior.

PRESENTATION

Choosing Standards and Best Practices 

for Environmental Design and Operation

JAMES M. REILLY
ABSTRACT. This paper contrasts the use of standards at two points of life in a museum: when it is built 

or retrofitted and as it is operated on a day-to-day basis. Even though the daily work of preservation 

requires thorough analysis, adjustment, and management of parameters, many organizations “default” 

to the preservation environment standard established at the outset of building a museum, library, or 

archives. This paper details the history of the preservation environment debate, describing the new tools 

that museums, archives, and libraries can use, especially in the practice of gathering and monitoring 

temperature and humidity data to establish benchmarks and make decisions. It is important to render 

null and void the notion that there is an ideal environment for museums such as 70°F/50% RH.
Choosing Standards and Best Practices 53

A shrunken head from the National Museum of Denmark in Copenhagen illustrates the 

complexity and diversity of real-world collections. Its collections managers must prioritize among chemical, biological, and mechanical hazards in conducting risk assessments 

and setting environmental standards. 

Museum environmental standards are our guideposts, and they arose for good reasons: 

to meet the need for guidance when planning museums or thinking about the adequacy of 

conditions and for some form of authority. Standards have become concise statements of best 

practices and have grown to be more reference, with few or no tables.

Standards play an important role at two points in the life of an institution: the design/

retrofit stage and the operations stage. Design/retrofit is a time-bound project, conducted by 

external architecture and engineering firms and overseen by construction managers who are 

project oriented and have a capital budget. At this stage, standards serve the purpose of authority documents (what others have thought and done) and represent normative definitions of 

best practice for both the client (the museum administrator and collections manager) and the 

designer. Environment is seen in the context of architectural programming: what the building 

is for, who will work in it, what they will do, and what parts are for storage, exhibits, research, 

etc. The design professionals are trying to understand what is wanted and what they have to 

do, keeping in mind code conformance such as how much outside air is minimal for a building 

that people will be in.

By contrast, the operations stage is continuous. Once the institution takes control of operating the building and systems on a day-to-day basis, standards serve as guidance to collections 

care and facilities managers and upper management as to how to actually go about it. Operations have become a collaborative, cross-disciplinary process. Because fiscal health is affected, it 

is essential that these disciplines that traditionally have not known each other’s business work 

together. In the operations stage, one must diagnose the quality of the environment with respect 

to preservation and manage the performance of systems while meeting goals of sustainability 

and fiscal responsibility. To do that well, “industrial strength” data gathering and analysis are 

needed to translate the ideas behind best practices and standards to decision making. The bottom line is that if you are going to be concerned with the goals of stewardship, sustainability, 

fiscal management, and global responsibility, you need monitoring and analysis tools in the 

operations stage.

Standards have tended to reflect more the needs of design/retrofit than operations. With 

that in mind, it is important to drive a stake through the heart of the notion that there is an ideal 

environment for museums such as 70°F/50% RH.
54 Smithsonian Institution Summit on the Museum Preservation Environment

Standards have evolved away from simplistic “received wisdom” embodied in short tables of 

numbers. Now, standards are a management strategy in which hard numbers have disappeared 

and in their place is a continuum of risk. The recently published UK Publicly Available Specification (PAS) 198 (British Standards Institute, 2012) has no tables at all. Rather than telling us what 

to do, standards now tell us what not to do. We all agree that at the extremes of relative humidity 

there are increased risks to collections, but the challenge now lies in where to be in the middle. PAS 

198 and chapter 23 of the American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE) applications volume (ASHRAE, 2011) provide much information to guide us.

To paraphrase Dr. Martin Luther King Jr., “The arc of the environmental standards universe 

is long but it bends toward sustainable operations.” We have gone from seeing standards as 

prescriptive to being part of a coherent design and operating philosophy.

It is important to understand where the idea of an ideal environment for museums came 

from. Tight temperature and RH control originated in UK galleries, where people came to visit 

collections that were always on view and, where, consequently, human comfort temperatures 

were a given. Standards for an ideal museum environment came out of the fact that UK galleries 

had to control temperature tightly in order to achieve the desired RH, not because of a particular need with regard to preservation of collections.

The people who did the work that informs our notions of an ideal standard—Garry Thomson (1978, 1986) and, prior to him, Harold Plenderleith (1956)—were concerned with UK museums in large masonry buildings without elaborate mechanical systems and with collections of 

mechanically sensitive objects such as paintings and composite wooden objects. Garry Thomson, who was a giant of preventive conservation and called for investigation and understanding 

of the real behavior of environmental limits, is considered to be the source of the tightly controlled 70°F/50% RH ideal or “standard.” 

Despite what Garry Thompson actually wrote and other conservation scientists have been 

saying for years, what we hear is: “blah blah blah temperature 70° ± 2° and blah blah blah 

humidity 50% ± 2%.” 

What Thomson actually said about temperature is that it is only important in so far as it 

begins to influence RH and the mechanical or physical sensitivity of objects. Pressed to give 

recommendations, he suggested different summer and winter levels: 67°F ± 2°F in winter and 

up to 75°F ± 2°F in summer. In addition, he noted, “temperature must be controlled to control 

RH, but the level is dictated by human comfort. For fuel economy, different summer and winter 

levels are suggested.”

In storage areas or buildings closed to the public in winter, temperatures can be allowed 

to fall, but not to the point where condensation may occur on cold or unventilated surfaces. 

A lower limit of 50°F is suggested. So really, the ideal temperature from the “horse’s mouth” is 

anywhere from 50°F to 77°F. 

What Thomson actually said about relative humidity is that it can be 50% or 55% ± 5% 

day and night throughout the year, adding that the level may be fixed higher or lower but for 

mixed collections a range of 45% to 60% is recommended. Thomson noted that the plus-minus 
Choosing Standards and Best Practices 55

sign in RH control is based more on what we can reasonably expect the equipment to do than 

on any deep knowledge of the effect of small variations on the exhibit.

Moving ahead a quarter century, new research by Mecklenburg (1982) and Michalski 

(1991, 1993, 1994a, 1994b, 1996) undermined and explained the old “ideal” of 70°F/50% RH 

and began to explore true safe limits for even very mechanically sensitive objects. To understand the mechanical risks to collections, Mecklenburg and his colleagues (Mecklenburg and 

Tumosa, 1991; Mecklenburg et al., 2004) used finite element modeling to study component 

materials of objects (e.g., cottonwood used in a panel painting). They sought to determine the 

point where risk begins and thereby to define safe RH tolerances. They found wider variations 

in RH tolerance than was the accepted wisdom. They also explored the forgotten dynamic of 

temperature and how temperature-driven chemical reactions are major factors for all sorts of 

collections. In the degradation of organic materials via spontaneous chemical reactions, the 

reaction rate is dependent on the combined influence of temperature and RH.

This and other research helped move the standards, including (1) deemphasizing tight 

RH control and need for ±5% for most materials, (2) a closer look at the function of decay and 

how much risk is generated by one type of environment or another based on kind of material, 

climate, risk tolerance, architectural design, and sustainability considerations, and (3) an active 

environmental management approach that is more data driven and collaborative across disciplines within facilities management and collections care.

Chapter 23 of ASHRAE (2011) was written primarily for heating, refrigerating, and airconditioning engineers with a bias toward design but is more modern in that it has much information not found in other kinds of standards. The handbook is revised every four years. The RH 

and temperature sections have changed little, but the pollution sections have developed substantially. PAS 198 from the British Standards Institute (2012) has less about design and more about 

management and operations, particularly section 3, which includes the following concepts:

• Good management is about accountability—it must be somebody’s job to look after the 

environment, and the institution itself is accountable for the environment it provides.

• Sustainability is important.

• An emphasis must be placed on monitoring.

• Every organization defines its own environmental specifications.

In other words, the answer to “What is the best environment for your museum?” is “You’ve got 

to figure it out for yourself.” 

Furthermore, the modern understanding of how decay works and how you understand the 

notions of risk and costs for different environments in different climates is a process of making 

choices along continua. Many ideal environments reflect the needs of different parts of your 

collection, and you must prioritize among them. You are always choosing from a continuum 

of preservation quality/degree of risk and energy savings. You prioritize among mechanisms of 

decay. Going back to the shrunken head, are you more worried about chemical decay (leading 

to cooler temperatures), biological decay (mold or insects), or mechanical or metal corrosion? 

Which is most important to you, and what can you provide in an economical way? 
56 Smithsonian Institution Summit on the Museum Preservation Environment

PAS 198 has color bands to show continua of risk depending on conditions and the nature 

of collections objects. For example, the temperature chart helps you find the sustainability 

point that you want. Allowing for wider drift and adapting to the building and climate you have 

can be a more sustainable approach than fixed set points throughout the year. In sum, standards 

today such as PAS 198 do not specify environmental choices that are optimal; at best, they define scenarios of excessive risk, and it is up to you to decide what is optimal.

At a large institution such as the Smithsonian, there is an inherent managerial limitation in 

taking the approach of an institution-wide range of allowable temperature and RH values. That 

is, within any given range there will be better and worse choices in terms of preservation quality, 

stewardship, energy consumption, and incremental improvement. 

A performance-based approach with “industrial-strength” data gathering allows you to 

bring together and leverage expertise within the organization, quantify risk, and get real-world 

feedback. You cannot manage what you cannot measure.

References

American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). 2011. “Museums, 

Galleries, Archives, and Libraries.” In ASHRAE Handbook: Heating, Ventilating and Air-Conditioning: 

Applications, pp. 23.1–23.22. Atlanta, GA: ASHRAE.

British Standards Institute. 2012. PAS 198:2012, Specification for Managing Environmental Conditions 

for Cultural Collections. London: British Standards Institute.

Mecklenburg, M. F. 1982. Some Aspects of the Mechanical Behavior of Fabric Supported Paintings. Washington, D.C.: Smithsonian Institution. 

Mecklenburg, M. F., and C. S. Tumosa. 1991. “Mechanical Behavior of Paintings Subjected to Changes in 

Temperature and Relative Humidity.” In Art in Transit: Studies in the Transport of Paintings, ed. M. F. 

Mecklenburg, pp. 173–216 Washington, D.C.: National Gallery of Art.

Mecklenburg, M. F., C. S. Tumosa, and D. Erhardt. 2004. New Environmental Guidelines at the Smithsonian Institution. Papyrus, 5(3):16–17.

Michalski, S. 1991. “Paintings—Their Response to Temperature, Relative Humidity, Shock, and Vibration.” In Art in Transit: Studies in the Transport of Paintings, ed. M. F. Mecklenburg, pp. 223–248. 

Washington, D.C.: National Gallery of Art.

———. 1993. “Relative Humidity: A Discussion of Correct/Incorrect Values.” In Preprints of the ICOM 

Committee for Conservation 10th Triennial Meeting, Washington, DC, 22–27 August 1993, vol. 2, pp. 

624–629. Paris: ICOM Committee for Conservation.

———. 1994a. Leakage Prediction for Buildings, Cases, Bags and Bottles. Studies in Conservation, 

39(3):169–186. http://dx.doi.org/10.1179/sic.1994.39.3.169.

———. 1994b. Relative Humidity and Temperature Guidelines: What’s Happening? CCI Newsletter, 

14:6–8.

———. 1996. Quantified Risk Reduction in the Humidity Dilemma. APT Bulletin, 27(3):25–29. [Vulnerability table adapted and online at http://www.cci-icc.gc.ca/resources-ressources/carepreventivecons

-soinsconspreventive/vuln-eng.aspx (accessed September 16, 2015 day, year).]

Plenderleith, H. J. 1956. The Conservation of Antiquities and Works of Art: Treatment, Repair, and Restoration. 

London: Oxford University Press.

Thomson, G. 1978. The Museum Environment. 1st ed. London: Butterworths.

———. 1986. The Museum Environment. 2nd ed., London: Butterworths.
PRESENTATION

An Overview of a Process and Specification: 

The British Standards Institute Publicly 

Available Specification (PAS) 198, 

“Specification for Managing Environmental 

Conditions for Cultural Collections”

JONATHAN ASHLEY-SMITH
ABSTRACT. This paper provides an overview of the origins and development of PAS 198, explaining 

the nature of a Publicly Available Specification, touching on the working methods and mindset of the 

team that created it, and the style and content of the finished product. Some of the drawbacks of the 

production process are described, and feedback after the first year is analyzed. The primary aim is to 

explore how much of the content and philosophy a large and diverse organization such as the Smithsonian can make use of. As with the presentation on which it is based, this paper is written from personal 

experience and expresses a personal point of view.
Overview of a Process and Specification 59

Introduction

PAS 198 (British Standards Institute, 2012) expounds a new way of thinking about environmental standards.1

 It does not tell you what to do, but it provides you with a framework for 

thinking about what you need to do. It also provides the route to a wealth of relevant information in the form of references to key publications that provide the evidence base to support 

preservation decisions. It encourages institutional autonomy by declaring that policies must be 

created and owned by individual institutions based on local needs, local philosophies, and the 

organization’s own budgetary constraints.

It may not be possible for an institution outside the United Kingdom to use the document 

without some local interpretation. It is written in a language unique to the British Standards 

Institute (BSI) and was conceived largely by people familiar with British institutions and the 

British climate. Whatever the structure, most of the references and some of the words and diagrams are universally understandable and applicable.

If you want to recreate something in the image of PAS 198 that is completely relevant to 

your local constituency, I would advise a simplification of the development procedure and suggest that a bit more attention is paid to the topic of energy use.

British Standards Institute

The British Standards Institute, despite its parochial title, is a global organization eclipsing 

smaller standards organizations worldwide. Its website is available in 16 languages. Its mission 

statement, “BSI helps organizations make excellence a habit,” goes beyond standardization for 

its own sake. Its headquarters in London has numerous meeting rooms in which you will find 

groups of specialists determined to regulate different aspects of their varied professions. The 

altruistic professionals have the motivation and they do the work. They pay BSI to provide conformity of style and language and to gain an internationally recognized mark of authority. The 

BSI owns the copyright and keeps the profit from sales.

The BSI is a secretive organization, and members of the working and steering groups are 

asked to sign a declaration that they “shall not make any public statements about their participation in the work of the Steering Group or Review Panel and shall not make use of any 

material or information of which they become aware through their role as a member of the 

Steering Group or Review Panel.” Therefore, this paper cannot be a totally explicit exposé of 

the process.
60 Smithsonian Institution Summit on the Museum Preservation Environment

The PAS as a Standard

It is best not to try to interpret the acronym PAS (Publically Available Specification); treat it like 

one of those organizations or phrases such as V&A, C&A, and NATO that are more familiar 

abbreviated than fully spelled out. The S hints at it being a standard, which it is not, but then it 

is not really a specification either.

The important thing to know about a PAS is that the process enables standards to be developed rapidly, which is why this format was chosen in this particular instance. The difference between a PAS and a full standard is the degree of consensus—in a British standard, all stakeholders 

have to reach consensus on the technical content, whereas a PAS can be open for comment. A 

PAS may be considered for further development as a British standard, or it could become part of 

the United Kingdom’s input into development of a European or international standard.

There are several caveats associated with a PAS:

• A PAS may take the form of a code of practice, lending guidance and recommendations. 

However, it should not be quoted as a “specification,” with special care to avoid misleading 

claims of compliance.

• If an organization wants to claim compliance with a PAS, it must justify any action that 

deviates from the recommendations.

• Compliance with a PAS does not confer immunity from legal obligations.

It is important to understand the vocabulary used in the PAS and in BSI standards in general. Degrees of insistence are implied by different auxiliary verbs. 

• Shall denotes requirements—what the issuer insists you do.

• Should expresses a recommendation—something that would be good for you to do.

• May is used to express permissibility—something you are allowed to do if you want.

• Can is used to express possibility—a consequence of an action or an event. 

For instance, “the usable life of collection items can be prolonged by means of preservation 

measures.”

An early draft of PAS 198 had the title “Specification for Environmental Conditions . . . ,” 

which might suggest that one should have 50% ± 5% RH. The title later became “Specification 

for Managing Environmental Conditions . . . ,” and consequently, the should refers to what one 

must do to manage, and 50% ± 5% RH becomes something that one may do. 

The concept of a PAS as guidance was familiar in the British heritage sector. PAS 197:2009 

(BSI, 2009) is a code of practice for cultural collections management that says that cultural 

collections organizations should have a collections development policy, a collections information policy, a collections access policy, and a collections care and conservation policy, all documented and approved by top management.

A Brief History

In the period running up to the publication of PAS 198, two UK research funding bodies (the 

Arts and Humanities Research Council and the Engineering and Physical Sciences Research 
Overview of a Process and Specification 61

Council) had collaborated to fund heritage science projects. One initiative was the formation 

of research clusters, one of which was called EGOR: Environmental Guidelines: Opportunities 

and Risks. The EGOR cluster, led by Nancy Bell, head of collection care at The National Archives, held three workshops that looked at the ramifications of existing environmental standards on collections, buildings, and users. Several members of EGOR went on to join either 

the working group or the steering group for PAS 198. Stefan Michalski and I had the privilege 

of serving on both the steering and working groups, although it must be added that we never 

physically met during the process.

