Project Objectives
Building upon results from a previous GCI project on humidistatically controlled ventilation and heating strategies for the protection of collections in historic structures (Collections in Hot and Humid Environments), this project focuses on the economical and sustainable application of these techniques to improve the physical environment of collections in historic buildings in hot and humid regions in order to prevent fungal and bacterial attacks. Specifically, it applies alternative strategies to conventional air-conditioning systems by controlling relative humidity through ventilation and heating or dehumidification while allowing for larger variations in temperature. The primary objectives of the project are:

• to document case studies for the application of ventilator-and heater/dehumidifier-based climate improvement strategies for historic buildings using locally sustainable technologies;
• to analyze the performance of climate control systems for improved operation;
• to disseminate information generated by the project through publications and presentations.

	Fungal growth on this book (part of the Historic Archive of La Laguna, Tenerife Island, Spain) is due to extended exposure to high levels of relative humidity. Photo: Shin Maekawa.

Project Overview
Biodeterioration has been a major threat to museum collections in hot and humid regions; this is a result of exposure to prolonged periods of elevated relative humidity. Although air-conditioning may be used to lower relative humidity in the collection space, excessive cost and intrusion to the fabric of historic structures are prohibitive factors in its installation. Field studies at Tenerife Island, Spain, and Jekyll Island, Georgia—initiated by the GCI in 1997 and completed in 2002—examined the use of humidistat-controlled ventilation and heating as a viable alternative to air-conditioning in maintaining preservation-level relative humidity in the collection space.

	Severe wood decay of interior sheathings and floors on the ground floor of Hollybourne Cottage in Jekyll Island, Georgia, the result of elevated relative humidity in the walls and basement. Photo: Shin Maekawa.

Results from these multiyear experiments quantified the efficacy of economically sustainable strategies and produced ventilating and heating requirements for the care of collections in historic buildings located in tropical and subtropical regions. These studies demonstrated an impressive capability to improve climates with systems that, relative to air-conditioning, are inexpensive and simple to install, operate, and maintain. Results of this research have been presented at the Indoor Air Quality meeting of the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) in San Francisco, California; the annual meeting of Passive, Low Energy Architecture (PLEA) in Florianópolis, Brazil; the 2003 meeting of the Western Association for Art Conservation (WAAC) in Honolulu, Hawaii; and ICOM-CC in Rio de Janeiro, Brazil.

Concurrent with continued experiments on additional variations of climate control strategies at Hollybourn Cottage, a number of past and present partners worked with the GCI to install alternative climate control systems in their facilities. These included:

• Autonomous Organization of Museums and Centers Tenerife Spain, in its mixed collection storage;
• Emilio Goeldi Museum, Belem, Brazil, in its storage facility of the Amazonian ethnographic collection;
• Casa de Rui Barbosa Museum, Rio de Janeiro, Brazil, in its library;
• Quinlong Garden of the Forbidden City, Beijing, China in the Lodge of Retirement .

These projects were supported through the use of local resources, which include funding for equipment and the hiring of local engineers, architects, and contractors. The GCI provided technical support during the design and installation of these systems, as well as performance monitoring and suggestions for improvement to these projects.

In April 2007, the GCI invited thirteen experts—architects, engineers, conservators, and conservation scientists with an established record of work in the fields of environmental research, management, or control—to a two-day roundtable in Tenerife, Spain. The objectives of this event, the Experts' Roundtable on Sustainable Climate Management Strategies, were to exchange knowledge and experiences, to identify areas in need of further study or new research, and to identify opportunities for education and training in this subject. Excepts from the roundtable discussion as well as discussion papers written for the event will be available on the Getty Web site.

As the Alternative Climate Controls project has completed its project objectives, current and future work will focus on disseminating the results of this project through project reports and publications.

Last updated: August 2008