Washington, DC, Sept. 3-5, 1997
Note: The following is for information only and should not be used to make decisions on appropriate collections environments without consulting the professional literature and/or consultants.
A meeting on Collections Environments was held at the Smithsonian Institution in Washington, D.C., from September 3 to 5, 1997. The purpose of the meeting was to critically evaluate present standards/recommendations for all aspects of the collections environments and to discuss the potential impact of recent research results.
The meeting was organized by the Conservation Analytical Laboratory (CAL) of the Smithsonian Institution and financially supported by the National Center for Preservation Technology and Training (NCPTT).
To foster open discussions the meeting was by invitation only and without an audience. Participants were: P.N. Banks, A. Beale, J.P. Brown, G. Cass, E. Conrad, M. Frost, L. Kelter, R. Kerschner, W.P. Lull, S. Maekawa, S. Michalski, P.N. Perrot, F.D. Preusser (chair), J. Reilly, W. Rose, D. Saunders, L. Stuebing, R. Waller, S. Weintraub, and A. Zhivov. Observers: R. Bishop, M. Gilberg, B. Schneider, M. Weininger Preusser, D. Williams, and L. v. Zelst.
Discussion topics included: The building envelope; HVAC technologies; chemical, mechanical and biological deterioration; relative humidity, temperature and air pollution; energy and cost savings strategies; and the work of the relevant committees of ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.) and ISIAQ (International Society for Indoor Air Quality and Climate). The meeting covered historic houses, museums, libraries and archives, both in historic structures and buildings constructed for the purpose of housing collections. It also addressed the problems of different climate zones. A significant amount of time was spent discussing risk assessment and the planning and decision-making process.
It is planned to prepare one or more publications on the subject of this meeting, incorporating its findings.
Decisions on control parameters for a collection cannot be made in isolation, but instead should result from a systematic process that starts with a review of the mission of the holding institution and the development of a master plan for the institution and the collection. All interested parties should be involved in the entire decision-making process from the very beginning.
Factors such as the use of the collection by the constituency of the holding institution and the frequency of access to the collection, as well as the character of the building in which these collections are housed, are of paramount importance when alternative options for improvements in the collection environment are subsequently evaluated. The next step should consist of a comprehensive risk assessment for the collection and the building in which it is housed. Often, natural and manmade disasters, frequent and improper handling, and inadequate security and fire protection pose a greater risk to collections than fluctuations in environmental parameters. Available resources should therefore first be invested in the mitigation of the greatest risks.
Once it is determined that existing environmental settings and fluctuations are the largest remaining threat to the long-term survival of a collection, a plan for environmental improvements can be drawn up. For this purpose it is essential to know the nature and condition of the collection and to fully understand the performance characteristics of the building within the local climate. Any environmental improvements should start with such improvements in the building envelope as are safe to its fabric and, where applicable, allowable within the historical/aesthetical context. Only after this task has been accomplished can one sensibly plan ways to further improve the interior environment.
Before deciding on the set points of humidity and temperature, permissible fluctuations, and seasonal drifts, one has to understand whether the deterioration of the collection is mostly chemical or mechanical. One also should know what percentages of the collection are of very high, high, medium, or low vulnerability to environmental damage.
Based on this knowledge of the collections, the building, and the local climate, one can approach a decision about the proper humidity and temperature settings. Different standards may be required for different types of collections. The use of microclimates should be considered as a valid strategy for protection of the more vulnerable parts of the collection.
A well-controlled environment with humidity fluctuations of ±5% is still considered the safest environment. However, individual conditions, including the nature of the building and the collections, can warrant the specification of more widely relaxed standards after careful consideration and with awareness that the risk for environmental damage may increase for parts of the collections as larger fluctuations are permitted.
A flagship HVAC system, providing a flatline environment, should only be considered if the resources for its operation and maintenance are assured in the long term. If budgetary considerations, the nature of the building, or other factors make this unfeasible, alternative strategies including multiple (micro) climates for different parts of the collection can be evaluated.
For most institutions that presently operate or plan to install a mechanical climate control system, a relaxation of the presently most common standards will not likely lead to great cost savings, although small to moderate savings may result. Any such savings, however, as well as the concomitant increase in risk to the collections, are dependent on the state and nature of the collections and the building in which they are housed.Frank D. Preusser