Both EGOR and PAS 198 explicitly credit the motive for their creation to the statement 

from the UK National Museum Directors’ Conference (2009): “Museums need to approach 

long-term collections care in a way that does not require excessive use of energy, whilst recognising their duty of care to collections. There is general agreement that it is time to shift museums’ policies for environmental control, loan conditions and the guidance given to architects 

and engineers from the prescription of close control of ambient conditions throughout buildings and exhibition galleries to a more mutual understanding of the real conservation needs 

of different categories of object, which have widely different requirements and may have been 

exposed to very different environmental conditions in the past.”

The final meeting of EGOR generated a list of six research priorities: science of material 

tolerances, modeling the built environment, energy use, biodeterioration, new technologies, 

and values and human adaptation. The EGOR findings enabled Nancy Bell to call for a review 

of British Standard (BS) 5454:2000, “Recommendations for the Storage and Exhibition of Archival Documents” (BSI, 2000). The standard had come under serious criticism as it is difficult to meet its stringent environmental requirements without introducing invasive, expensive, 

energy-consuming HVAC systems. If the standard had allowed for the temperature to drift, 

it would have been easier to control the RH within the guidelines. Moreover, even though it 

was intended for use only with archive material, BS 5454 was consistently and inappropriately 

being applied to other sorts of collections. 

This inappropriate application led to the call for a standard that would allow examination 

of more agents of deterioration and a wider range of collections. The PAS mechanism was chosen for reasons of speed.

The Core of the PAS

The PAS uses a diagram of concentric rings similar to Figure 1 to explain its guiding philosophy. 

Cultural collections sit in the center. The outer circle contains the traditional environmental 

considerations (temperature, RH, light, pollution). Between the two are less traditional considerations (material sensitivity, intended use, expected lifetime, energy economy). The diagram 

exposes one of the weaker parts of the project. Because the cultural collection is placed firmly at 

the center, the building envelope and existing hardware are not given sufficient weight, if they 

are considered at all. 
62 Smithsonian Institution Summit on the Museum Preservation Environment

The primary drive of PAS 198 is given in the following statement (emphasis added):

The organization shall develop an environmental management strategy for 

the collection. The strategy shall include a statement of the expected collection lifetime and the energy demand arising from the environmental conditions needed to achieve this, taking into account the sensitivity, significance 

and use of the individual collection items. NOTE: The strategy should make 

clear the balance the organization intends to aim for between preservation 

requirements, usage and display, and energy economy. (BSI, 2012)

This balance is the most difficult thing to achieve, namely, the need to optimize four competing and interconnected outcomes: stability, cost, sustainability, and accessibility (Figure 2). In 

such a complex system, the optimal solution will probably be suboptimal to at least one of the 

components.

The project organization for the PAS, although appearing from the diagram in Figure 3 to 

be logical and systematic, was in fact complicated and bureaucratic. At the top level the project director gave shape and direction to the project. The technical author was responsible for 

collating texts and giving shape to the final document. The BSI project manager ensured that 

the work stayed on track, that the language was suitable, and that the workings of the groups 

were kept confidential. The steering group of eight people made broad indications of scope 

and direction and checked progress. The working group of around eight people did the real 

work, supplying technical detail and appropriate citations. The review panel consisted of a 

FIGURE 1. The PAS uses a similar diagram of concentric rings to explain its guiding philosophy.
Overview of a Process and Specification 63

large number of individuals and institutions that were asked to read preliminary drafts, make 

comments, and suggest corrections and possible additions.

There were numerous channels of communication, formal and informal, overt and covert. 

But all iterations of content and comment went through one person, the technical author, 

whose job it was to select which version of the truth would appear in the final document. Needless to say, the technical author’s decisions were not always popular.

Structure

The document opens with an introductory section, which includes a historical overview, a 

glossary, and list of related standards. The first substantial chapter (titled “General”) gives the 

main nontechnical managerial thrust. In it are sections on assigning responsibility, developing 

strategy, data collection, risk assessment, environmental specification, environmental monitoring, energy economy, and data documentation. Each dictatorial “shall” statement is supported 

FIGURE 3. Organizational diagram for contributors to the development of PAS 198.

FIGURE 2. The PAS advocates for optimizing four competing and interconnected outcomes.
64 Smithsonian Institution Summit on the Museum Preservation Environment

by a note containing helpful “should,” “may,” and “can” sentences and references to relevant 

literature and to other parts of the document.

The main technical section consists of the four chapters on temperature, relative humidity, light, and pollution, with many “shall” statements on how these should be considered and 

managed. Then come several informative annexes and a comprehensive 15-page bibliography. 

Style

The PAS followed a tricky path with a style somewhere between a comprehensive educational 

textbook and a tersely stated directive standard. Although it contains a lot of text, it also has 

clear statements that encapsulate key points, for instance, “Light: specification of illuminance 

is always a compromise between preserving the collection item and making it clearly visible.”

The pollution section is different from the others in that it advocates an “evaluate-monitormitigate” approach; in other words, do not flood the place with monitors before you know you 

actually need them, a situation that is too late to rectify these days with RH and temperature 

monitoring.

Two of the annexes use brightly colored charts, visual aids that attempt to encapsulate the 

limits to allowable ranges of temperature and humidity. They indicate how it is possible to drift 

within ranges to minimize energy consumption; however, this drift is constrained by human 

comfort, UK law, and common sense (you may not freeze employees and would not want to 

freeze your water pipes).

Delay

Once the PAS was ready for publication, a delay of several months occurred because of some 

behind-the-scenes attempts to modify the document or ban its use completely. During the 

hiatus the National Gallery in London entered the public debate by launching a new website 

(National Gallery, 2011) that described its own environmental and sustainability policy with a 

standard attributed to early gallery scientist Garry Thomson with refinements by gallery staff 

member David Saunders: 55% ± 5% RH and temperature of 21°C ± 1°C in winter and 23°C ± 

1°C in summer. 

The National Gallery rationale included the view that easel paintings are exceptionally complex in their material construction and that unusually stringent demands of environmental control are required to ensure their preservation. This policy undermines the work of Mecklenburg 

and other conservation scientists to date, stating “Real paintings are very much more fragile 

than experimental test models which significantly over-simplify the nature of the problem, 

particularly with regard to their complex mechanical behavior.”

The National Gallery asks an interesting question: “Is active environmental control in museums responsible use of energy?” Their answer is that it is a matter of definition. In this case, 

the policy states that “only ducted air-conditioning systems can provide safe conditions for 

long-term preservation of real paintings, and these systems will consume a proportion of the 

Gallery’s energy budget.” It is a fair point to make because they are trying to balance two 
Overview of a Process and Specification 65

nonrenewable resources: old master paintings and a lifestyle that people in the West have become accustomed to. The PAS is meant to generate that sort of debate, asking “Which of these 

is the more important?” 

Feedback

A year after the publication of the PAS document I collated some of the informal and anecdotal 

feedback I had received. Common complaints were as follows:

• It doesn’t tell us what to do! 

• The concept of “lifetime” is difficult. 

• The concept of “lifetime” is dangerous. 

• The PAS is difficult to use in teaching. 

• Scientific experiments do not reflect the real world.

The first point is easy to answer. Not telling you what to do is the unique new feature of the 

document.

The concept of collections lifetime does not have to be difficult. You need to agree on an admittedly arbitrary planning horizon of say 50, 100, or 200 years. Understanding the nature and 

environment of your collections, you need to predict the point in the future at which they will 

cease to be fit for purpose. Figure 4 presents several different scenarios relating to the fade-out 

point. Thinking about and planning for the inevitable are surely helpful rather than dangerous. 

FIGURE 4. The concept of collections lifetime with fade-out points. In scenario a, the fade-out point comes before the 

planning horizon, indicating the choice of doing something about the lifetime or, if resources do not allow action, 

accepting the fade-out point is the collection lifetime. In scenario b the fade-out point is beyond the planning horizon, indicating that nothing needs to be changed. In scenario c the fade-out point is somewhere close to the planning horizon, 

indicating nothing needs to be changed in the present because a review at set intervals may involve new information 

and a new starting point.
66 Smithsonian Institution Summit on the Museum Preservation Environment

The PAS will appear difficult to use in teaching only if your previous approach has been to 

teach simple, easy-to-remember universal fixed numbers. The methodology of PAS 198 is ideal 

for teaching using case studies and group discussion. The actual document is not intended as a 

teaching text at student level:

It has been assumed in the preparation of this PAS that the execution of its 

provisions will be entrusted to competent people who are appropriately qualified and experienced in the care and management of cultural collections for 

whose use it has been produced.

With respect to scientific experiments, PAS 198 notes that:

Alongside empirical research, it continues to be important to take account 

of the experience of, and data collected by, conservation professionals who 

witness first-hand the changes to objects over time. (BSI, 2012)

Summary

Some key takeaway points about PAS 198 are as follows:

• It is very libertarian—it doesn’t tell you what to do. 

• It gives you a framework for thinking about what to do.

• It gives you the best set of tools that is available at the moment.

• It empowers you to follow your own local philosophy on sustainability or collections use 

and stay within your financial means. You can develop your own local compliance without 

being subservient to external normative pressures. You can devise your own conditions or 

your own criteria for different collections within your organization. “Compliance without 

subservience” could be a new slogan for collections care. 

To achieve a locally satisfactory product, the procedure for information gathering and consensus building could be made simpler and more transparent. Energy considerations should 

be incorporated more fully. The need for training in topics such as collection lifetime needs to 

be recognized and budgeted for. As for the Smithsonian, it should certainly use the framework, 

some of the text and visual aids, and the tools that are publicly available.

Note

1. PAS 198 was sponsored by The National Archives in the United Kingdom, with additional sponsorship from Collections Trust, CyMAL: Museums Archives and Libraries Wales, a division of the Welsh 

government, and the Museums, Libraries and Archives Council. Its development was facilitated by 

BSI Standards Limited and published under license from the British Standards Institute. It came into 

effect on February 29, 2012.

References

British Standards Institute (BSI). 2000. British Standard (BS) 5454:2000, Recommendations for the Storage and Exhibition of Archival Documents. London: BSI.

———. 2009. PAS 197:2009, Code of Practice for Cultural Collections Management. London: BSI.
Overview of a Process and Specification 67

———. 2012. PAS 198:2012, Specification for Managing Environmental Conditions for Cultural Collections. London: BSI.

National Gallery. 2011. Paintings and Their Environment. http://www.nationalgallery.org.uk/paintings

/caring-for-the-paintings/paintings-and-their-environment/*/viewPage/5 (accessed September 16, 

2015).

National Museum Directors’ Conference. 2009. NMDC Guiding Principles for Reducing Museums’ Carbon Footprint. http://www.nationalmuseums.org.uk/media/documents/what_we_do_documents

/guiding_principles_reducing_carbon_footprint.pdf (accessed September 16, 2015).

PRESENTATION

Sustainability: Climate for Culture

FIONA COUSINS
ABSTRACT. This paper demonstrates the challenges of retrofitting or designing museum spaces sustainably given the requirements of the preservation environment, highlighting several example solutions. 

Sustainability and green building goals are not just about energy savings but also about conservation of 

water resources, using sustainable building materials, coping with climate change, being a contributor 

to the built environment, and promoting operational sustainability.
Sustainability: Climate for Culture 71

F

rom the perspective of a mechanical engineer, the 70°F ± 2°F and 50% ± 5% RH preservation environment design “standard” set points are ubiquitous in the museum world. 

Maintaining these set points is a major expense for museums but in some cases is required 

to allow loans from other institutions. The prevalence of these tight temperature and humidity 

conditions demonstrates that museum staff and conservators are reluctant to establish different 

set points in the absence of expert guidance on the effects of temperature and humidity variation on the preservation of collections, even though these tight conditions are clearly not necessary for many kinds of artifacts. From a sustainability standpoint, maintaining 70°F ± 2°F/50% 

± 5% RH (70°F/50% RH) when it is not needed is energy wasteful; in addition, mechanical 

systems and buildings that can meet these set points, within the tight variations specified, especially when cooling and heating loads vary widely, are complex. The need or desire to maintain 

these set points affects every piece of the building, including the materials used to build the 

building, the size of the mechanical system, and the energy costs associated with humidity and 

temperature control. The ubiquity of the 70°F/50% RH standard makes it difficult to implement operational protocols that conserve resources, such as seasonal shifts in environmental set 

points or reducing 24-hours-a-day, 7-days-a-week operation. 

For the mechanical system to meet stated temperature and humidity set points the engineering team must understand all of the design conditions that might occur. These might arise 

as a result of weather or occupancy, for instance, when gallery spaces are filled with visitors with 

damp umbrellas or a large group of visitors moves together from gallery to gallery or the sun 

shines directly into the room. The system is then designed to provide 70°F/50% RH under all 

the likely design conditions. The more extreme these conditions are, the larger the system will 

be, with more variability expected over time and more complex controls. 

A system can, of course, be designed for 70°F/50% RH and then operate at a more relaxed 

set of conditions to reduce energy costs; for example, a museum can choose not to run the 

dehumidifiers or to run them less. In this case, temperature control will be unaffected. Many 

things can be done to hold design conditions more loosely and keep energy costs lower, including changing target design conditions over the course of the year or allowing a wider variation 

in temperature. At the end of the day, however, if the suit is too big it doesn’t actually fit. Installing and maintaining an HVAC system that can maintain tight temperature and humidity control 

and then operating it at a wider performance range is not money well spent.

Consider the types of environments and systems that influence design choices in the following buildings:
72 Smithsonian Institution Summit on the Museum Preservation Environment

Former Home of The Women’s Library, London. An archive (Figure 1) that does not have 

occupants can run very economically: the mass of the enclosing envelope and of the materials 

themselves helps to buffer temperature and humidity changes, and the only variable factor is 

the weather. The systems can be set to provide minimal fresh air to deal with chemical buildup 

and positive pressurization to reduce infiltration of outside air. 

Once people are introduced to the space, they act as both a source of heat and a source 

of moisture, and the fresh air ventilation rate must increase. They may also need lights to examine the materials, which introduces even more heat to the archive space. The complexity of 

the system design arises from the research and academic need to allow people into the archive 

(Padfield and Jensen, 2011).

Sainsbury Wing of the National Gallery, London, 1985–1986. As part of the commissioning 

of the mechanical system for this project (Figure 2), the temperature and humidity loads associated with a busload of visitors with damp umbrellas were simulated using electric kettles and 

light bulbs. Smoke bombs and a video camera were used to record the air flow patterns and to 

prove that the mechanical system could operate as designed.

Ashmolean Museum, Oxford. Historic structures like the Ashmolean Museum (Figure 3) are 

often built from materials that allow moisture migration. This construction can make it difficult 

Photographer: Peter Cook; architect: Wright & Wright.

FIGURE 1. Former home of The Women’s Library, London. 
Sustainability: Climate for Culture 73

Photo © The National Gallery, London. Photo © Ashmolean Museum, University of Oxford.

FIGURE 2. Sainsbury Wing interior. 

FIGURE 3. Forecourt of the Ashmolean Museum, University of Oxford. 
74 Smithsonian Institution Summit on the Museum Preservation Environment

to achieve tightly controlled temperature and humidity conditions because moisture cannot be 

contained within the conditioned space. This difficulty in controlling moisture may result in 

significant additional energy use, especially in winter when humidification is needed. It may 

also result in damage to the building envelope or mold if moisture within the building materials 

freezes or condenses. Great care should be taken with historic buildings if a decision is made to 

gain additional control over its internal environments.

Museum of Contemporary Art San Diego. This museum (Figure 4) adopted a historic train station as new gallery space. The building envelope allowed moisture migration, so a decision had 

to be made about whether to try to control humidity. The museum decided to keep the existing 

open space within a broad range of 65°F–80°F, comfortable for most visitors coming from outside, adequate for much of their collection, and relatively inexpensive to operate. The requirements of insurers and lending institutions for 70°F/50% RH are met in small exhibition spaces 

that are enclosed with vapor barriers and are served with systems that allow humidity control.

To implement design choices in a sustainable way, Arup, a global design and engineering 

firm, draws on six major concepts (Figure 5):

1. Aiming for carbon neutrality, through energy saving and the use of renewables

2. Minimizing water use by collecting and reusing water

FIGURE 4. Museum of Contemporary Art San Diego, Strauss and Farrell Galleries, downtown location, San Diego, 

California. 

Courtesy Museum of Contemporary Art San Diego. Photo © 2006 Philipp Scholz Rittermann.
Sustainability: Climate for Culture 75 FIGURE 5. Arup’s six sustainable inquiries. Courtesy Arup.
76 Smithsonian Institution Summit on the Museum Preservation Environment

3. Adopting sustainable materials, through use of recycled content, local content, selection for 

reduced embodied energy, or life cycle analysis

4. Adapting to future climate change through system sizing, building siting, or other measures appropriate to the location

5. Being a positive contributor to the community and the built environment

6. Operating in a sustainable way through energy use reductions, material supply choices, 

and other management efforts

Some of these concepts are clearly aligned with the mission of many museums—much of the 

work of museums is to contribute to the community through the provision of meeting places for 

the public to see and discuss material important to culture or heritage. The materials selected are 

often chosen to be safe for sensitive exhibits and are also benign for humans. Keeping operating 

costs down and reducing energy use also support museums’ overall mission, but the concepts of 

carbon neutrality and sustainable operations pose specific challenges for museums and galleries. 

