Libraries, archive rooms, and museum storage facilities are areas where irreplaceable cultural heritage is preserved, including books, manuscripts, historical documents, and audiovisual materials. Ambient humidity is critically important for these materials to remain in good condition for many years. Using a dehumidifier is the primary method for bringing the preservation conditions of these areas to international standards.
Effects of High Humidity on Library and Archive Materials
- Mold and Fungal Growth: Relative humidity above 60% creates conditions for mold colonies to establish on paper, binding materials, and photographs. This biological degradation, which can spread rapidly to an entire collection, causes irreversible damage.
- Paper Deterioration: Excessive humidity accelerates hydrolysis reactions in paper fibers; pages begin to yellow, become brittle, and disintegrate. This effect occurs even faster in acidic papers.
- Damage to Binding and Leather Materials: High humidity softens leather bindings, dissolves adhesives, and compromises the structural integrity of books.
- Film and Photographic Archives: Celluloid, film negatives, and photographic prints are extremely sensitive to excessive humidity. Condensation and humidity fluctuations cause permanent image deterioration.
Using Dehumidifiers in Archives and Libraries
ISO 11799 and ASHRAE standards require that relative humidity in archive and library environments be maintained in the range of 45–55%, with humidity fluctuations not exceeding ±5% daily. Dehumidifier systems maintain this delicate balance, significantly slowing the degradation rate of materials and extending the life of the collection.
Benefits of Humidity Control
- Long-Term Preservation: Correct humidity and temperature conditions allow collections to be stored in good condition for decades.
- Mold and Pest Control: A low humidity environment eliminates the developmental conditions for biological pests.
- Standards Compliance: Compliance with international archival standards is achieved, facilitating accreditation and insurance processes.
- Staff and Visitor Comfort: A controlled humidity environment improves the overall comfort of the working space.
For more information about the ideal dehumidifier system for your library or archive room, please fill out the contact form below to get in touch with NKT – Humidity Control Technologies and receive support from our specialist humidity control engineers.
