As a caretaker of cultural and natural artifacts, the Field Museum of Natural History in Chicago, Illinois, contains irreplaceable objects. In situations where environments for artifacts are not correctly maintained and controlled, permanent damage to these objects can result. A longitudinal environmental survey was performed at the museum to assess the performance of the facility's HVAC systems and controls. The primary objective was to develop and test a series of hypotheses to explain deterioration of a number of mammal mounts located in the museum's exhibition halls. In this paper, the environmental factors affecting artifact lifetime are reviewed and recommendations are summarized. In addition, a method for evaluating the tightness of display cases using carbon dioxide as a tracer gas is presented. The survey indicated that the temperature in certain areas of the museum often exceeded a recommended upper limit of 77ºF and humidity was uncontrolled in other areas.

Units: I-P