Reducing energy use is a significant component of achieving carbon neutrality and sustainable operations goals, and museums are typically high energy users because they run 24 hours a 

day, 7 days a week, and target 70°F/50% RH conditions at all times. Adding to the sustainability 

and operational challenges is the fact that museums tend to have many stakeholders, including 

donors, directors, curators, conservators, and visitors, whose purposes may be at odds. For example, directors often want to invite donors to eat and drink in the gallery spaces, and the heat 

and moisture resulting from the food and the dense occupancy can be a challenge in a closely 

controlled environment. In some cases, this scenario determines the design cooling condition 

and sets the size of the mechanical systems. 

The first question to ask when designing a museum or gallery with a focus on operational 

sustainability is, What do you want your building to do? Is it an iconic building or an art-centric 

space? Can it be both? Buildings like Centre Pompidou in Paris, the Royal Ontario Museum in 

Toronto, and the Guggenheim in Bilbao are very much about using iconic architecture to draw 

people to make a social connection with the building as well as what is inside it. This decision 

will influence the building form, its envelope, and its program and is likely to have the biggest 

impact on building sustainability.

The second question is, What do you want your visitors to get from the visit? Is the visitor 

experience to be a curated or naturalistic experience? This decision helps determine whether a 

museum will use electric or natural light. The typical European approach is to be naturalistic 

in design, with enough natural daylight to see the pictures in large open rooms. The North 

American approach is generally more curated in that exhibitions are frequently designed for 

display in dark rooms with highlighted objects and a focus on individual works. As heat from 

the sun can be a very large proportion of the peak cooling, any building that is designed for 

natural light must also consider how to screen direct sun and insulate the building envelope so 

that this load is kept as low as possible and the variation in cooling load over time is minimized. 

The museum may also decide to allow some variation in internal conditions in some spaces so 

that they can be sunlit. 
Sustainability: Climate for Culture 77

Another design question has to do with directness of experience versus technology mediated. Museums are adding greater dimension to the visitor experience through the use of electronic devices such as phones or interactive displays that provide additional information and 

allow the visitor to personalize their experience. The use of electric-powered devices typically 

leads to higher levels of energy use than traditional exhibits, but these devices do not require 

stringent environmental conditions. Changes in the use of technology affect both the size and 

variability of the cooling and heating loads and alter the way in which the building and HVAC 

systems need to respond to maintain the design conditions. The first step is to make these 

devices as energy efficient as possible, and other effects may be managed by allowing different 

conditions in different spaces, depending on the use. These exhibition innovations may require 

changes to system zoning, additional control intelligence in the building operating systems, and 

changes in the way the maintenance and curatorial teams operate the building. 

Another consideration for building sustainability is the trade-off between flexibility and 

low initial cost. On one end of the spectrum are spaces like the Richelieu Wing of the Louvre, 

a large, nonflexible gallery where everything—how it is used, how the light falls, how the 

exhibits are shown—is mostly fixed. At the other end are highly flexible temporary exhibition 

spaces where partitions are regularly moved to suit different exhibitions. Designing systems 

to allow for relocation of partitions at reasonable costs usually requires the development of 

a modular ceiling and floor layout and the addition of HVAC, lighting, and fire protection 

zones.

A key facet of sustainability is to retain and reuse building materials to reduce the environmental impact of the building. It is often less expensive and culturally interesting to reuse 

buildings for gallery space rather than building from scratch, and there are many museums and 

galleries that occupy repurposed buildings. These include the Museum of Contemporary Art in 

San Diego, mentioned earlier, which is in a disused train station, and Dia:Beacon, which is in 

an old factory. Unfortunately, there are often issues with the envelope of found spaces: the envelopes may be leaky or poorly insulated and are unlikely to be able to contain moisture within 

the space, making energy bills high and humidity control difficult. Leakiness is often solved 

through repairs, but the addition of a vapor barrier and insulation may cause condensation 

within the building envelope, especially in climates with wide seasonal or daily temperature 

variations, and this in turn can damage the building or create the conditions for mold growth. 

Depending on the types of exhibit planned, it may be appropriate not to use the 70°F/50% RH 

standard in these types of spaces, which was the approach taken at Dia:Beacon. 

The most direct link between operational costs and protocols and sustainability is the need 

to balance the requirements for collections conservation with the need to minimize operating 

costs for energy. As previously noted, the conservation requirements that lead to high energy 

costs are the maintenance of a stable 70°F/50% RH standard. In addition, energy costs are 

increased with the use of carbon filters to control pollutants. There may also be energy implications arising from the need to protect objects from ultraviolet radiation and for the limited 

illumination exposure that some artifacts are allowed. 
78 Smithsonian Institution Summit on the Museum Preservation Environment

Reducing operating energy follows a well-established process (Figure 6). First of all, the 

loads must be reduced, perhaps through relaxation of design conditions or controlling particular activities like gala events so that they occur on nonextreme weather days. Load reduction 

can also be achieved through controlling sunlight entering the spaces, good insulation, appropriate lobbying of entrances and exits, distribution of energy-using exhibits, and crowd control. 

Once the loads have been reduced, the systems can be designed to reduce the energy use first 

through passive means and then through active means and energy recovery. If the goal is for 

zero operational costs, then solar power or wind power may also be considered.

Many creative solutions to heating and cooling gallery space with the least possible energy 

exist, even where stable conditions are required. The Museum Brandhorst, Munich, is a top-lit 

flexible space gallery with under-floor air supply. This arrangement allows for great flexibility in 

partition layout without making system changes. The galleries also have “activated” slab walls 

that have water pipes running through them, containing chilled or heated water. The water in 

the pipes provides the effect of thermal mass, absorbing peaks in solar or occupant load. When 

the “peaky” heat gains are absorbed by thermal mass or pipes that create a similar effect, the 

loads on the air system are lower and more consistent. This reduction simplifies the air system design compared to an “all-air” system, perhaps allowing a constant-volume system, and 

FIGURE 6. Energy reduction process. ©Arup. NZEB: net zero energy building. The definitions of NZEB A–D are included 

in Shanti Pless and Paul Torcellini, “Net-Zero Energy Buildings: A Classification System Based on Renewable Energy 

Supply Options” (Technical Report NREL/TP-550-44586, National Renewable Energy Laboratory, Golden, CO, 2010), 

http://www.nrel.gov/sustainable_nrel/pdfs/44586.pdf.
Sustainability: Climate for Culture 79

reducing the variation in supply temperature, which simplifies the controls. Systems like this, 

in which the cooling loads are shared between air and water systems, typically reduce the size of 

the air-handling systems and ductwork and the associated space requirements. In many cases, 

this load sharing can reduce capital costs overall, although the mechanical system costs may be 

similar for both types of systems.

Another approach is found at the Kimbell Art Museum in Fort Worth, Texas, and the High 

Museum of Art expansion in Atlanta, Georgia. At both of these museums, cooling is provided 

through an all-air “displacement” system that distributes air via under-floor air distribution. 

This approach provides good flexibility for repositioning partitions and good comfort for the 

occupants. Heat tends to accumulate near the top of the galleries with displacement systems, 

and the 70°F/50% RH conditions are not always maintained at high levels. This effect can be 

mitigated by building galleries with high ceilings so that the off-conditions space is above the 

highest-placed objects.

To conclude the discussion of energy and sustainability and its relationship to museums 

and galleries, here are a few major steps that should be considered in the design of museum 

and gallery space:

1. Consider whether the 70°F/50% RH standard can be relaxed in any parts of the building or 

at any specific times. Wherever possible, reduce the variability in load over time by minimizing peak loads and reducing fresh air rates during unoccupied hours.

2. Reduce the heating and cooling loads on the building by controlling how much sun enters 

the building and insulating it well. Use efficient lighting systems, and turn them off whenever possible.

3. Select the most energy-efficient systems for temperature and humidity control. Start with 

passive approaches such as thermal mass and then look at active systems such as activated 

slabs, mixed air-water systems, and under-floor air distribution where possible. Aim for 

high levels of heat recovery, especially where simultaneous heating and cooling are needed 

for tight humidity control.

4. The most sustainable design for any museum will depend on the collection and the conservation requirements, the planned visitor experience, the need for flexibility in layout, the 

architectural design, and the ability to support operating expenses over time.

References

Padfield, Tim, and Lars Aasbjerg Jensen. 2011. “Humidity Buffering of Building Interiors by Absorbent 

Materials.” In Proceedings of the 9th Nordic Symposium on Building Physics, Tampere, Finland, May 2011, 

pp. 475–482. Tampere, Finaland: Tampere University of Technology.

PRESENTATION

Panel Discussion—Relationships, Respect, 

and Trust: Collaboration among Museum 

and Facility Professionals

MODERATOR: 

CECILY GRZYWACZ, Facilities Scientist, National Gallery of Art, Washington D.C.

PANELISTS: 

JONATHAN ASHLEY-SMITH, independent teacher and consultant 

(formerly Head of Conservation, Victoria and Albert Museum)

FIONA COUSINS, Principal, Arup

MICHAEL HENRY, Watson & Henry Associates/University of Pennsylvania

STEFAN MICHALSKI, Senior Conservation Scientist, Canadian Conservation Institute

JAMES M. REILLY, Director, Image Permanence Institute 

R. ROBERT WALLER, President and Senior Risk Analyst, Protect Heritage Corporation
82 Panel Discussion—Relationships, Respect, and Trust

The Moderator’s Postsummit Reflections

Collaboration—it is about relationships, respecting each other, and trusting that we all are 

working for collections preservation. Through our relationships we learn to respect each other’s areas of expertise and contributions to the museum environment, and we earn trust. Each 

quality builds on the other. We work together to develop relationships. We approach each other 

with mutual respect so that we can listen and understand the concerns and advice. We trust that 

there is significance to the concerns, that the advice is feasible and relevant, building relationships to get what needs to be done accomplished (Figure 1).

We all come to this table of collaboration with different areas of expertise: science, art, design, management. We achieve that expertise by different education and different backgrounds. 

Then there is the different professional lingo. Not only does this vary by profession, but regions 

of the country and internationally.

Preservation of collections melds conservation, management of the facility where those collections are housed, and leadership of the institution. The stakeholders range from the professional engineer to the custodial worker, the conservation technician to the curator, the architect 

to the preparator, the framer to the artist, director, the trustee, the patron, the visitor. We all 

must work together to preserve collections.

FIGURE 1. Collaboration is about relationships, respecting each other, and trusting that we all are working for collections 

preservation. Through our relationships we learn to respect each other’s areas of expertise and contributions to the 

museum environment, and we earn trust. Each quality builds on the other.
Panel Discussion—Relationships, Respect, and Trust 83

Preservation environments are a function of geographical location, the building, and the artifacts. The complexity of each of these factors means that there is not one set of parameters that 

can be specified unilaterally. Even within the same location or climate zone there are differences 

in the types of buildings and climate control systems. Once inside a building there are different 

types of spaces: galleries, storage rooms, display cases, and public spaces with no objects on 

view. We know that each type of collection can have separate requirements for stability and 

preservation. For example, we know that we should minimize light exposure for watercolors, 

whereas light damage to marble statuary is less of a risk. Finally, at the individual object level 

more stringent environmental controls may be required. Inorganic colorants are more light stable than organic colorants. Because of these global, local, and specific parameters, collaboration 

between diverse experts, such as those on this panel, is mandatory. 

Summit Panel Dialogue

Question: What are the perspectives of different professional specialists responsible for building and 

managing the preservation environment? What are the commonalities?

Grzywacz introduced the panel topic of collaboration among facilities, conservation, and collections management professionals. 

Collaboration is built upon relationships, trust, and respect. If you are on the collections 

side, how do you know when to go to the facilities people if there is a possible problem with 

the collection and vice versa? We need to stop worrying about asking people needless questions 

because we will eventually learn what we can help each other with.

Grzywacz to Robert Waller (referring to his presentation on risk management where facilities managers are responsible for source, collections personnel for path, and conservation science for helping us 

understand what the effect could be): We each perceive risk differently, so how can we make sure that 

we each understand the risks, which are very different in the three branches?

Waller: We all perceive risks differently and there are many common perceptual biases in risk. 

One is voluntariness of risk—if collection managers are able to control a risk by themselves, 

they will perceive it as much lower than if they had to rely on facilities personnel to deliver the 

protection. The trick is to come up with rational predictive numbers (e.g., we expect that 5% 

of the collection will experience loss). That provides a concrete common understanding, even 

though it may be difficult to achieve. As long as we only rely on our passion or intuitive sense 

of the risk, there will always be big differences depending on our perspective. We want to get to 

concrete numbers, even if they are approximate.

Grzywacz to Waller: If I’m the collection manager and I believe that I can handle that risk and don’t 

share that with facilities, how will facilities learn about that potential for risk?

Waller: We strive to be comprehensive in identifying and defining risks. To do that requires 

very good documentation so that it is clear to everyone if there is risk of an excursion to a high 

RH and how that is interpreted for each of the collections, i.e., what are the most vulnerable 
84 Smithsonian Institution Summit on the Museum Preservation Environment

objects and what is the median object, is it low vulnerability or is it also quite high? In that way 

you construct a profile based on the variability of the collection and the nature of the materials.

Audience Question: On a collaboration continuum, with facilities, collections, and science, where do 

vendors (e.g., HVAC components), contractors, and leased building managers fit in?

Reilly: It varies; each one is a different case. For example, in leased space people feel they 

have little control over things, making for what is often a fraught situation. Vendors operate a lot of buildings, and they should feel comfortable getting together with conservators; 

likewise, the management of the institution should feel comfortable having conservators talk 

to whoever is running the building to work things out. It does become more difficult when 

the parties involved don’t report to the same organization. At my university, for example, the 

provost is the highest academic officer and the vice president for administration is the boss 

of the facilities organization, so the onus goes to the top to facilitate that cross-disciplinary 

conversation. 

Henry: If you know you are going to put a collection environment in leased space, the owner/

operator of the building has to be brought into a collaborative discussion before the lease is 

signed rather than afterward when the cost, profit, and lease rates are set. With respect to vendors, if a major specialized piece of equipment is being installed such as a dehumidification 

system, the vendor needs to be brought in during design and made aware of what the expectations are for that equipment once the project moves into operation. 

Cousins: As Reilly said, the problem with operations is that it is not a project. When you are 

designing a building, making a lease, or doing a renovation, you have a project, and you know 

how to deal with vendors or manufacturers because it is part of the design process. It becomes 

an issue when they are not part of the design process; at that point there needs to be more collaboration than I currently see. 

Grzywacz: How can you zone or isolate areas within a building that are all on view and that have 

different exterior wall construction?

Cousins: In order to get close control you have to respond to what’s happening in the part that 

you are influencing. So you must have a zone for every room, sometimes multiple zones in a 

room. We are always dealing with controlling temperature and RH separately for spaces that 

are interior, exterior, east facing, south facing, north facing, brick, aluminum panel, glass—it is 

just part of the design work.

Henry: You can design for that, but in many museums one can observe that doors intended to 

maintain zone separations are propped open for various reasons. It is virtually impossible to 

maintain that separate zone performance if the museum staff allow doors to be propped open.

Grzywacz: Is it an education process—explaining the reason why we keep this door closed? We are 

all so busy running around and with new people coming on that we don’t take the time to do that. It’s a 

challenge to understand how each building works for collection preservation.
Panel Discussion—Relationships, Respect, and Trust 85

Cousins: Within the project process there are two stages of information handover. The first is 

where the institution says what it wants and the design team runs with it. In the second stage 

the designers deliver the building design and instructions on how it will operate. Neither of 

the stages of information transfer is done very well. Moreover, in new buildings, the facilities 

maintenance people often have not been hired yet, so there is no one to give that information 

to. It is not part of the design handover or standard services and takes greater effort to propagate 

that institutional knowledge.

Reilly: The building design process is complicated in that it disaggregates into ducting, piping, 

electrical, etc., and there are only a few people with an overall holistic sense of how it is supposed to work, making the first handover doubly hard. In addition, the commissioning process 

can be misleading in that the building and system commissioners have to verify that piece x, 

y, or z is working, but that does not provide the essential knowledge of how to operate. By the 

time it is fully handed over the holistic understanding is lacking. 

Grzywacz: How do we maintain and continue that knowledge in existing buildings? 

Cousins: Universities do this best. Because they have a large number of existing buildings that 

they manage over time, they have a facilities team that does technical review for every project 

and makes sure it is something they know how to maintain and complies with their standards. 

The facilities team’s role is to make sure there is an ongoing dialogue with the designers so that 

they understand what is wanted. 

Reilly: There is a strong need for documenting how everything is working on the facilities side. 

You know things are working well if you walk into a mechanical room and can immediately tell 

what is what—like an organized versus a messy bedroom. 

