Indoor environmental control: review of current recommendations and survey of conditions at a natural history museum.

The environment inside museums such as the Field Museum of Natural History in Chicago, USA is of utmost importance since permanent damage can be caused to artifacts in the environment is not correctly maintained and controlled. The article describes a longitudinal environmental survey carried out to assess the performance of the facility's HVAC systems and controls. A series of hypotheses was developed and tested to explain deterioration of a number of mammal mounts in the museum's exhibition halls. Reviews and makes recommendations on the environmental factors affecting artifact lifetime. Also presents a method for evaluating the tightness of display cases using carbon dioxide as a tracer gas. It was found that certain areas of the museum often exceeded a recommended upper limit of 77 deg F and humidity was uncontrolled in other areas.