Collections Code Orange
We’re now at the peak of summertime with all the season’s attendant dangers. James Reilly, Founding Director of the Image Permanence Institute, has asserted that “geography is a kind of preservation destiny.” Here in North Carolina, our biggest preservation risks occur in the summer, and the next two months or so are typically the most crucial.
Here are some common summertime conditions that create the need for special vigilance in conducting collection inspections, environmental monitoring, and disaster planning.
- High temperatures speed chemical reactions, leading to faster rates of deterioration for many materials.
- High relative humidity (above 65%) invites mold growth and infestations of certain types of insects. Corroding metals will continue to deteriorate even at moderate rates of RH (above 35%). Large and sudden RH fluctuations cause some materials to swell and shrink and may lead to losses. See the Image Permanence Institute’s “Dew Point Calculator” and “Preservation Evaluation” to learn more about these interrelationships.
- Hurricanes tend to strike the North Carolina coast in late August. Even without a direct hit on a cultural heritage institution, these storms can cause flooding and prolonged power outages that could damage collections severely.
In a recent webinar Reilly suggested several strategies:
- Reduce heat load in buildings by installing light-colored, reflective roofing materials. Use drapes or shades to block direct sunlight coming through windows.
- Repair leaks and maintain guttering systems to divert moisture from building foundations.
- Dehumidifiers may be the best option for institutions with high humidity. Often air conditioning systems at smaller sites only reduce temperature without affecting humidity. Reilly suggested several cautions about the use of portable dehumidifiers. Their motors generate heat in a space; their constant operation is a fire risk; and institutions using them need to provide for adequate drainage.
- Use enclosures to protect collection materials from RH fluctuations. IPI has researched the effect of container materials (metal, cardboard, and plastic) on rates of equilibration. While enclosures do not delay temperature changes much, plastic and metal containers slow the rates of moisture-level change for the contents significantly. Click here to view IPI’s findings.
How does your institution deal with summertime conditions? Have you used any of the above strategies with success?