Audience Question: How is the amount/need for outside air determined? Is it based on a formula or 

actual oxygen and carbon dioxide levels in the building? Wouldn’t it make sense to base the need for 

fresh air on actual levels of CO2

, particularly in high-air-volume, low-occupancy areas such as storage?

Cousins: Carbon dioxide is difficult to measure; you need a lot of sensors in different areas. 

The amount of fresh air in gallery space is determined by outside and inside conditions and the 

number of people. It is usually kept to a minimum based on code. Sometimes during unoccupied times it goes lower and is based on pressurization.

Henry: In storage areas, you can go to low levels of outside air but need to be aware of the 

potential for off-gassing of collections, for example, industrial collections or natural history 

collections in solutions. 

Audience Question: In mixed material collections, what is the recommended process for determining 

appropriate temperature and RH levels?

Michalski: Use a risk approach—if you are looking for a single magic number, you will get 

frustrated. It is better to ask where the most damage is happening for certain conditions and 

try to avoid that. If a sweet spot emerges, you’re lucky. There will probably be several sweet 
86 Smithsonian Institution Summit on the Museum Preservation Environment

spots where you have to trade off one collection or issue against another, and you have to have 

a metacriterion to determine which one you prefer. 

Within any risk assessment you need to think about significance. There are two components that make a risk large: one is the material science and the probabilities it suggests, and the 

other is whether it is a precious object relative to other things. If you know that your collection’s 

significance resides to a greater degree in some objects than in others and the material risks are 

similar, then clearly the priority is to avoid damage to the more precious objects. So you start 

with the sensitivities/susceptibilities of the collection and where, if it pertains, you have a higher 

percentage of your whole collection value. If that is not an issue, you can focus on the material 

science. It can become a feasibility issue, and some decisions based on resource constraints 

can generate more risk. In summary, do not look for a magic bullet that hits the bull’s-eye for 

all collections. You need to ask where the big, red, nasty spots are—identify and avoid the red 

danger zones rather than try to find the greenest zones.

Audience Question: With regard to thermal comfort versus collection preservation—explain to a 

noncollections staff member why preservation environments may not always be equivalent to human 

comfort?

Reilly: Collections are dead, they don’t feel hot and cold and like being cold because it slows 

down chemical reactions (though the point is conceded with regard to zoo collections).

Ashley-Smith: The National Gallery went from 19°C to 21°C as its basis for human comfort, 

whereas the Medieval Gallery of the Victoria and Albert Museum has temperatures in the winter 

of 16°C and lower and nobody complains. We have to define human comfort in a different way 

than traditionally where people are accustomed to being able to wander around in T-shirts.

Reilly: There is an ISO standard to calculate the probability that a given individual will be 

comfortable, taking into account level of activity, what they are wearing, the mean radiant temperature, humidity, etc. You get a probability that x% of people will feel comfortable in y set of 

circumstances. 

Henry: We know less about how to define what range of temperature and RH is appropriate 

for human thermal comfort than we do for collections. ASHRAE has studied this—the initial 

presumption was human thermal comfort in the heating season; then with the onset of air conditioning it became how to define comfort in the cooling season. There is now a tremendous 

amount of research on adaptive behavior in human thermal comfort where there is either no 

air conditioning or less air conditioning due to energy saving. The research is showing that the 

tolerance span for human thermal comfort is larger than previously thought.

Reilly: The Library of Congress Fort Mead facility is 50°F/30% RH. People were basically wearing moon suits of inch-thick fleece. People working at a similar 50°F/30% RH facility at Cornell 

University in Ithaca, New York, are more adapted, wearing sweaters, with some people running 

forklifts in T-shirts.

Ashley-Smith: To some extent it has to do with training. If you say to people that the temperature is for the good of the collection they’ve come to see, you will get a lot more tolerance. 
Panel Discussion—Relationships, Respect, and Trust 87

Cousins: Yes, if you go to a greenhouse, you expect it to be hot and humid because that is what 

plants need. 

Michalski: It would be rather pathetic if, at a moment when human comfort standards are 

relaxing or getting broader and more sophisticated, the heritage business would stick to a narrowly defined temperature that was historically driven by human comfort. One hopes that 

given sustainability targets like energy and carbon savings, the conversation is not so much 

about humidity or seasonal adjustment—that is more about savings in nonpurpose buildings. 

Temperature seasonal setback is where the big savings will be. We do not want to be the obstacle to serious carbon footprint savings due to seasonal adjustments in average temperature. 

You may have heard that now temperature control is necessary because of its interaction with 

relative humidity. That plays out over periods of a few hours with the air mixing over and the 

fact that if the building buffers, it does so to RH rather than to dew point. Outside of a day there 

is no reason not to be playing with temperature adjustments for sustainability.

Cousins to Michalski: What about rate of change of temperature and humidity? Mechanical engineers are sometimes asked to control the rate of change in addition to the actual value. 

Michalski: Tracking down the history of where that mythology emerged is difficult. To a 

large extent it is exaggerated. When Marion Mecklenburg presented “the box” at the Boston 

Museum meeting [see Michalski, this volume] to 50 chiefs of conservation from across North 

America, much of the discussion was focused on issues about the rate of change. Marion 

would say to his facilities people, I want you to stay inside the box, how you ping pong 

around in there is up to you. The good news is that they tend to ping pong around one side 

of the box in one season. To turn it around and have someone say, “We can’t do that; we are 

going to bounce around day by day—is that bad?” Within the kinds of boxes we are talking 

about, the answer is no. To the extent that I have tried modeling, I have not found any 

plausible stress gradients that would emerge. The classic argument is that there is a gradient 

through the object; it has thermal inertia or humidity inertia so that those gradients lead to 

internal stresses.

Reilly: That was the mechanical answer; the chemical answer is that there is no penalty in terms 

of the rate of spontaneous chemical decay, mostly hydrolytic oxidative reactions, from moving 

from one temperature and moisture content condition to another. What changes is the rate of 

reaction. Precisely, there’s no extra penalty just from changing from one condition to another. 

Every condition has a rate associated with it. We’ve proven through experimentation that what 

matters is the way the rates all integrate. It is unlike mechanical damage where there could be 

a plausible mechanism of deterioration that is related to the rate of moisture content change. 

On the chemical side it’s better to be colder because it slows things, and it’s better to withdraw 

moisture (but not get too dry due to physical or mechanical concerns), but basically, you can 

move around as much as you want and what will matter is how much time the object spent at 

each condition. Each condition has a rate, and if you properly integrate those rates, then you 

can come up with an overall effective rate of decay or rate of preservation. 
88 Smithsonian Institution Summit on the Museum Preservation Environment

The pharmaceutical industry does something similar with mean kinetic temperature. That 

is how it ensures drugs are not ineffective by the time you get them because somebody stored 

them at too high a temperature. It must be 25°C or less; if it gets to 30°C, your pharmaceutical is compromised. If the concern is chemical decay, you can move around in temperature 

and achieve sustainable savings that way. One underused sustainable method is duty cycling. 

Having the same temperature and humidity 24 hours/day, all year long, is not effective or 

sustainable.

Michalski: What about loans determining guidelines? The ASHRAE guidelines say the set point 

can be the historic average for your collection but notes that many lenders will require AA conditions centered on 70/50, so to meet contractual obligations, you will need a special exhibits 

room. Part of the reason I participate in panels like this is because whatever the Smithsonian 

settles on is going to trickle down—what credible organizations do sets precedent. (And this 

field is about precedents that get encrusted.) It is better to be at the beginning of those precedents and steer them in a good direction than to wait and deconstruct them. It takes longer to 

deconstruct a myth than to be there and give birth to the right story. If we can get the international community (like Bizot) to change the specification, that has huge trickle-down effect. The 

single most stringent requirement for museum projects is not for their own collections—it is 

about contractual obligations and wanting to be on the loan circuit. This spans mega museums 

to small house museums. The extent to which we can get fundamental restrictions from the 

world of international loans to go in the same direction we are trying to go will have a huge 

effect on architectural projects. 

Waller: Rates of change of temperature and humidity within a box probably don’t affect many 

collections; however, we can’t say categorically that they don’t affect anything. For example, 

mineral collections are the most vulnerable of all, and certain opal specimens are extremely 

vulnerable to crazing. So there are always exceptions, and we can improve communications 

between conservation science, collection care, and facilities by encouraging collection care professionals to identify the most vulnerable objects to any particular issue and work with conservation science to get an idea of how susceptible they are.

Henry: This panel has been about collaboration. Ashley-Smith talked about empowerment, 

and we have talked about decision making. 

Henry to the audience: How many of you feel that you are basically empowered, or have some 

fundamental knowledge to move forward on a different path rather than saying, “I want 70/50”?

[There was a sweeping show of hands across the audience.]

Moderator’s Summary

We started this conversation highlighting the importance of respect, trust, and relationships 

between the varied professionals involved in the preservation of collections. Today, we are fortunate because each professional discipline at the table recognizes the importance of the others 

in order to optimize climate control for preservation environments. There are already strong 
Panel Discussion—Relationships, Respect, and Trust 89

relationships built upon years of mutual respect and trust. What we all hope is that the exchange of dialogue here will be useful for each of you at your own institution. At the very least, 

we hope that by introducing you to the challenges of the interdisciplinary communication 

between the sciences, humanities, and business, you will be better equipped to foster collaboration to preserve your collections at your institutions.

Guides and Resources
92

A Guide to Discussions and Exercises 

Regarding the Preservation Environment: 

Determining and Implementing Your 

Institution’s Optimal and Sustainable 

Preservation Environment

Following the symposium, the group of organizers held a debriefing session on content, lessons 

learned, and where to go from there. In presenting proceedings of the symposium, the organizers wanted to provide tools to encourage and guide readers on how to take the next steps 

toward improving sustainable environments for their own and other museums, libraries, and 

archives. Toward this end, this guide offers ideas for exercises and meetings with suggested 

content that can be adapted and further applied to various types of collecting organizations. 

The authors encourage using this guide among a wide audience of required stakeholders and hope to encourage further open dialogue among collections managers, conservators, 

curators, facilities and operation staff, directors, and board members, as well as architects, engineers, vendors, and other contributors. It is through these dialogues that institutions can 

resolve often complex challenges and advance toward more sustainable solutions for collections 

preservation.

How to Use This Guide

This section provides both instructional and pedagogical guidance as well as subject content. 

Examples of pedagogical approaches are presented with sample subject content. Depending 

on the needs and desires of each user, the subject content can be exchanged for other content 

drawn from the suggested List of Questions presented below or from other sources. In an effort 

to help guide readers toward a sustainable environmental policy for collections preservation, 

the List of Questions follows a general order of steps that can be taken toward that goal. 

Guided Discussions

Overview

Guided discussions are frequently utilized as an instructional method, and a more detailed description is given by K. Ellenberg.1

 This method works best with a facilitator. Your group may 

know of a good facilitator, or you may prefer to identify a professional facilitator. Facilitator 

resources are provided by the International Association of Facilitators.2
Guide to Discussions and Exercises 93

The Basics

• Decide on who should attend the discussion; include representatives from each stakeholder and area of expertise such as administration, collections, and facilities. Consider 

consulting experts such as architects, engineers, and conservators as appropriate. 

• Identify an effective facilitator. 

• Preselect questions for a guided discussion. (See List of Questions.)

• Use effective facilitation tools to encourage open and balanced discussion.

• Capture outcomes by scribing on a board or projecting outcomes on a screen.

• Discuss the next steps such as topics for future meetings, tasks or homework, group exercises (see Exercises below), drafting new policies or procedures, etc.

Discussion Format Variations

To keep things interesting and foster collaboration, one of several facilitation techniques can 

be used. A couple of formats are noted here for basic guidance, although many approaches are 

available. An experienced facilitator will know how to design meetings to best fit the subject 

matter and group participants.

Facilitation Model: 2, 4, 8, All

The facilitator divides the group into teams of two and either starts each team with a different 

question or starts everyone with the same question. After a few minutes, participants combine 

into teams of four for a few more minutes of discussion (Figure 1); then teams combine into 

Photographs by Michael Barnes, Smithsonian Institution.

FIGURE 1. Smithsonian Institution staff participate in guided “2, 4, 8, All” discussions of the draft Declaration on the 

Collections Preservation Environment at Summit “Day Two” on March 22, 2013, at various locations through the Donald 

W. Reynolds Center for American Art and Portraiture and the Archives of American Art. 
94 Smithsonian Institution Summit on the Museum Preservation Environment

groups of eight participants for some additional minutes. Then the entire group holds a discussion while the facilitator scribes the outcomes on a board or projection screen.

Facilitation Model: The Book Club

The book club discussion format may use a facilitator but may also work well without a single 

group leader. This discussion model is described in more detail on several websites, including 

that of the American Library Association.3

• Prepare in advance by selecting questions. (See List of Questions.)

• Write each question on an index card.

• Convene a meeting of about one-hour duration.

• Review basic meeting rules such as no interruptions, keep to the question topic, table off 

topics to return to later, avoid refuting ideas, etc. (Refer to more detailed guidelines online.)

• If there is not a single facilitator, assign a scribe (optional), assign a timer (optional), pass 

around index cards with questions written on them, and ask each person to present a 

question in turn.

Exercises

Group exercises are intended to encourage interaction. In some cases learning to work as a 

team is just as important as the specified outcomes of the exercise. Learning to view common 

concerns from another’s perspective is key in problem solving for complex issues such as sustainable environments in museums. A few sample exercises are offered, although the team may 

wish to design their own exercises with guidance from the List of Questions below.

Group Exercise: Touring Facilities

Take turns touring each other’s departments, emphasizing environmental and sustainable 

needs or impacts for each building area. For instance, tour a storage area and describe the 

environment, equipment, type of materials, access, fire suppression, pest management, and 

other details, or walk through a mechanical room that serves a collection space and review 

the system features. Set aside a couple hours each week or month for one departmental tour. 

Include departmental participants from collections management, curation, conservation, and 

facilities operations. During each tour, department representatives can discuss how they are 

integrating or planning on implementing increased sustainable solutions to their day-to-day 

activities. 

Anticipated outcomes are that various specialists will understand perspectives, goals, and 

constraints of other departments. For example, collections managers, conservators, curators, 

and security staff will have a better understanding of how environmental mechanical systems work and are adjusted and maintained, what system restraints are, or how monitoring is 

achieved; facilities staff may better understand collections preservation concerns and how preservation risks are identified through looking at actual materials; curators, conservators, collections managers, and facilities staff may better understand concerns and operations for security.
Guide to Discussions and Exercises 95

Following each tour, the group may decide to distribute evaluation sheets and collect information such as the answers to the following questions:

• What information was new to you? 

• What areas of concerns and/or expertise overlap?

• What opportunities exist for further collaboration and finding new solutions for improved 

sustainability?

Group Exercise: Sketching Climate Zones

After a tour of the building, ask participants to identify and sketch out separate climate zones 

in the building. This exercise can be done in teams of two. Pairing participants from different 

departments together enhances the experience. Post the sketches on a wall and have each group 

of mixed professionals present their sketches.

Group Exercise: Sketching Mechanical Systems

Following a facilities tour and/or presentation with drawings and discussions, request participants make their own sketch of the building’s mechanical systems. For larger institutions, 

participants can break into teams, and each team can be assigned a separate building wing or 

climate zone. Post the sketches on a wall, and have each group of mixed professionals present 

their sketches.

Group Exercise: Designing an Environmental Collections Risk Assessment

Set up teams of two to four participants. Each team can have representatives from different 

departments. Ask each team to design a risk assessment for collections preservation. The focus 

of the risk assessment should be on the effects of the environment on collections. Have teams 

present their approaches to the group as a whole.

List of Questions

The following list of questions is organized into sections that reflect a stepped approach that can 

serve as a guide to institutions in developing a sustainable environmental policy for collections 

preservation and the museum as a whole.

Building the Team

1. Combining the expertise of stakeholders is an important theme for several of the authors of 

this book. Waller describes the stakeholders as being, at the least, the facilities engineer, the 

conservation scientist, and the conservator. When you consider your library, archive, or museum, who would you add to the list as a stakeholder? What role does each stakeholder have 

in establishing and maintaining the preservation environment? Who has the final say and why?

2. Who should be involved in making decisions about the environment for collections?

3. Who needs to be involved in decision making for the collections environment? What outside expertise needs to be brought in?
96 Smithsonian Institution Summit on the Museum Preservation Environment

Clarifying the Why

4. What is the main reason collecting institutions are looking toward more sustainable approaches for collections preservation?

5. Why is it important to preserve collections? Should all collections be preserved?

6. Why is it important for the Smithsonian to reconsider environmental standards for its 

collections?

7. How can long-term preservation of collections best be achieved while being energy 

conscious?

8. What types of collections are most susceptible to environmental changes? 

9. How does the environment affect preservation of collections?

10. How have environmental standards changed in the last century?

11. How have current standards evolved?

12. What myths and realities exist in the collections world about environmental controls for 

art preservation?

