Is Seasonal Humidity Change Damaging Your Important Documents?

If your organization stores paper documents, it’s vital to consider how seasonal humidity may affect your document preservation efforts. Without proper temporary climate control solutions, the weather can negatively affect and damage paper documents.

Relative Humidity and Temperatures

Books, documents, and other archived media are hygroscopic, meaning they absorb and release moisture. The materials expand and contract depending on the temperature and relative humidity. The more environmental changes the experience of the document, the more vulnerable they are to accelerated deterioration.

Relative humidity refers to the amount of moisture in the air. Scientifically, it’s the actual vapor pressure or density compared to the saturation vapor pressure or density. Actual vapor pressure refers to the amount of water vapor in a unit, or volume, of air. Saturated vapor pressure refers to the amount of moisture the air holds at a certain temperature; the number of molecules escaping a liquid is the same as the number returning.

In general, warmer air contains more water vapor. This is why it generally feels more humid during the summer than in the winter. When a building lacks temperature control, it also lacks humidity control. This combination can cause materials in documents to break down because of mold growth or chemical reactions that occur within the media. Similarly, overly dry environments can cause certain types of documents to desiccate and become brittle.

Document Preservation

The quality of the storage environment and its location are vital to document preservation. The ideal document storage environment has the following conditions:

• Constant temperatures between 65° and 70° F
• Constant relative humidity levels of 45 to 50 percent
• Dust-free
• Good air circulation
• Weight-bearing floors
• Tall ceilings
• Air filtration system
• Smoke detectors
• Moisture detectors
• Fire extinguishers and sprinkler system
• An area that is not underwater pipes
• Shelves that are made with items that do not release harmful gasses
• Shelves that are deep enough for storage boxes and are not near walls
• File cabinets that are fireproof
• The area is carpet-free

Maintaining a constant temperature and relative humidity level is important. However, maintaining a constant temperature and relative humidity level that’s less than ideal, is better than allowing the environmental conditions to vary.

Storage Location

When choosing a storage location, avoid basements and attics because these areas are more susceptible to weather- and water-related damage. The best storage rooms make it simple to retrieve records, are easy to clean and maintain, and have sufficient space for future storage needs.

Because light can damage stored documents and increase the temperature in a room, choose a room that does not have windows. If windows are unavoidable, make sure they filter the sun with UV-protective glass and install shades to block the natural light.

The floor in the storage room should be able to support shelves full of documents without causing structural damage. If the area has overhead water pipes, arrange the shelves so the pipes are over the aisles.

Storage Handling and Retrieval

The best storage materials are acid-free and do not emit volatile organic compounds, or VOCs. Boxes are good for keeping sensitive materials dust-free and out of the light. Use acid-free file folders to organize records. If the documents are particularly sensitive, like film negatives, wearing white gloves will protect them from the oil and dirt on your hands.

When labeling the files, use a pencil instead of a pen. Pens have a tendency to fade, bleed and leave unwanted marks on documents. It is a good idea to label boxes with numbers and include important information about their contents on the outside. This makes record retrieval simple and allows you to identify documents that need attention quickly if there’s a fire or water damage. In addition to labeling boxes, create a document that inventory each box and communicates their location in the storage room.

A Well-Rounded Solution

Temporary climate control is ideal for managing a storage environment. While some organizations depend on HVAC systems to maintain storage areas, doing so may reduce the lifespan of the unit and drive up energy costs. Temporary climate control solutions efficiently complement HVAC systems and can help reduce energy expenditures. Polygon can create a custom temporary environment for your storage needs that diminishes the effects of seasonal humidity variations. Contact the experts at Polygon today to learn more.

Photos by storebukkebruse and joiseyshowaa via CC license