13. What were environmental standards for collections based on?

14. How can the Smithsonian be the best leader in environmental controls for collections preservation? What decisions will the Smithsonian make that will trickle down to other museums? What can the Smithsonian learn from other institutions?

Gathering Information

15. The architect or mechanical engineer comes to you and asks what target set points you 

want for your collection. How do you respond? 

16. A small historic house museum has almost no budget and is run primarily by volunteers. 

How does staff go about improving the environment for their collections while still keeping 

energy costs to a minimum?

17. A large institution like the Smithsonian has the resources to study and improve environmental controls; how does a small museum with only 2.5 full-time employees achieve the same 

museum best practices when it comes to environmental controls for its collections? The small 

museum would like the same energy cost savings while still preserving its collections.

18. What steps should be undertaken in determining appropriate environments for collections?

19. How much time will it take to gather the information you need? Should you bring in outside 

experts? How do you determine which experts are the most appropriate for your institution?

20. What additional information do you need regarding the materials that you preserve in your 

collections? Some collection types are robust and can tolerate a wide range of temperatures, 

others are vulnerable to subtle changes, and still others are yet unstudied for their longterm preservation. What areas of research would you like to see pursued within your organization or at conservation research centers to help understand the role of the environment 

in the preservation of objects?

21. Many of the essays discuss the history of preservation science and the establishment of guidelines for temperature and humidity set points for exhibition and storage of collections. For 
Guide to Discussions and Exercises 97

instance, where does the guidance that museums should keep their collections in a tightly 

controlled environment of 70°F (22°C)/50% RH come from? What did you learn about the 

history of this discussion that surprised you? Did you understand historic guidelines to be 

a “standard”? What is the difference between guidelines and standards? What guidelines or 

standards have you used with your collections? What guidelines are currently available?

22. When you consider the life cycle management of the systems that provide heating, cooling, 

and ventilation, what areas would you like to know more about? Reilly describes walking 

through mechanical rooms with facilities engineers and collections managers; what activities 

could you do with the stakeholders that would provide a basis for further discussion and collaboration and that would meaningfully contribute to the preservation of collections? What 

activities might meaningfully contribute to sustainable use of energy or energy savings?

23. What environmental monitoring exists in your institution? What environmental monitoring would be needed to determine more sustainable methods for environmental controls? 

How would you go about assessing the current systems and determining whether you need 

additional or less monitoring for newer climate strategies?

24. How will the climate affect human comfort? 

25. How will the climate affect the original or existing fabric of historic buildings?

26. How will you provide funding for assessment, planning, and implementation?

27. What are different methods for conducting risk assessments?

28. What are the premises and limits of model structure, such as a risk model?

29. In assessing collections risks, what risks are used in determining environmental target set points?

30. What is ASHRAE? How was chapter 23 of the ASHRAE handbook developed? Who wrote it?

31. What is CPRAM, and how does it work?

32. Define source, path, and effect, and how they are used.

33. How can you assess what a building is passively capable of without introducing a dramatic 

temporary change in environment?

34. How can environmental controls be best utilized without further damaging the fabric of a 

historic building?

35. What are some passive or nonmechanical strategies that can be explored for controlling 

environments?

36. What is the WUFI computer model, and how effective can it be for museums?

37. What is PAS 198?

38. What is the best environment for your museum? How does one arrive at that?

39. What is EGOR, and what was its significance on changing environmental standards?

40. How long do the steps take in determining appropriate target set points?

Drafting a Plan

41. Many organizations that preserve cultural heritage have a mission statement and policy documents such as a preservation plan. Does your organization have a preservation plan that 

explicitly addresses temperature, humidity, and air quality and their role in preservation? 
98 Smithsonian Institution Summit on the Museum Preservation Environment

What would you do to add, refine, or upgrade your statement on the role of the preservation environment for your collections?

42. What steps are required for moving toward a more sustainable environmental plan?

43. What are the priorities of these steps?

44. How can these steps fit into a schedule?

45. How can the steps be funded?

Implementing a Plan

46. Who or what team will be responsible for carrying out these steps?

47. What follow-up mechanisms need to be in place to ensure steps are completed?

Evaluation

48. How should the planning and implementation phases be evaluated and adaptations made?

Notes

1. K. Ellenberg, “Guided Discussion in the Classroom” (“How To” Pedagogies 3, Tennessee Teaching 

and Learning Center, Knoxville, 2010), http://tenntlc.utk.edu/files/2010/12/Guided-Discussion1.pdf 

(accessed September 10, 2014).

2. International Association of Facilitators website, https://www.iaf-world.org (accessed September 16, 

2015).

3. American Library Association, “Book Discussion Groups,” http://www.ala.org/tools/atoz/book-discussion

-grps (accessed September 16, 2015).
99

Resources and References

Key Informational Resources

American Institute for Conservation of Art and Historic Works. Connecting to Collections Online Community (blog). http://www.conservators-converse.org/2015/01/changes-afoot-connecting-to-collections

-becoming-connecting-to-collections-care/ (accessed September 16, 2015).

American Institute for Conservation of Art and Historic Works Collections Care Network. http://www

.conservation-us.org/publications-resources/collection-care#CCN and https://netforum.avectra.com

/eweb/DynamicPage.aspx?Site=AICHAW&Webcode=LeadershipDetail&cmt_key=2205560c-2a9c

-449a-a7e0-27028e608578 (accessed September 16, 2015).

Department of Energy. DOE Announces Webinars on Building Energy Optimization Tool Training, Placing 

Utility Energy Service Contract Task Orders, and More. http://energy.gov/eere/articles/doe-announces

-webinars-building-energy-optimization-tool-training-placing-utility (accessed September 16, 2015).

Image Permanence Institute. Environmental Management. https://www.imagepermanenceinstitute.org

/environmental/overview (accessed September 16, 2015).

International Association of Museum Facility Administrators. Home page. http://newiamfa.org/ (accessed 

September 16, 2015).

References

Standards and Guidelines

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). “Museums, Galleries, Archives, and Libraries.” In ASHRAE Handbook: Heating, Ventilating, and Air-Conditioning Applications, pp. 23.1–23.22. Atlanta, GA: ASHRAE. 2011. [Available for purchase and download at http://

www.techstreet.com/ashrae/products/1801490#jumps (accessed September 16, 2015).]

British Standards Institute. 2010. BS EN 15757, 2010 Conservation of Cultural Property: Specifications for 

Temperature and Relative Humidity to Limit Climate-Induced Mechanical Damage in Organic Hygroscopic Materials. London: British Standards Institute. [Available for purchase and download at http://

shop.bsigroup.com/ProductDetail/?pid=000000000030173518 (accessed September 16, 2015).]

International Institute for Conservation of Historic and Artistic Works and International Council of Museums Committee for Conservation. 2014. Environmental Guidelines: IIC and ICOM-CC Declaration. 

https://www.iiconservation.org/node/5168 (accessed September 16, 2015).

National Information Standards Organization. 2001. ANSI/NISO Z39.79-2001, Environmental Conditions for Exhibiting Library and Archival Materials. Bethesda, MD: NISO Press. http://www.niso.org

/apps/group_public/download.php/6482/Environmental%20Conditions%20for%20Exhibiting%20

Library%20and%20Archival%20Materials.pdf (accessed September 16, 2015).

Seminal Publications

Bickersteth, Julian. 2014. Environmental Conditions for Safeguarding Collections: What Should Our 

Set Points Be? Studies in Conservation, 59(4):218–224. http://dx.doi.org/10.1179/2047058414Y

.0000000143. 

Kirby Atkinson, Jo. 2014. Environmental Conditions for the Safeguarding of Collections: A Background 

to the Current Debate on the Control of Relative Humidity and Temperature. Studies in Conservation, 

59(4):205–212. http://dx.doi.org/10.1179/2047058414Y.0000000141.
100 Smithsonian Institution Summit on the Museum Preservation Environment

Staniforth, Sarah. 2014. Environmental Conditions for the Safeguarding of Collections: Future Trends. 

Studies in Conservation, 59(4):213–217. http://dx.doi.org/10.1179/2047058414Y.0000000142.

Related Publications

Image Permanence Institute. Guide to Sustainable Preservation Practices for Managing Storage Environments. 

https://www.imagepermanenceinstitute.org/store/publications/sustainable-preservation-practices

-guidebook (accessed September 16, 2015).

Jensen, Kari, Paul Orselli, and Margaret Kock. 2013. Green Exhibit Checklist: Incorporating Sustainability into Exhibit Development. American Alliance of Museums. http://www.exhibitseed.org/green

-exhibit-checklist (accessed September 16, 2015).

Sannwald, William W. 2009. Checklist of Library Building Design Considerations. 5th ed. Chicago: American 

Library Association. [Available for purchase and download at http://www.alastore.ala.org/detail.aspx

?ID=2492 (accessed September 16, 2015).]

Related Bibliographies and References

The Getty Conservation Institute. 2007. Experts’ Roundtable on Sustainable Climate Management Strategies. http://www.getty.edu/conservation/our_projects/science/climate/climate_experts_roundtable.html 

(accessed September 16, 2015).

———. 2014. Key Resources, Collections Environment, Conservation Perspectives. http://www.getty.edu

/conservation/publications_resources/newsletters/29_2/key_resources.html (accessed September 16, 

2015).

The J. Paul Getty Trust, Netherlands Institute for Cultural Heritage, Museum Ons’ Lieve Heer op Solder. 

2008. Our Lord in the Attic: A Case Study, Bibliography. http://www.getty.edu/conservation/publications

_resources/teaching/case/olita/resources/bibliography.html (accessed September 16, 2015).
101

Summit on the Museum Preservation 

Environment Program

SUMMIT on the 

MUSEUM PRESERVATION ENVIRONMENT

March 5, 2013 | National Museum of the American Indian

Rasmuson Theater

Program

9–9:05 a.m. Welcome

Speaker: Bill Tompkins, Director, National Collections Program

9:05–9:20 a.m. Introduction to the Summit

Speaker: Scott Miller, Deputy Under Secretary for Collections and 

Interdisciplinary Support

9:20–10 a.m. History of Environmental Management in Museums: Evolution 

of Theory and Practice

Speaker: Stefan Michalski, Senior Conservation Scientist, Canadian 

Conservation Institute

Introduction by: Robert Koestler, Director, Museum Conservation Institute

10–10:45 a.m. Risk Assessment and Assignment of Environment Parameters

Speaker: R. Robert Waller, PhD, CAPC, FIIC, President and Senior Risk 

Analyst, Protect Heritage Corp.

Introduction by: Bill Tompkins, Director, National Collections Program

10:45–11:15 a.m. Break

11:15 a.m.–12 p.m. Conservation Environments, Museum Buildings, 

and Sustainability

Speaker: Michael C. Henry, PE, AIA, Watson & Henry Associates/University 

of Pennsylvania

Introduction by: Sharon Park, Associate Director, Architectural History and Historic 

Preservation

12–1:15 p.m. Lunch (on your own)

1:15–1:20 p.m. Introduction to the Afternoon 

Speaker: Bill Tompkins, Director, National Collections Program
102 Smithsonian Institution Summit on the Museum Preservation Environment

1:20–2:05 p.m. Standards and Best Practices, Part I: Choosing Standards 

and Best Practices

Speaker: Jim Reilly, Director, Image Permanence Institute

Introduction by: Sarah Stauderman, Collections Care Manager, Smithsonian 

Institution Archives

2:05–2:50 p.m. Standards and Best Practices, Part II: British Publicly Available 

Specification 198, “Specification for managing environmental 

conditions for cultural collections”

Speaker: Dr. Jonathan Ashley-Smith, Independent teacher and consultant 

(formerly Head of Conservation, Victoria and Albert Museum)

Introduction by: Catharine Hawks, Conservator, National Museum of Natural History

2:50–3:15 p.m. Break

3:15–4 p.m. Sustainability: Climate for Culture

Speaker: Fiona Cousins, PE, LEED AP BD+C, Principal, Arup

Introduction by: David Hauk, Supervisory Electrical Engineer, Energy Management, 

Office of Facilities Management and Reliability

4–4:45 p.m. Panel | Relationships, Respect, and Trust: Collaboration among 

Museum and Facility Professionals

Moderator: Cecily Grzywacz, Facilities Scientist, National Gallery of Art

Panelists: Stefan Michalski, R. Robert Waller, Michael C. Henry, James Reilly, 

Jonathan Ashley-Smith, and Fiona Cousins

4:45–5:15 p.m. Smithsonian Institution Collections Space Prototypes: Project 

and Principles

Speaker: Luanne Greene, Principal, Ayers/Saint/Gross

Introduction by: Ann Trowbridge, Associate Director for Planning, Office of Planning 

and Project Management

5:15–5:30 p.m. Concluding Remarks

Speaker: Kendra Gastright, Director, Office of Facilities Management 

and Reliability

5:30–7 p.m. Reception–Potomac Atrium
Program 103

Summit Day Two Program

Donald W. Reynolds Center for American Art and Portraiture, Nan Tucker 

McEvoy Auditorium

March 6, 2013

8:30 a.m. Summit Check-in Begins

9–9:05 a.m. Introduction to the Day

Speaker: Bill Tompkins, Director, National Collections Program

9:05–9:20 a.m. Welcome: Secretary Clough

9:20–10 a.m. Overview of Proposed Smithsonian Institution Declaration on 

the Museum Preservation Environment 

Speaker: Sarah Stauderman, Collections Care Manager, Smithsonian 

Institution Archives

10 a.m.–12 p.m. Smithsonian Institution Tools and Models for Successful 

Collaboration

 What Smithsonian tools exist to assist the museum and facilities professionals achieve and 

maintain the desired outcome of an established environment?

Moderator: Michael Carrancho, Associate Director, Office of Engineering Design 

and Construction

• SI Explorer and Collections Space Database (Paul Drake, Technical Services Division of OEDC)

• OFMR/System Engineering Division monitoring reports and automated systems 

(Paul Tintle, System Engineering Division of OFMR)

• Museum Conservation Institute services and specialized equipment (Paula DePriest, Museum Conservation Institute)

10:45–11 a.m. Break

 What models exist at the Smithsonian that highlight collaborative work for establishing 

environment in exhibition space design and preparation, and new long-term storage spaces?

• Case Study: Reynolds Center (Andy Smith, Zone Manager, OFMR)

• Case Study: Leased Facilities (Kendra Gastright, Director, OFMR)

Panel Discussion: Paul Drake, Paul Tintle, Paula DePriest, Andy Smith, Kendra Gastright

12–1 p.m. Lunch (on your own) Break-out Session Rooms

1–3 p.m. Break-Out Working Sessions

 During the breakout sessions, Smithsonian staff committed to vetting the declaration 

document in each of these subject areas will be asked to review and comment on the same 

questions, which will be reported out in the facilitated discussion at 3:15 p.m. All registered 

stakeholders will get a copy of the draft declaration prior to the Summit and will be asked to 

pre-select their break out session of choice. 
104 Smithsonian Institution Summit on the Museum Preservation Environment

Concurrent 

Working Sessions Roles Room Location

Environment and Collections 

Preservation 

Leaders: Sarah Stauderman, SIA,  and Kathy Makos, OSHEM

OP&A Facilitator: James Smith 

Note-taker:  Mary Ballard, MCI 

MacMillan 

Education Center 

(1st floor)

Collaboration with Diverse 

Professional Specialists

Leader: Michael Carrancho, OFEO

OP&A Facilitator: Ioana Munteanu

Note-taker: Jennifer Giaccai, MCI 

McEvoy Auditorium

Monitoring, Data Collection, 

and Data Interpretation

Leader: Paul Tintle, OFEO 

OP&A Facilitator: Kathy Ernst

Note-taker: Hanna Szczepanowska, MCI 

Auditorium Lobby

Risk Management Leader: Cathy Hawks, NMNH 

OP&A Facilitator: Claire Eckert

Note-taker: Nicole Little, MCI 

Kogod Courtyard

Performance Specifications Leader: David Hauk, OFEO 

OP&A Facilitator: Whitney Watriss

Note-taker: Carol Grissom, MCI 

Victor Building, 

Suite 2200 

Conference Room

3–3:15 p.m. Break

McEvoy Auditorium

3:15–4:30 p.m. Working Session Report Outs by Group Leaders

 1. Responses to Proposed Smithsonian Institution Declaration on 

the Museum Preservation Environment

 2. Participant Questions/Discussion

4:30–5 p.m. Concluding Remarks

Speakers: Nancy Bechtol, Director, Office of Facilities Engineering and 

Operations

 Scott Miller, Deputy Under Secretary for Collections and 

Interdisciplinary Support
105

Declaration on the Collections 

Preservation Environment

Introduction

With this Declaration on the Collections Preservation Environment, the Smithsonian Institution clarifies values, shared by the diverse professional disciplines that directly and indirectly care for Smithsonian collections, related to the collections preservation environment 

and likewise presents a shared vision for implementing environmental policy based on these 

common values.1 Collections stewardship is a key component and core priority of the Smithsonian’s Strategic Plan. Assembled over the course of 168 years, Smithsonian collections are 

fundamental to carrying out the Institution’s mission, serving as the intellectual foundation 

for scholarship, discovery, exhibition, and education. Smithsonian collections represent a diverse range of materials and disciplines, including works of art, historical artifacts, natural 

and physical science specimens, living animals and plants, images, archives, library volumes, 

audio and visual media, digital art and time-based media, and their associated information. 

Together, these irreplaceable national icons, examples of everyday life, and scientific material 

preserve the past, increase our understanding of society and the natural world in which we 

live, and support the research that expands human knowledge in the arts, humanities, and 

sciences. The scope, depth, and unparalleled quality of these collections make it imperative to 

ensure that they are properly preserved and made accessible for current and future generations 

to enjoy and study.

Environment and environmental control are fundamental components of collections preservation; appropriate environmental conditions provide collections with chemical, biological, 

and mechanical stability to extend their life, making them available to future generations. As 

described in the American Institute for Conservation’s Guidelines for Practice, assigning appropriate environmental conditions extends the life of cultural property.2

 The Smithsonian Institution aims to provide and actively manage optimized environments to promote collections 

preservation based on a balance of scientific research, engineering capability, collections management protocols, and environmental impact. The dynamic factors comprising the preservation environment, to which the common values and shared vision statements detailed below 

apply equally, are (1) humidity and acceptable ranges for relative humidity, (2) temperature 

and acceptable ranges for temperature, and (3) air quality and ventilation.3
106 Smithsonian Institution Summit on the Museum Preservation Environment

Common Values and Shared Vision

Core 

Area Common Values Shared Vision Collaborating

The Smithsonian Institution believes that 

collaboration is the foundation for establishing 

environmental parameters. Achieving optimal 

preservation environments requires defining 

objectives and finding consensus among all 

stakeholders. Agreement on environmental 

parameters is inherently challenging because 

it requires consideration of a number of factors, 

such as evolving material-specific environmental 

guidelines; building fabric, which may be of historic 

significance and fragile itself; system capability; 

limitations on staff and resources; and the growing 

impetus to reduce energy costs and operate more 

sustainably.

The Smithsonian Institution supports a workforce 

that collaborates across disciplines to establish, 

monitor, and maintain collections environments.

Roles and responsibilities of all stakeholders 

across all core areas are clearly delineated. 

Responsibilities include how each stakeholder 

contributes to routine planned discussions.

Architects, curators, conservators, collections 

specialists, energy managers, engineers, facility 

managers, scientists, industrial hygienists, IT 

specialists, administrators, exhibition specialists, 

and others are included in discussions of the 

establishment of collections environmental 

parameters.

Decisions are made by sharing information, 

negotiating positions based on information, and 

developing consensus toward the expressed value 

of progress toward an optimized environment.

Resources such as the National Collections 

Program and facility capital and maintenance 

planning are available to collaborators to foster the 

spirit and effect of collaboration.

Monitoring

The Smithsonian Institution recognizes monitoring 

as an essential element of preservation environment 

activities. Monitoring and the data derived from 

monitoring are the basis of conversations between 

stakeholders; they provide meaningful information 

for attempting diverse preservation management 

actions, such as establishing seasonal adjustments 

or rehousing priorities, and aid in the establishment 

of priorities for long-term improvements.

The Smithsonian Institution has a standard way in 

which environmental monitoring data are collected, 

reported, and interpreted across the organization.

All collections spaces are designed and built with 

monitoring plans and protocols established and 

defined at the outset of design discussions.

All collections spaces are designed and built 

with mechanisms for monitoring environmental 

conditions for the space and air handling systems.

Environmental monitoring data are readily 

accessible to all stakeholders.

Environmental monitoring of collections and 

exhibition spaces is automated and integrated.

Existing systems and spaces are studied for 

action and modeling, especially in historic or older 

spaces that may not be compatible with desired 

specifications.

The purchase of room- and system-level 

environmental monitoring equipment and 

associated software is reliably supported.
Declaration on the Collections Preservation Environment 107 Training

Training provides the opportunity for understanding 

the evolution of theory and practice in the 

application of environmental parameters. The 

Smithsonian Institution believes that education 

and training of the Smithsonian workforce on the 

role of the environment in collections preservation, 

including promoting the understanding of the 

relationship between material damage in collections 

and exposure to an improper environment, is 

fundamental to effective collaboration.

The Smithsonian Institution is committed to 

cultivating professional development and training 

the workforce on the essential role that a controlled 

and optimized environment has on collections 

preservation, as well as on the theory and practice 

of the preservation environment and the variety 

of means that ensure collections have optimal 

environments.

Likewise, Smithsonian employees commit to 

keeping current with the theory and practice of the 

preservation environment. It is incumbent on staff 

to take training to understand why reappraisal of 

established environmental parameters is part of the 

ongoing professionalism of collections care.

Guidelines and Best Practices

The Smithsonian Institution believes that standards, 

guidelines, and best practices for establishing, 

monitoring, and maintaining the collections 

environment form the basis for reasoned collections 

environment decisions and therefore does not 

support a single specification for all collections. A 

broad range of choices may be made with respect 

to relative humidity, temperature, and air quality to 

provide optimal preservation environments and to 

meet operational and energy sustainability goals.4

Smithsonian scientists are poised to play a 

role in the research that leads to establishing 

environmental parameters.

The Smithsonian Institution conducts research 

concerning the relationship between the 

environment and collections preservation in order 

to continue refining an understanding of the role of 

the preservation environment and the mechanisms 

for damage to collections.

Standards are routinely reviewed, and continuing 

research contributes to the refinement of existing 

guidelines and best practices.

Standards and regulations regarding fire 

safety, health, building envelope, and HVAC are 

well understood as part of the discussion of the 

preservation environment.

Risk Management

Some Smithsonian collections are tolerant of a 

wide range of environments because of their robust 

physical nature; other collections have specific 

requirements and special needs for long-term 

preservation. The Smithsonian recognizes that 

different approaches may be used to characterize 

the requirements of a particular collection or facility.

Comprehensive risk management models used 

in collections management have an important 

role to play in establishing environmental 

parameters. Standards may be used in tandem 

with risk management models to develop reasoned 

collections environments.

Smithsonian Institution collections staff are trained 

to be knowledgeable about the profiles of the 

materials in their collections and apply modern 

approaches to categorizing collections’ fragility and 

hardiness.

Environmental requirements for a collection are 

thoroughly discussed with stakeholders, and the 

methodologies used to make decisions, including 

the resulting decisions themselves, are well 

documented.

Historic structures are considered when 

performing risk management exercises and are 

evaluated for building performance.

(continued)
108 Smithsonian Institution Summit on the Museum Preservation Environment Sustainability

The Smithsonian Institution acknowledges 

that the preservation environment, operational 

sustainability, and environmental sustainability 

are interdependent. More sustainable preservation 

environments and operations also may extend the 

lifetime of collections.

Sustainable preventive conservation methods have 

the potential to influence the type of preservation 

environment required for collections.

Improving the sustainability of collections 

preservation environments requires implementing 

strategies to conserve energy and water and to 

ensure the continued operations of preservation 

environment systems. The Smithsonian pursues 

these strategies while also fulfilling its responsibility 

to preserve, and to make accessible to present and 

future generations, the collections in its care.

Energy and water conservation measures that 

may affect the preservation environment are 

developed in collaboration with all stakeholders.

The process for selecting systems utilized in the 

preservation environment takes into account life 

cycle costs impacting operational and financial 

sustainability.

Customized Specifications

The Smithsonian Institution considers the 

preservation environment of each collections 

space to be one of the paramount mechanisms for 

ensuring the longevity of collections. Therefore, 

the preservation environment specifications of 

each collections space are actively defined to meet 

practical and sustainable parameters. Because of the 

wide variety of collections materials and collections 

spaces across the Smithsonian and because 

conservation research has acknowledged the 

variety of approaches to establishing preservation 

environment parameters, there is not a default 

preservation environment specification. The space 

may be intentionally unconditioned or may be 

continually refined on the basis of new data through 

a collaborative process among stakeholders, 

but tightly controlled 70°F/50% RH is no longer 

considered an appropriate, practical, sustainable, or 

useful set point for all collections.5

The Smithsonian captures the many data points 

of the preservation environment, allowing 

stakeholders to discuss it flexibly and openly, to 

adapt to changing information, and to account for 

differences of findings on environmental readings.

At a minimum, all collections spaces receive 

proactive specification of relative humidity and 

temperature allowances and seasonal adjustments.

Several core areas from this document—

monitoring, guidelines and best practices, risk 

management, and sustainability—are factors that 

contribute to the collaborative establishment of 

the optimal preservation environment for each 

collections space.

Notes

1. Participants in the Summit on the Museum Preservation Environment held in Washington, D.C., in 

March 2013 affirmed the goals of this declaration in a straw poll after discussion and review of presentations by experts in the fields of preservation, facilities management, and sustainability.

2. Guidelines for Practice of the American Institute for Conservation of Historic and Artistic Works, 

Section 20, “Preventive Conservation,” http://www.conservation-us.org/about-us/core-documents/

code-of-ethics-and-guidelines-for-practice/code-of-ethics-and-guidelines-for-practice#.VpPq3lL0-rg

(accessed January 11, 2016).

3. Environmental factors such as light and integrated pest management, which have an interrelated role 

in the preservation environment, will be specifically addressed in separate policy statements.

4. Several guidelines and standards are especially valued for their helpfulness in formulating a rationale 

for the specification of relative humidity and temperature for collections:
Declaration on the Collections Preservation Environment 109

• British Standards Institute, PAS 198:2012, Specification for Managing Environmental Conditions for Cultural Collections (London: British Standards Institute, 2012). 

• American Society for Heating and Air-Conditioning Engineers (ASHRAE), “Museums, Galleries, 

Archives, and Libraries,” in ASHRAE Handbook: Heating, Ventilating and Air-Conditioning: Applications (Atlanta, GA: ASHRAE), 23.1–23.22. 

• Smithsonian Institution Facility Design Standards, http://www.ofeo.si.edu/ae_center/pdf/SI%20

Standards_Jan2012.pdf (accessed June 6, 2014).

• American Institute for Conservation of Historic and Artistic Works, Interim Guidelines for 

Loans, http://www.conservation-wiki.com/wiki/Environmental_Guidelines (accessed June 19, 

2014).

• Smithsonian Institution, Smithsonian Directive 600, Collections Management, https://www.si

.edu/content/pdf/about/sd/SD600andAppendix.pdf (accessed January 11, 2016).

5. In recent years, the Smithsonian Institution has actively pursued specifications that reflect seasonal 

adjustments, setbacks, and shutdowns calculated to avoid condensation in building envelopes. Research by the Smithsonian Institution Museum Conservation Institute demonstrated that a broad RH 

range can be tolerated by many objects. For exhibition spaces where the need for human comfort 

and protection of building structures is frequently cited, a guideline of 37%–53% RH and 66°F–74°F 

has been developed. See Marion F. Mecklenburg, Determining the Acceptable Ranges of Relative 

Humidity and Temperature in Museums and Galleries: Part 1, Structural Response to Relative Humidity (Washington, D.C.: Smithsonian Museum Conservation Institute), http://www.si.edu/mci

/downloads/reports/mecklenburg-part1-RH.pdf (accessed June 6, 2014). Many spaces for collections 

at SI have adopted a “cooler and drier” methodology as well.

111

Contributors

Jonathan Ashley-Smith is an independent teacher, researcher, and consultant and former head 

of conservation at the Victoria and Albert Museum. He studied chemistry to postdoctoral level 

at the University of Bristol and University of Cambridge. He joined the Victoria and Albert Museum (V&A), London, in 1973 as scientist and trainee conservator. Between 1977 and 2002 he 

was head of conservation at the V&A. Between 1988 and 2010 he was actively involved with 

the Royal College of Art (RCA)/V&A postgraduate program of training and research. He was 

visiting professor at the RCA between 2000 and 2010. In 2000 he was awarded the Plowden 

Medal for his contribution to the conservation profession. He was secretary-general of the International Institute for Conservation from 2003 to 2006. In 1994 he was awarded a Leverhulme 

Fellowship to study risk methodologies, resulting in the book Risk Assessment for Object Conservation, published in 1999. He has run risk assessment workshops for students and professionals throughout Europe. He has supervised research students at a number of UK universities 

on projects relating to risk, ethics, and ethnography. He has written about the relevance of 

environmental standards and controls. “Let’s Be Honest—Realistic Environmental Parameters 

for Loaned Objects” (Studies in Conservation, 1994) is still required reading. He is currently 

a “work package leader” within the European Commission–funded research project “Climate 

for Culture,” in which his major preoccupation is the search for damage functions that might 

help predict risks for collections in historic buildings whose environments may be affected by 

climate change. He recently co-organized the international conference “Climate for Collections: 

Standards and Uncertainties” with the Doerner Institut in Munich, Germany.

Nancy Bechtol, the Smithsonian’s director of the Office of Facilities Engineering and Operations (OFEO), leads the largest unit at the Smithsonian with a staff of 1,900 who are responsible 

for facilities planning, programming, real estate, and architectural history and preservation; 

engineering, design, construction, and cost estimating; security, maintenance, operations, and 

horticulture; and safety, health, and environmental management. OFEO performs these centralized facilities services to 12 million square feet of space, including 19 museums, 9 research 

centers, and the National Zoo located in Washington, D.C., six states throughout the country, 

Panama, and Chile. She oversees a budget of over $175 million in capital funding and over 

$185 million in operations and maintenance. Prior to her role as the director of OFEO, she was 

the director of the Office of Facilities Management and Reliability at the Smithsonian Institution 

from 2001 to 2012. She managed all facilities management utilizing an in-house workforce of 

over 850 and an operating budget of $100 million. She was also responsible for overseeing the 

exhibition quality gardens that surround the museums. She graduated from the University of 

Maryland in 1980 with a bachelor of science degree in horticulture. She received her master’s 
112 Smithsonian Institution Summit on the Museum Preservation Environment

degree in 1984 from the University of Delaware through the Longwood Program in Public Garden Administration. In 2007, she became a certified facility manager through the International 

Facility Management Association.

G. Wayne Clough (pronounced “cluff”) was the twelfth secretary of the Smithsonian Institution, the world’s largest museum and research complex. The Smithsonian includes 19 museums and galleries, 20 libraries, the National Zoo, and 9 research centers and has activities in 

nearly 100 countries. Since becoming secretary in July 2008, he has taken the Smithsonian in 

new directions. A comprehensive strategic plan—the first of its kind for the Smithsonian—

creates a new framework for goals, enterprises, and operations. The Smithsonian focus is on 

four grand challenges: Unlocking the Mysteries of the Universe, Understanding and Sustaining 

a Biodiverse Planet, Valuing World Cultures, and Understanding the American Experience. 

Complementing the grand challenges is a goal to use digital technology to engage all Americans. He is responsible for an annual budget of $1 billion and about 6,000 employees. As a 

federal trust, the Smithsonian receives about 65% of its funding from the federal government 

and generates funding from contributions and business activities such as museum shops. Since 

he became secretary, more than 350 exhibitions have opened across the Smithsonian. He has 

overseen the opening of major permanent exhibitions, including the Star-Spangled Banner at the 

National Museum of American History, the Hall of Human Origins at the National Museum of 

Natural History, the new wing at the National Air and Space Museum’s Udvar-Hazy Center, and 

Asia Trails at the National Zoo. Before his appointment to the Smithsonian, he was president 

of the Georgia Institute of Technology for 14 years. He received his bachelor’s and master’s 

degrees in civil engineering from Georgia Tech in 1964 and 1965 and a doctorate in 1969 in 

civil engineering from the University of California, Berkeley. He was a member of the faculty at 

Duke University, Stanford University, and Virginia Tech. He served as head of the department of 

civil engineering and dean of the College of Engineering at Virginia Tech and as provost at the 

University of Washington. He is the recipient of eight honorary doctorates.

Fiona Cousins, PE, LEED AP BD+C, principal, Arup, leads the sustainability team in the New 

York office of Arup, is one of the leaders of the mechanical engineering team, directs technical 

investments for Arup’s Americas Region, and is a member of the Arup Americas Board. She has 

a background as a mechanical engineer and has spent much of her career engaged in HVAC 

design, with an area of specialization in thermal comfort and energy efficiency. She developed 

a strong interest in sustainability during the 1990s and has been working since then to incorporate sustainability into her projects. The other major strand of her professional career has 

been interdisciplinary design and integration, and she is most interested in complex projects 

in which collaboration between disciplines can achieve breakthrough results. She has been a 

LEED accredited professional since 2001 and has served as both manager and director for a 

number of projects that are pursuing the highest levels of LEED goals. She also served for two 

years as the chair of the New York Chapter of the U.S. Green Building Council (Urban Green). 
Contributors 113

She is currently chair-elect of the board of the U.S. Green Building Council. A frequent presenter on transformative sustainable building design, she has presented technical papers in the 

areas of low-energy design and sustainability.

Cecily Grzywacz is a facilities scientist in the AFM–Sustainability Office of the Facilities Management Division at the National Gallery of Art (NGA). She is a liaison between conservation, 

science, and facilities and considers herself a voice for the collection within Facilities. She works 

closely with the engineers to ensure that operation and maintenance and AFM projects continue 

to provide preservation environments for NGA collections. Previously, she worked at the Getty 

Conservation Institute of the J. Paul Getty Trust from 1985 until 2010 as a research scientist. 

She developed protocols that reduced energy consumption while maintaining a preservation 

environment at the Getty Center Museum and conducted research to understand the deterioration of cultural heritage. She is a senior research scientist with nearly 30 years of professional 

experience in environmental monitoring and analytical chemistry, specializing in the study of 

the potential risk of pollutants to cultural heritage, especially for preservation microclimates 

and the evaluation of air monitoring technologies and passive sampling devices. In 2006, she 

authored the book Monitoring for Gaseous Pollutants in Museum Environments, a summation of 

her experience of air quality monitoring for both outdoor and indoor-generated pollutants. 

She is a frequent guest lecturer in preventive conservation. Since 2003, she has been a primary 

reviewer of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers 

(ASHRAE) applications handbook chapter “Museums, Galleries, Archives, and Libraries”—a 

guideline for designing, heating, ventilation, and air-conditioning systems. In 2010, she received the ASHRAE Distinguished Service Award.

Michael Henry, PE, AIA, is principal engineer/architect with Watson & Henry Associates. For 

the past 30 years, he has specialized, nationally and internationally, in the preservation of historic 

buildings, in engineered stabilization of large artifacts, and in analysis and design of environments for cultural heritage collections. He is a registered profession engineer in New Jersey and 

several other states and is a registered architect in New Jersey. He received a bachelor of science 

in mechanical engineering from the University of Houston and a master of science in engineering from the University of Pennsylvania. He is adjunct professor of architecture in the graduate 

program in historic preservation at the University of Pennsylvania and is a guest lecturer and 

independent study supervisor for the graduate program in art conservation at the University 

of Delaware/Winterthur. From 2005 to 2009, he taught sustainable strategies at the Centre for 

Sustainable Heritage at University College London, UK. In 2006, he received a Fulbright Distinguished Scholar award to teach and research on the topic of low-energy collections environments in historic buildings. He has been an instructor and consultant for the Getty Conservation 

Institute in North Africa and Latin America. His recent environmental management projects and 

consultations range from Ernest Hemingway’s Finca Vigía near Havana, Cuba, to the renovations 

of the subterranean archives at the Harriett Beecher Stowe Center in Hartford, Connecticut.
114 Smithsonian Institution Summit on the Museum Preservation Environment

Stefan Michalski is a senior conservation scientist at the Canadian Conservation Institute 

(CCI). In 1989, he developed the CCI light damage slide rule, which was recently replaced by a 

light damage calculator on the CCI website. He provided all the colorant sensitivity tables used 

in publications on museum lighting from both the CIE and the Illuminating Engineers Society 

of North America. In 1993 he published the article “Relative Humidity: A Discussion of Correct 

and Incorrect Values,” which was recently selected for a book of selected historical readings 

in preventive conservation. In 1994, he coined the “nine agents of deterioration and stages of 

control” and initiated the CCI poster “Framework for Preservation of Museum Collections.” In 

1999, he authored the section on humidity and temperature specifications in the “Museums, 

Libraries, and Archives” chapter of the ASHRAE handbook. In 2000, he authored the CCI 

Guidelines for Humidity and Temperature for Canadian Archives. Between 2003 and the present, in 

partnership with the International Centre for the Study of the Preservation and Restoration of 

Cultural Property and Instituut Collectie Nederland, he developed and taught at the three-week 

course “Reducing Risks to Collections,” which has been held in Ottawa, Rome, Sibiu, Beijing, 

Quito, and Istanbul. Currently, he is finalizing a manual and a software tool for the risk assessment method developed during that partnership and now used by CCI in its risk assessments. 

In 2005, at the invitation of the International Council of Museums and the UN Educational, 

Scientific and Cultural Organization, he wrote the “Collection Preservation” chapter in Running 

a Museum: A Practical Handbook, available now in five languages. Also in 2005, he received the 

Harley J. McKee Award from the Association for Preservation Technology International, given to 

“individuals who have made outstanding contributions to the field of preservation technology.” 

This award was primarily for work on minimizing humidity risks to the frequent combination 

of collections plus historic building. He was on the steering committee, as well as a contributing 

writer, for the British Standards document called PAS 198, published in 2012. His primary foci 

now are two projects: a computerized prediction model for crack risk in a varied collection and 

a book on the museum environment to be coauthored with Jim Druzik of the Getty Conservation Institute.

Scott Miller, deputy undersecretary for collections and interdisciplinary support at the Smithsonian Institution, serves as the principal advisor to the Institution’s senior staff on the central 

planning and development of collections and interdisciplinary support operations, including 

collections management, conservation and preservation, and related functions. On matters of 

collections management, he serves as a liaison between the Smithsonian and various commissions, advisory boards, federal agencies, foreign governments, and private and professional 

cultural and scientific organizations in the United States and around the world, fostering cooperative programs and promoting the Institution’s programs. He previously served as deputy 

under secretary for science, helping oversee the Smithsonian’s science museums and research 

facilities, major research initiatives, collections management, exhibitions, and educational programs. From 2004 to 2006, he was the associate director for science at the National Zoological 

Park, spearheading the rehabilitation of the Conservation and Research Center in Front Royal, 
Contributors 115

Virginia. From 2000 to 2006, he was chairman of the departments of entomology and systematic biology at the National Museum of Natural History. He currently leads the Consortium for 

the Barcode of Life, an international network that uses systematics, genomics, and bioinformatics to develop DNA-based identification tools to make biodiversity information more widely 

available. Before joining the Smithsonian in 2000, he designed and implemented an international biodiversity and conservation program for the International Centre of Insect Physiology 

and Ecology in Nairobi, Kenya, and led the biodiversity programs at the Bishop Museum in 

Hawaii. He maintains an active research program as a curator of entomology at the National 

Museum of Natural History. He has published more than 190 publications and coedited four 

books. His current research focuses on moths of Papua New Guinea and Africa, especially the 

integration of systematics, ecology, biogeography, and conservation of insects and plants in 

Papua New Guinea. He is a cochair of the Interagency Working Group on Scientific Collections. 

He serves on the boards of the Friends of the National Zoo, the American Entomological Institute, and the Mpala Research Center in Kenya. He is a fellow of the American Association for the 

Advancement of Science and the Royal Entomological Society of London. He holds a B.A. from 

the University of California, Santa Barbara, and a Ph.D. in biology from Harvard University.

James M. Reilly is the founder and director of the Image Permanence Institute (IPI) at Rochester Institute of Technology in Rochester, New York, a world leader in preservation research 

since 1985. He is well known for his own research on deterioration of nineteenth-century 

photographic prints. Under his guidance, IPI has made important contributions to image preservation, management of film archives, environmental monitoring and control, and sustainable 

preservation practice. He oversaw the creation of the Preservation Environment Monitor datalogger and Climate Notebook software, which were supported by the National Endowment 

for the Humanities, the Mellon Foundation, and the Institute of Museum and Library Services. 

During its tenure, he was codirector of the Advanced Residency Program in Photographic Conservation, a program comanaged by the George Eastman House International Museum of Photography and Film. He is the author of numerous publications, including Care and Identification 

of 19th-Century Photographic Prints, “Preserving Photographic Collections in Research Libraries: 

A Perspective,” New Tools for Preservation: Assessing Long-Term Environmental Effects on Library 

and Archives Collections, IPI Storage Guide for Acetate Film, and Storage Guide for Color Photographic Materials. He is a consultant to many cultural institutions and is sought after worldwide 

as a teacher and seminar speaker. He was given a Technical Achievement Award from the Academy of Motion Picture Arts and Sciences in 1998, was presented with the Silver Light Award 

for Lifetime Achievement from the Association of Moving Image Archivists in 2002, and was 

the first winner of the Hewlett-Packard Image Permanence Award from the Society for Imaging 

Science and Technology in 2007.

Sarah Stauderman, director of collections, Hirshhorn Museum and Sculpture Garden, was 

formerly the associate director of collections care at the Smithsonian Institution Archives. She 
116 Smithsonian Institution Summit on the Museum Preservation Environment

focuses on preservation management for the wide variety of materials found in collecting institutions, especially electronic media, and maintains close ties to the communities who create, 

collect, and conserve cultural property. She has lectured widely on the preservation concerns 

of videotape and audiotape and was a founding member of the Electronic Media Group of the 

American Institute for Conservation. She has been an officer of the Washington Conservation 

Guild and served as a director on the board of the American Institute for Conservation. 

William G. Tompkins, director, National Collections Program, Smithsonian Institution, serves 

as an advisor to Smithsonian senior management, unit directors, and staff on matters relating 

to collections management. With 30 years’ experience at the Smithsonian, he strives to improve 

the overall stewardship and management of Smithsonian collections by providing central leadership, policy oversight, strategic planning, and support of Smithsonian-wide collections initiatives. He is responsible for the development, administration, and implementation of collections 

management standards at the Institutional level, including the review and approval of individual Smithsonian collecting unit policies to ensure collections are acquired, maintained, and 

used according to Smithsonian policy, professional standards, and legal obligations. Previously, 

he served as assistant director of the Smithsonian’s Office of the Registrar and as the collections 

manager of the National Numismatic Collection at the National Museum of American History.

R. Robert Waller, CAPC, FIIC, is currently president and senior risk analyst with Protect Heritage Corp., a firm dedicated to helping institutions and organizations improve heritage management. His career includes 33 years with the Canadian Museum of Nature, which included 

periods as chief of the Conservation Section and as managing director of the Collection Services 

Division. He holds appointments as a research associate at the Canadian Museum of Nature 

and as an adjunct assistant professor in the Art Conservation Program at Queen’s University. 

He holds a Ph.D. in cultural property risk analysis from Göteborg University and professional 

accreditation with the Canadian Association of Professional Conservators. His research interests 

center on risk analysis approaches to rational decision making for collections management and 

preservation. He has taught, lectured, and served as a consultant at museums and universities 

throughout North America, Europe, Asia, Australia, and New Zealand. He is a fellow of the 

International Institute for Conservation and has recently received the Carolyn L. Rose Award 

for lifetime achievement from the Society for the Preservation of Natural History Collections.
117

Index

Page numbers in italic text indicate illustrations and tables

acetate film, 21

Adams, John Quincy, vi

air and ventilation, 46, 49, 85

air-water systems for climate control, 78–79

American Institute for Conservation of Historic and 

Artistic Works (AIC) climate guidelines, 16–17, 19, 

28, 106–7n4

American Institute for the Conservation of Art and 

Historic Artifacts, 46

American Society of Heating, Refrigerating, and 

Air-Conditioning Engineers (ASHRAE)

ASHRAE Handbook, chapter 23, 46–47, 54, 55, 

106–7n4

climate guidelines from, 15, 16–17, 28, 55, 88, 

106–7n4

human thermal comfort research by, 86

revision of Handbook, 55

Art in Transit conference, 23–24

Arts and Humanities Research Council, 60–61

Arup, 74–76

Ashley-Smith, Jonathan, 2, 3, 26

Ashmolean Museum, 72–74, 73

Association for Preservation Technology and American 

Institute for the Conservation, 46

Association of Art Museum Directors (AAMD) climate 

guideline, 16–17, 19

Australian Institute for the Conservation of Cultural 

Materials (AICCM) climate guidelines, 16–17, 19

Barden, Richard, 2, 5

Bell, Nancy, 61

below-grade or bermed structures, 49n1

Bizot Group climate guidelines, 15, 16–17, 19, 28, 88

Boston climate zone, 45

Boston Museum of Fine Arts, 11–12, 18

British Museum, 11, 12

British Standard (BS) 5454:2000, “Recommendations 

for the Storage and Exhibition of Archival Documents,” 61

British Standards Institute (BSI)

mission and purpose of, 59

PAS compared to a standard, 60

PAS development and compliance, 60

secretive nature of, 59

vocabulary in PAS and standards, 60

British Standards Institute Publicly Available Specification 

(PAS) 197 (cultural collections management), 60

British Standards Institute Publicly Available Specification (PAS) 198 (environmental conditions 

management)

applicability for institutions outside the UK, 59

balance between competing and interconnected 

outcomes, 62, 63

climate guidelines in, 20, 28, 54, 55–56, 59, 64, 66, 

106–7n4

collections lifetime concept, 65, 65, 66

delay in publication of, 64

development of, 15, 18, 59, 66n1

feedback on, 65–66

framework nature of, 59, 66

history of, 60–61

organization for and contributors to development of, 

62–63, 63

philosophy of, concentric rings to explain, 61–62, 62

structure and organization of, 63–64

teaching with, 65, 66

vocabulary used in, 60

bronze disease, 10, 20

budgets and funding

air handling unit operation modifications, cost savings 

from, v–vi

climate guidelines and, 53

construction and long-term maintenance, financial 

investments for, viii

energy costs, v–vi, viii, 1, 25–26, 71, 77–79, 78

environment choices and costs, 55–56

mechanical systems, operating costs of, 71

operating costs, sustainability, and stewardship of 

collections, 77–79, 78

PAS guidelines and, 62, 63

building envelopes

classes of based on construction characteristics and 

occupancy, 47

codes and guidance for building envelopes and 

collections environment, 46–47

concept of, 46

damage to and risks to collection, 48–49

exterior air for ventilation, 46

moisture loads and moisture performance, 46, 47

multiple (box-in-box) envelopes, 48
118 Smithsonian Institution Summit on the Museum Preservation Environment

building envelopes (continued)

passive (nonmechanical) strategies for environmental 

control, 47–48

repurposing buildings and issues with, 77

thermal loads and thermal performance, 46, 47

building materials, reuse and recycling of, 75, 76, 77

buildings/facilities

age of, challenges related to, v

day-to-day operations standards, 53–56, 85–86

design choice concepts for sustainability, 74–79, 75

design choice examples, 71–74, 72, 73, 74, 78–79

design process, 84–85

design/retrofit standards, 53

existing buildings, documentation and information 

sharing about maintenance of, 85

flexibility of space and sustainability, 77

green building technologies, availability of, viii

improvements to, v–vi

information sharing about design and operation of, 

84–85

repurposing buildings as museums and galleries, 77

risk assessment and facilities management, 38, 39

Canadian Conservation Institute (CCI)

climate specification recommendations, 13, 14

purpose of, 13

risk assessment approach, 35

Canadian Museum of Nature, 35

Cultural Property Risk Analysis Method (CPRAM), 

36, 36

carbon dioxide, 85

carbon footprint and neutrality, 74, 75, 76, 87

Carrancho, Michael, 2, 6

Cary, Susan, 2, 6

Centre Pompidou, 76

chemical deterioration, 87–88

climate, external

geography, climate zones, and, 45

global climate change and climate change projections, 

45–46

historical temperature and moisture data, 45–46

sustainability and adaptation to global climate 

change, 75, 76

climate, indoor

basis for standards and specifications for, 9, 12, 13

chemical deterioration and, 10, 25

collection-specific specifications, 13–14, 20–22, 28, 

35, 53, 55–56, 83, 85–86, 106, 107n5

compliance without subservience, 66

conservation science and control of, 9

deterioration processes related to, awareness and 

prevention of, 9–10, 20–22

energy use and development of guidelines for, 59, 

61, 66

evolution of standards, 54–56

fiscal responsibilities and guidelines on, 53

guidelines on ranges, fluctuations, set points, and 

damage risks, 15–19, 16–19, 28, 106–7n4

history of specifications, mechanical systems, and 

building design, 9

ideal environment for museums, 53–56, 85–86

loans and traveling exhibitions, guidelines for, 

18–20, 28, 88

magic numbers, 12, 22, 53–56, 85–86

mechanical systems for control of, 9, 11–12, 28

microclimates, 11, 15

nineteenth-century discoveries about role of, 9–10

passive methods for control of, 9, 10–11, 20–21, 28, 

47–48

recommendation for specifications, 28

relaxed recommendations on, 14

research on damage related to, 22–25, 25, 55

science behind guidelines, skepticism about, 14

set points for mechanical systems, 11–12, 71, 79

Smithsonian collection-specific customized specifications common values and shared vision statement 

on, 106, 107n5

stable climate, errors in arguments about, 25–28

stable climate, goodness of, 25

standards and specification ranges and fluctuations, 

9, 13–14, 53–56, 85–86

sustainability and control of, 9, 13

sustainability and guidelines on, 53, 56

zones and control of, 84, 95

See also humidity; temperature

collaboration and communication among stakeholders

challenges of, viii–ix, 82

commitment to improvement of, viii

development of procedures for, 1

discussions, guided, 92–94

documentation and information sharing about maintenance of existing buildings, 85

exercises, group, 94–95

information sharing about design and operation of 

buildings, 84–85

relationships, respect, trust, and, 82–83, 82, 88–89

risk assessment and management and, 37, 39, 82–84

Smithsonian common values and shared vision statement on, 104

vendors, contractors, and leased building managers, 84

collection management

collection care and risk assessment, 38–39, 85–86

preservation and accessibility goals of, 35

as risk management, 35

stewardship of collections, vii–ix, 5, 77–79, 78, 103–6

collections lifetime concept, 65, 65, 66

Collection Space Planning Initiative, viii

Collections Trust, 66n1
Index 119

Collum, Malcolm, 2, 6

Commission on Preservation and Access, U.S., 21

community, being a positive contributor to, 75, 76

conservation science

climate control and, 9

risk assessment and, 39

science behind guidelines, skepticism about, 14

contractors, 84

Cornell University, 86

Cousins, Fiona, 2

Cultural Property Risk Analysis Method (CPRAM), 36, 36

CyMAL, 66n1

data collection and analysis

environmental monitoring, Smithsonian common 

values and shared vision statement on, 104

environment decisions and continuum of preservation/

degree of risk, 56

temperature and RH monitoring, 48–49

“Declaration on the Collections Preservation Environment,” 2–3, 5, 103–6, 106n1

DePriest, Paula, 2, 6

Dia:Beacon, 77

discussions, guided, 92–94

2, 4, 8, All model, 93–94, 93

book club model, 94

facilitator for, 92, 93

questions to guide development of a sustainable 

environmental policy, 92, 93, 95–98

EGOR: Environmental Guidelines: Opportunities and 

Risks research cluster, 61

electronic devices, technology, and energy use, 77

energy

air handling unit operation modifications and energy 

savings, v–vi

climate guideline development and attention to 

energy use, 59, 61, 66

collection care and attention to energy use, 61

costs for temperature and humidity parameters and 

standards, viii, 1, 71

electronic devices, technology, and energy use, 77

National Gallery environmental policy for use of, 

64–65

operating costs, sustainability, and stewardship of 

collections, 77–79, 78

process for reducing use of, 78, 78

reduction in use of, 76

seasonal relative humidity setbacks and energy savings, v, 25–26, 87

seasonal temperature setbacks and energy savings, v, 87

set point requirements and energy use and costs, 

71, 79

stewardship of and stewardship of collections, 5

Engineering and Physical Sciences Research Council, 

60–61

English Heritage risk assessment approach, 35

environment/preservation environment

classes of environmental control, 47

collaborative and interdisciplinary approach to, vii–

ix, 1, 3–5, 82–85, 82, 88–89

compliance without subservience, 66

continuum of preservation/degree of risk, 55–56

day-to-day operations standards, 53–56, 85–86

design choice examples, 71–74, 72, 73, 74, 78–79

design/retrofit standards, 53

framework to support decisions about, 4–5

geography and, 45

guidelines and best practices, Smithsonian common 

values and shared vision statement on, 105, 106–7n4

human comfort and, 86–87

long-term preservation of collections, environments 

for, 1

monitoring of, Smithsonian common values and 

shared vision statement on, 104

policy document on, discussion and adoption of, 1

precedents set by decisions made by credible 

organizations, 88

questions to guide development of a sustainable 

environmental policy, 92, 95–98

skilled and nuanced approach to, 5

standards on, 1, 4–5, 53–56

verification (confirmatory) monitoring, 38

See also buildings/facilities; climate, indoor

Ernst, Kathy, 2, 6

Estoque, Justin, 2, 6

exercises, group, 94–95

risk assessment, design of, 95

sketching climate zones, 95

sketching mechanical systems, 95

tours of facilities, 94–95

exhibitions, traveling. See loans and traveling exhibitions

Fort Mead facility, Library of Congress, 86

fresh air and ventilation, 46, 49, 85

Gastright, Kendra, 2, 6

geography, 45

glass

climate guidelines for, 25

humidity and damage to, 20

Gorman, Joshua, 2, 6

Greene, Luanne, 2

Grzywacz, Cecily, 2, 3

Guggenheim Museum Bilbao, 76

Hauk, David, 2, 6

Hawks, Catharine, 2, 6
120 Smithsonian Institution Summit on the Museum Preservation Environment

Henry, Michael, 2, 3

Heritage Preservation risk assessment approach, 36

High Museum of Art, 79

human comfort and preservation environments, 86–87

humidity

air handling unit operation modifications and fluctuation of, v–vi

building system recommendations, 49

case leakage and RH drift, 11

changes in, scientific evidence of tolerance to, viii

claims of control, issues related to, 26–27

Class I recommendations, 14

Class II recommendations, 14

deterioration processes related to, 9–10, 20–22

enclosures and cases for passive RH control, 10–11, 

20, 28

energy costs and parameters and standards for, viii, 1

evolution of standards for, 54–56

fluctuations and stable conditions, errors in arguments about, 25–28, 26

fluctuations in, research on damage related to, 

22–25, 25, 55

framework to support decisions about, 4–5

guidelines and best practices, Smithsonian common values and shared vision statement on, 105, 

106–7n4

guidelines on ranges, fluctuations, set points, and 

damage risks, 15–19, 16–19, 28

heating systems and low RH, 9–10

human comfort and, 86–87

light damage and, 10

magic numbers, 12, 22

monitoring data collection and analysis, 48–49

original material and RH fluctuations, 27

proofed fluctuations, 24, 27

rate of change of, 87–88

recommendation for specifications, 28

restorations and RH fluctuations, 27

seasonal setbacks, v, 25–26, 87, 106, 107n5

set points for mechanical systems, 11–12, 37, 71, 79

specific risk example of RH, 37

standards and specification ranges and fluctuations, 

13–14, 53–56, 85–86

standards on, 1

temperature control and RH control, 54

zones and control of, 84, 95

HVAC systems. See mechanical systems/HVAC systems

image media

acetate film, 21

climate and damage to, 21

climate guidelines for, 16–19

color dye fading, 21

nitrate film, 21

Image Permanence Institute (IPI)

climate and image archives specifications, history of, 9

climate guidelines, 18–19, 21, 22, 28

establishment of, 21

research on damage related to climate, 25

International Centre for the Study of the Preservation and 

Restoration of Cultural Property (ICCROM), 35

International Council of Museums Committee for 

Conservation (ICOM-CC) climate guidelines, 

19–20, 28

International Institute for the Conservation of Artistic 

and Historic Works (IIC) climate guidelines, 

19–20, 28

International Standards Organization (ISO), 86

Jessup, Wendy, 2, 6

Joice, Gail, 2, 6

Kimbell Art Museum, 79

Kodak, 21

Kozlowski, Roman, 24

leased spaces, 84

LEED status and construction projects, vi

Library of Congress, Fort Mead facility, 86

light

design choice concepts for sustainability, 76, 79

framework to support decisions about, 4–5

humidity and damage from, 10

PAS guidelines on, 64

loans and traveling exhibitions

climate guidelines for, 18–20, 28, 88

conference on climate fluctuations and vibration 

during transit, 23–24

set point requirements for loans, 71

shipping (transit) crates and climate control, 11

Louvre, Richelieu Wing, 77

magnetic tape preservation, 22

Makos, Kathryn, 2, 6

mechanical systems/HVAC systems

air handling unit operation modifications and energy 

savings, v–vi

air-water systems for climate control, 78–79

all-air displacement systems, 79

climate control with, 9, 11–12, 28

common mode failure, 38

complexity and size of to meet set point 

requirements, 71

design choice examples, 71–74, 72, 73, 74, 78–79

energy-efficient systems, 79

framework to support decisions about, 4–5

low RH and, 9–10

maintenance and operating costs of, 71
Index 121

maintenance and reliability of, 12

recommendation for, 49

set points for, 11–12, 37, 71, 79

sizing of, basis for, 45–46

specific risk example of RH, 37

verification (confirmatory) monitoring, 38

Mecklenburg, Marion

climate and humidity research by, 10, 55

climate specification recommendations, 14–15, 87

contributions to temperature and humidity 

research, viii

research on damage related to climate, 22, 23–24

Medieval Gallery, Victoria and Albert Museum, 86

metals

climate guidelines for, 16–19, 25

humidity and damage to, 10, 20

passive RH control by enclosures, 10

Miami climate zone, 45

Michalski, Stefan, 2, 3, 61

microclimates, 11, 15

minerals

climate guidelines for, 20–21, 25

collection care and risk assessment, 38

rate of change of temperature and humidity and 

damage to, 88

vulnerability to environmental conditions, 35

moisture/moisture loads

below-grade or bermed structures, 49n1

building envelope performance, 46, 47

building system recommendations, 49

nonmechanical (passive) strategies for control of, 

47–48

thermal mass and, 48, 49n1

Museum Brandhorst, 78–79

The Museum Environment (Thomson), 13–14

Museum of Contemporary Art San Diego, 74, 74, 77

museums

core activities of, vii

mission of, 76

visitor experience, 76–77

Museums, Libraries, and Archives Council, 66n1

Museum Support Center, v

The National Archives, 15, 18, 66n1

National Bureau of Standards (NBS), 21

National Gallery, London

energy use policy of, 64–65

environmental and sustainability policy of, 64–65

human comfort and the preservation environment, 86

light damage study by, 10

mechanical systems for climate control in, 11

research on damage related to climate, 22, 25

Sainsbury Wing, 72, 73

set points for mechanical systems, 11–12

National Gallery of Canada, 10

National Information Standards Organization (NISO), 

21–22

National Museum Directors’ Conference (NMDC) 

climate guidelines, 15, 16–17, 18, 19, 61

National Park Service, 46

natural resources, stewardship of and stewardship of 

collections, 5

Nelson, Harley, 22–23

New Jersey Zinc Company, 22–23

nitrate film, 21

nonmechanical (passive) strategies for environmental 

control, 9, 10–11, 20–21, 28, 47–48

paintings

climate guidelines for, 16–19

collection care and risk assessment, 38

enclosures and cases for passive RH control, 10–11

humidity and damage to, 9–10, 20

mechanical systems for climate control for, 11–12

National Gallery environmental policy for, 64–65

old material and RH fluctuations, 27

research on damage to related to climate, 22, 23–25, 

25, 55

restorations and RH fluctuations, 27

paints and varnishes, research on damage to related to 

climate, 22–23

paper

climate and damage to, 21

climate guidelines for, 16–19, 21, 25–26

Park, Sharon, 2, 6

passive (nonmechanical) strategies for environmental 

control, 9, 10–11, 20–21, 28, 47–48

Passman, Jane, 2, 6

Phoenix climate zone, 45

Plenderleith, Harold, 54

pollution

ASHRAE Handbook, chapter 23, guidelines on, 55

from display case materials, 11

framework to support decisions about, 4–5

PAS guidelines on, 64

proofed fluctuations, 24, 27

Publicly Available Specification (PAS) 198. See British 

Standards Institute Publicly Available Specification (PAS) 198 (environmental conditions 

management)

Reilly, James, 2, 3, 9, 21, 45

Richards, Mervin, 18

Richelieu Wing, Louvre, 77

risk assessment

approaches and methods, 35–36

as basis for decision making, 4–5

bias in perception of risks, 83
122 Smithsonian Institution Summit on the Museum Preservation Environment

risk assessment (continued)

collaboration in, 37, 39, 82–84

collection care and, 38–39, 85–86

collection stewardship and, 35

complexity and diversity of collections and, 35, 37, 

38–39, 53–56, 83, 85–86

comprehensive risk model, 39

designing a risk assessment as group exercise, 95

effect of departure from goal, 37, 39

facilities management and, 38, 39

knowledge about and adjustments to new knowledge, 

39–40

model structure, 36–37

path of damage, 37, 39

process for specifications development, 39–40

source of risk, 37, 39

specific risk, 37

system-based approach to, 36, 36

variability, ignorance, randomness and, 38–39

risk management

climate guidelines and damage risks, 15–19, 16–19

collaboration and, 37, 39, 82–84

collection management as, 35

continuum of preservation/degree of risk, 55–56

effectiveness of, 39

humidity fluctuations and damage risks, 25–28, 26

maintenance and reliability of mechanical systems, 12

Smithsonian common values and shared vision statement on, 105

Rogers, Mary, 2, 6

Rosenfeld, Scott, 2, 6

Royal Ontario Museum, 76

Sainsbury Wing, National Gallery, London, 72, 73

scientific collections

policies and procedures for developing, maintaining, 

and preserving, vii

value of to scientific research, vii

Scorsese, Martin, 21

Securing the Future for Smithsonian Collections, viii

shipping (transit) crates, 11

Siegal, Matthew, 18, 26

Smithsonian Institution

access to collections, improvements to, viii

access to collections, methods of, vii

climate guidelines, 15, 16–17, 28, 103, 106, 

106–7nn3–4

collaboration, common values and shared vision 

statement on, 104

collaborative and interdisciplinary planning initiative, viii

collections care, storage, and digitization, progress in 

raising level of, viii

collection-specific customized specifications common 

values and shared vision statement on, 106, 107n5

common values and shared vision, 103–6

core activities of, vii

diversity of items in collections, v, vii–viii, 103

environmental monitoring, common values and 

shared vision statement on, 104

guidelines and best practices, common values and 

shared vision statement on, 105, 106–7n4

mission and goal of, v, vi, vii

precedents set by decisions made by, 88

risk management, common values and shared vision 

statement on, 105

stewardship of collections, vii–ix, 103–6

sustainability common values and shared vision 

statement on, 106

temperature and RH values, 56, 103, 106n3

workforce training, common values and shared 

vision statement on, 105

Staniforth, Sarah, 18

Stauderman, Sarah, 2, 3, 5

strategies/preservation strategies

evidence-based decision making as basis for, viii

passive (nonmechanical) strategies for environmental 

control, 9, 10–11, 20–21, 28, 47–48

pragmatic and responsible approach to, viii–ix

reassessment of standards, practices, and behaviors, 

v, 1, 4

sharing of deliberations, resources, and perspectives 

on, 1

urban legend or tradition as basis for, viii

Summit on the Museum Preservation Environment

context for, 1

“Declaration on the Collections Preservation Environment,” 2–3, 5, 103–6, 106n1

diversity of disciplines represented by participants, 

3–4

goals for, 1

participants at, 3–4, 4

planning committee for, 1–3, 2, 5–6

program schedule and scope, 1–2, 99–102

purpose of, 1

speakers at, 2, 2

success of, 3–4

weather and rescheduling of Day Two, 3, 3

sustainability/sustainable strategies

benefits of, v

climate control methods and, 9, 13

climate guidelines and, 53, 56

design choice concepts for, 74–79, 75

development and implementation of, 4–5

development of, priority of, vii

enclosures and cases for passive RH control, 11

flexibility of space and, 77

human comfort and, 86–87

operational choices and decisions for, 75, 76
Index 123

PAS guidelines and, 62, 63

questions to guide development of a sustainable 

environmental policy, 92, 95–98

set point requirements and, 71, 79

Smithsonian common values and shared vision statement on, 106

stakeholder expectations and, 76

visitor experience and, 76–77

See also energy

Tate, 15, 18

technology, electronic devices, and energy use, 77

temperature

air handling unit operation modifications and fluctuation of, v–vi

changes in, scientific evidence of tolerance to, viii

Class I recommendations, 14

Class II recommendations, 14

control of and RH control, 54

energy costs and parameters and standards for, viii, 1

evolution of standards for, 54–56

framework to support decisions about, 4–5

guidelines and best practices, Smithsonian common values and shared vision statement on, 105, 

106–7n4

guidelines on ranges, fluctuations, set points, and 

damage risks, 15–19, 16–19, 28

human comfort and, 86–87

magic numbers, 12, 22

monitoring data collection and analysis, 48–49

rate of change of, 87–88

seasonal setbacks, v, 87, 106, 107n5

set points for mechanical systems, 11–12, 71, 79

standards and specification ranges and fluctuations, 

13–14, 53–56, 85–86

standards on, 1

zones and control of, 84, 95

thermal loads

building envelope performance, 46, 47

nonmechanical (passive) strategies for control of, 

47–48

thermal mass, 48, 49n1, 78, 79

Thomson, Garry, 54–55, 64

Tintle, Paul, 2, 6

Tompkins, William, 2, 3, 6

Trowbridge, Ann, 2, 6

United Kingdom (UK), ideal museum environment and 

galleries in, 54

University College London, 15, 18

University of California Berkeley Library risk assessment approach, 36

vendors, 84

ventilation and outside air, 46, 49, 85

Victoria and Albert Museum, Medieval Gallery, 86

visitor experience, 76–77

Wallace, Jim, 21

Waller, Robert, 2, 3

Washington, D.C., climate zone, 45

water use, 74, 75

Wilhelm, Henry, 21

Wilson, William K., 21–22

The Women’s Library, London, former home of, 72, 72

workforce training, Smithsonian common values and 

shared vision statement on, 105

WUFI computer model, 48
P.O. Box 37012, MRC 957

Washington, D.C. 20013-7012

www.scholarlypress.si.edu

ISBN (online): 978-1-935623-87-8

ISBN (print): 978-1-935623-86-1

Available for download at Open SI (http://opensi.si.edu). 

The Summit on the Museum Preservation Environment was convened at and 

organized by the Smithsonian Institution in March 2013. It was held over two days 

at venues in the National Museum of the American Indian and the Smithsonian 

American Art Museum.